高品质GCr15轴承钢80t转炉-钢包炉精炼渣的研究

A Study on 80 t Converter-Ladle Furnace Refining Slag for High Quality GCrl5 Bearing Steel Steelmaking

GCr15轴承钢的冶炼流程为80 t顶底复吹转炉-LF精炼-VD-180 mm×220 mm连铸工艺。研究了碱度3～8的CaO-SiO_2-Al_2O_3-CaF_2-MgO精炼渣系对高品质GCr15轴承钢(/%:0.95～1.05C、0.15～0.35Si、0.25～0.45Mn、1.40～1.65Cr、≤0.025P、≤0.025S、≤0.001 2[O])冶金质量的影响。生产结果表明,采用碱度5.8的精炼渣(/%:50～55CaO、6～12SiO_2、15Al_2O_3、10CaF_2、≤0.5FeO、≤8MgO)可有效地降低钢中氧含量和夹杂物,GCr15轴承钢的氧含量为(5～9)×10^(-6),平均氧含量为5.6×10^(-6),硫含量达0.005%～0.009%,夹杂物0～0.5级。

Steelmaking flow sheet for GCrl5 bearing steel is 80 t top and bottom combined blowing converter-LF refi- ning-VD-180 mm x 220 mm CC process. The effect of CaO-SiO2-A1203-CaF2-MgO refining slag series with basicity 3 -8 on metallurgy quality of high quality GCrl5 bearing steel （/% ： 0. 95 -1.05C, 0. 15 - O. 35Si, 0. 25 -0.45Mn, 1.40 1,65Cr, ≤0. 025P, ≤0. 025S, ≤0. 001 2[ O] ） is studied. Commercial production resuhs show that with using 5.8 ba- sicity refining slag （/% ： 50 -55CaO, 6 -12SiO2, 15A1203, 10CaF2, ≤0. 5FeO, ≤8MgO）, it is available to decrease the oxygen content and inclusions in steel, the oxygen content in GCrl5 bearing steel is （5 -9 ） × lO-6, average oxygen content is 5.6 × 10-6 , the sulphur content in steel is 0. 005% -0. 009%, and the rating of inclusion in steel is 0 -0. 5.