不同RH脱氧方式对含铝电工钢的影响

Effect of RH deoxidization on aluminum-containing electrical steel

研究了RH脱氧方式(铝脱氧,先铝后硅;硅脱氧,先硅后铝)对含铝电工钢洁净度、渣成分、夹杂物演变及连铸过程的影响。2种脱氧方式下钢包顶渣的氧化性相似,热力学计算表明硅脱氧的顶渣对铝酸盐夹杂物的吸收能力强于铝脱氧渣。铝脱氧钢中夹杂主要为Al2O3-CaO-CaS复合氧化物,硅脱氧钢中夹杂物主要是Al2O3。2种脱氧方式下,热轧钢卷中的典型夹杂物都是AlN、MnS和复合铝酸盐。由于脱氧方式和钢中N、S含量的差异,铝脱氧热轧卷中夹杂物的含量是硅脱氧的2~3倍,这与理论的预测结果完全吻合。由于钢液中Ca含量不同,硅脱氧的钢水在CSP连铸过程中会引起中包塞棒上涨,因此建议在传统的连铸工艺中采用硅脱氧,在CSP工艺中采用铝脱氧。

The effects of RH deoxidization on cleanliness, ladle top slag, inclusion evolution and continuous casting of aluminum-containing electrical steel were studied. The oxidizability of top slag by two deoxidization methods are similar. The result of thermodynamic calculation indicates the capacity of Si-deoxidization slag to absorb aluminate inclusions is stronger than that of Al-deoxidization slag. Al2O3-CaO-CaS composites are the main inclusions in Al-deoxidized steel and Al2O3 is the main inclusion in Si-deoxidization steel. Typical inclusions in hot rolled coils under two different deoxidization methods both are AlN, MnS and composite aluminates. The amount of inclusions in Al-deoxidization hot rolled coils is about 2-3 times as much as that in Si-deoxidization hot rolled coils, which is in good agreement with the theoretical prediction. Because of different calcium contents in molten steel, during continuous casting of Si-deoxidization molten steel in CSP process, the tundish stopper will rise. It is suggested that Si-deoxidization should be used in traditional continuous casting process while Al-deoxidization should be used in CSP process.