常化温度对2.5%Si无取向硅钢第二相析出行为的影响

采用扫描电镜、透射电镜和双束扫描电镜对不同常化温度2.5%Si无取向硅钢中不同类型第二相析出物的析出行为和演化规律进行了研究。结果表明，常化温度从850℃升高至1100℃,微米级大尺度第二相粒子呈一次长大-析出-二次长大-回溶的变化规律；当常化温度<920℃时，析出相以AlN+MnS复合长大为主；随后小尺寸的MnS、AlN及其复合析出物数量迅速增多，并在950℃时达到峰值；随着常化温度的进一步升高，第二相粒子析出数量快速减少，然后缓慢增长至趋于平衡，大尺寸析出物出现部分回溶。纳米级析出物则以Cu₂S和Cu₂S+MnS复合析出为主。并且950℃常化时，2.5%Si无取向硅钢的铁损最低。

Effect of normalizing temperature on precipitation behavior of second phase in 2.5%Si non-oriented silicon steel

Precipitation behavior and evolution law of second-phase precipitates in high-grade non-oriented silicon steel with content of 2.5% silicon normalized at different temperatures were investigated by means of scanning electron microscopy, transmission electron microscopy and focused ion beam scanning electron microscopy. The results show that as the normalizing temperature increases from 850 ℃ to 1100 ℃, the micron-scale second-phase particles show the order of primary growth-precipitation-secondary growth-dissolution; When the normalizing temperature is lower than 920 ℃, the composite growth of AlN+MnS is dominant; then the number of small-sized MnS, AlN and their composite precipitates increases rapidly, reaching a peak at 950 ℃; When the normalizing temperature is further increased, the number of second-phase particles decreases rapidly and then slowly increases to equilibrium, and the large-size precipitates appear to partially dissolve. The nano-scale precipitates are mainly Cu₂S and Cu₂S+MnS composite precipitation. And when normalized at 950 ℃, 2.5%Si non-oriented silicon steel has the lowest iron loss.