Abstract: The 1 mm deep cracks occured at surface of 80~95 mm square bars of 12Mn2VB non-quenching-tempering steel containing 0. 10%～0. 15% C produced by EBT EAF-LF steelmaking-650kg ingot casting with compound casting powder:16~20C,≥10Al₂O₃,35～40SiO₂,10~16CaO at Special Steel Co Lad,Benxi Iron and Steel,and the C cont- ent of surface at parts of an area was up to 0.62%.After using improved process -EBT EAF-LF steelmaking-3. 16t ingot casting with lower C content compound casting powder:≤12C,≥10Al₂O₃,35～40SiO₂,10～16CaO,the surface recarburization of rolled products obviously deceased which was available to control surface crack formation, therefore the yield of finished products increased to 82% from 74%.

Key words: Non-Quenching-Tempering Steel 12Mn2VB, Casting Powder, Surface Recarburization, Surface Crack

摘要： 本钢特钢采用EBTEAF LF冶炼 复合保护渣 (% :16～20C ,≥10Al₂O₃,35～40SiO₂ ,10～16CaO)浇注650 kg钢锭生产0.10 %～0.15 %C的 12Mn2VB非调质钢80～95mm方轧材时出现1mm深裂纹 ,钢材表面C含量局部高达0.62 %。在采用EBTEAF LF冶炼 降低渣中C含量的复合保护渣 (% :≤ 12C ,≥ 10Al₂O₃,35～40SiO₂ ,10～16CaO)浇注3.16t钢锭后 ,轧材表面增碳明显减小 ,有效控制表面裂纹的产生 ,成材率由 74 %提高到 82 %。

关键词: 12Mn2VB非调质钢, 保护渣, 表面增碳, 表面裂纹