取向硅钢夹杂物控制

Inclusion control of oriented silicon steel

取向硅钢夹杂物的类型、含量和尺寸对磁性能有重要影响,针对在转炉出钢过程加入硅铁进行合金化的工艺,在转炉出钢、RH精炼全过程取样,对钢中的夹杂物进行了分析。转炉出钢脱氧合金化后形成的夹杂物主要是氧化铝和硅酸铝,尺寸约为20μm。保持RH炉渣碱度为1.4~1.6,使炉渣处于低熔点区。RH处理后钢中全氧质量分数平均值降低到0.001 2%。取向硅钢热轧板中夹杂物主要为凝固过程中析出的MnS,MnS与Al2O3的球状或短棒状的复合夹杂物,尺寸为1~2μm,对磁性能影响较小。

Different types,contents and sizes of the inclusions in oriented silicon steel have an important influence on magnetic properties.According to the alloying process of adding ferrosilicon during tapping,steel samples are taken after tapping and in the whole process of RH refining to analyze the inclusion.After deoxidizing and alloying,inclusions are mainly alumina and aluminosilicate,and the size is about 20μm.Alkalinity of RH slag was maintained to be between 1.4 and 1.6,and the slag was placed in the low melting point area.After RH treatment,the average total oxygen mass fraction in steel was reduced to 0.0012%.Inclusions in the hot rolled plate of oriented silicon steel are mainly the MnS precipitated out in the solidification process and the spherical or short rod-shaped composite inclusions of MnS and Al2 O3.The size is 1-2μm,which has little influence on the magnetic property.