提高20CrMnTiH齿轮钢夹杂物合格率的工艺实践

Practice of Process for Increasing Ratio of Qualified 20CrMnTiH Gear Steel Products with Non-metallic Inclusion Examination

本钢特殊钢厂20CrMnTiH齿轮钢采用EAF(出钢量45t)-LF-CC工艺流程生产。通过控制电弧炉脱碳量≥0.25%C,保证脱碳速度0.02%C/min,出钢前加0.2%锰铁,使终点碳≥0.10%;电弧炉出钢加铝铁或硅钡钙铝3.0 kg/t_钢进行沉淀脱氧,LF加入3～5 kg/t_钢脱氧剂扩散脱氧,使(FeO)≤0.5%,钢包钢水浇铸前在0.1～0.3 MPa氩气压力镇静吹氩≥15min,使20CrMnTiH钢的夹杂物一次合格率从88.35%提高到92.49%。

20CrMnTiH gear steel is produced by EAF （tapping 45 t steel）-LF-CC process flow sheet at Special Steel Works, Bensteel. With controlling arc furnace liquid steel decarburizing amount ≥0. 25% C, insuring decarburizing rate 0. 02% C/min, adding 0. 2% manganese iron before tapping, end [C] ≥0. 10% , adding ferro-aluminium or Si-Ba-Ca-Al by 3.0 kg/t for killing, diffusion-deoxidizing by adding 3 - 5 kg/t deoxidant during LF refining, （FeO） ≤0. 5%, and before casting with 0. 1 -0. 3 MPa argon blowing ≥ 15 rain, the ratio of qualified 20CrMnTiH steel products with first inclusion examination increased to 92.49% from original 88.35%.