南钢100tUHPEAF-LF(VD)-CC生产GCr15轴承钢的工艺实践

Practice of Process for Bearing Steel GCr15 Produced by 100t UHP EAF-LF(VD)-CC Flow Sheet at Nanjing Steel

南京钢铁公司采用100 t高阻抗超高功率电弧炉-100 t钢包精炼炉-5流150 mm×150 mm方坯连铸-连轧工艺生产GCr15轴承钢。GCr15轴承钢生产结果统计表明,通过炉料中配入55%～70%铁水,电弧炉出钢时碳含量0.22%～0.24%、磷含量0.004%～0.006%、硫含量0.040%～0.043%;精炼渣成分(%):53～58CaO、13～16SiO_2、15～20Al_2O_3、3～5MgO,碱度2.3～3.3;精炼时全程吹Ar搅拌,67 Pa VD处理≥20min,连铸全程保护浇铸,使真空处理后GCr15轴承钢平均氧含量为10×10^(-6),铸坯中最低氧含量为7×10^(-6)。

Bearing steel GCrl5 is produced by 100 t high impedance UHP EAF steelmaking - 100 t ladle furnace refining - 5 strand 150 mm × 150 mm billet coneasting - continuous rolling process at Nanjing Iron and Steel Co Ltd. The statistic results of bearing steel GCrI5 production data showed that with charging 55% - 70% hot metal, controlling end point carbon 0. 22% - 0.24% , phosphorus 0. 004% - 0. 006% and sulphur 0. 040% - 0. 043% in liquid steel at EAF tapping, ladle refining by slag （% ：53 -58CAO, 13 - 16SiO2, 15 -20Al2O3,3 -5MgO） with basicity 2. 3 -3. 3 and whole period Ar stirring, 67 Pa VD treating ≥20 min, eoncasting with shielding practice in whole period, the average oxygen content in bearing steel GCr15 after VD treatment was 10 × 10^-6, and the lowest oxygen content in cast billet was 7 × 10^-6.