低温热轧高磁感取向硅钢板常化组织及析出相研究

Microstructure and precipitate of low temperature hot rolled HGO silicon steel plate by normalizing

对低温热轧Fe-3%Si高磁感取向硅钢板不同温度常化处理后的组织及析出相进行了讨论和分析。结果表明,热轧板在950～1 120℃范围常化处理时组织无明显变化,为铁素体+珠光体,随常化温度的提高基体带状组织变窄且逐步消失,当常化温度为1 120℃时,钢板表层和次表层晶粒明显长大,晶粒的不均匀性增大。热轧板和常化板析出相是以AlN为主的复合相,主要由AlN+CuS或AlN+MnS+CuS构成,同时存在少量单一AlN,其中热轧板和950℃常化板析出相形态主要为不规则片状、条状,1 020℃和1 120℃常化板析出相形态主要为球状;3种常化工艺中以1 020℃常化析出相尺寸最小。常化加热温度为1 020℃和1 120℃时取向硅钢的平均磁性能分别达到P1.7/50=1.194 W.kg-1,B800=1.891 T和P1.7/50=1.002 W.kg-1,B800=1.912 T。

The microstructure and precipitate of low temperature hot rolled Fe-3 % Si high permeability grain oriented （HGO）silicon steel were investigated by normalizing at different temperatures. The results show that, after normalizing at 950-1 120 ℃ the microstructure of the hot rolled plate, mainly ferrites and pearlites has no obvious change. The band-like microstructure becomes narrow and disappears gradually with the normalization temperature increasing. When normalized at 1 120 ℃, the grains in the surface and sub-surface of the plate grow up obviously and become more inhomogeneous. The precipitates in hot rolled plates and normalized bands are composite with AIN being the main phase, such as A1N ＋ CuS or A1N ＋ MnS ＋ CuS and a few single A1N. The precipitates in the hot rolled plates and 950 ℃ normalized bands are in the shapes of irregularlly sheets or strips ,while the precipitates in the 1 020℃ and 1 120℃ normalized plates are sphere. Among the three normalizing processes,the precipitates in the 1 020 ℃ normalized plates are the smallest in size. When normalized at 1 020 ℃ and 1 120 ℃ ,the average magnetic properties of the oriented silicon steel are PL7/50 = 1. 194 W· kg^-l , B800 = 1. 891 T and P1.7/50 = 1. 002 W·kg^-1,B800 = 1. 912 T,respectively.