Study of the Texture Formation during Strain Induced Boundary Migration in Electrical Steel Sheets

Abstract

Texture formation through strain induced boundary migration (SIBM) was investigated. Temper rolling reduction before final annealing for SIBM was varied between 0 and 26% and grain sizes and textures were measured using EBSD. In the specimen which was temper rolled to 5%, in which grain growth by SIBM occurred most efficiently, a strong Goss component (which was a minor component after rolling), developed during annealing. From the EBSD image quality analysis, it was found that stored energy increased significantly in the Goss component with strain (from 5 to 9 %), whereas it was always relatively small in the D-Cube component ({001}<110>), compared to Goss and g-fibre components. Based on these results, a mechanism of grain growth by SIBM was suggested. Texture evolution during annealing could thus be explained by the hypothesis, speculated from the analysis of orientation stability, that D-Cube grains are associated with more homogeneous dislocations distributions than Goss grains, in which the co-existence of high and low dislocation density zones could favour grain growth by SIBM.

Microstructure and its stability at elevated temperature in friction stir seam welded dissimilar joints of 5083 and 6061 aluminium alloy plates

“…The migration speed of the grain boundary is for example a function of the grain boundary structure 9 , and, when the structural conditions continue to be satisfied within which grain boundary whose migration speed is as high as that of the coincidence boundary exists with only specific grain, this is considered to be the cause of the anomalous grain growth of the Goss orientated grains of silicon steel sheets 10 . The histological factors which induce spatial heterogeneity of the grain boundary migration speed are not just this distribution of grain boundary structure but they are thought to include difference in grain diameter 11 , composition gradient 12 , pinning 13 owing to precipitation, and difference in dislocation 14 .…”

Effect of Tensile Deformation on the Grain Size of Annealed Grain Non-Oriented Electrical Steel

“…The driving force for this kind of recrystallization is the difference in stored energy between two neighboring grains and also depends on the differences in grain orientations [2,3]. The stored energy due to small deformations is insufficient to produce nucleation of new recrystallized grains and only the grains with the lowest stored energy grow at the expense of grains with higher stored energy [6,9]. As shown in Fig.…”

“…The recrystallized grain size varies with deformation before the final annealing treatment [6,7]. However, there exists a critical deformation which produces the coarsest grain size after annealing.…”

Improved Processing Technique for Preparation of Non-Oriented Electrical Steels with Low Coercivity

“…During the annealing a deformation induced grain growth and elimination of residual stresses take place [2,3]. The nal annealing of this steel, according to the norm which is used in industrial conditions, has some disadvantages from the point of view of deformation-induced grain growth.…”