70t BOF-LF-VD-CC-HR流程试制磨球钢80MnCr棒材的开发

Development of 80MnCr Steel Bar for Grinding Ball by70 t-BOF-LF-VD-CC-HR Flowsheet

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,0.0004~0.001 2O)的生产流程为BF-70 t BOF-LF-VD-Φ450 mm圆坯连铸-Φ90 mm棒材轧制。通过控制BOF终点[P]≤0.015%,终点[C]≥0.12%,出钢用1.5 kg/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%。

Abstract The production flowsheet of pilot-produced steel 80MnCr （/% ： 0. 79 - 0. 81C, O. 92 - 0. 97Mn, 0. 26 - O. 32Si, 0. 009 - 0. 017P, ≤0. 005S, 0. 92 - O. 97Cr, 0. 06Mo, O. 03 - 0. 05Ti, 0. 027 - 0. 032A1, 0.000 4 - 0.001 20） is BF-70 t BOF-LF-VD-450 mm Round bloom casting- rolling to qb90 mm bar. With the process measures including con- trolling BOF end [ P] ≤0. 015% and end [ C] 〉0. 12%, pre-deoxidizing with 1.5 kg/t steel cored aluminium at tapping, deoxidation by feeding aluminium wire in LF, refining slag basicity t〉4, 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 macro- structure 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%.