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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} in the surface layer to {001} 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.

Using a Thermecmastor-Z hot simulator, dynamic recrystallization (DRX) and static recrystallization (SRX) behavior of a Nb-microalloyed steel was investigated by single-hit compression tests and double-hit compression tests, respectively. The experimental results show that DRX will more easily occur at higher deformation temperature and lower strain rate. The deformation activation energy and stress exponent for the Nb-microalloyed steel are calculated to be 379.29 ± 23.56 kJ/mol and 5.76 in temperature range of 950 °C to 1100 °C by regression analysis, respectively. Furthermore, a semi-empirical model is developed to identify the peak stress and strain for DRX. It is found that SRX kinetics follows Avrami’s law, and the softening fraction predicted by the model agrees well with experimental results.