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Gaude-Fugarolas, Daniel. "Modelling of transformations during induction hardening and tempering." Thesis, University of Cambridge, 2002. https://www.repository.cam.ac.uk/handle/1810/218539.
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There are many circumstances in industry where steel components are locally heated into the austenite phase field, and then quenched rapidly to produce a hardened region. Induction hardening is one such process used widely in the manufacture of automobile components, in particular to enhance the wear and contact-fatigue resistance of rubbing surfaces.
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Candeo, Alessandro. "Induction hardening of components for the aerospace industry." Doctoral thesis, Università degli studi di Padova, 2012. http://hdl.handle.net/11577/3422162.
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Induction heating has been widely used for heat treating and especially surface hardening in a broad variety of applications, ranging from the automotive to the renewable energy market. However, the lack of precise knowledge about the interrelation between all the concurrent physical phenomena occurring within the part during the heating cycle has restricted its use to mass-production items (mostly gears). The benets of this technology, which is clean, repeatable, and cost-eective, could boost its introduction into more conservative industry sectors, such as aerospace, where furnace-based treatments (e.g., carburizing) represent the golden standard. The major limitation is related to the optimization of the induction hardening process, which usually requires signicant material know-how and can thus be very long and expensive. Computer simulation could provide a general tool for understanding and improving the critical aspects of each step of the process, thus speeding up the preading of the induction technology into new markets.Il riscaldamento a induzione è stato diffusamente impiegato nel settore dei trattamenti termici di componenti per i settori automobilistico ed eolico, in particolare per la tempra di indurimento in una varietà di applicazioni. I principali vantaggi legati all'utilizzo di questa tecnologia risiedono nell'elevato grado di ripetibilità ottenibile nel prodotto trattato, unitamente alla elevata velocità ed automazione di trattamento, fattori entrambi in grado di garantire una produzione efficiente e dal ridotto impatto ambientale. Tuttavia, a causa degli elevati requisiti di qualità del prodotto nito e dei ristretti quantitativi prodotti, alcuni settori industriali rimangono ancor oggi legati ai tradizionali processi di cementazione in forno, che risultano piuttosto dispendiosi per la lunga durata del trattamento termico ed il numero di operazioni di rettica necessarie a valle dello stesso. L'impiego di metodologie di simulazione numerica al calcolatore permette un'accurata messa a punto del processo di tempra a induzione attraverso prove sperimentali mirate, che ne consentano una rapida implementazione a nuovi settori applicativi.
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Spezzapria, Mattia. "Multiphysyical Finite Element Simulation of Contour Induction Hardening of Gears." Doctoral thesis, Università degli studi di Padova, 2016. http://hdl.handle.net/11577/3424333.
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Induction heating has been widely applied in the field of heat treatment of components for the automotive and aerospace sectors, in particular for the hardening of a huge variety of applications. The main advantages of using this technology counts the high level of repeatability achievable in the treated product, together with the high velocity and automation of treatment, factors both able to ensure production efficiency and reduced environmental impact.
Nowadays, numerical methods are becoming more and more important as a reference method of analysis, in order to optimize the main parameters of the process, also thanks to the possibility of coupling different physical between them, a result which until a few years ago would not have been possible.
The aim of this work is the analysis and numerical modeling of the process of induction hardening of gear wheels for the aerospace industry.
In this thesis it will be shown how, starting from the electromagnetic and thermal coupled models, already extensively used in the last years by both the research and the industrial sectors, it is possible to calculate the phase transformations that occur in the steel during the heating and cooling stages.
The algorithm developed will be firstly applied on the case of a simple 2D geometry, and then the complexity level will be gradually increased (both from computational and process point of view), applying the algorithm to an induction hardening process of a gear. The numerical results thus obtained will be verified experimentally.Il riscaldamento a induzione è stato diffusamente impiegato nel settore dei trattamenti termici di componenti per i settori automobilistico ed aerospaziale, in particolare per la tempra di una vasta varietà di applicazioni. I principali vantaggi legati all’utilizzo di questa tecnologia risiedono nell’elevato grado di ripetibilità ottenibile nel prodotto trattato, unitamente alla elevata velocità ed automazione di trattamento, fattori entrambi in grado di garantire una produzione efficiente e dal ridotto impatto ambientale. Oggigiorno, i metodi numerici si stanno affermando sempre più come principale metodo di analisi, in modo da ottimizzare i principali parametri di processo, anche grazie alla possibilità di accoppiare diverse fisiche tra di loro, risultato che fino a pochi anni fa non sarebbe stato possibile. Scopo di questo lavoro è l’analisi e la modellazione numerica del processo di tempra ad induzione su ruote dentate per l’industria aerospaziale. Nel corso della tesi si mostrerà come, partendo dai modelli elettromagnetici e termici accoppiati, già diffusamente sviluppati negli anni sia a livello di ricerca che a livello industriale, è possibile anche calcolare le trasformazioni di fase che avvengono nell’acciaio nel corso del riscaldamento e del raffreddamento. L’algoritmo sviluppato verrà poi applicato dapprima su di un caso semplice 2D, per poi incrementare la difficoltà (sia computazionale che di processo), applicandolo ad un trattamento di tempra ad induzione di una ruota dentata. I risultati numerici così ottenuti verranno verificati sperimentalmente.
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Pasic, Anel. "The influence of the cooling rate during induction hardening on residual stresses and fatigue strength." Thesis, KTH, Hållfasthetslära (Avd.), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-103718.
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A vital part in the transmission for Scania lorries is the shaft in the rear axle. Since this shaft is divided into two identical parts, these are termed half shafts. Close control of the manufacturing process of these is required. Influence of flow rate, temperature and polymer concentration of the quenchant was investigated. An important controlling factor is the cooling rate used in the hardening process. This factor was selected for investigation in the present study. It was found that high flow rate, low temperature and low polymer concentration gives high cooling rates. Further investigation was performed how the residual stresses, surface hardness and the case depth of the half shafts were affected by the cooling rate. The results show that residual stresses are particularly affected by the cooling rate. Higher cooling rates results in higher residual stresses. Since residual stresses are important for fatigue lifer, a fatigue study was also undertaken. Five half shafts were quenched with a polymer concentration of 5%, and another five with 15%. All ten half shafts were fatigue tested in torsion, using a Scania standardized method. The shafts were loaded in torsion torque with company confidential amplitude, mean equal to zero number of cycles to failure was recorded. In normal production the half shafts are quenched with 10% polymer concentration. No tests with a polymer concentration of 10% were carried out in this investigation since results from this concentration are available from earlier studies. Residual stresses were measured using a relatively new method developed by Scania, called the core drilling method. A 20 cm long portion of the shaft was center drilled in steps, gradually increasing the drill diameter. After each step, the relaxation of surface strain was measured in the longitudinal and transversal directions. Having obtained these data, stresses can be calculated. Residual stresses were also measured by x-ray diffraction. Only surface stresses are obtained in this way, however. These measurements were made for each of the three polymer concentrations. An attempt was also made on trying to simulate the stress formation in the shafts during the heat treatment with FEM and also to calculate the residual stresses after the treatment. Results from the measurements were then compared with the FEM calculated results. Since the number of tested shafts is small, results are not statistically relevant. One may conclude, though, that fatigue life increases with increasing cooling rate, i.e. with decreasing polymer concentration. The fatigue life requirement for all tested shafts was fulfilled. The compressive residual stresses for 5% and 10% polymer concentration are of same magnitude and higher than for those quenched with 15% polymer concentration. The result also shows that the cooling rate does not affect the surface hardness, nor the case depth.
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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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Le, Moal Patrick. "Fatigue optimization of an induction hardened shaft under combined loading." Thesis, Virginia Tech, 1996. http://hdl.handle.net/10919/44959.
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An integrated procedure, combining finite element modeling and fatigue analysis methods, is developed and applied to the fatigue optimization of a notched, induction hardened, steel shaft subjected to combined bending and torsional loading. Finite element analysis is used first to develop unit-load factors for generating stress-time histories, and then, employing thermo-elastic techniques, to determine the residual stresses resulting from induction hardening. These stress fields are combined using elastic superposition, and incorporated in a fatigue analysis procedure to predict failure location and lifetime. Through systematic variation of geometry, processing, and loading parameters, performance surfaces are generated from which optimum case depths for maximizing shaft fatigue performance are determined. General implications of such procedures to the product development process are discussed.
Master of Science
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Petzold, Thomas [Verfasser], Dietmar [Akademischer Betreuer] Hömberg, and Alfred [Akademischer Betreuer] Schmidt. "Modelling, analysis and simulation of multifrequency induction hardening / Thomas Petzold. Gutachter: Dietmar Hömberg ; Alfred Schmidt. Betreuer: Dietmar Hömberg." Berlin : Technische Universität Berlin, 2014. http://d-nb.info/1066162824/34.
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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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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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Lind, Fredrik. "Polymerkoncentrationens inverkan på härdresultatet av seghärdningsstål." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-65989.
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Ovako Sweden AB i Hällefors har vid seghärdning av stål problem med sprickor. Studier visar på att tillsatser av polymer i kylvattnet ger ett långsammare och jämnare kylförlopp, vilket minskar risken för sprickor. För att fastställa vilken mängd polymer som är lämplig att tillsätta i kylvattnet vid härdning av deras låglegerade segment av seghärdat stål, så har undersökningar utförs på två stålsorter. Skillnaden i härdresultat mellan de olika testade koncentrationsnivåerna var små, men vid högre polymerkoncentration så fördelades hårdheten något jämnare genom hela tvärsnittet.Ovako Sweden AB have problems with cracks during the process of hardening of steel. Studies show that the additives of polymer in the cooling water gives a slower and more even cooling process, which reduce the risk of crack onset. To decide the amount of polymer that is suitable to put in the cooling water at the hardening of their low-alloy steel segment of quenched and tempered steel, so studies have been conducted on two types of steel. The difference in hardening results between different tested concentration levels were small, but at higher polymer concentration the hardness was distributed slightly more evenly throughout the cross section.
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Fahlkrans, Johan. "Effects of manufacturing chain on mechanical performance : Study on heat treatment of powertrain components." Licentiate thesis, KTH, Industriell produktion, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-163665.
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The increasing demands for lightweight designs with high strength call for improved manufacturing processes regarding heat treatment of steel. The manufacturing process has considerable potential to improve the mechanical performance and to obtain more reliable results with less variation. The goal of this thesis is to establish new knowledge regarding improved manufacturing processes in industrial heat treatment applications. Three research questions with associated hypotheses are formulated. Process experiments, evaluation of the mechanical performance, and modelling of the fatigue behaviour assist in answering the questions. The gas quenching procedure following low-pressure carburising differs from the conventional procedure of gas carburising and oil quenching. It is shown that the introduction of a holding time during the low-temperature part of the quench has a positive effect on mechanical properties, with some 20 percent increase in fatigue strength. This is attributed to increased compressive surface residual stress and stabilisation of austenite. Tempering is a common manufacturing process step following hardening in order to increase the toughness of the steel. However, the research shows that the higher hardness from eliminating tempering from the manufacturing process is beneficial for contact fatigue resistance. The untempered steel showed not only less contact fatigue damage but also a different contact fatigue mechanism. Straightening of elongated components is made after heat treatment in order to compensate for distortions. The research shows that straightening of induction hardened shafts may lead to lowering of the fatigue strength of up to 20 percent. A fracture mechanics based model is developed to estimate the effects of straightening on fatigue strength.Ökande krav på höghållfasta lättviktskonstruktioner kräver förbättrade tillverkningsprocesser för värmebehandling av stål. Det finns stor potential att förbättra mekanisk prestanda och att erhålla mer tillförlitliga resultat med mindre variation genom att förbättra tillverkningsprocessen. Målet med denna avhandling är att etablera ny kunskap kring tillverkningsprocesser inom industriella värmebehandlingsapplikationer. Tre forskningsfrågor med tillhörande hypoteser formuleras. Processexperiment, utvärdering av mekanisk hållfasthet och modellering av utmattningsbeteende bygger upp besvarandet av frågorna. Gaskylning som följer lågtrycksuppkolning skiljer sig från det konventionella förfarandet med gasuppkolning och släckning i olja. Resultaten visar att en hålltid i den nedre delen av kylningsförloppet har positiv inverkan på utmattningshållfastheten. Orsaken till förbättringen hänförs till ökade tryckrestspänningar samt stabilisering av austenit. Anlöpning är en vanlig tillverkningsprocess som efterföljer härdning för att öka stålets seghet. Forskningen visar däremot att den högre hårdheten för oanlöpt stål är fördelaktig för motstånd mot kontaktutmattning. Oanlöpt stål visade mindre mängd kontaktutmattningsskador och även en annan skademekanism. Riktning av långa komponenter görs efter värmebehandling för att kompensera för de formförändringar som uppstår. Forskningen visar att riktning av induktionshärdade axlar kan leda till sänkning av utmattningshållfastheten med upp till 20 procent. En brottmekanisk modell som uppskattar effekten av riktning på utmattningshållfasthet presenteras.
QC 20150410
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Klonk, Steffen. "Modélisation numérique du chauffage par induction de pièces à géométrie complexe." Phd thesis, Ecole Nationale Supérieure des Mines de Paris, 2013. http://pastel.archives-ouvertes.fr/pastel-00982312.
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Le chauffage par induction électromagnétique est un procédé efficace permettant de chauffer directement une zone d'épaisseur contrôlée sous la surface de pièces métalliques en vue de les tremper. Cette thèse présente un modèle mathématique couplé électromagnétique/thermique et des approches numériques pour modéliser le procédé. Le modèle électromagnétique est basé sur une formulation en potentiel vecteur magnétique. Les courants de source sont imposés à l'aide d'une formulation en potentiel scalaire électrique permettant de modéliser des inducteurs de forme géométrique arbitraire. Le problème du transfert de chaleur est modélisé à l'aide de l'équation classique de diffusion de la chaleur. Le modèle électromagnétique est entièrement transitoire, afin de permettre l'introduction des effets non linéaires. La discrétisation spatiale est basée sur une approche éléments d'arêtes en utilisant un domaine global air/pièce/inducteur. Le système linéaire d'équations issu de la formulation implicite est creux et défini semi-positif ; il possède un noyau de taille importante. Il est démontré qu'un préconditionneur basé sur une méthode multigrille algébrique construit conjointement avec un solveur du type Krylov réduit substantiellement le temps de calcul du problème électromagnétique par rapport aux méthodes classiques de solution et peut être très efficace pour le calcul parallèle. Des exemples d'application pour le traitement thermique d'un pignon et pour un vilebrequin automobile sont présentés. Le traitement thermique des surfaces des pièces aux géométries complexes nécessite l'introduction d'un mouvement relatif de la pièce et de l'inducteur pour assurer un traitement homogène de la surface. Une nouvelle méthode est proposée, basée sur une représentation discrète d'une fonction level set du mouvement de l'inducteur qui peut être utilisée pour générer des maillages éléments finis conformes dans le cadre d'une configuration lagrangienne.
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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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Neduchal, Bronislav. "Povrchové kalení litiny s kuličkovým grafitem." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-417081.
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This diploma thesis is focused on the surface hardening of cast irons with spheroidal graphite. The work describes a theoretical analysis of the structure and properties of cast irons and individual methods suitable for surface hardening. The practical part describes the production of cast iron castings with spheroidal graphite, on which the surface hardening is performed, tensile test, hardening of produced castings by induction and laser surface hardening, preparation of samples for measuring microhardness and metallographic analysis of metal structures.
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Ostrowski, Jörg. "Boundary element methods for inductive hardening." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=973933941.
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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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Vibrans, Tobias. "Induktive Erwärmung von Formplatinen für die Warmumformung." Doctoral thesis, Universitätsbibliothek Chemnitz, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-215862.
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Die vorliegende Arbeit untersucht den Einsatz einer induktiven Längsfelderwärmung im Wärmebehandlungsprozess der direkten Warmumformung automobiler Karosserieblechbauteile. Zur Charakterisierung des Erwärmungsvorgangs werden sowohl experimentbasierte Regressionsmodelle als auch ein FEM-Simulationsmodell entwickelt. Der Einfluss der induktiven Erwärmung auf die Ausbildung der AlSi-Beschichtung, die Widerstandspunktschweißbarkeit so-wie die Korrosionsbeständigkeit gefertigter Blechbauteile wird dargelegt. Abschließend wird ein Anlagenkonzept entwickelt, das durch den Einsatz der induktiven Längsfelderwärmung eine Verringerung der Erwärmungsdauer um etwa 50 % sowie eine Verkürzung der erforderlichen Ofenlänge um etwa 37 % ermöglichtThe present thesis investigates the usage of longitudinal induction heating in the austenitization process of direct press hardening. In order to describe the induction heating procedure, experiment-based regression models as well as a FEM model are developed. The influence of an induction heating process on the properties of press hardened parts with aluminum-silicon coating is depicted. Therefore, resistance spot welding tests, paint adhesion tests and corrosion tests are performed. Finally, a heating concept for series production including a longitudinal induction heating is developed, which allows a decrease in heating time of about 50 % and a reduction of furnace length of about 37 %
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Nunes, Rafael Menezes. "Estudo de distorção de barras cilíndricas de aço ABNT 1045 em uma rota de fabricação envolvendo trefilação combinada e têmpera por indução." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2012. http://hdl.handle.net/10183/75893.
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As distorções de forma de componentes mecânicos, que ocorrem durante a fabricação, constituem um sério problema enfrentado pela indústria metal-mecânica. Neste trabalho, avaliou-se uma rota de fabricação de barras de aço ABNT 1045 envolvendo os processos de trefilação, alívio de tensões e têmpera por indução utilizando-se uma visão holística do processo. Após um estudo detalhado, variou-se 5 parâmetros do processo, sendo eles: corrida, ângulo de fieira, ângulo de endireitamento, temperatura de alívio de tensões e profundidade de camada temperada. Caracterizou-se as tensões residuais, em todas as etapas do processo, utilizando-se as técnicas de difração de raios-X, difração de nêutrons e difração de radiação Síncrotron, bem como, a microestrutura do material. Após as etapas de trefilação combinada e tratamento térmico avaliou-se as distorções de forma, utilizando-se um equipamento de medição por coordenadas e posteriormente calculou-se os vetores distorção. Os dados obtidos foram analisados utilizando-se o software Minitab® através da montagem de uma matriz DoE (Design of Experiments). A partir dos resultados obtidos, avaliou-se quais etapas do processo induzem maior "potencial de distorção" nos componentes. A partir das medições de tensões residuais foi obtida uma visão detalhada de como estas tensões residuais se distribuem no material após cada etapa do processo, os dados mostram diferenças significativas ao longo das posições periféricas nas etapas de pré-endireitamento e trefilação. Dados apontam que a distribuição da zona de segregação é responsável pelo comportamento diferente nas duas corridas analisadas em relação às distorções. As tensões residuais geradas no endireitamento do fio-máquina são responsáveis por causar heterogeneidades no material e induzem um alto “potencial de distorção”. Nos parâmetros de processo estudados as deformações induzidas no processo de trefilação não foram capazes de eliminar as distribuições heterogêneas de tensões residuais geradas no pré-endireitamento, porém utilizando-se o ângulo de fieira de 15º houve uma diminuição da distorção após a têmpera por indução. Após o processo de endireitamento por rolos cruzados (PERC) a distribuição das tensões residuais na superfície é mais homogênea para os ângulos de ferramenta avaliados neste trabalho (16º e 18º), entretanto existem diferenças significativas na distribuição de tensões residuais no núcleo do material, e estas diferenças são umas das causadoras das distorções após o processo de têmpera por indução.Shape distortions are a serious problem in the metalworking industry, distortion due to heat treatment is responsible for additional and cost machining operations. Minimizing or even avoiding heat treatment distortion is one of the key factors to minimize production costs. In the past, investigations had focused on single effects or isolated parameters steps in a manufacturing chain. It is well established now that each step of the process chain generates a “distortion potential” and a new global approach, treating distortion as a system attribute, analyzing the entire manufacturing chain from steelmaking to heat treatment process is necessary. The main idea of distortion engineering is that all steps of the manufacturing chain together contribute to the final distortion behavior. In this work, a steel route of combined cold-drawing process to induction hardening of ABNT 1045 steel bars was investigated. The residual stresses characterizations were carried out using X-ray diffraction, neutron diffraction and synchrotron diffraction methods. The identification and interaction between factors on distortion behavior was carried out using statistical analysis, with the aid of DoE (Design of Experiments). For the DoE method the number of causes that can be considered were 5 parameters of the process, including: different batches, drawing angle, PERC angle, stress relief temperature and induction hardening depth. From the results obtained, the evaluation of which steps in the process induce higher "distortion potential" during the various steps of the process was carried out. From the measurements of residual stresses a detailed view of how these residual stresses are distributed for material in each step of the process was obtained, the results show significant differences along the peripheral positions in the pre-straightening and drawing stages. The experimental results indicate the microstructure of the material, wire rod geometry and the die angle process parameters as main "distortion potentials".
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Záveský, Filip. "Návrh robotické buňky pro navařování sklářských forem." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-382417.
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This diploma thesis contains description of design of robotic cell, which automates process of glass neck ring welding. Robot arm is used as manipulator of part between entry conveyor, induction heating, automatic welding machine and outgoing palette. Construction process contains of making layout of the cell, design of needed workstations and minimalize risk of harm for human operator. The final construction design is simulated to verify robot reach and find manipulation time.
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LinChun-Ming and 林俊明. "Study of Ball Rod Induction Hardening Heat Treatment." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/65549204842207737594.
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碩士崑山科技大學
機械工程研究所
95
The transmission ball rod requires long-term of worn out test, and various bumpy transportation test. The condition of worn out and crack usually takes place. This study is to investigate induction hardness, machined automotive ball rod, changing the induction hardness parameter, changing the design of the heating coil, different machining design hardening the surface and strengthening the core tenacity. After the induction hardness, it improved the worn-out and fatigue resistance. The internal strong microstructure can reinforce the surface hardness to resist the impact and meet customer’s requirements.
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Chih, Young, and 江永智. "Study of Induction Hardening Treatment Distortionon S45C Turbine Hub." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/mbw8da.
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碩士國立高雄第一科技大學
機械與自動化工程所
96
In production, the chemical composition of material in each lot is different. The key to keep induction hardening process successful is how to control the stable and uniform microstructure of raw parts in forging process and pre heat treatment process. In this research, we analyzed the relations of deformation between before and after induction hardening treatment. And it will reduce the percentage of bad quality parts by adjusting parameters in pre treatment. According to the research data, the microstructures by different pre treatments would affect the deformation of induction hardening. And the geometric shapes would also affect the surface temperature and the metamorphosis of microstructure. The dimensions of thick wall shrank due to the microstructure stress and the dimensions of thin wall enlarged due to the heat stress. It also caused differential of hardening depth. The imperfect microstructures after normalizing or quenching and tempering and discordant hardness distribution came from un-uniform forging microstructures. The hardening effect of microstructure treated by quenching and tempering is better than what by normalizing. This is because of the residual stress after quenching and it will affect the roundness of wall.
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Jheng, Jia-Siang, and 鄭佳祥. "Application of Induction Heating to Partial Hardening of Workpiece." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/14992422127164220299.
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碩士國立臺灣大學
機械工程學研究所
92
Abstract The characteristics of high frequency induction heating were that it could heat the surface of metal workpiece at a specific part quickly. The time of heating was so short that the oxidation and decarburization were negligible. This article used these features of high frequency induction heating to strengthen the metal workpiece. This experiment includes two parts: 1. To harden the tip of the sewing needle, which was manufactured from SK4 carbon tool steel. In order to make the sewing needle possessing toughness and partial high hardness, double quenching was performed in this experiment and the parameters affecting the hardness distribution and microstructure of the needles were discussed. The parameters were that whether using partial quenching or not and the different time holding in quenching temperature. 2. Workpiece could be heated quickly and reach to high temperature by high frequency induction heating. To make use of these characteristics, low-carbon steel was carburized in a short time at high temperature. Carburizing time and temperature are variables of this experiment. The parameters affecting the hardness distribution, microstructure, and carburization depth were discussed. The major results are shown as follows: 1. It would indeed get the result of tough needle and hard pinpoint when the sewing needle was hardened locally by high frequency induction heating in advance, because more Fe3C of the pinpoint would be dissolved into the matrix. 2. When low-carbon steel was heated by high frequency induction heating and carburized at high temperature for seconds, the speed of carburization was very fast. In addition, the effect of surface hardening was very good after quenching. Compared with the traditional method, this new method saves more time than the old one. 3. When high frequency induction heating was used in gas carburization, the Ledeburite would be developed in the surface if the carburizing temperature is above the eutectic point of cast iron. It may be useful in the surface modification of steel because of high hardness, good wear resistance and corrosion resistance.
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Xu, Jun-Zhuan, and 徐俊專. "The Research on the Property of Induction Hardening Cast Iron Roller." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/64t83c.
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碩士逢甲大學
材料與製造工程所
91
The projective of this research was to investigate the effects of normalizing temperature, quenching temperature, chemical composition (carbon and silicon content) on the property and metallographic microstructure of the gray cast iron (FC250、FC350) roller with dimension of ψ70mm×L120mm which was treated with high frequency induction hardening. The experimental results show that：(1)The metallographic microstructure in the surface hardened layer of the gray cast iron roller after high frequency induction hardening was changed from ferrite-pearlite and flake graphite to few ferrite-retained austenite , martensite, and flake graphite. (2)The hardness value of the surface hardened layer and non-hardened layer for the low carbon and low silicon (FC350) gray cast iron roller which was treated with high frequency induction hardening or treated with normalizing plus high frequency induction hardening , is higher than the high carbon and high silicon (FC250) gray cast iron roller. (3)The higher the quenching temperature, the higher the hardness value for the surface hardened and non-hardened layers of the gray cast iron roller is. The hardened layer can reach 5mm in depth. (4)The hardness of the gray cast iron roller which was treated with normalizing and high frequency induction hardening in the surface hardened and non-hardened layers is higher than the roller whichIIwas treated with high frequency induction hardening only.Moreover, the higher the normalizing temperature, the higher the average value of the hardness of the roller in the surface hardened and non-hardened layers is. In this research , both the image and XRD analysis of the metallographic microstructure were adopted to analyze and to discuss the property of the high frequency induction hardened gray cast iron roller.
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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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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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HONG, YOU-ZONG, and 洪侑宗. "Fretting Wear Properties of the Materials of Drive Elements after Induction Hardening." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/qnur22.
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碩士崑山科技大學
機械工程研究所
106
According to the experiences of the related industry, the destructions of machine caused by fretting wear of drive elements have been thought of itself as the important problem for the engineers. Hence, the micro vibration and the fretting wear caused by the micro vibration are the key technologies for improving the high performance of the drive elements. In order to enhance competitiveness, high-precision, high-life, high-efficiency, high-rigidity, high-load force, and other requirements are required. Hence, the surface engineering is improved by the novel heat treatments to decrease the fretting wear and increase the fatigue life in this study. Based on the above statements, the self-developed fretting wear tester with the measurement systems was used to study the effects of surface hardening on axial fretting wear for the materials of drive elements after induction hardening. To monitor the tribological behaviors between the interfaces, the variations of friction coefficient is recorded during dynamic friction process. After each friction test, the worn surface is observed. Moreover, the wear depth is measured by the XP2. According to the above experimental results, the effects of induction on fretting wear for the base materials of linear guides can be clarified. Therefore, the decreasing of micro vibration and fretting wear will be completed successfully to further develop the mechanical industries.
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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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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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Huang, Shun-Hong, and 黃舜宏. "The Effect of High Frequency Induction Hardening Parameters, Pre-heat Treating Conditions and Quenching Mediums on Surface Hardening Characteristics for Some Selected Steels." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/ab3sja.
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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
104
In this study, JIS-S45C, JIS-SCM440 and JIS-SUJ2 steels which were pre-heat treated with different conditions were conducted high frequency induction surface hardening by using different quenching mediums. The objective of this study was to clarify the effect of high frequency induction hardening parameters (input power, motion velocity of the coil), pre-heat treating conditions (normalizing, thermal refining) and quenching mediums (water, 5%PVP polymer quenchant) on the distribution of hardness, hardening depth, microstructures, quenching distortion and wear resistance by a series of experiments. The experimental results show that as the input power is increased or the motion velocity of the coil is reduced, the hardening depth of all steels specimens through the high frequency induction hardening will increase; and will also increase the surface hardness of JIS-SUJ2, it was increased about HV20~HV180, but it will not significantly affect the surface hardness of JIS-S45C and JIS-SCM440. With increasing depth of hardening (the hardness which is more than HV550), the quenching distortion of induction hardened steels specimens will be increased, but the wear resistance of steels specimens will be better. Comparing with the normalizing (JIS-SUJ2 is as-spheroidized steel), the JIS-S45C and JIS-SUJ2 steels specimens which were thermal refined will obtain the higher surface hardness and hardening depth through the high frequency induction hardening (the surface hardness of JIS-S45C was increased about HV20~30, JIS-SUJ2 was increased about HV110~290, and the hardening depth of both steels specimens was increased about 0.2mm~0.5mm). Either the quenching distortion or the wear resistance of both steels specimens will be increased. The wear weight loss of JIS-S45C was reduced 0.6mg under parameter of 85kW-30mm/s and JIS-SUJ2 was reduced 0.17mg under parameter of 90kW-25mm/s. The JIS-SCM440 steels specimens with two different pre-heat treatment conditions show have no significant differences in surface hardness, hardening depth and quenching distortion after high frequency induction hardening, but the JIS-SCM440 which was thermal refined has the better wear resistance, the wear weight loss was reduced 6.6mg under parameter of 85kW-30mm/s. By using 5% PVP polymer quenchant to replace water as a quenching medium for three kinds of steels, it has no effect on their surface hardness, hardening depth and wear resistance; it will only improve the quenching distortion (maximum deflection of unit length) of JIS-SUJ2 steel, the quenching distortion of as-spheroidized steel was improved about 27~44% and thermal refined steel was improved about 32~40%, but it has no distinct improvement for the others. The surface layers of all steels specimens through the high frequency induction hardening, except for the JIS-SUJ2 which was thermal refined, have ferrite microstructure by reducing the input power or increasing the motion velocity of the coil, but the ferrite will significantly decrease by increasing input power or reducing the motion velocity of the coil. The amount of ferrite microstructure will be increased with the distance farther from the surface of the specimen; the transition zone will be widened as the motion velocity of the coil reduces, and considerable quantity of original microstructures at transition zone will appear. Only JIS-SUJ2 steel specimen which was thermal refined hasn’t ferrite microstructure from optical microscope observation in the three kinds of steels specimens through the high frequency induction hardening. The major diffraction peak of JIS-SUJ2 steel specimen which was thermal refined is martensite by X-ray diffraction analysis; and the diffraction peaks of the others steels specimens are martensite and ferrite, all of the three kinds of steels specimens through the high frequency induction hardening have not retained austenite.
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Wang, Chung-Shu, and 王仲澍. "Investigation of the Depth of Hardening of Aerospace Parts after Induction Heat Treatment by using Eddy Current Inspection Method." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/31626514469152610692.
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碩士淡江大學
航空太空工程學系
88
This research is concerned with the experimental investigations of the depth of hardening of aerospace parts after medium and high frequency induction hardening or carburizing by using non-destructive methods. The rod-shaped steel have been widely used in aerospace industry; e.g., turbine's transmission shaft and leading edge flap actuator . For the steel rod which have the mentioned purposes, their outer surfaces have to keep certain strength or hardiness but at the same time their cores have to keep soft for maintaining the ductility. The main heat treatment method for certain special high strength alloy to conform the specifications have to use medium or high frequency hardening or carburizing and nitriding. In general, the steel rod has to be cut to a slice in order to get the hardening information after certain heat treatment processes. It is a time consuming process and will cost a lot of materials and will not have an immediate results. It has to repeat the whole processes if the results does not conform to the standard. Therefore, a main object of this work is use the eddy current method to measure the depth of hardening non-destructively which will be more effectiveness and practicality. Nevertheless, all results studied by this work can be an important data for aerospace engineering used for process control and predict the part's service life.
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Tsai, Chih-Chiang, and 蔡志強. "Investigation of the Depth of Hardening of Aerospace Parts after Induction Heat Treatment or Carburizing by using Non-destructive Method." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/79176214988570550292.
Full textAbstract:
碩士淡江大學
航空太空工程學系
86
This research is concerned with the experimental investigationsof the depth of hardening of aerospace parts after medium and high frequency induction hardening or carburizing by using non-destructive methods. The rod-shaped steel have been widely used in aerospace industry; e.g. turbine's transmission shaft and leading edge flap actuator . For the steel rod which have the mentioned purposes, their outer surfaces have to keep certainstrength or hardiness but at the same time their cores have to keep soft for maintaining the ductility. The main heat treatment method for certain special high strength alloy to conform the specifications have to use medium or high frequency hardening or carburizing and nitriding. In general, the steel rod have to be cut to a slice in order to get the hardening information after certain heat treatment processes. It is a time consuming process and will cost a lot of materials and will not have an immediate results. It have to repeat the whole processes if the results does not conform with the standard. Therefore, a main object of this work is use the eddy current method to measure the depth of hardening non-destructively which will be more effectiveness and practicality. Nevertheless, all results studied by this work can be an important data for aerospace engineering used for process control and predict the part's service life.
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Ostrowski, Jörg [Verfasser]. "Boundary element methods for inductive hardening / vorgelegt von Jörg Ostrowski." 2003. http://d-nb.info/973933941/34.
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Opitz, Tobias. "Vermeidungsstrategien fluiddynamischer Effekte beim Einsatz von Schnellerwärmungstechnologien in der Warmumformung." 2017. https://monarch.qucosa.de/id/qucosa%3A38678.
Full textAbstract:
Aufgrund fluiddynamischer Effekte bei der Schnellerwärmung für die Warmumformung wird die Applikation der Technologie erschwert. Die vorliegende Arbeit thematisiert diesen Effekt und evaluiert die Triebkräfte sowohl numerisch als auch im Experiment. Aufbauend darauf werden Vermeidungsstrategien aufgezeigt und experimentell validiert um eine Verschiebung der Beschichtung zu verhindern. Es können insbesondere die temperatursensitive Marangonikraft als auch die magnethydrodynamische Wirkung der Lorentzkraft bei einer induktiven Erwärmung als Haupttriebkräfte identifiziert werden, die sich aufgrund identischer Kraftvektorrichtungen überlagern und verstärken. Es hat sich gezeigt, dass für den vorliegenden Fall einer 20-30 μm dünnen AlSi-Beschichtung die Marangonikraft gegenüber der Lorentzkraft um einen Faktor von mindestens 68 überwiegt. Ein vergleichbarer Effekt ist auch bei konduktiver Erwärmung zu beobachten. Hinsichtlich möglicher Vermeidungsstrategien einer globalen Beschichtungsverschiebung bietet die Applikation von lokalen Flussbarrieren mittels Laser, Induktion oder Walztexturierung, sowie das Vermeiden einer freien Flüssigkeitsoberfläche durch Aufbringen einer Zusatzbeschichtung, das größte Potential.
In der zweiten Versionierung der Dissertationsschrift wurde auf S. IV im Vorwort, sowie auf S.72, Kapitel 4.2 eine ergänzende Nennung eines Instituts und Kooperationspartners hinzugefügt.The application of fast heating technologies for hot forming is hindered by fluiddynamic effects and a resulting coating shift. Present thesis investigates this effect to evaluate the driving forces numerically as well as experimentally. Based on this evaluation, strategies are developed and investigated to avoid a global displacement of the AlSi-coating. In case of inductive fast heating the main driving force is represented by a superposition of Lorentzian forces as well as surface tension related Marangoni forces with a force vector pointing from hot to cold regions on the blank. The numerical evaluation shows that in case of 20-30 μm thin layers of AlSi the Marangoni force is at least 68 times higher than the Lorentz force and therefore represents the main driving force. A comparable effect is observable in case of conduction heating. Local flow barriers realized by Laser, inductive heating or texturing as well as the avoidance of a free liquid-surface due to application of additional coating layers show huge potential to prevent a global coating flow.