高磁感取向硅钢中AIN的析出研究

A Study on Precipitation of AIN in High Magnetic Induction Oriented Silicon Steel

通过热力学和动力学计算相结合的方法,系统地分析了高磁感取向硅钢中AlN在均热过程中的析出机制。计算结果表明,在高磁感取向硅钢的均热温度下,AlN处在α+γ两相区,同时具备热力学析出条件。在均匀形核、晶界形核和位错形核3种机制下,AlN的临界形核尺寸处在同一数量级且随温度降低而减小。相同温度下,AlN晶界形核的临界形核功最小,相对形核率最大,即较易发生晶界形核。AlN在α相和γ相中均匀形核、晶界形核和位错形核的最快析出温度分别为1203 K、1303 K、1243 K和1213 K、1305 K、1233 K。AlN在均热温度下以晶界形核为主。

The precipitation mechanism of AlN in high magnetic induction oriented silicon steel during the soaking process is systematically analyzed by the method of combining thermodynamics and kinetic calculations.The calculation results show that,at the soaking temperature of high magnetic induction oriented silicon steel,AIN in the α+γ two-phase and has the thermodynamic precipitation conditions.With uniform nucleation,grain boundary nucleation and dislocation nucleation three kinds of mechanisms,the critical nucleation size of AlN is in the same order of magnitude and decreases with decreasing temperature.At the same temperature,the critical nucleation work of AlN grain boundary nucleation is the smallest and the relative nucleation rate is the largest,that is,grain boundary nucleation is easier to occur.The fastest precipitation temperatures for uniform nucleation,grain boundary nucleation and dislocation nucleation of AlN in a phase andγ phase are 1 203 K,1 303 K,1 243 K and 1 213 K,1 305 K,1 233 K,respectively.AlN mainly nucleates at grain boundaries at soaking temperature.