100 t EAF-LF-RH-CC流程生产洁净管线钢的工艺实践

天津钢管公司X65等洁净管线钢的生产流程为100t UHP EAF-LF-RH-Φ310mm～Φ500 mm CC工艺通过电弧炉配加35%～40%铁水,控制Al消耗量1.85kg/t时渣量不低于22kg/t,控制精炼渣指数(CaO/SiO₂/Al₂O₃)0.18～0.32,RH喷粉脱硫,电弧炉终点[C]≥0.05%,熔清钢水磷含量≤0.005%,延长泡沫渣持续时间,RH高真空处理时间≥10min,钙处理后软搅拌10～15 min,使用高碱度中间包覆盖剂等措施可使10MnVNbMo等X65管线用无缝钢管的洁净度达≤0.001%S、≤0.008%P、≤75×10^-6 N、≤20×10^-6O、≤1.5×10^-6H。

Technology Practice for Clean Pipeline Steel Steelmaking by 100 t EAF-LF-RH-CC Flow Sheet

The production flow sheet for X65 etc. clean pipeline steel at Tianjin Pipe is 100 I UHP EAF-LF-RH- Φ310 ~Φ500 mm CC process. With using the process measures including charging 35% 〜40% hot metal in arc furnace, controlling slag amount no less than 22 kg/1 at Al consumption 1. 85 kg/t, controlling refining slag index ( CaO/SiO₂/ Al₂O₃) 0. 18 〜0. 32. RH powder injection for desulphurization, EAF end [C]≥0. 05%, phosphorus content in melting down liquid ≤0.005% , prolonging foaming slag maintaining time, RH high vacuum treated time ≥10 min, soft stirring for 10 ~ 15 min after calcium treatment and using high basicity shielding agent in tundish, the cleanliness of l0MnVNbMo etc seamless steel tube of X65 pipeline steel is ≤0. 001 %S, ≤0. 008% P, ≤75 x 10^-6 N, ≤20 x 10^-6O, and ≤l. 5 x 10^-6H.