Structure of ⟨110⟩ Fiber Texture in the Mid-thickness of Hot-rolled Silicon Steel Sheet

Abstract

In an attempt to clarify the structure of the 〈110〉 fiber texture in the central area of a hot-rolled silicon steel sheet, computer color mapping was performed with an image analyzer by using the orientation and strain data measured by a Kossel examination. The results are summarized as follows:(1) The central area of the hot-rolled silicon steel sheet was composed of grains elongated in the rolling direction, and had 〈110〉 fiber textures of {100}〈011〉, {100}〈001〉, near {113}〈110〉, and near {223}〈142〉 orientations. In this area, no {110}〈001〉 grains were formed.(2) In all the elongated grains, strain existed inside the grains. Among them, the elongated {100}〈011〉 and {100}〈001〉 grains had a small amount of strain and a low lattice curvature (within 10°) in the same grain, whereas those of near {113}〈110〉 and near {223}〈142〉 grains had a large amount of strain and a high lattice curvature (max. 30°).(3) This result is consistent with many previous experimental results for cold rolling and recrystallization with single crystals of silicon steel.(4) Most of the elongated grains had high-angle grain boundaries displayed with a boundary width of 3 pixels, where the deviation angles of mutual grains were more than 25°.(5) An alternate formation of {100}〈011〉 or {100}〈001〉 and near {112}∼{111}〈110〉 elongated grains occurred during the processes from slab heating to hot rolling. Thus, the energy decrease due to this alternate formation of elongated grains with these orientations played a more important role in the development of (110) [001] secondary grains than the energy increase due to the formation of high-angle grain boundaries. This alternate formation is indispensable for developing (110) [100] secondary grains in the processes up to secondary recystallization after hot rolling.