Rajib Kalsar

Evolution of Texture in Some Mn Steel

Deformation texture, microstructure, and tensile properties have been studied in a high Al containing TWIP steel with a composition Fe–12Mn–0.6C–5.5Al. Alloy was cold rolled to a large reduction in thickness (e t ≈ 3). The deformed microstructure has been characterized by X-ray diffraction and electron backscatter diffraction. Bulk X-ray texture reveals the development of Bs-type texture with deformation. Microstructural features indicate the occurrence of different deformation mechanisms at different reduction levels. At very early stage of deformation, dislocation slip is the dominant mechanism, at intermediate stage, deformation takes place by twinning, and at large strains, the deformation is governed by shear banding. Significant improvement of yield strength is observed by the addition of Al.

Effects of Deformation Texture and Microstructure on Recrystallization and Grain Growth in Twip Steels

The importance of TWinning Induced Plasticity (TWIP) and TRansformation Induced Plasticity (TRIP) has increased drastically in the recent past due their potential for automobile applications. These steels have good combination of specific strength and ductility, which could improve the crash resistance or energy absorption capacity in the situations like accidents. Stacking Fault Energy (SFE) is the most important parameter for the design of such steels. In low SFE TWIP steels, Brass (Bs)-type texture typically develops during rolling. Present investigation deals with the role of deformation texture, microstructure and SFE in recrystallization kinetics and grain growth, during processing in medium Mn steels. The SFE of Fe-12Mn-0.5C (wt %) alloy could be altered by the addition of alloying elements, such as Al. Recrystallization experiments have been carried out in cold rolled samples for different annealing times. In order to understand the recrystallization kinetics and grain growth phenomenon, detailed microstructural characterization has been performed by using Electron back-scatter diffraction (EBSD).

Role of stacking fault energy on texture evolution revisited

Three materials, pure aluminium, Al-4 wt.% Mg, alpha-brass have been chosen to understand the evolution of texture and microstructure during rolling. Pure Al develops a strong copper-type rolling texture and the deformation is entirely slip dominated. In Al-4Mg alloy, texture is copper-type throughout the deformation. The advent of Cu-type shear bands in the later stages of deformation has a negligible effect on the final texture. alpha-brass shows a characteristic brass-type texture from the early stages of rolling. Extensive twinning in the intermediate stages of deformation (epsilon(t) similar to 0.5) causes significant texture reorientation towards alpha-fiber. Beyond 40% reduction, deformation is dominated by Bs-type shear bands, and the banding coincides with the evolution of parallel to ND components. The crystallites within the bands preferentially show parallel to ND components. The absence of the Cu component throughout the deformation process indicates that, for the evolution of brass-type texture, the presence of Cu component is not a necessary condition. The final rolling texture is a synergistic effect of deformation twinning and shear banding.