包晶钢12Cr1MoVG小方坯表面凹陷原因及改进

SURFACE DEPRESSION CAUSES AND IMPROVEMENT OF PERITECTIC STEEL 12Cr1MoVG BILLET

包晶钢铸坯在凝固过程中线收缩和体积收缩大,裂纹敏感性强,铸坯质量不易控制。分析了河钢邯钢包晶钢12Cr1MoVG小方坯生产过程中铸坯表面凹陷形成的原因,并提出了改进措施。通过控制碳含量、优化包晶钢保护渣、提高拉速、降低结晶器水流量、优化足辊喷嘴等措施,包晶钢铸坯表面质量得到了明显改善,铸坯表面凹陷率由100%降低到5%以下,凹陷深度不大于1.5 mm的达标率100%。

The peritectic steel slab has large line shrinkage and volume shrinkage in the solidification process,strong crack sensitivity,which is difficult for quality control.This paper analyzes the causes of the surface depression of 12Cr1MoVG billet in the production process of HBIS Hansteel peritectic steel,and puts forward the improvement measures.By controlling the carbon content,optimizing the mold flux of peritectic steel,increasing the casting speed,reducing the water flow of mold,optimizing the foot roller nozzle and other measures,the surface quality of peritectic steel slab has been significantly improved,the concave rate of slab surface has been reduced from 100%to less than 5%,and the standard-reaching rate of depression depth less than 1.5mm is 100%.