Abstract: The production flowsheet of pilot-produced steel 80MnCr (/%: 0.79~0.81C, 0.92~0.97Mn, 0.26~0.32Si, 0.009~0.017P, ≤0.005S, 0.92~0.97Cr, 0.06Mo, 0.03~0.05Ti, 0.027~0.032Al, 0.0004~0.0012O) is BF-70t BOF-LF-VD-Φ450mm Round bloom casting-rolling to Φ90mm bar. With the process measures including controlling BOF end [P]≤0.015% and end [C]≥0.12% , pre-deoxidizing with 1.5kg/t steel cored aluminium at tapping, deoxidation by feeding aluminium wire in LF, refining slag basicity N4, after VD feeding calcium wire, mold-EMS and end-EMS in casting, the rating units of inclusions in steel are heavy series 0 and thin series ≤0.5, the rating of macrostructure are central porosity ≤1.5, general porosity ≤0.5, central segregation ≤0.5 and ingot square-segregation zone 0； and the qualified rate of steel products by ultrasonic nondestructive measuring is up to 93.07%.

Key words: 80MnCr Steel for Grinding Ball, 70t BOF-LF-VD-CC Flowsheet, Macrostructure, Nonmetallic Inclusions, Ultrasonic Detection

摘要： 试制的80MnCr钢（/%:0.79~0.81C,0.92~0.97Mn,0.26~0.32Si,0.009~0.017P,≤0.005S,0.92~0.97Cr,0.06Mo,0.03~0.05Ti,0.027~0.032Al,0.00040~0012O）的生产流程为BF-70t BOF-LF-VD-Φ450mm圆坯连铸-Φ90mm棒材轧制。通过控制BOF终点[P]≤0.015%,终点[C]≥0.12%,出钢用1.5kg/t钢芯铝预脱氧、LF喂铝线脱氧,精炼渣碱度≥4,VD后喂钙线,连铸结晶器和末端电磁搅拌等工艺措施,钢中非金属夹杂物级别为:粗系0、细系≤0.5;低倍组织级别为:中心疏松≤1.5、一般疏松≤0.5、中心偏析≤0.5、锭型偏析0;钢材经超声波无损探伤检测,合格率达93.07%。

关键词: 80MnCr磨球钢, 70t BOF-LF-VD-CC流程, 低倍组织, 非金属夹杂, 超声波探伤