RH精炼脱氧方式对无取向硅钢氧化物夹杂演变的影响

Effects of RH Refining Deoxidation Method on Heredity of Oxide Inclusions in Non-oriented Si Steel

氧化物夹杂对无取向硅钢的电磁性能有显著影响,RH精炼的脱氧方式是影响氧化物夹杂形态的重要因素之一。结合工业化生产的1.45%Si-0.25%Al含铝硅钢,研究了Si、Al两种脱氧方式下,RH精炼过程中氧化物夹杂的行为及遗传变化规律。结果表明:在RH精炼结束时,采用Si脱氧试样的氧化物夹杂以Al-Si系氧化物为主,只有20%左右的Al-O单独结合,试样中Al-O、Al-Si-O和Al-Si-Mg(Ca)-O结合的氧化物占86.6%;采用Al脱氧试样的氧化物夹杂,则以Al系氧化物为主,没有发现Si系氧化物,试样中Al-O结合的氧化物占62.5%,其余分别为18.8%的Al-Mg-O、12.5%的Al-Mg-Mn-O和6.2%的Al-Mg-Ca-O。此外,在RH精炼脱氧之后,采用Si脱氧试样的氧化物夹杂数量高于采用Al脱氧方式,两者分别为5.11个/mm2和4.52个/mm2;而在随后的脱气过程中,前者的氧化物夹杂数量下降速度明显高于后者,并在RH精炼结束时分别达到1.75个/mm2和2.12个/mm2。此时,两种脱氧方式对应的氧化物平均尺寸均也达到最小,但前者的氧化物夹杂平均尺寸大于后者,分别为1.58μm和1.41μm,均大于脱碳结束时的氧化物夹杂平均尺寸1.34μm。

The electromagnetic properties of the non-oriented silicon steel sheets decrease significantly accout for oxide inclusions. RH refining deoxidation method significantly impacts the type and size of the oxide inclusions. Base on industrial 1.45% Si-0.25% Al silicon steel manufacture,the behavior and heredity of the oxide inclusions deoxidized by Si or Al are researched during the RH refining. The results show that the main oxides are Al-Si oxides with the Si deoxidation method after RH refining, only 20% oxides are Al-O, and the Al-O, Al-Si-O and Al-Si-Mg（Ca）-O oxide inclusions account for 86.6% of all the oxides; the main oxide inclusions are Al oxides and without Si oxide for Al deoxidation method, the Al-O oxide inclusions account for 62.5% of all the oxides, the rest are 18.8% Al-Mg-O, 12.5% Al-Mg-Mn-O and 6.2% Al-Mg-Ca-O. Moreover,the number of oxide inclusions for Si deoxidation method is larger than that for Al deoxidation method after the RH refining deoxidation, which are 5.11/mm2 and 4.52/mm2, respectively. The number of oxide inclusions with Si deoxidation method fall faster than the rate through the Al deoxidation method during the following pure degassing procedure, which are 1.75/mm2and2.12/mm2, respectively. Meanwhile, the average size of oxide inclusions for the two deoxidation method both reach the minimum value, and the size for Si deoxidation method is larger than that for Al deoxidation method, which are 1.58 μm and 1.41 μm, respectively. Both the size of oxide inclusions for Si or Al deoxidation method are larger than that 1.34 μm after RH refining decarburization.