Abstract: In this paper, the causes and control measures of laminar defects in rolled steel during ingot rolling in Wuyang Iron and Steel Works are studied. The results show that cluster Al2O3 inclusions with a size of more than 80 μm in the middle zone along the thickness direction of the plate and inclusions formed by the inclusions involved in the mold flux are the main reasons for the unqualified ultrasonic flaw detection. Based on this, a scheme to solve the laminar defect of ingot tail part is proposed: adopting sequential deoxidization method, implementing soft argon blowing system, and implementing protective casting；optimizing the physical and chemical properties of mold powder to prevent its involvement. Through the above measures, the laminar defects of ingot tail decreased from 3.5 % to 1.5 %.

Key words: laminar defect；tail of ingot；inclusion, mould powder