Transformation Texture Analysis with BAIN Relation -Monte Carlo Simulations

Abstract

The merit of use of BAIN relation in analizing the transformation texture was first described, as compared with that of NISHIYAMA (N) or KURDJUMOV-SACHS (K-S) relation. This was primarily because there were only three variants in BAIN, while 12 and 24 variants in N and K-S relations respectively, and each variant in N or K-S was oriented close to one of the three BAIN variants. Secondly, computer simulations of transformation textures were conducted on steels transformed from rolled austenite using variant selection rules. In these rules, the work done by specific stress on rolling against the lattice deformation (BAIN distortion) of martensite transformation was calculated for each <001>axis of austenite, and such BAIN variants that had the work larger than certain critical value were selected.
Transformation textures simulated in this way were successful in explaining Fe-Ni textures experimentally determined by other authors. Evidence which showed the effect of the sense of the specific stress was presented; calculations based on the forward rolling stress could explain the case of transformation during rolling, whereas simulations due to reverse or internal stress of rolling were coincident with the transformation after rolling. Some explanations were given to the nature of such hypothetical internal stress and to the mechanisms of variant selection in martensite transformation.