Abstract: It is obtained by analysis that the edge cracks occur during bending and straightening of strip due to 70 mm thin slab horizontal plane non-homogeneous cooling and edge over-cooling during production of SS400 steel strip Coil with irrational secondary cooling water rate led to precipitation of AIN in austenite and grain boundary britle. The high-quality product rate of SS400 steel strip coil increased from 92.27% to 98.09% by improved technology measure including to control Al_S content 0.02%～0.03% in steel, decrease nitrogen pick-up during concasting and secondary cooling water rate at plate slab edge.

摘要： 经分析得出涟钢采用CSP工艺生产SS400钢板卷时,因不合理的二冷水量使70 mm薄板坯横向冷却不均匀和角部过冷,导致奥氏体中AlN析出造成晶界脆性,带钢在弯曲和矫直时产生边裂。通过控制钢中Al₂含量为0．02％～0．03％及减少连铸过程吸氮和降低板坯边缘二冷水量等工艺措施,使SS400钢板卷的优等品率从92．27％提高到98．09％。

关键词: 薄板坯, 热轧板卷, 边 裂 , 控制工艺