Dissertations / Theses on the topic 'Cast Iron Production Simulation'

The constantly tightening emission regulations demand the engines to be moreefficient, to get more power out of smaller engines. Higher engine loads andcomponent temperatures are causing more stresses to engine components. Therefore,a company that produces engines wanted to study if it would be possible to increasethe capabilities of the components by optimising the used material. In this final project work, a cylinder head will be studied. The cylinder heads for theengines are made of ductile cast iron. The limits of that material are near safety limits,and therefore a better material is needed. In this work are some previous studiesanalysed and tried to find how to optimise the used material. The optimised materialshould have better thermal conductivity properties combined with sufficient strengthproperties. Previous studies were analysed to gather knowledge of the elements that affect thematerial parameters. Those studies showed that copper, silicon, pearlite fraction, andthe use of chills are the elements to be optimised. Silicon and pearlite fraction waschosen as optimisation parameters because of their effect on the thermal conductivityand strength properties. Copper was chosen as an optimisation variable due to its effecton the pearlite formation. Chills were used to affect the cooling rate and thereby thepearlite formation. The work was made using MAGMASOFT™ simulation software to simulate cylinderhead casting. The simulated cylinder head was divided into 4 parts for the simulations.For those sections were then set targets for pearlite fraction according to previousstudies. The silicon content was kept constant in the simulation, based on the studiespresented in this work. Copper content was simulated with variations from 0 to 0.7weight-%, and chill heights were simulated from 20 to 60 mm and without chills. After simulating the different variables, the results were analysed. Then the selectedcasting simulation result was mapped to finite element simulation mesh to include thelocal material parameters to finite element simulation. With the finite elementsimulation, the estimated lifetime of the component was simulated. By analysing the casting simulation results, an optimal combination was found. Theoptimal material parameters for a cylinder head casting would be copper 0.5weight-%, silicon 1.9 weight-% and chills thicker than 40 mm on the flame plate. Theoptimised material gives more possibilities to develop engines even further when thecomponent demands are growing.

The main purpose of the thesis work is based on achieving same mechanical properties on the three different sized bearing housings. The key mechanical property that had to be focused on was the hardness of the parts. In order to achieve this goal, chemical compositions of the parts have studied. However there were some limitations on the composition variants. Allowed variables of the compositions are silicon, nickel and copper. Due to necessity another element, Molybdenum (Mo), was also introduced. After many simulations three different compositions are proposed. Then the feasibility of results of casting simulation software investigated. And finally an optimization guideline has proposed. Chemical composition researches have carried on casting simulation software, which is called Magma5. Following the completion of the simulations phase, proposed compositions trial casted at the company. Subsequent to trial castings cast parts had tested for their hardness values. In order to bring the thesis to completion simulation outputs and trial test results had compared. With the help of a casting simulation software composition optimisation of different sized parts could be easily optimised in order to achieve same results. Many simulations are executed with different composition for the silicon, nickel, copper and molybdenum variants. It was seen that Mo additions significantly increase the mechanical properties of the parts. Nickel and copperacts similarly on the hardness values, however nickel addition reduce undercooling tendency at a greater rate. Good inoculation is vital for the parts with thin sections. Decent inoculation helps to improve the microstructure and helps to get closer results tothe simulated values. However software represents key information aboutundercooled zones on the part. Software ensures 95% to 97% correct values on hardness results.

Spheroidal graphite cast iron is a material widely used in the industry for the manufacturing of all kind of covers and protective casings thanks to its good combination of mechanical properties, processability and cost. When cast iron components are put into service in corrosive environments the most common approach to protect the components is painting them. The protective painting has been found to flake off with time when aggressive washing procedures, such as the ones used in the Food & Beverage industry, are applied several times. In this project, the coating of cast iron with a corrosion resistant AISI 316L stainless steel by Laser Metal Powder Deposition has been studied as an alternative protection against corrosion. Several samples with different combinations of substrate preparation, number of layers and surface conditions were produced and analysed by optical microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, wash down tests and salt spray chamber corrosion tests. Main results show that the diffusion of carbon from the carbon-rich cast iron to the stainless steel coating, which would have a negative effect on the corrosion resistant properties, was significantly low as a result of the low penetration and dilution achieved during the laser metal powder deposition process. The deposited stainless steel coatings successfully protected the substrate during the corrosion tests and the integrity of the coatings is not expected to fail during the washing producers applied in the industry.

Lamellar graphite iron (LGI) is commonly used in diesel engine applications such as piston rings–cylinder liner where an excellent combination of physical and tribological properties is essential to avoid scuffing and bore polishing issues. The excellent tribological behaviour of LGI alloys is related to the graphite lamellas, which act as solid lubricant agents by feeding onto the tribosurfaces under sliding conditions. However, increasingly tighter emissions and fuel economy legislations and the higher demands on enhanced power and durability have encouraged both engine designers and manufacturers to introduce pearlitic compacted graphite irons (CGI) as an alternative material replacing LGI, although the poor machinability of pearlitic CGI alloys compared to the LGI remains a challenge. The focus of this study is placed on investigating how the microstructure of LGI and CGI alloys affects their mechanical and tribological properties. This was initially undertaken by investigating representative, worn lamellar cast iron piston rings taken from a two-stroke large-bore heavy-duty diesel engine. As known that it is tribologically essential to keep the graphite open under sliding conditions, in particular under starved lubrication regimes or unlubricated conditions to avoid scuffing issues; however, this study revealed the closure of a majority of graphite lamellas; profoundly for those lamellas that were parallel to sliding direction; due to the severe matrix deformation caused by abrasion. Both microindentation and microscratch testing, which were used to crudely simulate the abrasion under starved lubricated condition in combustion chamber, suggested a novel mechanism of activating the graphite lamellas to serve as lubricating agents in which the matrix deformation adjacent to the graphite initially resulted in fracturing and then extrusion of the graphite lamellas. Additionally, in order to investigate the relation between matrix constituents, mechanical properties and machinability of cast iron materials, solution-strengthened CGI alloys were produced with different levels of silicon and section thicknesses. The results showed significant improvements in mechanical properties and machinability while deteriorating the ductility. Moreover, multiple regression analysis, based on chemical composition and microstructural characteristics was used to model the local mechanical properties of high Si ferritic CGI alloys, followed by implementing the derived models into a casting process simulation which enables the local mechanical properties of castings with complex geometries. Very good agreement was observed between the measured and predicted microstructure and mechanical properties.

Ferros fundidos cinzentos ligados com cromo e molibdênio são utilizados em cabeçotes de motor para se obter alta resistência à tração e à fadiga (com menores seções), maior resistência à temperaturas elevadas e maior estabilidade térmica. No presente trabalho é feita uma avaliação da influência da adição dos elementos de liga cromo e molibdênio na solidificação e na formação de rechupes em ferros fundidos cinzentos, através da fundição de corpos de prova com diferentes composições químicas, variando porcentagens de cromo e molibdênio comumente utilizadas em ferros fundidos cinzentos de alta resistência. Além da composição química, foi variada a porcentagem de inoculação nas ligas, através da adição de 0,2% e 0,6% do inoculante FeSi75. A simulação de fundição, utilizando o software para simulação do processo de fundição Magmasoft, foi aplicada para desenvolver um corpo de prova com tempo de solidificação similar ao de um cabeçote de motor. Depressões foram detectadas no topo dos corpos de prova, tendo sido caracterizadas como rechupes primários; microrechupes foram detectados no centro térmico, caracterizados por rechupes secundários. O volume das depressões foi medido, através de preenchimento com água. Os microrechupes foram avaliados de forma qualitativa através do ensaio de líquidos penetrantes e análise metalográfica. A avaliação da seqüência e morfologia de solidificação das fases formadas foi realizada através de análise térmica e, posteriormente, através de análises metalográficas. As temperaturas de reação eutética estável e metaestável foram calculadas através de software de termodinâmica computacional Thermocalc. A adição dos elementos de liga Cr e Mo em menores teores não causaram diferenças significativas no volume das depressões, tão pouco na presença de microrechupes. Porém adições combinadas de 0,4%, 0,6% e 1,0% de cromo e molibdênio apresentaram um aumento significativo no volume de depressão. Os resultados de simulação apresentaram resultados e curvas de solidificação similares às obtidas na prática industrial e maior tendência para a formação de rechupes primários com adições crescentes de cromo e molibdênio. Já em relação à tendência à formação de microrechupes somente adições combinadas de 0,6% e 1,0% apresentaram efeito significativo. Maiores porcentagens de adição de inoculantes aumentaram o volume tanto de depressões quanto de microrechupes, principalmente nas ligas contendo 1,0% de cromo e molibdênio.<br>Grey cast iron alloyed with chromium and molydnenum are used in cylinder heads to obtain high fatigue and ultimate strength (with less wall thickness), higher strength to elevated temperatures and higher thermal stability. This research presents an evaluation of the influence of chromium and molybdenum in solidification and shrinkage defects of grey cast iron alloys. The evaluation was made varying the percentages of chromium and molybdenum commonly used in high resistance grey cast iron alloys. Also the percentage of inoculation was varied with additions of 0,2% and 0,6% of the inoculant FeSi75. The foundry simulation, applying the software to simulate the foundry process MagmasoftÒ, was used to develop a test cast that should present the same solidification time of a cylinder head. Primary shrinkage defects were detected in the top of the test parts characterized as sinks and secondary shrinkage defects were detected in the hot spots, characterized as micro shrinkage porosity. Sinks volumes were measured by water filling. The micro shrinkage porosity was evaluated by liquid penetrant examination and metallographyc analysis. The solidification sequence and morphology of the phases were evaluated by thermal and metallographyc analysis. The stable and metastable eutectic reaction temperatures were calculated by ThermocalcÒ software. The compositions with less alloy additions did not present differences in the sinks or in the micro shrinkage porosity volumes. But combinations of 0,4%, 0,6% and 1,00 % of chromium and molybdenum presented a significant increase of sinks volumes. The simulation results presented similar results of solidification and cooling curves measured in the foundry and also presented the same tendency of primary shrinkage defects increase with additions of chromium and molydenum. Combinations of 0,6% and 1,00% of chromium and molybdenum presented an increase of micro shrinkage porosity volumes. Higher inoculant additions increased the volumes of both defects, mainly in combinations of 1,00% of chromium and molybdenum.

Orientador: Amauri Hassui<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica<br>Made available in DSpace on 2018-08-23T09:41:04Z (GMT). No. of bitstreams: 1 Machado_MarcioAlexandreGoncalves_M.pdf: 7046476 bytes, checksum: c4116e182c526a80c0f1d8c7b1fe8d4a (MD5) Previous issue date: 2013<br>Resumo: Sabe-se que atualmente a competitividade das empresas é fator de sobrevivência. Assim, a busca por redução de custo é um constante desafio. Um aspecto dentro dos processos de fabricação que atua diretamente nesse tocante é o desenvolvimento de melhores ferramentas de corte. Este trabalho trata da reafiação de ferramentas de corte denominadas bedame, que possuem custo mais elevado que as demais ferramentas. O material usinado foi o ferro fundido nodular, que possui propriedades mecânicas características e consumir menor energia em sua fusão. Nos processos de usinagem são utilizadas as mesmas ferramentas para os ferros fundidos nodulares e cinzentos, porém o primeiro é um material dúctil, diferente do segundo que é frágil. Isso implica em um comportamento diferente na usinagem, mostrando que cabe neste caso uma melhor adequação das ferramentas de corte. Após a utilização de bedames novos, estes foram reafiados em quatro modelos diferentes. Posteriormente foram testados quatro tipos de revestimento PVD. Na sequência avaliou-se também a influência da velocidade de corte, avanço e concentração do fluido de corte. O critério adotado para a determinação do fim da vida dos bedames foi à qualidade da face usinada. Os ensaios foram feitos em sequência, sendo que o passo seguinte utilizava apenas os melhores resultados do passo anterior. Os resultados indicaram que bedames com ângulo de saída positivo, revestidos com AlTiN, usinando com menores velocidades de corte e avanço e com maior concentração de óleo no fluido de corte, apresentaram vida mais longa. Por outro lado, o mesmo bedame, só que revestido com TiCN e operando nas mesmas condições, apresentou a melhor relação custo benefício dentre os bedames reafiados. Concluiu-se assim que é viável economicamente a reafiação dos bedames<br>Abstract: It is known nowadays that the companies' competitiveness is a survival factor. So, the search for cost reduction is a constant challenge. One aspect of the manufacturing processes that act directly in this aspect is the development of better cutting tools. This work is about cutting tools to part materials named parting tools that has higher costs than the other cutting tools. The machined material was the nodular cast iron that has specific mechanical characteristics and demands less energy in its melting. In the machining processes it is usually used the same cutting tools to machine nodular and grey cast iron, but the first is ductile different from the second that is fragile. This implies in a different machining behavior, showing that is possible in this case a better adequation of the cutting tools. After using the new parting tools, they were resharpened in four different models. After that were tried four different PVD coatings. In the sequence it was also evaluated the influence of the cutting speed, the feed and cutting fluid concentration. The criteria adopted to determine the end of the parting tool life was the quality of the machined surface. The tests were carried out in sequence in such a way that the next step used just the best results of the former step. The results indicated that parting tool with positive rake angle, coated with AlTiN, operating in lower cutting speeds and feeds and with higher cutting fluid concentration, presented longer tool life. On the other hand, the same parting tool, but coated with TiCN and operating at the same cutting conditions, presented a better cost benefit relation among the resharpened cutting tools. It can be concluded that is economically feasible the parting tools resharpening<br>Mestrado<br>Materiais e Processos de Fabricação<br>Mestre em Engenharia Mecânica

This thesis deals with design for manufacturing technology single part on machine FS, which is the connecting part. Work deals with the material of this component, therefore, cast iron with lamellar graphite, the properties of this material, primarily focusing on the machinability. Due to the shape and dimensions of the workpiece is also described problems cutting of box parts, the most common operations used in their manufacture, including cutting tools and materials. These findings are then applied in terms of the company TOS Kuřim - OS a.s. An analysis of current manufacturing technology and design is made for its amendment. In conclusion with the technical-economic evaluation.

The diploma thesis is concerned with evaluation of actual production technology of part “hydraulics cover” and with design of new, progressive variation machining of this part. Solution is focused at first on rationalization of cutting tools and choice of suitable cutting tools. An effort is to achieve shorter production time and decrease costs on production of component. With this problem is related alteration of technological documentation and technical economic evaluation for determination return rate of investments into progressive cutting tools.

Welspun Steel Limited produces steel billets of various dimensions 30% of which are sent to produce Re-bars. WSL’s TMT is presently the second best TMT available for business and industry based constructions in the market after JINDAL’s. As per the Welspun Fellowship Program, the student has undergone a training period alongside doing the project in optimizing the production of the WSL plant in Anjar, Gujarat. The thesis details the findings and discusses the current issues that a typical secondary steel industry, namely WSL, is facing along with some theoretical suggestions. DRI + Scrap is the raw material in the secondary steel production in WSL. A conclusive study is conducted to check the tap times, just by melting DRI without the steel scrap. The results indicate a success and so a new method, posing a new set of problems though, to be experimented and researched on. Finally, sets of loopholes, neglected zones and bottlenecks have been identified all through the process of steel making and casting. Suggestions have been insisted and some of them were effectively implemented.

碩士<br>國立清華大學<br>材料科學工程學系<br>106<br>Via the use of iron-carbon phase diagram and the theory of graphitization of carbon in cast irons, this study investigates an innovative method for continuously, effectively and efficiently, as well as environment-friendly producing graphite in a catalytic cast iron bath. It is concluded that the transformation from amorphous carbon to graphite via the method is available, and the degree of graphitization (DOG) described in this study reaches a high value of more than 93% like that of Acheson’s. Furthermore, the DOG is process-controlled and is independent of carbon source in the hypereutectic catalytic cast iron melt. The observance of graphite flotation in liquid catalytic cast iron bath manifests the production of graphite is achievable by the fluidized bed method. The first part of this study describes the inductive melting (IM) of alloys of iron, carbon, and silicon at 1600oC for full melting; holding at temperatures higher than the eutectic temperature of 1500oC for 4 h for graphitization of carbon; and then lower the temperature to 25oC for test specimens. The IM specimens, being XRD and OM-checked firstly, are further pickled to obtain graphite that is also XRD-, OM- and ICP-analyzed to compare with graphite obtained from nodular cast iron and gray cast iron. The second part is about the vacuum arc re-melting (VAR) experiment of the specimens that are obtained in the first part. The effects of the number of VAR process and the addition of synthetic graphite on the DOG are checked with OM. The graphite samples of VAR specimens after pickled are checked with graphite production yield analysis, XRD for the comparison of the DOG, and ICP for the composition analysis.

The impact of production optimization and scheduling mainly depends on availability of the machineries; their break-down maintenance schedule and minimization of their idle time i.e. increase in their availability which maximizes their utility. The simulation work-sheet prepare here for the same purpose only for shovel-dumper transport system. In next phase all the machineries are analyzed of their break-down record by random number distribution for preventive maintenance so as to minimize the same and increase their availability in work condition to maximize productivity and hence production optimization. Simulation Work-Sheet developed here states that if one or more dumper is added in the system. There is no need for a dumper to wait in the queue. But, before effecting any decision, the cost of having an additional shovel has to compare with the cost due to dumper waiting time. The breakdown of different machineries is analyzed with random number distribution. The different event falls under definite random number distribution range. Such as if random number comes as 1 - 6875 indicates the shovel breakdown and if it comes 6876- 13125 it will be considered as dumper break-down, etc. Hence a clear idea can be made for the break-down of different machineries also precautions can be taken for preventive maintenance to minimize these break-down periods by analyzing this method and thus production can be set as Optimum and steady-state.

博士<br>國立成功大學<br>材料科學及工程學系碩博士班<br>98<br>Brake discs are subject to wear and overheating during normal use and may distort, causing disc thickness variation(DTV) and feedback to the driver as brake judder through the brake pedal. Disc thickness variation on the brake disc may be due to relaxation of residual stresses through heating during continuous severe braking or by uneven wear. In order to improve mechanical properties of a brake disc casting to reduce the brake judder phenomena, proper design of casting condition is of great importance. In this study, a computer-aided engineering software; ProCAST, is applied to simulate the mold filling, solidification phenomena, residual stresses and hardness of a FC250 gray cast iron brake disc casting as well as to obtain optimum design. Then, brake judder phenomena can be alleviated. First, a numerical model is adopted to simulate the mold filling and solidification phenomena as well as to predict the occurrence of the related casting defects for a brake disc casting. The goal is to conduct numerical experimentation to improve the running and gating system of the brake disc casting to obtain better casting quality. Numerical simulations are conducted for the brake disc casting with a preliminary running and gating system. The mold filling and solidification phenomena are examined to predict the occurrence and extent of the casting defects. They are found to be consistent with the defects observed in the actual casting. Based on the findings of the simulated results, a modified running and gating system is then proposed. The mold filling and solidification phenomena for the modified design are simulated. The results show that the problem of casting defects is alleviated with use of present results. The numerical modeling of residual stresses and hot tear prediction model for a brake disc are also presented in this study. The goal is to conduct numerical experimentation to reduce the residual stresses of the brake disc casting to obtain better casting quality. Numerical simulations were conducted for the brake disc casting with different shake-out times. The solidification phenomena were examined to observe distribution of residual stresses and the optimized shake-out time was then proposed based on the simulated results to alleviate residual stresses of the brake disc casting. Experimentation procedures were also conducted to measure residual stresses of the brake disc casting. The predictions of residual stresses were validated by comparison with experimental measurements and consistency was found between the two results. The simulation results shows that 7200 seconds is a better shake-out time design and it can pass actual track testing. Besides, hot tearing phenomena are also simulated both with a preliminary and a modified running and gating system. Simulation results reveal that hot tearing phenomena is alleviated with a modified running and gating system. The purposes of hardness simulation are to develop a technique of numerically simulating the hardness of a FC250 gray cast iron brake disc casting and verified by experimental measurements. As the numerical model is proven reliable, numerical experimentation is then conducted to homogenize the hardness distribution of a brake disc to obtain better casting quality. The Oldfield’s model was adopted to simulate the nucleation and grain growth during solidification of the casting. A calibration brake disc casting was first made. By comparing the hardness of the calibration brake disc casting with the simulated results using different nucleation and growth coefficients (Ae, Be) in Oldfield’s model, the most appropriate set of values for Ae and Be was obtained. Then, this set of values was applied to the hardness simulation of a test brake disc casting and confirmed by experimental measurements. Through this approach, a set of nucleation and growth coefficients was obtained for the brake disc casting. Subsequently, numerical simulations were conducted for the brake disc casting with different shake-out times to evaluate its distribution of hardness and an optimized shake-out time was then proposed based on the simulated results. The predictions of hardness were validated by comparison with experimental measurements and actual track testing. The simulation results shows again that 7200 seconds is a better shake-out time design.

碩士<br>國立臺灣大學<br>機械工程學研究所<br>104<br>The primary purpose of this research is to establish the optimal conditions for the production of compacted graphite cast iron by investigating the effects of metallurgical and processing parameters (types of compactizer, addition amounts of compactizer, holding time, holding temperature and late inoculation) on graphite morphology and mechanical properties of compacted graphite cast iron. The results show that, for a fixed C.E. value of 4.2% and addition amounts of 0.3% inoculant and 0.6% Mg-RE compactizer without late inculation, a carbide-free compacted graphite cast iron with 80~90% vermicularity can be obtained. For the same treatment condition, again a carbide-free compacted graphite cast iron but with lower vermicularity about 50~70% and was attained by conducting late inculation. In addition, flake graphite will generate when Mg-RE compactizer decayed at about 13~20 minutes after compactization and inoculation treatment, but lower holding temperature can slow down this phenomenon. Besides, compacted and spheroidal graphite cast iron can’t be reach by conducting late inculation after flake graphite generate. For using RE alloys as the compactizer, a fixed C.E. value of 4.2% and addition amounts of 0.3% inoculant and 0.6% RE compactizer without late inculation, compacted graphite cast iron with 40~70% vermicularity but with carbide can be obtained. For the same treatment condition, carbide can be eliminates by conducting late inculation and a carbide-free compacted graphite cast iron with lower vermicularity about 10~60% can be attained. RE alloys will decay at about 20~27 minutes after compactization and inoculation treatment due to less volatile. In terms of the optimal conditions for the production of compacted graphite cast iron, addition amounts of 0.3% inoculant and 0.6% Mg-RE compactizer without late inculation, a carbide-free compacted graphite cast iron with about 80~90% vermicularity can be obtained at about 13 minutes after compactization and inoculation treatment. In the other hand, addition amounts of 0.3% inoculant and 0.8%~1.0% RE compactizer with late inculation, a carbide-free compacted graphite cast iron with 60% vermicularity can be obtained at about 20 minutes after compactization and inoculation treatment.

碩士<br>逢甲大學<br>機械與電腦輔助工程學系<br>106<br>The objective of this study is to investigate the effects of physical properties on the mold filling and solidification process using CAE Software, JS-CAST. Gating system for flake graphite cast iron(FC350) and spheroidal graphite cast iron (FCD450-10)are chosen as the research targets. The method adopted for studying mold filling and solidification of casting is as followed. First, obtain the total cross-sectional area of the gate. Then choose a suitable gating ratio to design a gating system. Finally, modify the physical properties’ settings (specific heat, thermal conductivity, initial temperature, solid and liquid phase temperature) within the JS-CAST simulation software to simulate and analyze the mold filling and solidification process of casting. It is observed that physical properties of the casting have the maximum effect on the maximum and minimum temperature difference for the filling process. Comparing with the original settings, specific heat and thermal conductivity have shown the most obvious effects on the temperature difference. It is observed from the solidification rate curve that the required solidification time is significantly reduced by reducing the specific heat and the initial temperature, but reducing the thermal conductivity has the opposite effect. It is also observed from the curve of temperature variation, the required cooling time is significantly reduced by reducing the settings of specific heat and the initial temperature value when the required cooling temperature is below the eutectoid point, but reducing the thermal conductivity has the opposite effect. When changed specific heat, thermal conductivity, and initial temperature at the same time to compare the effect. It is observed that specific heat has shown the most obvious effects on the minimum of the filling temperature, attain 100% solidification rate, and the cooling time required when the temperature is below the eutectoid point. It is also observed that modify the physical properties’ settings haven’t shown obvious effects on the simulation results of Niyama criterion (index of shrinkage defect).

Thesis (M.S.)--University of Wisconsin--Madison, 1991.<br>Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 112-120).