Phase-field modelling of martensitic transformation in low alloyed steel considering the effect of large elasto-plastic deformation

• Applicant: Dr. Oleg Shchyglo
• Subject Area: Computer-Aided Design of Materials and Simulation of Materials Behaviour from Atomic to Microscopic Scale ; Thermodynamics and Kinetics as well as Properties of Phases and Microstructure of Materials
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 452543515

The project addresses advanced modelling and simulation of martensite microstructure formation in low carbon steel. This shall give new insight into the complex interplay between autocatalytic nucleation and anisotropic growth of martensite variants of different type. The aims of the project are: systematic investigation of the competition between the accommodation of elastic energy and plastic activity in both FCC and BCT phases and the resulting hierarchical ordering of martensite microstructure into laths, blocks and packets, study of the effect of residual internal stresses on the resulting martensite yield strength, and providing a tool for predicting martensite transformation kinetics in technical processes. In the continuation period these objectives remain almost unchanged. While in the first project period a consistent treatment of full Bain variants rotations leading to the formation of 24 Kurdjumov-Sachs martensite variants in a large strain setting has been accomplished and realistic calibration of the plastic slip in austenite to emulate true kinetics of martensitic transformation has been achieved, the consistent treatment of Hadamard jump at multi-junctions and elastic energy minimization at different interfaces in the martensite structure has been unsolved. Addressing these open questions is the goal of the continuation project. This will enable realistic representation of all relevant microstructural features of martensitic transformation in a consistent model.

• DFG Programme: Research Grants