Multi-scale Modelling Of Phase Transformations In Advanced Steels
Prof. Matthias Militzer
Department of Materials Engineering
University of British Columbia
Date & Time
Room 7-37, Haking Wong Building, HKU
Next generation advanced high-strength steels are an essential part of the multi-material solutions for clean energy materials including energy production, energy transportation and energy end-use, e.g. in the design of lightweight vehicles. Non-traditional alloying concepts are proposed for these steels with significantly increased alloying levels of Mn, Al and Si. Microstructure evolution during thermo-mechanical processing assumes a critical role in tailoring the mechanical properties, e.g. the austenite-ferrite transformations are a key metallurgical tool to improve properties of advanced low-carbon steels. Computational materials science offers now tremendous opportunities to formulate next generation process models which are informed on the atomistic mechanisms of microstructure evolution thereby reducing the number of empirical parameters that are typically used in current process models. The challenges and opportunities of implementing advanced computational materials science tools into process models will be critically reviewed. Microstructure evolution kinetics depends on interface migration rates that can be significantly affected by alloying elements, e.g. Mn, Mo and Nb in steels. Here, an approach is illustrated that links atomistic scale models for the solute-interface interaction with phase field modelling to describe the formation of microstructures with complex morphologies. The overall status of the multi-scale modelling approach will be analyzed for intercritical annealing of dual-phase steels and the rapid heat treatment cycles in the heat affected zone of line pipe steels. A critical outlook will be provided to propose future research directions to enhance the computational modelling strategies by truly integrating models across different length and time scales and by extending fundamental model concepts to multi-component systems that are relevant for commercial steel chemistries.
Professor Matthias Militzer is the ArcelorMittal Dofasco Chair in Advanced Steel Processing and the Director of the Centre for Metallurgical Process Engineering at the University of British Columbia in Vancouver. He received a Diploma in Physics from the University of Technology in Dresden, Germany in 1983 and a Ph.D. in Metal Physics from the Academy of Sciences in East Germany in 1987. He moved to Canada in 1990 where he was first a Postdoctoral Fellow at McGill University before joining the University of British Columbia in 1993. He has published more than 200 papers in refereed journals and conference proceedings. His primary field of research is modelling the microstructure evolution during thermo-mechanical processing of steels and other metals. Currently, his major research activities include multi-scale modelling of phase transformations in steels, accelerated cooling of steels and in-situ measurements of microstructures using laser ultrasonics for metallurgy. He is a Fellow of the Canadian Institute for Mining, Metallurgy and Petroleum (CIM) and received the ASM Henry Marion Howe Medal 2010 and the Canadian Metal Physics Award in 2014.