Abstract: With using 50 t EAF-LF(VD)-CC-slow cooling pross, controlling EAF end [C] 0.12%-0.25% and end [P]≤ 0.015%, pre-deoxidizing and alloying in tapping, using CaO-Al₂O₃ free fluorine pre-melting refining slag, and integrate casting control technology including 19 t tundish with liquid depth ≥ 800 mm, casting speed 0.35-0.45 m/min, liquid overheating extend 15-25 T , optimum secondary cooling schedule and F-EMS parameter (350 A/8 Hz) etc. for steel 4130 (/% ： 0.29-0.31C, 0.25-0.28Si, 0.51-0.54Mn, 0.96-0.98Cr, 0.19-0.20Mo,0.016-0.025A1) Φ350 mm casting round bloom the [O] and [N] are respectively (12-16) x 10^-6 and (55-70) X 10^-6, the rating of macrostructure ≤ 1.0, and in forged bar the rating of nonmetallic inclusion A and B ≤ 1.0, C and D ≤ 0.5 , the rating of ultrasonic detection, dimension tolerance and surface quality of forgings all meet the requirement of user.

Key words: 50 t EAF-LF (VD) -CC Flow Sheet, Steel 4130, Round Bloom, Production Practice

摘要： 采用50 t EAF-LF(VD)-CC-缓冷工艺,通过控制电弧炉终点[C]0.12%~0.25%,终点[P]≤0.015%,出钢预脱氧和合金化,LF精炼时采用CaO-Al₂O₃系无氟预熔精炼渣,以及连铸综合铸坯控制技术包括钢水深度≥800 mm 19 t中间包,控制拉速0.35~0.45 m/min,钢水过热度15~25℃,优化二冷制度和末端电磁搅拌参数(350 A/8 Hz)等工艺措施,所生产的4130钢(/%:0.29~0.31C、0.25~0.28Si、0.51~0.54Mn、0.96~0.98Cr、0.19~0.20Mo、0.016~0.025A1)Φ350 mm连铸圆坯的[O]、[N]分别为(12~14)×10^-6、(55~70)×10^-6,低倍组织≤1.0级,锻件的非金属夹杂物A、B≤1.0级、C、D≤0.5级,锻件超声波探伤级别、尺寸公差及表面质量等质量指标均满足用户要求。

关键词: 50tEAF-LF(VD)-CC流程, 4130钢, 圆坯, 生产实践