Basudev Bhattacharya

Evolution of Crystallographic Texture and Microstructure During Cold Rolling of Twinning-Induced Plasticity (TWIP) Steel: Experiments and Simulations

A systematic investigation of the evolution of deformation microstructure and texture of twinning-induced plasticity (TWIP) steel during cold rolling has been carried out using electron backscatter diffraction and X-ray diffraction, as well as viscoplastic self-consistent simulations. It is found that extensive twinning leads to the formation of the strong Brass {110}〈112〉 and Goss {110}〈001〉 components in TWIP steel even at low strains. At higher reduction, heterogeneous deformation contributes to further strengthening of Brass (Bs) component. The origin and stability of Bs component as well as the impact of the evolution of texture and microstructure on mechanical anisotropy is further explored using viscoplastic self-consistent simulations.

Annealing texture of a cold-rolled Fe–Mn–Al–Si–C alloy

The study of recrystallization texture of a cold deformed Fe–Mn–Al–Si–C alloy, with about 30% Mn, has been discussed in this paper. The alloy is fully austenitic at room temperature, and therefore, principal FCC rolling textures were developed in this material at different stages of cold rolling. The present study was undertaken to observe the transformation of FCC rolling texture during recrystallization of a heavily cold deformed specimen. It was observed that isothermal annealing at 750 °C led to a weak recrystallisation texture, which was quite similar to the deformation texture developed at the early stage of cold rolling. During recovery stage, a strong Bs/Goss-type texture was developed, which was identified as a new observation in this work.

Evaluation of factors affecting the edge formability of two hot rolled multiphase steels

In this study, the effect of various factors on the hole expansion ratio and hence on the edge formability of two hot rolled multiphase steels, one with a ferrite-martensite microstructure and the other with a ferrite-bainite microstructure, was investigated through systematic microstructural and mechanical characterization. The study revealed that the microstructure of the steels, which determines their strain hardening capacity and fracture resistance, is the principal factor controlling edge formability. The influence of other factors such as tensile strength, ductility, anisotropy, and thickness, though present, are secondary. A critical evaluation of the available empirical models for hole expansion ratio prediction is also presented.

Improvement of Crystallographic Texture of High Strength Interstitial Free Steels by the Control of Steel Chemistry and Coiling Temperature

Effects of steel composition and coiling temperature on textures of a series of high strength IF steels were studied. An intermediate coiling temperature (6200C), instead of a high coiling temperature (7100C), was found most beneficial for the steels containing moderate to high phosphorus content. On the other hand, high coiling temperature was found beneficial for the steels containing low amount of phosphorus.