Orientation Dependence of Deformation-Induced Martensite Transformation During Uniaxial Tensile Deformation of Carbide-Free Bainitic Steel.

The present study investigates the orientation dependence of deformation-induced martensite (DIM) transformation in carbide-free bainitic steel using experimental macrotexture analysis and crystal plasticity-based modelling. The results indicate that the P {110}〈122〉 component of retained austenite preferentially undergoes DIM transformation during uniaxial tensile deformation at room temperature. It is also found that the P component of retained austenite possesses the lowest Schmid factor value compared with other possible texture components. The lowest Schmid factor value of the P component results in the highest resolved shear stress value for its slipping. As a result, during plastic deformation when most of the initial components of the retained austenite reorient themselves to other relatively stable orientations, the P component remains almost unaffected. Accumulation of stress concentration thus increases along this component, which eventually leads to its deformation-induced transformation to martensite. [ABSTRACT FROM AUTHOR]