控制高铝钢45CrAlMo中Al2O3夹杂的工艺实践

45CrAlMo钢（/%:0.40～0.50C,≤0.60Mn,0.15～0.45Si,1.30～1.70Cr,0.15～0.30Mo,0.85～1.20Al）的生产工艺流程为60 t EAF-LF-VD-氩气保护浇铸2.1 t锭-锻成120 mm×120 mm材。分析了电弧炉冶炼和LF精炼过程脱氧,VD脱气、浇铸过程的工艺参数对钢中氧含量和Al₂O₃夹杂的影响。通过将LF终点S含量从≤0.015%降至0.008%,喂铝线改成加铝锭、VD真空度从100 Pa降至67 Pa,加CaSi改成不进行Ca处理,浇铸温度从1 585～1 595℃降至1 570～1 580℃等工艺措施,消除了低倍点状夹杂,B类和D类夹杂分别从1.5级降至0.5级,探伤合格率从67%提高到98%,成材率由55%提高到68%。

Process Practice to Control Al2O3 Inclusions in High Aluminium Steel 45CrAlMo

The production process flowsheet of steel 45CrAlMo (/% : 0. 40 - 0.50C, ≤ 0.60Mn, 0.15 - 0.45Si, 1.30 ~ 1. 70Cr, 0.15 ~ 0. 30Mo, 0. 85 ~ 1.20Al) is 60 t EAF-LF-VD-argon shielding casting 2. 1 t ingot-forged to 120 mm x 120 mm products. The eSect of parameters of deoxidation in EAF steelmaking and LF refining process, VD degassing and continuous casting process on oxygen content and Al₂O₃ inclusions in steel has been analyzed. With the process measures including decreasing S content in liquid at end LF from original <0, 015% to 0. 008% , modifying feeding aluminium wire to adding aluminium ingot, decreasing VD vacuum from 100 Pa to 67 Pa, modifying adding CaSi to non calcium treatment and decreasing casting temperature of liquid from original 1 585 ~ 1 595℃ to 1 570 - 1 580 °C , the macro inclusions are eliminated, the B series and D series inclusions in steel decrease respectively from rating 1. 5 to rating 0. 5, the ratio of nondestructive-testing qualified steel increases from 67% to 98% and the yield of products increases from 55% to 68%.