Abstract: With the process measures including KR pre-sulphurizing hot metal [S] ≤0.008% , to increase BOF preoxidizing adding aluminium amount from 0.010%-0.025% to 0.020%-0.035% , to increase adding Fe-Ca wire from 3.0 m/t to 4.0 m/t, LF refining time ≥35 min and white slag time ≥15 min , improving tundish structure, controlling temperature of liquid in tundish 1520-1540 ℃., increasing M-EMS current from 160 A to 200 A, improving fog cooling process in secondary cooling zone and controlling casting speed 2.2-2.4 m/min, the carbon segregation index of produced 160 mm x 160 mm casting billet of cold-heading steel SWRCH35K (/% : 0.29-0.31C, 0.07-0.llSi, 0.69-0.71Mn, 0.009-0.010P, 0.008S, 0.038-0.041 Al) is ≤1.06, and the structure of Φ6.5-20 mm hot-rolled coil is P + F, the die attritions wear rate of ≥8.8 class standard products manufactured by the coil without annealing is only about 8. 5%.

Key words: 120 t BOF-Argon Blowing-LF-CC Flowsheet, Cold-Heading Steel SWRCH35K, Coil, Refining Slag, Tundish Structure, Inclusion, Metallurgical Quality

摘要： 过KR铁水预脱硫[S]≤0.008%,BOF预脱氧加铝量由0.010%~0.025%提高到0.020%~0.035%,LF精炼时加Fe-Ca丝由3.0 m/t增至4.0 m/t,LF精炼时间≥35 min,白渣≥15 min,改进中间包结构,控制中间包钢水温度1520~1540℃,M-EMS电流由160 A提高至200 A,改善二次段喷雾冷却,控制拉速2.2~2.4m/min等工艺措施,生产的SWRCH35K冷镦钢（/%:0.29~0.31C，0.07~0.11Si，0.69~0.71Mn，0.009~0.010P，0.008S，0.038~0.041A1）160 mm×160 mm铸坯的碳偏析指数≤1.06,Φ6.5~20 mm热轧盘条组织为P+F,用其生产的8.8级及以上的标准件,免退火后模具损耗率仅约为8.5%。

关键词: 120 t BOF-吹氩-LF-CC流程, SWRCH35K冷镦钢, 盘条, 精炼渣, 中间包结构, 夹杂物, 冶金质量