In situ EBSD observation of grain boundary character distribution evolution during thermomechanical process used for grain boundary engineering of 304 austenitic stainless steel

Application of Grain Boundary Engineering to Improve Intergranular Corrosion Resistance in a Fe–Cr–Mn–Mo–N High-Nitrogen and Nickel-Free Austenitic Stainless Steel

“…As a new method to improve IGC resistance, GBE has been applied in 304 ASS [3,5], 316 ASS [4], Alloy 690 [7], high-nitrogen ASS [9], etc. Although the GBCD optimization mechanism induced by annealing twins (ATs) is still a debatable point, most of the researchers agreed that the grain clusters [7,9,34] or twin-related domains (TRD) [35,36] are a basic feature of GBCD optimization. The higher the f SBs is, the larger the size of the grain cluster is (Fig.…”

“…Therefore, totally speaking, the SFE of Fe-20Cr-19Mn-2Mo-0.82 N steel should be much higher than that of Fe-18Cr-18Mn-0.63 N. For this reason, in the present steel, a low strain deformation cannot provide a sufficient strain energy, and a much higher thermal energy is thus needed for GBCD optimization by prolonging the time of subsequent annealing process. The formation of ATs actually includes two parts, i.e., one part appearing in the grain cluster is induced by SFs in the early stage of recrystallization, and the other part is formed by impingement of the growing clusters during prolonging annealing time [9,34], which is the fundamental cause for the highest f SBs obtained by high-temperature and long-time annealing in the experimental steel.…”

“…Although the view or appearance of interruption of the random boundaries by low ∑CSL boundaries is consistent, the disconnection mechanism and interrupting effect of low ∑CSL boundaries were reported to be distinctive in different materials. Specifically, concerning the disconnection mechanism, Tokita et al [34] considered that disconnection of the random boundaries was achieved by the formation of the SBs through the impingement of the growing clusters during the thermo-mechanical process in the 304 ASS. In contrast, the research findings on the 304 ASS [3] and Fe-Cr-Mn-N ASS [9] demonstrated that the occurrence of annealing twins inside a grain cluster created the low-energy fragments of SBs in the random boundary network and the low-energy fragments interrupted the connectivity of the random boundaries.…”

“…The grain cluster is referred to such a grain encircled by the random boundary containing a large amount of SBs inside [7,9]. After GBCD optimization, the large-sized grain clusters become typical microstructures of the samples [5,7,9,34]. As seen in Fig.…”

Quasi in-situ analysis of geometrically necessary dislocation density in α-fibre and γ-fibre during static recrystallization in cold-rolled low-carbon Ti-V bearing microalloyed steel

“…With the advancement of hot stage Electron Back-Scattered Diffraction (EBSD) it is possible to study instantaneously the microstructural changes during annealing [12][13][14][15][16][17][18][19][20]. Kerisit et al studied microstructural evolution in Ta-alloy to evaluate nucleation rate, grain growth rate and grain boundary velocity by generating EBSD scans at certain time intervals during in-situ annealing [21].…”