Abstract: The process flowsheet of gear steel 20CrMnTiH (/%: 0.17~0.23C, 0.80~1.20Mn, 0.17~0.37Si, 1.00~1.45Cr, 0.04~0.10Ti, ≤0.035S, ≤0.030P, ≤0,0020O) is desulphurized metal-120t BOF-LF-160mmx160mm billet casting- rolling to Φ20~45mm products. With process measures including aim controlling LF refining slag basicity 4.0~8.0, ( FeO) in slag ≤0.75% , [ Als] 0.020%~0.035% , LF white slag time ≥30min, calcium treatment and argon stirring, the 145 heats analysis results show that T[O] in steel is 0.0006%~0.0018% , and the 158 heats statistic results obtains that as Ca/Als =0.10~0.14, the rating of A, B and C thin series inclusions in steel is ≤2 and that of rating of heavy series is ≤1.5 , and the rating of Ds series inclusion in steel is ≤1.0, the metallurgical quality of gear steel 20CrMnTiH improves markedly.

摘要： 20CrMnTiH齿轮钢（/%:0.17~0.23C,0.80~1.20Mn,0.17~0.37Si,1.00~1.45Cr,0.04~0.10Ti,≤0.035S,≤0.030P,≤0.0020O）的工艺流程为脱硫铁水-120t BOF-LF-160mm×160mm坯连铸-轧制Φ20~45mm材。通过目标控制LF精炼渣碱度4.0~8.0,渣中（FeO）≤0.75%,[Als]0.020%~0.035%,LF白渣时间≥30 min等并经过Ca处理和吹氩搅拌等工艺措施,145炉分析结果表明,T[O]为0.0006%~0.0018%,158炉统计结果得出,当Ca/Als=0.10~0.14时,钢中非金属夹杂物A、B、C细系≤2.0级,粗系≤1.5级,Ds类≤1.0级,20CrMnTiH齿轮钢的冶金质量显著提高。

关键词: 20CrMnTiH齿轮钢, 120t BOF-LF 160mmx160mm坯CC流程, LF精炼渣碱度, 钢中氧含量 , 夹杂物, 应力裂纹