Effects of RH Refining Deoxidation Method on the Non-metallic Inclusions in Non-oriented Si Steel Sheets Containing Al

The oxygen element is harmful to Si steel,and the RH refining deoxidation method has an important effects on oxygen concentration. Based on the industrial non-oriented Si steel containing Al,the effects of RH refining deoxidation method on non-metallic inclusions was investigated. The results show that the oxygen concentration in liquid steel from Si-Al deoxidation sequence method is higher that of AlSi deoxidation sequence method. The average yield of Si and Al for Si-Al deoxidation sequence method are 90.7% and 78.2%,respectively,and those for Al-Si deoxidation sequence method are 97.5% and 63.7%,respectively. The Si-Al deoxidation method is superior to the Al-Si deoxidation method in terms of Si and Al yields. Thus,from the viewpoint of controlling magnetic properties,Si-Al deoxidation sequence method is recommended. The major non-metallic inclusion is composite of MnS and Cu_xS generating from Si-Al deoxidation sequence,and individual Al N and complex Mn S and Al N inclusions dominate in Al-Si deoxidation sequence. Average inclusion sizes are 0.73 μm from Si-Al deoxidation sequence and 0.38 μm from Al-Si deoxidation sequence.