Abstract: Abstract The production process flowsheet of steel C38N2 (/% : 0. 36 ~0. 40C, 0. 50 ~0. 65Si, 1. 40 ~ 1. 55Mn, ≤0.025P, 0.010 ~ 0.040S, 0. 10 ~0.25Cr, ≤0.01A1, 0.015 ~ 0.020N) is 120 t-BOF-LF-RH-410 mm x 530 mm bloom casting-continuous rolling to ϕ170 mm products. The statistics of effect of refining slag basicity (2.0 ~2.5) , Ca content in finished steel (0 ~ 0. 075% ) , tundish shielding agent basicity (5. 94 and 1. 70) , secondary cooling water (0. 14 ~0. 24 L/kg) and mould electromagnetic stirring current (250 A and 100 A) on sulfide in steel has been analyzed. With process measures including using 2 ~3 low basicity slag in refining, controlling [ Ca]/[ S] > 0. 03, using tundish shielding agent basicity 1.70, secondary cooling water rate 0. 24 L/kg and mould electromagnetic stirring current 100 A, the ratio of rating ≤2. 5 of A-thin series sulfide in steel increases from 80% before process improvement to 95% , and the fine, dispersed distributed spheroidal and spindle-shaped sulfide in steel increases markedly.

摘要：  C38N2 钢( /% ：0. 36 ~ 0.40C, 0.50 ~0.65Si, l. 40 ~ 1.55Mn, ≤0.025P，0.010 ~0. 040S, 0. 10 ~0.25Cr, ≤ 0.01Al, 0.015 ~ 0. 020N)的生产工艺流程为120 t BOF-LF-RH-410 mm x530 mm连铸坯-连轧成ϕ170 mm材。统计分 析了精炼渣碱度(2. 0 ~ 5.5)、成品钢中Ca含量(0 ~ 0. 075% )、中间包覆盖剂碱度(5. 94和1. 70)、二冷水(0. 14 ~ 0.24 L/kg)和结晶器搅拌电流(250 A和100 A)对钢中硫化物的影响，通过釆用2 ~ 3低碱度精炼渣，控制[Ca]/ [S] >0.03,使用1.70碱度中间包覆盖剂,二冷水0. 24 L/kg,结晶器搅拌电流100 A等工艺措施,使钢中A类细系硫化物≤2.5级的比率从工艺改进前80%提高至95%, 钢中小尺寸、弥散分布的球形或纺锤形硫化物明显增多。

关键词: 含硫易切削钢, C38N2, MnS, 钙处理, 形态控制, 二冷水, 结晶器电磁搅拌