Microstructural Origins of Plastic Work Partitioning during Deformation of 310S TWIP Steel
The microstructural mechanisms governing the plastic work partitioning in twinning-induced plasticity (TWIP) steels remain insufficiently understood, particularly under strain localization. This study provides a crystallographic-scale interpretation of the fraction of plastic work stored during deformation of 310S TWIP steel exhibiting complex deformation mechanisms. Electron backscatter diffraction (EBSD) was used to characterize local crystallographic orientation and microtexture during uniaxial tensile deformation using two complementary approaches: tracking the same surface region at successive strain levels and analyzing regions corresponding to known local plastic strain. Deformation was initially dominated by dislocation slip, whereas twinning activity increased significantly beyond an equivalent plastic strain of approximately 0.3. Progressive deformation produced pronounced lattice rotations and a dual-fiber texture comprising dominant 111 parallel to rolling direction (RD) and secondary 100 parallel to RD components. Correlation of the EBSD observations with previously quantified evolution of the energy storage rate reveals that intensified twinning and texture redistribution in strain-localized regions are accompanied by a pronounced decrease in the fraction of plastic work stored in the material. Twin-matrix refinement and progressive lattice rotation promote non-uniform strain distribution and create favorable conditions for shear-band-mediated deformation, contributing to a reduction of the energy storage rate toward zero or negative values at advanced stages of localization.