高级别焊丝钢磷硫控制工艺优化

Optimization of phosphorus and sulfur in high-grade welding wire steel production process

为了研究采用全三脱工艺KR铁水脱硫→脱磷转炉→脱碳转炉→RH精炼→板坯连铸工艺生产的高级别焊丝钢洁净度水平,进行了5炉工业试验。通过对冶炼过程系统取样分析,研究了钢中总氧含量变化、夹杂物的转变规律及机理。结果表明,转炉终点氧质量分数平均为610.2×10^(-6),进站钢水氧质量分数平均为484×10^(-6),加Al前氧质量分数为220×10^(-6),破空氧质量分数为4.6×10^(-6),整体控制较好。RH进站时夹杂物主要为MnO-SiO_2-Al_2O_3类复合夹杂,夹杂物大多为球形,其中有部分夹杂物尺寸超过20μm;RH破空后,中包至铸坯夹杂物均主要为Al_2O_3型夹杂物,同时含有少量的MgO-SiO_2类夹杂。

Five heats of industrial trials were performed to investigate the cleanliness of high level welding wire steel produced with hot metal after desulfurization and dephosphorization pretreatment.The variation of T.O contents and the transformation route and mechanism of inclusions in the steel were studied by system sampling during steelmaking processes.The results showed that the average oxygen mass fraction was 610.2× 10^（-6） at the converter end,484 × 10^（-6） at RH start,220 × 10^（-6） before adding aluminum alloy,4.6 × 10^（-6） at RH end,and the overall control was better.The inclusions were mainly MnO-SiO_2-Al_2O_3 at RH start,which shapes were mostly spherical,and the sizes of some inclusions were more than 20 μm.The inclusions were mainly Al_2O_3 inclusions and a little MgO-SiO_2 inclusions after RH treatment to slabs.