Author: O. Vázquez-Gómez Publisher: ISBN: Category : Ductile iron Languages : en Pages : 14
Book Description
Austempering of ductile iron is a heat treating process designed to improve the mechanical properties of ductile iron: Increasing its strength and wear resistance while maintaining the tenacity and ductility associated with the untreated condition. This task is achieved by rapidly cooling the part from the austenitizing temperature to the austempering temperature and holding it during a specific time. Austempering promotes the formation of an ausferrite matrix, i.e., a mixture of bainitic ferrite and retained austenite, along with graphite nodules. In order to achieve the required microstructural control, a detailed knowledge of the phase transformation evolution coupled with a heat transfer analysis is required. Thus a thermostructural model has been developed to simulate the phase transformations during austempering of a ductile iron cylindrical probe. The thermal and microstructural submodels were coupled within the Abaqus software. The predictions were validated by austempering ductile iron probes from an austenitizing temperature of 920°C to an austempering temperature of 300°C in a molten salt bath and comparing predictions versus experimental data. It was concluded that the model is suitable to predict the thermal behavior and the final microstructure of the austempered ductile iron.
Author: Duncan Colin Putman Publisher: ISBN: Category : Languages : en Pages :
Book Description
Austempered ductile iron (ADI) has a microstructure consisting mainly of high carbon austenite, bainitic ferrite and graphite nodules, produced by a two stage austenitisation and austempering heat treatment. The resulting microstructure gives these materials a combination of high strength and toughness, making them attractive for a wide range of applications. To increase surface hardness, ductile iron alloys can also be cast into chilled moulds to induce carbide formation in the required areas of components. These chilled ductile iron alloys can also be subjected to austenitisation and austempering heat treatments, therefore further improving the mechanical properties of the components core, whilst retaining the hard carbides present in the surface layers. This work encompasses three main areas; two are concerned with the production of generic microstructure models, which work in conjunction with thermodynamic modelling software MTDATA, and one relates to high temperature X-ray diffraction experiments. The first modelling section details how a computer program was developed that can be used to investigate how chemical composition influences the chill tendency of ductile iron alloys. The model predictions were shown to be in good agreement with a wide range of experimental measurements. The second modelling section considers ADI alloys. A computer program was developed which, given the chemical composition and austenitisation and austempering temperatures, produces a prediction of the microstructure of the alloy at the end of stage 1 of the austempering heat treatment, taking into account segregation of alloying elements. Experimental segregation profiles produced during this work showed good agreement with the model predictions. Furthermore, predictions of the stage 1 transformation kinetics as a function of alloying element segregation, are also made by the model. Therefore, the local microstructural transformation times during austempering can be predicted. Good agreement has been observed between phase volume fractions, transformation times and mechanical property predictions made using the model and those found in literature, therefore a useful tool for new alloy development has been produced. High temperature X-ray diffraction experiments were also performed as part of this work. Microstructures typical of ADI alloys were produced during these experiments, although small quantities of pearlite were observed in the samples, and care was taken to minimise any effects of decarburisation and/or oxidation. The austenite carbon content was monitored during austenitisation and austempering, enabling comparisons to be made between high temperature and low temperature X-ray diffraction measurements in ADI alloys.
Author: Taurista Perdana Syawitri Publisher: Springer Nature ISBN: 9464631341 Category : Technology & Engineering Languages : en Pages : 633
Book Description
This is an open access book. MEST2022 invites all potential authors from universities and various organisations to submit papers in the area of mechanical, manufacturing, materials sciences and related interdisciplinary engineering fields. This conference is part of a conference program called International Summit on Science Technology and Humanity (ISETH) 2022 Organized by Universitas Muhammadiyah Surakarta. The 6th Mechanical Engineering, Science and Technology (MEST2022) International conference is an annual the Mechanical Department of Universitas Muhammadiyah Surakarta event. All possible writers from universities and other organizations are invited to submit papers. The conference is a forum for academic exchange that provides a prompt presentation of articles on experimental, numerical, and theoretical studies that shed light on the critical topics of mechanical, thermal, fluid, and aerothermodynamics internal flow, heat and mass transfer, multiphase flow, turbulence modelling, combustion, engineering thermodynamics, thermophysical properties of matter, measurement, and visualization techniques. Contributions range from intriguing and significant research immediately applicable to industry development or practice to high-level student textbooks, explanations, distribution of technology, and good practice.
Author: J Lin Publisher: Elsevier ISBN: 0857096346 Category : Technology & Engineering Languages : en Pages : 409
Book Description
Monitoring and control of microstructure evolution in metal processing is essential in developing the right properties in a metal. Microstructure evolution in metal forming processes summarises the wealth of recent research on the mechanisms, modelling and control of microstructure evolution during metal forming processes.Part one reviews the general principles involved in understanding and controlling microstructure evolution in metal forming. Techniques for modelling microstructure and optimising processes are explored, along with recrystallisation, grain growth, and severe plastic deformation. Microstructure evolution in the processing of steel is the focus of part two, which reviews the modelling of phase transformations in steel, unified constitutive equations and work hardening in microalloyed steels. Part three examines microstructure evolution in the processing of other metals, including ageing behaviour in the processing of aluminium and microstructure control in processing nickel, titanium and other special alloys.With its distinguished editors and international team of expert contributors, Microstructure evolution in metal forming processes is an invaluable reference tool for metal processors and those using steels and other metals, as well as an essential guide for academics and students involved in fundamental metal research. - Summarises the wealth of recent research on the mechanisms, modelling and control of microstructure evolution during metal forming processes - Comprehensively discusses microstructure evolution in the processing of steel and reviews the modelling of phase transformations in steel, unified constitutive equations and work hardening in microalloyed steels - Examines microstructure evolution in the processing of other materials, including ageing behaviour in the processing of aluminium
Author: O. Vázquez-Gómez
Author: Morten Ingar Onsoien
Author: Duncan Colin Putman
Author: Ravi Vijayaraghavan
Author: Taurista Perdana Syawitri
Author: Miguel Angel Yescas-Gonzáles
Author: J Lin
Author: Øystein Grong
Author: Qiang Yu
Author: