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

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.