Texture and microstructure evolution during different rolling methods in strip-cast grain-oriented 6.5% Si steel

Abstract

Grain-oriented 6.5% Si steel was produced by strip casting and the effect of warm rolling and cold rolling at the latter stage of rolling was investigated. The result showed the rolling method had a minor influence on the rolling microstructure but significant on the rolling texture. Compared to the cold-rolled sheet, the warm-rolled steel showed strong α-fiber and γ-fiber texture at the surface but weak α-fiber and γ-fiber texture in the center layer. After primary annealing, the warm-rolled sheet showed inhomogeneous microstructure and strong {223}〈110〉 texture together with weak γ-fiber texture. By comparison, the cold-rolled sheet showed fine equiaxed grain with favorable {111}〈112〉 texture component. During secondary annealing, the warm-rolled sample displayed significantly normal grain growth at the initial stage and abnormal grain growth at ~1150 °C. The final microstructure was characterized by coarse matrix grains and abnormal Goss grain. In contrast, the cold-rolled sheet showed complete abnormal grain growth. The different secondary annealing behavior was attributed to different grain structure and texture.