Full-field simulation of tempered martensite: Quenching, tempering and mechanical characterization
Johannes Görler, ICAMS, Ruhr-University Bochum, Bochum, Germany
Ferritic steels with a microstructure consisting of tempered martensite have many applications, be it in aerospace engineering, chemical engineering or power generation. Stiffness and toughness of the material can be precisely adapted to the application by means of tempering. This process is to be supported by simulations, as has happened here using the example of three different steels, each with two different tempering treatments. The full-field approach used is based on the multi-phase field model of Steinbach et al. . For the first time consecutive full field simulations of quenching, tempering and mechanical testing have been performed using the phase-field library OpenPhase. The simulation of quenching describes the transformation of austenite into martensite under consideration of the Kurdjumov-Sachs relationship. Tempering is then simulated using the resulting microstructure. Cementite forms and consumes the carbon from the martensite matrix, reducing tetragonal distortion. A virtual tensile test finally provides information on strain hardening, damage and the macroscopic material response to the load. Validation against experiments proves the predictive capability of the simulation approach. The talk will shortly summarize the approach and spotlight the benefit of full-field simulations for the understanding and optimization of materials.
 Ingo Steinbach, Phase-Field Model for Microstructure Evolution at the Mesoscopic Scale. Annual Review of Materials Research 43 (2013) 89-107