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BATISTA, GILMAR ZACCA. "INDUCTION HOT BENDING OF STEEL PIPE API 5L X80." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2005. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=8660@1.
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PETRÓLEO BRASILEIRO S. A.Neste trabalho são apresentados os efeitos do processo de curvamento a quente por indução na microestrutura e nas propriedades mecânicas do tubo API 5L X80, fabricado pelo processo UOE, com chapa produzida através do processo de laminação controlada sem resfriamento acelerado. O curvamento foi realizado com aquecimento localizado, provocado por uma bobina de alta freqüência, seguido de resfriamento por jatos de água. O tubo curvado foi avaliado e comparado com o tubo reto. Adicionalmente, foi realizado um tratamento térmico de revenido em parte da região curvada. Foram realizados ensaios mecânicos de tração, microdureza e impacto Charpy-V, análises dimensionais e avaliação microestrutural. Verificou-se uma alteração significativa na microestrutura da região curvada, resultando em uma curva com menores valores de temperatura de transição e limite de escoamento inferior ao do tubo original e ao requerido por norma. O tratamento térmico aplicado na região curvada, mostrou-se eficiente para elevar o limite de escoamento para valores acima do mínimo especificado pela norma API 5L para o X80.
The present work discusses the effect of the induction bending process on the microstructure and the mechanical properties of an API 5L X80, 20 pipe produced by the UOE process. The key characteristic of the pipe was the manufacturing process of the steel plate, involving thermomechanical controlled rolling without accelerated cooling. The pipe bending was carried out applying local induction heating followed by water quenching and a further temper heat treatment was applied to the curved section. The methodology of analysis compared the curved section with the original body pipe, taking into account dimensional analysis, microstructural evaluation and mechanical tests which included Charpy-V impact, tensile and microhardness. A significant microstructural change and decrease, not only in the transition temperature, but also in the yield strength ocurred after induction bending, this reduction was below the standard requirements. The subsequent tempering heat treatment applied to the curved section produced an increase in the yield strength to achieve the API 5L requirements for this class of steel.
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Yan, Pei. "High frequency induction welding & post-welding heat treatment of steel pipes." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609702.
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Hayford, Frank. "CLEANLINESS ASSESSMENT OF STEEL BARS PRODUCED FROM A HIGH FREQUENCY INDUCTION FURNACE." Thesis, KTH, Tillämpad processmetallurgi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-125018.
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To stay competitive in the steel industry, steelmakers are utilizing different production methods to reduce production cost without compromising on the quality of their products. In steelmaking, the production process plays a significant role on the steel cleanliness. Recent increasing demands on the cleanliness level therefore require optimization of production process to meet the requirement. Often, the types and distribution of non-metallic inclusions in steel determines the steel cleanliness. In order to optimize the production process, complete assessment of the non-metallic inclusions in the steel is necessary, leading to implementation of measures to control and/or remove non-metallic inclusions in the steel. The present study was performed to investigate the cleanliness level of steel bars produced from a high frequency induction furnace (HF) route at Uddeholms AB. Experimental studies were carried out and characteristics such as number, composition, size distribution and morphology of non-metallic inclusions were investigated. Total oxygen and total nitrogen content were also measured for indirect assessment. Further, the production operations at the HF were observed and evaluated to determine their influence on the inclusion characteristics. The characteristics obtained were compared with characteristics of inclusions in steel bars produced from an electric arc furnace production (EAF) route at Uddeholms AB and a competitor producer sample. The results showed that the level of cleanliness varies from different production routes and is hence dependent on the process at each production route. The number, maximum and mean size of inclusions were found to be higher in the HF route compared to the other routes. More so, there were differences in the types of oxide inclusions observed from each process route. However, sulphide inclusions exhibit similar characteristics from the different process routes. Further, the compositions of oxide inclusions observed from the HF route were found to be closely related to the steel chemistry. More importantly, the types of inclusions formed in the HF route were found to be sensitively affected by the extent of aluminium and calcium contents in the steel. Thus, the oxide inclusion types in the HF samples could be traced to the extent of different additions and operations such as deoxidation and calcium treatment that were carried out during the steelmaking process.
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Peabody, Frank Gerald. "An investigation of high speed, thin steel rotor, annular, double sided, linear induction motors." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/29056.
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The objective of this dissertation is to analyse the performance of a linear induction motor suitable to drive a circular saw blade. A selection of analytical methods available from the field of electrical machine theory was used to investigate the particular type of motor. The theoretical analysis is supported by an extensive experimental investigation.
Although LIMs have been designed, analyzed and applied in other applications, significant differences exist between those LIMs and the one used for the new application. These include: the annular shaped motor, the smaller air gap, and the rotor which is thin and made of steel. Because of these differences, the methods used by previous investigators were not sufficient to design the LIM required.
The theoretical analysis used a selection of methods described in the literature to quantify the effect of the rotor material, the end effect and the edge effect. New methods are described to analyse the effect of the annular shape, the normal forces on the rotor and the coil connection. In addition, a new consideration in the optimisation of these type of motors is described. An extensive experimental program was undertaken. Six different linear motors were constructed with output powers ranging from one to fifty kWatts. In addition, inverters, dynamometers, flux measurement apparatus, speed measurement, thrust measurement and friction measurement apparatus were designed and constructed. The effects on performance of slot harmonics, winding connections, the end effect and the edge effect were measured.
Several contributions to the field of electrical machine theory are presented. The first is a new annular disc motor resistivity correction factor. Second, is the analysis of the effects of poles in parallel versus in series in linear induction motors. Third, is the experimental comparison between odd and even pole designs. The fourth is a second optimum goodness consideration for LIMs, which had not previously been considered. The fifth is the analysis of the rotor/stator attractive force for magnetic rotor double sided motors and a description of the flux (crenelated flux) which causes the force. Finally, a criterion for when the re-entry effect may occur is presented.Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
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Berger, Rikard, Andreas Kopp, and Harald Philipson. "A feasibility to electrify the combustion heated walking beam furnace : Applying induction and resistance heating." Thesis, KTH, Materialvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-231460.
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The carbon footprint from the iron, steel and other metal sectors has become a problem both environmentally and economically. The purpose of this report is to propose a concept of an electrified reheat furnace for the steel industry in the making of sheet metal. The aim is to reduce the environmental impact from the steel industry. The approach in this report has been to analyse relevant facts to propose a fully electrified concept. The concept is divided into two sections. The first section of the concept consists of a preheating furnace with the purpose to heat the slabs to 850 °C before it enters the second section. The preheating furnace contains 1447 – 2412 MoSi2 heating elements due to considering different efficiencies. The second section consists of 13 induction heating modules heating the slabs to a homogenous temperature of 1250 °C. By applying electrical heating in a walking beam furnace approximately 100 000 tonne carbon dioxide can be reduced annually. In conclusion, the proposed concept could be a feasible solution in order to avoid carbon emission and obtain the same production rate as the existing reheating furnaces. However, it is suggested that further investigations and analysis are performed regarding this concept to verify the total efficiency of the reheating furnace and to theoretically determine the required power inputKoldioxidutsläppen från järn, stål och andra metallindustrier har blivit ett problem både urmiljö och ekonomisk synpunkt. Syftet med denna rapport är att föreslå ett koncept av en heltelektrifierad uppvärmningsugn för stålindustrin i processen för att skapa plåt. Målet meddenna studie är att reducera stålindustrins påverkan på växthuseffekten. Metoden i denna rapport har varit att analysera relevant fakta för att sedan kunna föreslå ettkoncept av en helt elektrifierad ugn. Det föreslagna konceptet är uppdelad i två delar. Denförsta delen består av en förvärmningsugn med målet att värma stålet till 850 °C innan ståletgår in i den andra delen. Förvärmningsugnen består av 1447 – 2412 stycken MoSi2värmeelement med hänsyn till ugnens verkningsgrad. Den andra delen består utav 13 styckeninduktionsvärmemoduler som värmen stålet till en homogentemperatur på 1250 °C. Genomatt använda elektricitet för att värma ugnen minskar koldioxidutsläppen med 66 kg per tontillverkas stål. Sammanfattningsvis, det föreslagna konceptet kan vara en möjlig lösning för att minskakoldioxidutsläpp och samtidigt bibehålla samma produktionshastighet som existerandeuppvärmningsugnar. Däremot är det förslaget att vidare studier och analyser görs påkonceptet för att verifiera den totala verkningsgraden av ugnen och för att bestämma denexakta energiförbrukningen.
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Davenport, Rebecca A. "An investigation into the manufacture and mechanical properties of an Al-steel hybrid MMC." Thesis, Brunel University, 2018. http://bura.brunel.ac.uk/handle/2438/17033.
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One of the most significant challenges in the composite development field is to find a low-cost manufacturing route capable of producing large volumes of material. This thesis develops and characterises a potential avenue for addressing this, an induction furnace-based process. This process produced a composite of A357 matrix and 10% wt Dramix 3D 80/30 SL steel fibres. The method was evaluated by microstructural analysis and optimum casting parameters were approximated. The fibres were introduced to liquid A357 at 700°C and the composite was brought to a measured temperature of 650°C over not more than 120 seconds before being removed from the furnace and cooled. 10% wt was the ideal reinforcement ratio for this process. Characterising the tensile and compressive strength of the composite material, it reached a peak stress 130% higher than A357 produced under the same conditions, though the peak stresses were still 20% of the literature values for T6 tempered A357. This suggests the need for development of a temper which does not degrade the properties of the composite. 3-point bending tests and some tensile specimens also showed post-failure strength. Under dynamic loading, the composite showed a peak stress in excess of 100 MPa without reaching maximum compression under SHPB loading, and comparable performance to SiC-reinforced MMCs under ballistic testing. The linear decrease in work-hardening with increasing distance from the impact site shows shock and pressure-pulse dissipation properties, attributed to the difference in acoustic impedance between the matrix and the reinforcement.
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Pettersson, Natalie. "Investigation of material removal techniques for residual stress profile determination on induction hardened steel." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-62618.
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The residual stress profile is a major factor on the fatigue life of components that are subjected to cyclic loading. In order to measure these stresses x-ray diffraction (XRD) is commonly used. The penetration depth of x-rays is limited for this method and thus, it must be combined with material removal to determine in-depth stress profiles.At SKF Manufacturing Development Center (SKF MDC), where the work for this thesis was carried out, the current layer removal method is restricted to a depth of 0.5 mm. Consequently, an additional method of material removal is necessary to obtain information at greater depths. The purpose of this thesis was to investigate possible material removal techniques that can be implemented with XRD measurements. Two different material removal techniques were studied; electrochemical etching and milling in combination with electrochemical etching. The electrochemical etching equipment was developed at SKF MDC prior to this thesis but needed further testing and validation. The residual stress profiles of induction hardened cylinders were studied using the two different removal techniques combined with XRD measurements and the results were compared with stresses measured by Electronic Speckle Pattern Interferometry (ESPI) with hole drilling. In addition, the results were compared with simulations performed at SKF MDC India. It was concluded that both the material removal methods could be successfully combined with XRD measurements. However, for practical reasons the methods should be refined before being implemented on a regular basis. Unfortunately, poor correlation between XRD and ESPI measurements were obtained due to reasons not fully understood.
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Nounezi, Thomas. "Light Weight and High Strength Materials Made of Recycled Steel and Aluminum." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/20523.
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Recycling has proven not only to address today’s economical, environmental and social issues, but also to be imperative for the sustainability of human technology. The current thesis has investigated the feasibility of a new philosophy for Recycling (Alloying-Recycling) using steel 1020 and aluminum 6061T6. The study was limited to the metallurgical aspects only and has highlighted the potential of recycled alloys made of recycled aluminum and steel to exhibit substantially increased wear resistance and strength-to-weight ratio as compared to initial primary materials. Three alloy-mixtures are considered: TN3 (5wt% 1020 +95wt% 6061T6); TN5 (0.7wt% 1020 + 99.3wt% 6061T6); and TN4 (10wt% 6061T6 + 90wt% 1020). A Tucker induction power supply system (3kW; 135-400 kHz) is used to melt the alloy mixtures for casting in graphite crucibles. Heat treatment of the cast samples is done using a radiation box furnace. Microscopy, Vickers hardness and pin-on-disc abrasive wear tests are performed.
Casting destroyed the initial microstructures of the alloys leading to a hardness reduction in the as-cast and solution heat-treated aluminum rich samples to 60 Hv from 140 Hv. Ageing slightly increased the hardness of the cast samples and provided a wear resistance two times higher than that of the initial 6061T6 material. On the steel rich side, the hardness of the as-cast TN4 was 480 Hv, which is more than twice as high as the initial hardness of steel 1020 of 202 Hv; this hints to strong internal and residual stress, probably martensite formation during fast cooling following casting. Solution heat treatment lowered the hardness to the original value of steel 1020, but provided about ten (10) times higher wear resistance; this suggests higher ductility and toughness of normalised TN4 as compared to 1020. In addition, TN4 exhibits about 25% weight reduction as compared to 1020.
The actual recycling process and the effect of non-metallic impurities shall be investigated in future works. Also, the casting and heat treatment processes need to be improved.
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Javaheri, V. (Vahid). "Design, thermomechanical processing and induction hardening of a new medium-carbon steel microalloyed with niobium." Doctoral thesis, Oulun yliopisto, 2019. http://urn.fi/urn:isbn:9789526223582.
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Abstract This thesis has been made within the European Industrial Doctorate (EID) project called Mathematics and Materials Science for Steel Production and Manufacturing, abbreviated as MIMESIS, which has five partners: EFD Induction in Norway; SSAB, Outokumpu, and the University of Oulu in Finland; and Weierstrass Institute for Applied Analysis and Stochastics (WIAS) in Germany. The main aim of this work was to develop a steel composition and processing route suitable for making a slurry transportation pipeline with the aid of induction hardening, and to characterize the phase transformations and microstructures involved in the various stages of the processing route. A novel steel chemistry was designed based on metallurgical principles assisted by computational thermodynamics and kinetics. The designed composition is a medium-carbon, low-alloy steel microalloyed with niobium, in wt.% 0.40 C, 0.20 Si, 0.25 Mn, 0.50 Mo, 0.90 Cr, and 0.012 Nb. This was subsequently cast, thermomechanically rolled on a laboratory rolling mill to two bainitic microstructures, and finally subjected to the thermal cycles predicted to be encountered with the internal induction hardening of a typical pipe geometry. The phase transformations and microstructures found at various stages of the simulated production process have been characterized and algorithms developed to enable the optimization of microstructure and hardness through the pipe wall thicknessTiivistelmä Tämä väitöskirja on tehty osana Euroopan teollisuustohtori (European Industrial Doctorate, EID) -ohjelmaa projektissa eli Matematiikka ja materiaalitiede teräksen valmistuksessa ja käytössä (Mathematics and Materials Science for Steel Production and Manufacturing, MIMESIS). Ohjelmassa on viisi partneria: EFD Induction Norjasta; SSAB, Outokumpu ja Oulun yliopisto Suomesta; ja Weierstrass Institute for Applied Analysis and Stochastics (WIAS) Saksasta. Työn päätavoitteina oli kehittää teräksen koostumusta ja prosessointireittiä, jotka soveltuvat lietteen kuljetusputken valmistukseen induktiokarkaisun avulla, sekä karakterisoida prosessin eri vaiheiden aikana tapahtuvat faasimuutokset ja mikrorakenteet. Uusi teräskoostumus suunniteltiin metallurgisten periaatteiden pohjalta hyödyntämällä laskennallista termodynamiikkaa ja kinetiikkaa. Suunniteltu teräs on niobilla mikroseostettu, matalaseosteinen ja keskihiilinen, eli painoprosentteina 0,40 C, 0,20 Si, 0,25 Mn, 0,50 Mo, 0,90 Cr ja 0,012 Nb. Teräs valettiin, valssattiin ja jäähdytettiin termomekaanisesti laboratoriovalssaimella kahdeksi bainiittiseksi mikrorakenteeksi ja lopulta altistettiin lämpösykleille, joiden ennustettiin olevan tyypillisiä sisäisesti induktiokarkaistulle teräsputkelle. Simuloidun tuotantoprosessin eri vaiheissa havaitut faasimuutokset ja mikrorakenteet on karakterisoitu. Sen lisäksi on kehitetty algoritmit, jotka mahdollistavat mikrorakenteen ja kovuuden optimoinnin putken seinämän paksuuden läpi
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Al-Obaidi, Amar Baker Salim. "Induction Assisted Single Point Incremental Forming of Advanced High Strength Steels." Universitätsverlag der Technischen Universität Chemnitz, 2018. https://monarch.qucosa.de/id/qucosa%3A31527.
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Induction Assisted Single Point Incremental Forming (IASPIF) is a die-less hot sheet metal forming. The IASPIF does not apply characteristic complex tooling like those applied in deep drawing and bending. In this thesis, induction heating was used to heat up the sheet while simultaneously forming with a tool. The research goal is to improve the formability of high strength steels by heating. The IASPIF consists of non-complicated set up that allows induction heating to be utilized through the coil inductor moved under the sheet and synchronized with the forming tool that moves on the upper side of the sheet. The advanced high strength steel alloys, DP980, DP600 and 22MnB5 steels, were investigated. The influence of induction heating on formability was evaluated by the maximum wall angle that can be achieved in a single pass. Additionally, tool diameter and tool feed rate was also varied. The most influencing parameters were tool feed rate, induction power, and the profile depth. A new forming strategy was also developed by control the heating temperature through coupling the formed profile depth with a successively increased tool feed rate. The forming forces of DP980 steel sheet, were reduced from 7 kN to 2.5 kN when forming process was performed at room and elevated temperature, respectively. Stretching stresses were developed during forming process causing a high reduction in the resulting wall part thickness. New findings in this investigation were the reverse relationship between the step-down depth and the thickness reduction percentage. The smaller the tool diameter, the better was the formability. The finite element simulation of the investigated forming process showed that the increase in heating temperature has a direct effect on rising the plastic strain from 0.2 at room temperature to 1.02 at 800 ◦ C. The maximum true strain achieved in the resulting wall part thickness was determined by FEM simulations and validated with experimental trials. The part shape accuracy was measured and the highest deflection was founded when the part was formed by the highest step-down depth. Moreover, the minimum deflection in the part shape was achieved by utilizing a high induction power in the experiments. Finally, the resulting mechanical properties of the 22MnB5 alloy sheet material were tailored during IASPIF. For this purpose, the sheets were locally heated by induction during the forming process and subsequently quenched at different rates. As a result, the produced tailored parts consist of three different regions, which consist of a ductile, transitional and hardened region. The proposed procedure allows forming and quenching at the same time without transfer and thus, process time was reduced.Die induktionsgestützte, inkrementelle Blechumformung (englisch: Induction Assisted Single-Point Incremental Forming IASPIF) ist Warmumformprozess, bei dem keine komplexen Werkzeuge wie beim Tiefziehen und Biegen benötigt werden. Inhalt dieser Arbeit ist die inkrementelle Umformung eines Bleches mit gleichzeitig ablaufender induktiver Erwärmung. Das Forschungsziel bestand in der Verbesserung der Umformbarkeit von hochfesten Stahlwerkstoffen wie DP600, DP980 und 22MnB5 durch eine gezielte partielle Erwärmung. Der prinzipielle Aufbau des Versuchsstandes besteht aus einem Spuleninduktor, der unterhalb des umzuformenden Blechs platziert ist, und der synchron mit dem Werkzeug – einem Drückdorn – während des Umformvorganges verfährt. Ein wesentlicher Untersuchungsschwerpunkt bestand in der Ermittlung der Einflussgrößen auf den untersuchten IASPIF-Prozess. Für die Bewertung der Umformbarkeit wurden hierbei der maximal erreichbare Teilwandwinkel und die Profiltiefe, die in einem Umformdurchgang herstellbar waren, ermittelt und ausgewertet. Darüber hinaus konnten im Rahmen der Arbeit die Induktionsleistung des Generators, der Werkzeugdurchmesser und die Werkzeugvorschubgeschwindigkeit als relevante Prozessparameter identifiziert werden. Im Ergebnis der durchgeführten Untersuchungen zeigten die Werkzeugvorschubgeschwindigkeit und die Induktionsleistung einen wesentlichen Einfluss auf die erreichbare Profiltiefe. Aufbauend auf den erzielten Ergebnissen konnte eine prozessangepasste Umformstrategie entwickelt werden, bei der eine konstante Erwärmungstemperatur durch das Koppeln der momentanen Profiltiefe mit einer sukzessiv steigenden Werkzeugvorschubgeschwindigkeit erreicht wird. Weiterhin ließen sich die Kräfte bei der Umformung eines Stahlbleches aus DP980 von 7 kN (bei Raumtemperatur) auf 2,5 kN (bei erhöhter Temperatur) reduzieren. Aufgrund des mit einem Streckziehvorgang vergleichbaren Spannungszustandes während des Umformprozesses war eine starke Verringerung der resultierenden Wanddicke zu beobachten. Als neue Erkenntnis in dieser Untersuchung konnte die umgekehrte Beziehung zwischen der Zustelltiefe und dem Dickenreduktionsprozentsatz abgleitet werden. Aus der Finite - Elemente - Simulation des vorgestellten Umformprozesses wurde erkennbar, dass die Erhöhung der Erwärmungstemperatur einen direkten Einfluss auf die plastische Dehnung von 0,2 (bei Raumtemperatur) auf 1,02 (bei 800 °C) hat. Mittels der numerischen Simulation und der nachfolgenden experimentellen Validierung erfolgte darüber hinaus die Bestimmung der maximalen wahren Dehnung, die in der resultierenden Wanddicke erreicht wurde. Bei den Versuchen mit der größten Zustellung ließ sich durch die Bestimmung der Teileformgenauigkeit die höchste Abweichung von der Sollgeometrie CAD Modell feststellen. Abschließend wurde nachgewiesen, dass der IASPIF Prozess auch zur Einstellung maßgeschneiderter Bauteileigenschaften wie der resultierenden mechanischen Eigenschaften des Blechmaterials aus 22MnB5 einsetzbar ist. Zu diesem Zweck wurden die Bleche während des Umformprozesses lokal induktiv erwärmt und anschließend zur Einstellung des gewünschten Gefüges bei unterschiedlichen Abkühlgeschwindigkeiten abgeschreckt.
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Alexandre, Rex T. "Induction Bending of Internally Clad Steel Pipes: Failure Mechanisms & Processing Parameter Optimization in Ni-base Alloy Weld Overlays." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1480422106975311.
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Plodpradista, Wisuwat. "Study of tubular linear induction motor for pneumatic capsule pipeline system /." free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3052209.
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Kullman, Nicholas Allen. "Metallurgical Characterization of Armor Alloys for the Development and Optimization of Induction Bending Procedures." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1316013868.
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Hoseini, Saba. "Experimental simulation of gear hobbing through a face milling concept in CNC-machine." Thesis, KTH, Materialvetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-126804.
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Dyčka, Martin. "Optimalizace technologie perlitizace masivních vývalků." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-319561.
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This thesis deals with heat treatment of pearlitic steel beams with using of induction heating. The aim of this heat treatment is to improve mechanical properties of steel beams. In theoretical part are described pearlitic steels and theory of induction heating. In experimental part of this thesis analysis of current state of technology with its results was made. Numerical model describing current state of technology was assembled. Then this model was used to recommend adjustments in current technology of heat treatment, which leads to enlargement of heat treated depth. Experiments with adjusted parameters were executed on heat treating machine. Analysis of microstructure using LM and EM, measurement of hardness and fractographic analysis were done. The result of adjustments is enlargement of heat treated depth about half compared with current technology.
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Safa, Meer. "3D study of non-metallic inclusions by EEmethod and use of statistics for the estimationof largest size inclusions in tool steel." Thesis, KTH, Materialvetenskap, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-93770.
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The control of non-metallic inclusions is very important for the improvement of performance during the application of tool steel. This present study was performed to see the effect of changing of some process parameters during the vacuum degassing of the melt and how these changing parameters affects the characteristics of inclusions in tool steel. The main parameters that were changed during the vacuum degassing were the change of induction stirring, argon flow rate from both the plug 1 and 2 and different ladle ages for different heat. Electrolytic extraction method was used to observe the morphology and characteristics of inclusions as a 3 dimensional view in tool steel. Four lollipop samples from four different heats were used for the experiment and all the samples were after vacuum (AV) degassing. In this study four different types of inclusions were found and they are classified as type 1, 2, 3 and 4. Of them type 1 inclusion was the major one with mostly spherical shaped. This study shows that among the three parameters, induction stirring has the biggest effect for the total number of inclusions per volume in the sample than the other two parameters Heat 4A showed the lowest number of inclusions per volume comparing with the other heats. The main reason behind this can be said that the induction stirring was the lowest comparing with the other heats with moderate argon flow and ladle age of 12. Extreme value analysis was used in this study to predict the probability of getting largest size inclusions in a certain volume of the metal. For the prediction of the largest inclusion size, both the electrolytic extraction (3D) and cross-sectional (2D) method was used. Later in this study comparison was done to determine the accuracy of both the methods and it is concluded that for the type 1 inclusions electrolytic extraction method shows almost similar trend with cross-sectional method and electrolytic extraction method shows better accuracy for the prediction of largest size inclusions than the cross-sectional method. Electrolytic Extraction method is also applicable for the prediction of largest size inclusions for multiple types of inclusions.
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Camarão, Arnaldo Freitas. "Um modelo para previsão de tensões residuais em cilindros de aço temperados por indução." Universidade de São Paulo, 1998. http://www.teses.usp.br/teses/disponiveis/3/3133/tde-08032018-094937/.
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A previsão e entendimento da formação de tensões residuais oriundas da têmpera plena ou superficial nos aços tem sido objeto de estudo por um número considerável de pesquisadores, devido ao seu grande interesse tecnológico. Neste trabalho o objetivo principal consistiu no desenvolvimento de um modelo numérico para a previsão das tensões residuais em peças cilíndricas temperadas por indução. A têmpera por indução executada num componente previamente \"beneficiado\", isto é, temperado e revenido, é capaz de produzir uma camada superficial de alta dureza e tensões compressivas num núcleo resistente e tenaz. É esperado, entretanto, que o aumento da camada endurecida possa gerar tensões trativas indesejáveis abaixo da superfície, comprometendo a integridade estrutural do componente e levando as falhas prematuras. Portanto, neste trabalho ênfase foi dada no estudo da influência da profundidade de camada induzida no perfil e magnitude das tensões residuais em corpos de prova cilíndricos (c.ps.) de aço. O método de elementos finitos foi adotado para a solução do problema térmico (distribuição de temperatura) e estrutural (cálculo das tensões) com o emprego do programa ANSYS 5.3. Os efeitos metalúrgicos da mudança de fase Austenita - Martensita, responsável pelas altas tensões compressivas residuais na superfície, como resultado da expansão volumétrica inerente a esta transformação, foi modelado através de uma rotina FORTRAN especialmente desenvolvida neste trabalho e acoplada ao programa ANSYS 5.3. A criação da geometria do modelo e passos da solução foram automatizados através do uso da linguagem paramétrica APDL (ANSYS Parametric Design Language) do programa ANSYS 5.3. Trata-se de um problema termo-elasto-plástico onde as propriedades termo-físicas e mecânicas necessárias para o cálculo foram consideradas dependente da temperatura. Verificação e calibração do modelo computacional foi efetuada através da medição das ) tensões residuais em c.ps. cilíndricos de aço com o emprego da técnica de difração de raios X. Finalmente, são discutidos aspectos de precisão e principais fontes de erro, como também proposta de melhorias e futuras aplicações deste modelo.Large efforts have been made to predict and understand the residual stresses formation in through hardening and case hardening of steel. In the present work the objective was to develop a model to predict the residual stresses in induction hardening of cylindrical steel bars. Induction hardening, i.e. electromagnetic heating and subsequent quenching, is a surface treatment of great use in industry because it is suitable to improve locally mechanical properties of the high stressed regions of the part. A hard surface layer with high compressive residual stress is normally obtained, while retaining ductility and toughness in the core. Applied to components that undergo severe duty cycles, such as gears, shafts axles and bearings, it is also clean, fast and suitable for on-line applications. It is expected however, that increasing the hardening depth leads to undesirable high subsurface tensile stress, which can cause premature failure of the component. Emphasis has been on investigating the influence of case depth on the residual stress distribution of the cylindrical steel specimens. A finite element model was developed to compute the temperature history, phase transformation and residual stress for the induction hardening process. The Austenite to Martensite phase transformation during quenching, responsible for the high surface compressive stress, as result of volume expansion, was evaluated by a custom FORTRAN routine linked to the ANSYS5.3 FEA code. The model geometry and solution process were automated by the use of ANSYS Parametric Design Language (APDL). The thermoelastoplastic behavior of the material was studied, considering material properties temperature dependent. The results of the calculations have been compared to experimental measurements of the residual stresses at the surface, using X Ray diffraction technique. Finally, accuracy and main source of erros are discussed. Future improvements and applications of this model are proposed.
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Mikuš, Tomáš. "Vliv trajektorie elektronového svazku na vlastnosti povrchu oceli 42CrMo4." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-377874.
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The thesis deals with surface quenching of steel 42CrMo4 by electron beam. Influence of technologic parameters and beam deflection on properties and structure of prepared layers is studied. Electron beam surface quenching was applicated with and without melting of the surface. Structures of layers made by electron beam quenching were compared with structures made by laser and electromagnetic induction. Structures and phases were analysed by optical microscopy, SEM and roentgen diffraction. Hardness was measured on hardened layers.
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Felippe, Douglas Marquezin. "Comparação entre os processos de tratamentos térmicos convencional e por indução de rolamentos do aço DIN 100Cr6." Universidade Presbiteriana Mackenzie, 2010. http://tede.mackenzie.br/jspui/handle/tede/2746.
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Previous issue date: 2010-02-23Fundo Mackenzie de Pesquisa
Heat treatment processes are related to control heating and quenching with the aim of improving physical properties, such as: hardness, abrasion resistance, toughness, among others. During the heat treatment process, the quenching media are of great importance steps, because it extracts heat from the part with the achieve of obtaining specification properties. However, the hardening process causes undesired distortion that can be related to the permanent residual stress in the parts, generated during quenching. Some conventional hardening heat treatments do not have the control of the position during quenching, this control is usually applied in induction heat treatment, improving the homogeneity of heat exchange in the quenching process, suggesting lower distortion. The induction process can be a sustainable one, because the heating is applied just in the part. This survey compared both metallurgical and mechanical properties between two heat treatment processes of DIN 100Cr6 steel bearings: conventional and induction. With the result of this survey, it is intended, to change the conventional heat treatment process for the induction process in bearing manufacturing, with the objective of reducing the typical out-of-roundness from the conventional heat treatment process, and a reduction the bearing manufactured costs.
A têmpera compreende operações de aquecimento e resfriamento controlado, que objetivam melhorias nas propriedades físicas como dureza, resistência à abrasão, tenacidade entre outras. Durante o processo de têmpera, o meio de resfriamento é uma das etapas mais críticas, pois extrai calor da peça com o objetivo de obter as propriedades desejadas. Porém, o processo de têmpera gera deformações não desejadas, que podem estar relacionadas às tensões residuais que ficam permanentes na peça, introduzidas durante o resfriamento. Alguns tratamentos térmicos de têmpera convencional não têm controle da posição da peça durante o resfriamento. Este controle é normalmente utilizado em processos de têmpera por indução, melhorando a homogeneidade da extração de calor durante o resfriamento, sugerindo menores índices de deformação. O processo por indução pode ser considerado sustentável, pois o aquecimento é localizado apenas no componente. Este trabalho comparou as propriedades metalúrgicas e mecânicas entre dois processos de têmpera de rolamentos do aço DIN 100Cr6: convencional e por indução. Como resultado deste trabalho, pode-se substituir o tratamento térmico com aquecimento convencional pelo tratamento térmico com aquecimento por indução para a manufatura de rolamento, com objetivo de redução da deformação de ovalização característica do processo de tratamento térmico convencional.
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Lemos, Guilherme Vieira Braga. "Análise de tensões residuais em eixos automotivos do aço DIN 38B3 temperados por indução." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2012. http://hdl.handle.net/10183/55439.
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As distorções de forma e variações dimensionais, em muitos casos, manifestam-se de maneira mais expressiva após a têmpera por indução ocasionando o chamado empenamento. Tais efeitos usualmente trazem despesas em reparos e restauração de peças, equipamentos e estruturas. Assim, a análise de tensões residuais é uma etapa obrigatória na produção de peças e elementos estruturais para a estimativa da sua confiabilidade sob condições reais de serviço. No presente trabalho foram realizadas medições de tensões residuais em semi-eixos automotivos fabricados com o aço DIN 38B3 temperados por indução. Estes eixos apresentaram diferenças quanto ao comportamento em distorção, com um eixo tendo sido endireitado e outro não. Devido a estas diferenças também se esperam diferenças em termos de distribuição de tensões residuais e propriedades dos eixos. As tensões residuais foram medidas através do método de difração de raios-X com dois equipamentos de medição (difratômetro portátil e difratômetro fixo). Complementando o trabalho foram feitas análises químicas, metalográficas, perfil de microdureza e profundidade de camada efetiva para verificar eventuais diferenças ou semelhanças entre os eixos analisados. Com os resultados de tensões obtidos foi possível obter uma visão geral da variação do perfil de tensões residuais superficiais após a têmpera por indução e a grande influência da etapa de endireitamento na redistribuição de tensões no material.The distortions of form and dimensional variations, in many cases, appear after induction hardening causing the often called warping. These effects usually usually increase the costs of maintenance and restoration of parts, equipment and structures. Thus, the residual stress analysis is an important step in the production of parts and structural elements to estimate of its reliability under actual service conditions. In this study, measurements of residual stresses were carried out for a driveshafts manufactured from the DIN 38B3 steel after induction-hardening and straightening, if necessary. These shafts showed different behavior in distortion, with a shaft has been straightened and the other not. Due to these differences also are expected differences in the distribution of residual stresses and properties of the shafts.The residual stresses were measured by the X-ray diffraction method with two measuring equipment (a portable and a fixed diffractometers). Complementing this work chemical analysis, metallographic, of the microhardness profile and of effective case depth were accessed to eventually find differences or similarities between the analyzed driveshafts. With the residual stress results obtained it was possible to get an overview of the variation of the surface profile of residual stresses after induction hardening and the influence of straightening steps on the redistribution of residual stresses in the material.
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Bénéteau, Adeline. "Étude in situ des évolutions microstructurales d'un acier inoxydable martensitique à l'azote au cours d'une succession de traitements thermiques." Thesis, Vandoeuvre-les-Nancy, INPL, 2007. http://www.theses.fr/2007INPL016N/document.
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L’acier inoxydable martensitique à l’azote XD15NW (Fe–15,5%Cr–0,4%C–0,2%N–1,7%Mo–0,3%V) est un candidat attractif pour les bagues de roulement des moteurs spatiaux. Il possède de bonnes propriétés mécaniques et une bonne résistance à la corrosion grâce à l’azote qui contribue à la formation de précipités de petite taille dans une matrice à grains fins. Nous avons étudié les évolutions microstructurales de cet acier au cours d’une succession de traitements thermiques: austénitisation et trempe, revenu, traitement de surface par induction. Outre les techniques usuelles d’analyse microstructurale (MEB, MET, dilatométrie), nous avons utilisé la diffraction des rayons X de haute énergie in situ (rayonnement synchrotron). Cette technique nous a permis d’obtenir les cinétiques d’évolution des phases en fonction de la température et du temps, les gradients de microstructure au sein de pièces traitées par induction en surface et les évolutions de paramètres de maille des phasesThe nitrogen martensitic stainless steel XD15NW (Fe–15,5%Cr–0,4%C–0,2%N–1,7%Mo–0,3%V) is an attractive candidate for the bearing rings of the space engines turbopumps. It owns good mechanical properties and a good corrosion resistance thanks to the nitrogen which contributes to the formation of little size precipitates in a fine grains matrix. The microstructural evolutions of this steel during a succession of thermal treatments were studied: austenitisation and quenching, tempering, induction surface heat treatment. In addition to the usual techniques of microstructural analysis (SEM, TEM, dilatometry), the in situ high energy synchrotron X-ray diffraction was used. It allowed to obtain the evolution kinetics of the phases as a function of temperature and time, the microstructural gradients in induction treated samples and the lattice parameters evolutions which are linked to the chemical composition or the internal stresses evolutions of the phases
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Binns, Richard. "Smart inductive sensors for the steel industry." Thesis, Lancaster University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.403924.
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Penin, Rémi. "Evaluation à priori des performances environnementales d'un noyau magnétique de transformateur triphasé sur la base de tests simplifiés." Thesis, Artois, 2014. http://www.theses.fr/2014ARTO0209/document.
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Le transformateur est aujourd’hui l’un des convertisseurs statiques les plus utilisé notamment dans la distribution électrique. Les tôles magnétiques servant à la construction de leurs circuits magnétiques sont devenues de plus en plus performantes permettant une réduction des pertes produites. Néanmoins, les tests normalisés permettant de caractériser les tôles magnétiques ne reflètent pas totalement le comportement énergétique du transformateur. De plus, une autre problématique a gagné en importance durant ces dernières années : le bruit acoustique émis. Malheureusement, il n’y pas encore de lien entre la qualité de la tôle à grains orientés choisie pour construire le circuit magnétique et le bruit acoustiques que va produire celui-ci. L’objectif de cette thèse est de répondre à cette double problématique à partir de tests simplifiés. En effet, de nombreux dispositifs expérimentaux et méthodologies ont été développés tels que la méthode des trois cadres, permettant d’étudier la répartition des pertes fer dans le transformateur, les circuits magnétiques décalés, permettant d’étudier les phénomènes à l’origine des bruit acoustique, et des modèles de transformateurs monophasés et triphasés. De plus, des simulations numériques ont été effectuées afin d’approfondir nos analyses des résultats expérimentaux. L’étude des dispositifs ont permis de mettre en évidence trois paramètres relatifs à la qualité des tôles magnétiques, entrainant des différences de répartition d’induction set donc des différences de répartition de pertes fer, d’une part, et de bruit acoustique dans les transformateurs, d’autre partThe transformer is now a static converter most notably used in electrical distribution. The electrical steel sheet used in the construction of their magnetic circuits have become more efficient to reduce losses occurred. However, standardized tests to characterize the electromagnetic steel do not fully reflect the energy behavior of the transformer. In addition, another issue has gained importance in recent years: the acoustic noise. Unfortunately, there is no link between the quality of grain oriented steel selected to construct the magnetic circuit and acoustic noise that will produce it. The objective of this thesis is to answer this dual problem from simplified test. Indeed, many experimental devices and methodologies have been developed such as the method of three frames, to study the distribution of core losses in the transformer, the magnetic circuits shifted, to study phenomena at the origin of acoustic noise, and models of single and three phase transformers. In addition, numerical simulations were performed to deepen our analysis of the experimental results. The study of the devices have allowed to identify three parameters relating to the quality of grain oriented electrical steel, resulting from differences in the distribution of the flux density and therefore, first, the differences in distribution of core loss and, hand, acoustic noise in transformers
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Cozonac, Dorin. "Conception d'une machine asynchrone haute température." Thesis, Artois, 2015. http://www.theses.fr/2015ARTO0209/document.
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Les bobinages des machines électriques tournantes actuelles sont, pour la plupart, isolés avec des matériaux issus de la chimie organique. La limite en température des bobinages actuels se situe au-dessous de 240°C. L’augmentation significative de la température de fonctionnement d’une machine permettrait d’envisager, indirectement, une augmentation de la densité de courant dans les conducteurs actifs. Dans ces conditions, ces nouvelles machines peuvent présenter une puissance, tant massique que volumétrique, supérieures à celles exploitées actuellement. De plus, les matériaux magnétiques permettent vraisemblablement de fonctionner jusqu’à 800°C. La limite technologique actuelle pour les machines est clairement l’isolant des conducteurs électriques. Ce sujet de thèse propose de définir une approche théorique couplée à des validations expérimentales pour définir les matériaux les mieux adaptés aux machines hautes températures en termes de mise en œuvre et de performances électriques. La conception, repensée autour du bobinage, sera concrétisée par le calcul d’une machine asynchrone à haute température (400°C au cœur du bobinage). Le bobinage devra être placé au cœur de la démarche de conception des machines en adaptant les formes et les propriétés des circuits magnétiques aux caractéristiques des nouvelles bobinesThe windings that are currently used in electrical machines are mostly insulated based on organic insulation. The temperature limit of these windings is up to 240°C. Increasing the working temperature of electrical motors means, indirectly the increasing of current density on the main conductors. Therefore these new motors may provide a higher mass and volume power as classical machines. Furthermore, the magnetic materials can work up to 800 °C. Indeed, in reality technical limit today is the wire insulation. The objective of thesis is to define a theoretical approach combined with experimental validations for identify the appropriate electrical materials used on high-temperature electrical machines. Design is fixed around the winding, that will implemented by calculating a high-temperature asynchronous machine (400°C of windings). The windings are placed as the base of machine design and will determine the geometrical shape and properties of magnetic core
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Svoreň, Jan. "Návrh vysokootáčkového asynchronního motoru." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219753.
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This work deal with troubleshooting of problem parts of high-speed induction machines. Introduction is about conception of induction machines with reference to construction specialities due to high rpm and because machines are fed by inverter. Next part is focused to design problems. A classical induction machine was measured to determination change of various losses in classic and high-speed induction machines. The computation of laboratory sample high-speed motor was specified for calculation of effective resistance and leakage reactance of solid-steel rotor with copper layer. The results of numerical calculation were validated by using finite elements method and machine design was adjusted for improving operation characteristic.
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Hihat, Nabil. "Modèles quasi 3D pour l'analyse de structures présentant une anisotropie 3D." Thesis, Artois, 2010. http://www.theses.fr/2010ARTO0206/document.
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Les travaux présentés dans cette thèse s'inscrivent dans le cadre de l'analyse et la modélisation de la distribution du champ magnétique dans les machines électriques à circuit magnétique feuilleté avec des tôles à grains orientés. L'anisotropie des tôles magnétiques des transformateurs induit des phénomènes 3D complexes au niveau des joints magnétiques où les tôles se chevauchent. Concernant l'augmentation de l'efficacité énergétique des machines tournantes, de nouvelles structures à base de tôles à grains orientés font leur apparition. Néanmoins, simuler finement en 3D un paquet de tôles minces recouvertes d'un isolant de quelques microns d'épaisseur conduit à des temps de calculs très importants.Dans cette optique, nous présentons une méthode d'homogénéisation dont le but est de définir les caractéristiques magnétiques équivalentes d'un empilement quelconque de tôles et d'entrefers. Sa formulation est basée sur la minimisation de l'énergie et la conservation du flux magnétique. Les résultats de cette méthode appliquée à un joint magnétique de transformateur à joints step-lap sont confrontés à des mesures expérimentales et à un modèle élément fini 3D. Ce dernier requiert de connaître les caractéristiques magnétiques des tôles dans les directions de laminage, transverse et normale. La détermination de la perméabilité des tôles dans la direction normale est problématique et constitue un point original de notre étude. Deux méthodes, analytique et numérique, s'appuient sur les mesuresd'un banc de caractérisation en régime statique pour déterminer cette perméabilité normaleThis thesis focuses on the analysis and the modeling the magnetic flux distribution in electrical machines with anisotropic laminated magnetic circuit. The anisotropy of magnetic sheets in transformers induces complex 3D phenomena in step-lap magnetic joints where the sheets are overlapped. Moreover, in order to increase the energy efficiency of rotating machines, new structures based on grain-oriented electrical steel are developed.However, an accurate 3D simulation of a laminated core with thin sheets and insulation of a few microns leads to very large computation time. In this context, we present a homogenization method, which purpose is to define the equivalent magnetic characteristics of any laminated core made of sheets and air gaps. Its formulation is based on the energy minimization and the magnetic flux conservation. The results of this method applied to a step-lap magnetic joint are compared with experimental measurements and a 3D finite element model. The latter requires to know the magnetic characteristics of the sheets in the rolling, transverse and normal directions. The determination of the sheets permeability in the normal direction is problematic and it constitutes an original point of our study.Two methods, analytical and numerical, based on measurements obtained with a static characterization bench makes possible the determination of the normale permeability
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Bourchas, Konstantinos. "Manufacturing Effects on Iron Losses in Electrical Machines." Thesis, KTH, Elektrisk energiomvandling, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-172373.
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In this master thesis, the magnetic properties of SiFe laminations after cutting and welding are studied. The permeability and the iron loss density are investigated since they are critical characteristics for the performance of electrical machines. The magnetic measurements are conducted on an Epstein frame for sinusoidal variations of the magnetic ux density at frequencies of 50, 100 and 200 Hz, according to IEC 404-2. Mechanical cutting with guillotine and cutting by means of ber and CO2 laser are performed. The inuence of the ber laser settings is also investigated. Especially the assisting gas pressure and the power, speed and frequency of the laser beam are considered. In order to increase the cutting e ect, the specimens include Epstein strips with 1, 2 and 3 additional cutting edges along their length. It is found that mechanical cutting degrades the magnetic properties of the material less than laser cutting. For 1.8% Si laminations, mechanical cutting causes up to 35% higher iron loss density and 63% lower permeability, compared to standard Epstein strips (30 mm wide). The corresponding degradation for laser cut laminations is 65% iron loss density increase and 65% permeability drop. Material of lower thickness but with the same Si-content shows lower magnetic deterioration. Additionally, laser cutting with high-power/high-speed characteristics leads to the best magnetic characteristics among 15 laser settings. High speed settings have positive impact on productivity, since the cutting time decreases. The inuence of welding is investigated by means of Epstein measurements. The test specimens include strips with 1, 3, 5 and 10 welding points. Experiments show an iron loss increase up to 50% with a corresponding 62% reduction in the permeability. A model that incorporates the cutting e ect is developed and implemented in a FEMbased motor design software. Simulations are made for a reference induction motor. The results indicate a 30% increase in the iron losses compared to a model that does not consider the cutting e ect. In case of laser cut core laminations, this increase reaches 50%. The degradation prole considers also the deteriorated magnetizing properties. This leads to increased nominal current up to 1.7% for mechanically cut laminations and 3.4% for laser cut laI detta examensarbete studeras hur de magnetiska egenskaperna hos SiFe-plat paverkas av skarning och svetsning. Permeabilitet och jarnforlustdensitet undersoks eftersom de ar kritiska variabler for elektriska maskiners prestanda. De magnetiska matningarna genomfordes pa en Epstein ram med en odesfrekvens pa 50, 100 och 200 Hz, enligt IEC 404-2. E ekterna av mekanisk skarning med giljotin samt skarning med ber- och CO2-laser studerades. Inverkan av olika berlaserinstallningar undersoktes ocksa genom att variera gastrycket, skarhastigheten samt frekvensen och e ekten av laserstralen. For att oka skare ekten inkluderades Epsteinremsor med ytterligare 1, 2 och 3 langsgaende skarsnitt. Det visas att mekanisk skarning har en mindre paverkan pa de magnetiska egenskaperna hos materialet an vad laserskarning har. Matningar pa plat med 1.8% Si visar att da prov med tre extra langsgaende giljotinklipp anvands kan permeabiliteten reduceras med upp till 63% och jarnforlusterna kan oka med upp till 35%. Motsvarande resultat for laserskurna platar visar en permeabilitetsreduktion pa upp till 65% och en jarnforlustokning pa upp till 65%. Ur studien av de tva studerade skarprocesserna framkommer aven att tunnare plat paverkas mindre negativt an tjockare plat. Ett antal olika installningar har provats for att utreda hur olika parametrar paverkar e ekterna av laserskarning. Studien indikerar att skarning med hog e ekt och hog hastighet ger den minsta paverkan pa materialets magnetiska egenskaper. Vilket aven har en positiv inverkan pa produktiviteten vid laserskarning. Epsteinprover har aven utforts for att undersoka vilka e ekter som introduceras da SiFe-plat svetsas. Provstyckena bestod av remsor med en, tre, fem och 10 svetspunkter. Experimenten visar en jarnforlustokning med upp till 50% samt en permeabilitetsreduktion upp till 62% da platarna svetsats samman tva och tva. En modell for att studera e ekterna av de forandrade materialegenskaperna vid skarning pa en induktionsmotor utvecklas och implementeras i en FEM-baserad mjukvara. Resultaten tyder pa en jarnforlustokning med 30% da skare ekten orsakad av giljotin beaktas. Vid simulering av laserskuren plat kan denna okning vara sa stor som 50%. Det framkommer aven att laserskarningen kan reducera e ektfaktorn sa mycket som 2.6%.
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Heathcote, Lydia. "An Inductive Scanning System for Detection of Corrosion in Reinforcing Steel Bars at Distances of up to 90mm and a Procedure to Extract Bar Dimensional Information." Thesis, University of Manchester, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.525292.
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Al-Obaidi, Amar Baker Salim [Verfasser], Dirk Akademischer Betreuer] [Gutachter] Landgrebe, Lutz [Gutachter] [Lachmann, and Verena [Gutachter] [Akademischer Betreuer] Kräusel. "Induction Assisted Single Point Incremental Forming of Advanced High Strength Steels / Amar Baker Salim Al-Obaidi ; Gutachter: Dirk Landgrebe, Lutz Lachmann, Verena Kräusel ; Dirk Landgrebe, Verena Kräusel." Chemnitz : Universitätsverlag der Technischen Universität Chemnitz, 2018. http://d-nb.info/1215908733/34.
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Růžek, Václav. "Řídicí jednotka pro zjišťování polohy kovové šipky v terči." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-217912.
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Problematics of sensing position metal darts in targets is new and in this time is no too explored problem. This work analyses accessible method, what can realize this scan. There are lot of accessible methods like best applicable reflect method inductive, based on change inductivity and method capacitive, based on change capacities tabular condenser. Capacitive sensing should be realized by the plate couple, where stiring electrode supplies signal.Sensing electrode receiving this signal. On the basis changes thorough electrostatic field measures change capacities. By the changes capacities fit algorithm we can evaluate, whether is in sensing field visible foreign subject – dart. For capacitive method is also designed driving and scanning unit. Various method were to be laboratory tested and was achieved satisfactory results.
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Jahn, Axel. "Umformbarkeit laserinduktionsgeschweißter Strukturen aus höherfesten Stahlfeinblechen." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-73795.
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Konventionelles Laserstrahlschweißen von Halbzeugen aus höherfesten Stahlfeinblechen führt zum drastischen Verlust an Umformbarkeit im Schweißnahtbereich. Durch integrierte induktive Erwärmung können der Temperaturverlauf beim Schweißen modifiziert, die Verbindungseigenschaften beeinflusst und die Umformbarkeit verbessert werden. Die Zusammenhänge zwischen Prozessparametern und mechanischen Verbindungseigenschaften werden beschrieben und Anwendungspotenziale aufgezeigt.
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Jahn, Axel. "Umformbarkeit laserinduktionsgeschweißter Strukturen aus höherfesten Stahlfeinblechen." Doctoral thesis, Fraunhofer Institut für Werkstoff- und Strahltechnik, 2010. https://tud.qucosa.de/id/qucosa%3A25673.
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Konventionelles Laserstrahlschweißen von Halbzeugen aus höherfesten Stahlfeinblechen führt zum drastischen Verlust an Umformbarkeit im Schweißnahtbereich. Durch integrierte induktive Erwärmung können der Temperaturverlauf beim Schweißen modifiziert, die Verbindungseigenschaften beeinflusst und die Umformbarkeit verbessert werden. Die Zusammenhänge zwischen Prozessparametern und mechanischen Verbindungseigenschaften werden beschrieben und Anwendungspotenziale aufgezeigt.
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Liu, Chao-Lun, and 劉兆倫. "Induction motor electromagnetic steel manufacturing process improvement." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/k452s7.
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碩士國立高雄應用科技大學
電機工程系博碩士班
104
In this thesis explore motor manufactur impact on motor performance.Motor stator and rotor using a non-directional electromagnetic steel sheet, continuous high speed stamping and the argon welding process which it have strain effects on electromagnetic steel sheet electromagnetic properties. According to motor size requirements for stamping die design so that it can meet the requirements. Using appropriate annealing process caused by the Elimination of stamping process of plastic deformation and residual stresses. Also we can improve electromagnetic properties of electromagnetic steel sheet by using heat treatment process. Stator argon welding manufactur bring residual stresses in electromagnetic steel sheet, so that using heat treatment process to improve electromagnetic properties of electromagnetic steel sheet. Using Taguchi quality engineering method, find optimal parament for Stator argon welding manufactur and new process of stator in motor manufacture. Using this method we can get Electromagnetic steel sheet finished stator, heat distortion can be effectively reduced. Improved results for the stator magnetic steel sheet finished, there was significant variation in size and shape effects. Assemble motor, reduction of stress concentration on the process to avoid deterioration of the electromagnetic characteristics of electromagnetic steel sheet so that it can better achieve the motors overall electromagnetic characteristics of high productivity, in line with the global trend of energy saving and carbon reduction.
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Huang, Cheng-Yu, and 黃晟瑜. "Jointing of steel wire by ultra-high frequency induction heating." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/00756544782992649968.
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碩士國立臺灣大學
機械工程學研究所
97
The ultra-high-frequency induction heating characterized as its high heating rate, short treating time, and effective heating on miniature tools. The joining stainless steel wire and carbon steel wire by ultra-high frequency induction heating has been studied in the article. The experiment in this study is divided into two parts: (1) Induction welding： 1. 202 stainless steel 2. extremely low carbon steel 3. piano wire (2) Induction brazing with Cu filler metal： 1. 202 stainless steel / extremely low carbon steel 2. 202 stainless steel / 304 stainless steel The effects of different parameters on the mechanical properties/microstructures of the joint parts were investigated for evaluation of the feasibility. The results of the study are shown as follows: 1. The microstructures of the joint for 202 stainless steel wire after induction welding were austenite and ferrite. Moreover, when heating temperature or heating time increased, ferrite also increased. The tensile strength of the joint was superior with higher heating temperature. 2. The microstructures of the joint for extremely low carbon steel wire after induction welding were pearlite and ferrite. Moreover, The tensile strength of the jointed part was higher than the tensile strenth in the matrix of extremely low carbon steel wire. 3. The microstructure of the joint for piano wire after induction welding and high temperature tempering was tempered martensite. Moreover, The tensile strength of the jointed part was higher than the others parts of the workpiece. 4. The tensile strength of the jointed part of brazing 202 stainless steel wire and extremely low carbon steel wire with Cu filler metal was best at 950℃ for 10 seconds, higher than the tensile strength in the matrix of extremely low carbon steel wire. 5. The tensile strength of the jointed part of brazing 202 and 304 stainless steel wire with Cu filler metal by induction heating would be higher under fixed temperature for longer time. Moreover, when heating temperature was higher, there would be welding at the center of the joint, and increasing the strength of the joint significantly.
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WANG, HSIANG-YU, and 王祥宇. "Tribological Properties of the High Carbon Chromium Alloy Steel after Induction Hardening." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/43547055553692160149.
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碩士崑山科技大學
機械工程研究所
105
The effects of heavy loads on the drive elements under extreme contact pressures must be carefully considered. Due to the great contact stress between the steel ball and the track, likely to cause significant deformation, serious wear and fatigue damage and other issues. Therefore, it is very important to establish the key technology of well tribological properties for the drive elements under extreme contact pressures in the future. Based on the above statements, this paper is focused on the effects of induction hardening on friction and wear of the original materials by improving the reciprocating friction tester. Moreover, the results are compared with the current production of long-term carburizing low-carbon alloy steel. Therefore, the standards of heat treatments and source materials will be established for the related industries.
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Chen, Yu-Yi, and 陳有毅. "Partial Hardening of SK5 Tool Steel Saw Teeth by Induction Heat Treatment." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/25074230922772116219.
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碩士國立交通大學
機械工程學系
98
Tool steels usually are used in a variety of cutting tools and hand tools, because they are easy to process, can achieve high hardness and have good wear resistance. However, tool steels have some drawbacks, such as low hardenability and temper softening. Tool steels must impose the appropriate heat treatment to improve the mechanical properties. The material of this study is JIS SK5 tool steel often used in Japanese woodworking handsaw blade. High frequency induction heating could heat a specific part of workpiece. To make use of this characteristic together with subsequent heat treatment, we hope to make an ideal saw tooth which have high hardness on the cutting edges and good wear resistance. However, if the saw don’t have appropriate toughness in the saw body, it will shorten the life of saw blade. The heat treatments in this study were high-frequency induction heating and air quenching, low temperature tempering after high-frequency induction heating and air quenching, double quenching after high-frequency induction heating and air quenching, and low temperature tempering after double quenching. To evaluate the effect of heat treatments we measured the hardness distribution on the saw teeth, examine the micro-structures of the teeth and wear testing. The results showed that the saw teeth treated with high-frequency air quenching and tempering for 30 minutes at 150℃had higher hardness on the cutting edges and better wear performance. On the other hand, the saw teeth rupture and shortening the life of the saw blade were caused by hard teeth tip without soft body texture to absorb the cutting force.
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Lourens, Leon. "Reduction of iron ore fines in the Ifcon furnace." 2008. http://upetd.up.ac.za/thesis/available/etd-08192008-125855.
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Liao, Kuan-Chueh, and 廖冠爵. "Effect of Notch and Hardness on the Failure of Steel by Induction Hardening." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/xyw6zg.
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碩士大同大學
材料工程學系(所)
102
This study investigates in the different hardness and different groove, U-shaped, V-shaped and no groove, for medium carbon steel, S45C, SCM440, SNCM439, crack after high frequency hardened. Austenitized all specimens at 850℃ and tempered at 170~670℃. And we got the specimens for 28 to 55 HRC. Selected specimens were high frequency induction heated at 950℃ and oil quenched. Higher hardness specimens were appearing crack easier. Add alloying elements or not is influence the resistance of crack produce. Lower hardness SCM440 and SNCM439 specimens are no cracks, but all S45C specimens appearing cracks. The U-shaped groove edge discontinuous spot is stress concentration points. All U-shaped groove crack is appearing at stress concentration points.
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Huang, Jen-Yu, and 黃仁煜. "Simulation and Monitoring Study of Induction Motor Operating Maintenance for Rolling Steel Factories." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/12217094509778977425.
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碩士國立成功大學
電機工程學系碩博士班
94
In this study, the simulation and measurement technique is integrated to apply for the design of operating maintenance system of rolling steel factories. In the method, thanks to the complete visualization simulation module along with the satisfactory computation performance, the wavelet transform as well as Park’s transform were carried out to monitor the transformer inrush current and various disturbances of distribution systems. Meanwhile, the virtual instrument system aided by hardware measurement modules and digital signal processing techniques were also embedded into the proposed system, by which the measurement data were analyzed thoroughly. From these test outcomes, they are deemed useful to support the feasibility of this proposed approach.
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Yang, Tsung-Lin, and 楊宗霖. "Cladding of Cobalt-based and Nickel-based Alloy on Steel Surface Using High Frequency Induction Heating." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/54820309598625627039.
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碩士國立臺灣大學
機械工程學研究所
99
In this research, Co-based alloy Stellite6（Co-28Cr-4W-1.1C）and Ni-based alloy Deloro60（Ni-14.4Cr-3.2B-4.4Si）were clad on carbon steel using high frequency induction heating. With different processing parameters, the properties of the clad layer were studied through observing the microstructure, measuring the chemical composition and hardness distribution, indentifying the phases in the layer, and conducting the corrosion test. The results show that the microstructure of Co-based alloy layer can be divided into dendrite, interdendritic eutectics and needle structure. If the microstructure of the clad layer is dendrite and interdendritic eutectics, the matrix is Co-rich solid solution containing chromium, iron and other elements with network M7C3 carbide distributed along the grain boundary. The hardness of the clad layer will decrease with increasing the heating time. However, when the content of iron is more than 40％, the microstructure will transform into needle structure, and the hardness of the clad layer will increase with increasing the heating time. Ni-based alloy layer consists of γ-Ni matrix, Ni3B, Ni31Si12, CrB, Cr7C3 and Ni-Cr-Fe compounds. The interface compound of Ni-Cr-Fe will increase and both CrB and Cr7C3 will decrease with increasing the heating time, leading to a slightly decrease in the hardness near the interface. In the clad layer, the coarsening of CrB and Cr7C3 becomes more obvious as the heating time increases. In other words, the volume fraction of hardening phases（CrB and Cr7C3）increases and lead to the increasing of hardness. High heating power and short heating time will increase the compounds of CrB and Cr7C3 as well as the volume fraction ofγ-Ni and Ni3B ,and lead to increase in hardness of the clad layer. The specimen clad with Co-based alloy or Ni-based alloy has excellent resistance to the corrosion of hydrochloric acid, nitric acid and sulfuric acid. No matter which alloy is clad, the ability of anti-corrosion will decrease with increasing the heating time, owing to the dilution of iron in the clad layer.
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Chang, Hou-Ting, and 張浩庭. "Application of High Frequency Induction Heating to the Cladding of Cobalt-based Alloy on Steel Surface." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/39729833864855418147.
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碩士國立臺灣大學
機械工程學研究所
94
SUS304, S45C, and SK3 are cladded with cobalt-based Stellite 6 alloy by means of high frequency induction heating. The influence of heating power and heating time on the microstructure, hardness and chemical compositions of the caldded layer has been studied. The results show that there are two types of microstructure in the cladded layer depending on the heating power and heating time if SUS304 is used as base metal. They are cellular dendrite and columnar dendrite. When the heating power or the heating time increases, the hardness of the cladded layer will decrease. The content of Co and Fe within the grain is much more than that at the grain boundary, but the content of Cr and W is more at the grain boundary. If S45C or SK3 is used as base metal, there are three types of microstructure in the cladded layer depending on the heating power and heating time. They are cellular dendrite, columnar dendrite and needle structure. If the microstructure of the cladded layer is cellular dendrite or column dendrite, the hardness of the cladded layer will decrease with increasing the heating power or heating time. If the needle structure appears, the hardness of the cladded layer will increase with increasing the heating power or heating time owing to the precipitation of carbide in the matrix. No matter what the microstructure is, the content of Co and Fe within the grain is much more than that at the grain boundary, but the content of Cr and W is more at the grain boundary.
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Chen, Kuang-Hsi, and 陳光熙. "Characteristic Analyses of Induction Motors for Driving Coke Oven Plant’s Coke Transfer Cars of China Steel Corporation." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/16927142739789174566.
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碩士國立成功大學
電機工程學系碩博士班
92
This thesis investigates the characteristics of induction motors (IMs) for driving coke oven plant’s coke transfer cars of China Steel Corporation (CSC). The employed mathematical model and parameters of the studied IMs are very important for performance analyses of the studied system. The induction machine’s q-d axis and a-b-c axis equivalent-circuit models are respectively utilized to analyze both transient and dynamic behaviors of the studied IMs. This thesis discusses and compares the output performance of four independent IMs driven by four independent small frequency converters and four parallel-operated IMs driven by a large frequency converter. By comparing field measured results and computer simulated outcomes, it can be confirmed that the employed model and parameters for the studied IMs are proper and feasible.
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Samosamo, Mothusi George. "Impact of induction on employee perceptions of health and safety at ArcelorMittal." Thesis, 2015. http://hdl.handle.net/10352/322.
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M. Tech. (Human Resource Management, Faculty of Management Sciences), Vaal University of Technology.Workplace health and safety is a global concern. South African companies are bound by the stipulations of the Occupational Health and Safety Act (OHSA) (85 of 1993), which regulates employer and employee duties to identify and eliminate hazards, thereby controlling and minimising the risk to health and safety within the working environment. Employees are regarded as the strength of ArcelorMittal. The on-board programme of this employer is designed specifically to support the integration of new employees into ArcelorMittal’s environment and enable them to maximise their contribution to the performance of their team, implementation of a business plan and strategy and realisation of the group’s objectives. This study investigates the perceptions that ArcelorMittal (Vanderbijlpark) employees uphold regarding the effectiveness of the health and safety induction they received. The iron division was identified purposefully for selection of the target population because of its high rate of health and safety incidents. Simple random sampling was used within a quantitative research design to select 317 respondents out of 634 employees. Accordingly, questionnaires were distributed within the demarcated division and a total of 160 questionnaires were completed and returned. The collected data were statistically analysed and presented. The results indicated that the majority of employees perceive the health and safety induction they received to be effective. Respondents also indicated that ArcelorMittal was effective in providing them with the support they need towards their health and safety. Hence, it is recommended that the zero tolerance approach towards safety hazards be reinforced on a continuous basis within the work context of this leading steel manufacturer.
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Lin, Wei-Chen, and 林韋辰. "Using two-phase dynamics simulation analysis for the induction furnace of steel-making process : foam formation with different recycling slag ingredient formulation." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/14151467457813452662.
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碩士國立中興大學
精密工程學系所
104
Foam formation has become essential of condition for steel-making refine process in the steel industry, there is a high concentration of phosphorus pile up by the (MiO)x · P2O5 form for the interface of slag and liquid steel during the dephosphorization processes, if high concentration of phosphorus piles up excessively and easily prone to the phenomenon of phosphorus back. This is not only phosphorus back into liquid steel but also hinders the dephosphorization processes. if we are able to blow gas for the stirring of liquid steel and foaming slag, high concentration of phosphorus for the interface of slag and liquid steel can diffuse above the foamed slag, simultaneously foamed slag surface to be higher than the electric arc furnace grate slag notch, (MiO)x · P2O5 can flow out along with the partial slag and accelerate the dephosphorization processes. The main idea of this research is to build a two-phase dynamics simulation system to analyze variety of different foaming dephosphorization slag formula, based on three-dimensional model of induction furnace is constructed , the results of foam formation with different ingredient formulation, the best design of recycling dephosphorization slag is chosen to manufacture steel of high quality.
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Asad, Amjad. "Numerical and Experimental Investigation of Particle Separation and Flow Behavior Inside an Induction Crucible Furnace." 2020. https://tubaf.qucosa.de/id/qucosa%3A72447.
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Die Existenz der nichtmetallischen Einschlüsse in der Metallschmelze führt zur Verschlechterung der physikalischen Eigenschaften des gegossenen Stahls. Die im Rahmen des SFB 920 entstandene Arbeit beschäftigt sich hauptsächlich mit der Untersuchung der reaktiven Reinigung und aktiven Filtration der Metallschmelze im Induktionsofen mithilfe der numerischen Strömungsmechanik. Dazu werden im Rahmen der Arbeit neue numerische Simulationsmodelle entwickelt. Die Ergebnisse zeigen, dass die reaktive Reinigung einen ausschlaggebenden positiven Einfluss auf die Entfernung der Einschlüsse aus der Metallschmelze hat, wobei der Reinheitsgrad der Metallschmelze innerhalb einer kurzen Eintauchzeit des kohlenstoffgebundenen Filters ansteigt.
Der in der reinen aktiven Filtration erzielte Reinheitsgrad ist deutlich niedriger als im Falle der reaktiven Reinigung. Des Weiteren befasst sich die Arbeit mit dem Effekt der Turbulenzmodellierung auf die Beschreibung der Schmelzeströmung und der Verteilung der Einschlüsse. Weiterhin stellt die Arbeit ein experimentelles Wassermodell zur Nachbildung der rezirkulierenden Schmelzeströmung im Induktionsofen vor.:Abstract
List of figures
List of Tables
Nomenclature
1 Introduction
2 State of the Art
3 Numerical Model
4 Results
5 Summary and Conclusion
6 Outlook
BibliographyDuring the continuous casting, non-metallic inclusions such as deoxidation or reoxidation products may arise in steel melt due to different reactions. These inclusions have to be removed from the melt with the aim of improving the cleanliness of steel products. There are many approaches in continuous casting to enhance inclusion removal from the melt. However, this Phd thesis focuses particularly on inclusion removal by reactive cleaning and active filtration during the melt casting in an induction crucible furnace using ceramic foam filter developed in CRC 920. For this purpose, a numerical model is developed in OpenFOAM in order to simulate the melt flow and reactive cleaning as well as active filtration. Besides the numerical model, an experimental water model are created to validate the capability of the numerical model to predict the recirculating turbulent flow in the induction crucible furnace. The results show that reactive cleaning and the formation of carbon monoxide bubbles, which arise on the inclusions, have a positive impact on the melt cleanliness. Reactive cleaning can improve inclusion removal and enhance the melt cleanliness sufficiently. Based on the results, one can conclude that the rate of inclusion removal in case of reactive cleaning is considerably higher than that in case of active filtration. Furthermore, the results indicate the considerable influence of filter position and filter number on the flow field as well as on the cleaning efficiency in the induction crucible furnace. Moreover, the results shows that turbulence modeling has a considerable impact on the prediction of the melt flow and inclusion dispersion in the induction crucible furnace.:Abstract List of figures List of Tables Nomenclature 1 Introduction 2 State of the Art 3 Numerical Model 4 Results 5 Summary and Conclusion 6 Outlook Bibliography
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Wang, Sz-Kai, and 王思凱. "Induction Heat Treatment of Medium Carbon Steels." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/a3hb6b.
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碩士國立臺北科技大學
材料及資源工程系研究所
98
High frequency induction heating and quenching is often used to surface harden steels. The process parameters of induction heating are greatly dependent on experience. This study intends to vary specimen size (diameter 10,20 and 30mm), power (12.5,15,17.5 and 20kW), and time (15,20 seconds) for induction heat treatments using 50KHz high-frequency furnace . It is found that the most appropriate size for heat treatment is 20mm diameter bar. At power 12.5kW, surface exhibits large amount of ferrite indicating insufficient heating. Whilst at power 17.5 kW and 20kW, surface structure are mixed with bainite and martensite, they can all achieve similar surface hardness. The depth of hardened layer is over 5mm using 20kW power which does not meet surface hardening requirement. Through the diagram of hardening depth versus entering heat , a good rule of thumb for selecting induction heating parameters may be obtained. Wear tests are also performed on the untreated, 15kW treated, and 17.5kW treated specimens. It is found that the specimen treated using 17.5kW power for 20 seconds obtain an optimal wear resistance because of uniform microstructure formation in the hardened layer.
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Fung, Justin. "Induction heat treated high strength suspension spring steels." 2006. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=442093&T=F.
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Loureiro, Carlos Daniel Aleixo. "Utilização de resíduos siderúrgicos como elemento potenciador de soluções de reparação de pavimentos." Master's thesis, 2021. http://hdl.handle.net/1822/71316.
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Dissertação de mestrado integrado em Engenharia CivilA premência de mitigar o consumo de energia e de recursos naturais levou a indústria de pavimentação a mudar o seu paradigma de produção atual, para promover o desenvolvimento de novos materiais e soluções de reparação que aumentem a durabilidade e a qualidade das infraestruturas rodoviárias, de uma forma economicamente sustentável. A presente dissertação tem como objetivo estudar a influência de aplicar resíduos industriais (escória siderúrgica) e de fibras metálicas como elementos potenciadores de soluções de autorregeneração de pavimentos rodoviários. Através do aquecimento das misturas betuminosas com um equipamento de indução (micro-ondas) e com a realização de ensaios de caraterização mecânica avaliou-se a capacidade de autorregeneração das misturas. Neste trabalho foram produzidas três misturas de betão betuminoso (AC14), uma de controlo, outra com fibras metálicas e, por último, uma composta por agregados de escória siderúrgica (ASIC) e fibras metálicas. No início, a eficácia da indução por micro-ondas para aquecimento das misturas betuminosas foi o foco do estudo. Posteriormente, avaliou-se a capacidade de recuperação de resistência das misturas através de múltiplos ciclos compostos por ensaios de caraterização mecânica (fadiga e fratura) e ensaios de indução por micro-ondas. Os resultados de indução nos provetes cilíndricos foram muito encorajadores, visto que se notou que o ASIC e as fibras promoveram temperaturas de regeneração mais altas do que nas misturas convencionais para o mesmo tempo de indução. Relativamente aos ensaios de caraterização mecânica, o dano induzido pelo ensaio de fratura foi recuperado de forma bem mais significativa na mistura betuminosa com ASIC. Nos restantes ensaios mecânicos, na determinação da resistência à fadiga e do módulo de rigidez, verificou-se que o ganho de vida à fadiga derivado da recuperação do módulo de rigidez após regeneração por indução ocorreu em todas misturas. No entanto, a mistura que incorporava apenas fibras metálicas apresentou os piores resultados.
The urgency to mitigate energy and natural resources consumption has led the paving industry to change its current production paradigm by promoting the development of new materials and repair solutions that increase the durability and quality of road infrastructures in an economically sustainable way. Thus, the present dissertation aims to study the influence of applying industrial by-products (steel slag and metallic fibers) as enhancing elements for road pavement repair solutions. The repair process, resulting from heating the asphalt mixtures, was simulated with an induction piece of equipment (microwave), with subsequent evaluation of the self-healing ability through mechanical characterization tests. Three asphalt concrete (AC14) mixtures were produced in this work, a conventional or control one, another with metallic fibers and, finally, one composed of steel slag aggregates (ASIC) and metallic fibers. In the beginning, the study’s focus was the effectiveness of microwave induction for heating asphalt mixtures. Subsequently, the capacity to recover the mixtures’ strength was evaluated through multiple cycles composed of mechanical characterization tests (fatigue and fracture) and microwave induction tests. The induction results in the cylindrical test specimens were very encouraging since it was noticed that ASIC and fibers promoted higher healing temperatures than in conventional mixtures for the same induction time. The fracture test’s damage was significantly recovered in the asphalt mixture with ASIC regarding the mechanical characterization tests. In the bending beam tests, carried out to determine the fatigue resistance and the stiffness modulus, it was found that the fatigue life gain derived from the recovery of the stiffness modulus after induction healing occurred in all mixtures. However, the mixture that incorporated only metallic fibers presented the worst results.
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CHEN, JIE-HONG, and 陳玠宏. "Effect of Carburizing Heat Treatment Condition on Induction Hardening of Medium Carbon Steels." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/485hfc.
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碩士國立虎尾科技大學
材料科學與工程系材料科學與綠色能源工程碩士班
107
In this study, AISI 1045 carbon steel, AISI 4140 alloy steel, AISI 4340 alloy steel three different steel material test bars were subjected to carburizing treatment at different temperatures and then oil quenching at different temperatures. Through a series of experiments to understand high-frequency induction hardening parameters (high-frequency input power, coil moving speed), pre-heat treatment with or without carburizing on steel hardness distribution, hardening depth, microstructure. The experimental results show that the amount of alloying elements of steel will affect the surface hardness. If manganese, nickel and the other alloying elements which can improve the hardenability, the surface hardening ability of the steel material will be improved, and the surface hardness of the steel material after quenching and tempering treatment will be improved. After three kinds of steel materials are quenched and tempered, high- frequency induction hardening treatment is carried out with different high- frequency induction parameters. The slower of the moving speed parameter of the induction coil, the better the surface hardness; the higher of the input power parameter of the high-frequency induction hardening, the larger the surface hardness. Martensitic structure or toorsite structure can be obtained by oil quenching treatment under different carburizing conditions. Among them, higher carburizing temperature with lower oil quenching temperature can get more martensitic structure. The surface hardness of the three steel materials will increase with the carburizing temperature, and the hardness can be obtained by induction hardening. Quenching with the lower oil temperature, the steel material is subjected to induction hardening under the same conditions to obtain higher hardness. If the appropriate input power and the moving speed of the induction coil are used, the carburized steel is further refined in the induction hardened structure. If the appropriate input power and the moving speed of the induction coil are used, the carburized steel material is further refined in induction hardening, and the amount of residual austenite is relatively small, can increase the hardness. It can be observed from the microstructure that the steel material subjected to the carburizing treatment is not only harder in hardness than the non-carburizing treatment, and the effective hardening layer is also larger than the non-carburized steel.
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Chiu, Tez-Tsang. "Effects of microalloying elements and rapid induction heating on the microstructure of suspension spring steels." 2005. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=370382&T=F.
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