Microstructure, texture and precipitates of grain-oriented silicon steel produced by thin slab casting and rolling process

Abstract

A grain-oriented silicon steel strip with AlN as main inhibitor was produced by thin slab casting and rolling (TSCR) process. The microstructure, texture and precipitates of the hot-rolled strip were investigated by use of optical microscope (OM), X-ray diffractometer, transmission electron microscope (TEM) and energy dispersive spectroscope (EDS). The result shows that the microstructure and texture exhibit a through-thickness gradient similar to that of the hot-rolled strip produced by conventional high-temperature slab-reheating process; the preferred orientation varies from {110} <001> in the surface layer to {001} <110> in the center layer, and the Goss texture with a maximum intensity mainly concentrates on the surface layer. In addition, some other texture components, for example rotated Goss texture, form in the 1/4 thickness layer, which are not observed in the hot-rolled strip produced by conventional high-temperature slab-reheating process. The precipitates in the hot-rolled strip are mainly (Mn, Cu)S and AlN compound particles with dimension of 100 — 200 nm, and the fine precipitates are significantly less than that in the hot-rolled strip produced by conventional high-temperature slab-reheating process. Moreover, the areal density of the fine precipitates in the center layer is more than that in the surface layer.