Microstructural Evolution and Texture Analysis in a Thermomechanically Processed Low SFE Super‐Austenitic Steel (Alloy‐28)

Abstract

Microstructural evolution and texture analysis after 80% cold rolling and subsequent annealing in the temperature range of 750-1050 C is surveyed in Alloy-28. This is precisely studied through electron back scattered diffraction and also is declared through elaborating the hardness map. The occurrence of partially recrystallization is clearly evident in the microstructure which was treated 850 C annealing for 30 min. The recrystallization process is completed at 950 C even after 3 min, but in an inhomogeneous manner, that is, coexistence of relatively large and fine recrystallized grains. This microstructure contains a high volume of special grain boundaries ended to the complete and homogenous recrystallization at 1050 C, where further grain growth is occurred with increasing time. Texture analysis shows the retaining of Goss texture after annealing at 850 C and this component is introduced as the main reason for retarding recrystallization and, therefore, creation of inhomogeneous microstructure. Finally, the specimens processed at 1050 C indicate the α-fiber texture due to occurrence of grain growth. The mechanical properties improvement is mainly attributed to the development of S component and also formation of high fraction of annealing twin. Although, predominant the appearance of Goss texture and grain growth are also known as the main reason for deteriorating strength.

Substructure Development and Deformation Twinning Stimulation through Regulating the Processing Path during Multi‐Axial Forging of Twinning Induced Plasticity Steel

“…As is reported in Table , during conventional rolling the dislocation slip accommodates the strain at lower strains and at higher strains twinning becomes the predominant deformation mechanism. According to the previous researches, the deformation twinning would be suppressed at 60% reduction during rolling and the further strains are accommodated by shear bands without any contribution of twinning and slip . The deformation mechanism in severe plastic deformation processes such as HPT is quite different from rolling condition.…”

“…Therefore, deformation twinning and substructure development both contribute in strain hardening during the 3rd compression. It is worth mentioning that the previous works regarding the deformation behavior of TWIP steels through cold rolling, high pressure torsion, and equi‐channel angular pressing all reported the suppression of twinning at the early stage of processing; these are summarized in Table .…”

“…As is seen in Figure f, after one MAF pass the initial texture components distributions are reassembled to the new deformation texture. The most of researches on the deformation textures of low SFE TWIP steels subjected to the cold working, reported the formation of specified fibers texture . However, the new fiber texture in the ODF section is obtained after one MAF pass which is formed by the high intensity of the E {111} <011> and the Cube {001} <100> components.…”

The Correlation of Macrostructure, Microstructure, and Texture with Room Temperature Mechanical Properties of a Twinning‐Induced Plasticity Automotive Steel after Friction Stir Spot Welding/Processing

“…Deformation twinning strongly depends on grain size and orientations, and more attention should be paid to microstructure and texture evolution caused by the severe deformation and plastic dissipation during FSSW/P of TWIP steel. Bimodal grain structures obtained during FSSW/P exhibit superior combination of strength and ductility through high work hardening capacity of coarse grains along with the strengthening ability of fine grains.…”