Abstract: 200 mm x 200 mm cast bloom of tyre-cord steel 72A (% : 0. 71 ~ 0. 72C, 0. 50 〜0. 60Mn, 0. 22 〜 0. 30Si,≤0. 010P, ≤0. 008S) is melted by hot metal pretreatment-LD-LF-RH-CC process flow sheet. During casting in conditions of liquid overheat 10 ~20℃ , cast speed 0. 98 m/min, secondary cooling water ratio 0. 32 L/kg, mold cooling water rate 220 ^m3/h and mold electromagnetic stirring (EMS) with 1. 5 Hz and 500 A, the study of final mold electromagnetic stirring (F-EMS) process parameters are carried out. Results show that as the F-EMS is carried out at distance from liquid meniscus- 8 m with 18 Hz and 450 A, the central carbon segregation index of cast bloom of tire-cord steel 72A is ≤1.05.

Key words: Tyre-cord Steel 72A, Bloom Casting, Central Carbon Segregation, F-EMS

摘要： 帘线钢72A(%:0.71～0.72C、0.50～0.60Mn、0.22～0.30Si、≤0.010P、≤0.008S)的冶炼工艺流程为铁水预处理-LD-LF-RH-CC-200 mm×200 mm连铸。在连铸时钢水过热度10～20℃,拉速0.98 m/min,二冷比水量0.32 L/kg,结晶器冷却水220 m³/h,结晶器电磁搅拌1.5 Hz、500 A的条件下进行了末端电磁搅拌(F-EMS)的工艺研究。结果表明,当离钢液弯月面8 m处以18 Hz、450 A进行F-EMS,可使帘线钢72A铸坯的中心碳偏析指数≤1.05。

关键词: 帘线钢72A, 方坯连铸, 中心碳偏析, 末端电磁搅拌