Microstructural origins of energy storage during plastic deformation of 310S TWIP steel

TL;DR

This study investigates the microstructural mechanisms of energy storage during plastic deformation of 310S TWIP steel, revealing how twinning and texture evolution influence energy storage and deformation localization.

Contribution

It provides a crystallographic-scale interpretation of energy storage in TWIP steel, linking microstructural evolution to energy storage behavior during deformation.

Findings

Twinning activity increases significantly beyond 0.3 strain

Texture evolution includes a dual-fibre texture with specific orientations

Enhanced twinning correlates with reduced energy storage rate

Abstract

The microstructural mechanisms governing energy storage during plastic deformation of twinning-induced plasticity (TWIP) steels remain insufficiently understood, particularly under conditions of strain localization. This study provides a crystallographic-scale interpretation of energy storage in 310S TWIP steel exhibiting complex deformation mechanisms. Electron backscatter diffraction (EBSD) was used to characterize the evolution of local crystallographic orientation and microtexture during uniaxial tensile deformation using two complementary approaches: tracking the same surface region at successive strain levels and analysing regions corresponding to known local plastic strain. Deformation was initially dominated by dislocation slip, while twinning activity increased significantly beyond an equivalent plastic strain of approximately 0.3. Progressive deformation produced pronounced lattice rotations and the development of a dual-fibre texture consisting of a dominant 111 parallel to RD component and a secondary 100 parallel to RD component associated with deformation twinning. Correlation with previously quantified energy storage behaviour obtained from coupled digital image correlation and infrared thermography measurements reveals that intensified twinning and texture evolution in strain-localized regions are accompanied by a marked reduction in the energy storage rate. The results indicate that twin-matrix refinement and lattice rotation progressively reduce the material's capacity to store deformation energy and create favourable conditions for shear-band-mediated deformation.