低温取向硅钢初次再结晶动力学模型及织构演变

研究了低温取向硅钢在625~850℃的等温退火过程,根据Avrami方程建立了其初次再结晶动力学模型,并利用EBSD技术对初次再结晶织构演变过程进行了分析。结果表明:当退火温度为850℃时保温5s即可发生完全再结晶;而在625℃下保温1.7h以上再结晶才能进行完全。当退火温度在625~700℃时,Avrami指数n在0.82~0.89之间,当退火温度在750~850℃时,n值在1.25~1.27之间,相对应的再结晶激活能QRX分别为239.3、160.4kJ/mol。初次再结晶早期主要发生在高储存能的γ纤维织构上,而中后期则主要发生在低储存能的α纤维织构上。初次再结晶完成后织构类型主要是以{111}112组分为主的γ织构、{114}418织构及少量分布在次表层的Goss织构。

Primary recrystallization kinetics and texture evolution during annealing of low temperature grain-oriented silicon steel

The isothermal annealing process of low temperature oriented silicon steel was studied at 625 - 850℃ .The primary recrystallization kinetics model was established according to the Avrami equation,and the evolution of texture was investigated by EBSD technology.The results show that the primary recrystallization is completed at 850 ℃ for only 5 s,and more than 1.7 h at 625 ℃ .The value of the Avrami exponent n is in the range of 0.82 - 0.89 ,and the activation energy Q RX is 239.3 kJ/mol at 625 - 700 ℃ .The value of the Avrami exponent n is in the range of 1.25 - 1.27 ,and the activation energy Q RX is 160.4 kJ/mol at 750 - 850℃ .The primary recrystallization mainly occurs in γ fiber texture with high storage energy at the early stage, and occurs in αfiber texture with low storage energy at the later stage.After the primary recrystallization,the textures are mainly composed of {111 }< 112 > component,{114 }< 418 > component and a little amount of Goss component at the subsurface.