宽厚板边部黑线缺陷分析与控制

针对包钢宽厚板边部黑线缺陷进行了分析研究，通过坯角钻坑跟踪轧制试验表明钢板边部黑线是由铸坯角部在轧制过程中折叠产生。过程控制分析与实践表明，通过减小出加热炉后铸坯上下表面温差，可减少该缺陷向钢板内部延伸的程度，减小初轧到精轧之间的钢板边部与内部的温差，可提高精轧过程对边部黑线的焊合效果。对铸坯角部进行处理，使铸坯角部接近弧形，可减轻该缺陷的产生。同时可根据产品规格合理安排投料铸坯断面，尽可能将展宽比设计到最低，以达到通过正常钢板切边量将钢板边部黑线缺陷切除的目的。

Analysis and control of black line defect on the edge of wide and heavy plate

In this paper， the black line defect at the edge of the thick and heavy plate is analyzed and studied. The results of the drill hole on the slab corner and tracking rolling test show that the black line at the edge of the plate is folded by the angle of the slab during the rolling process. Process control analysis and practice show that by reducing the temperature difference between the top and bottom surface of the slab， can reduce the degree of defects extending to the plate internal， reduce the temperature difference and the ministry of interior to the blooming mill between the plate edge， can improve the bonding effect of rolling process on edge black line. The angle of the casting slab is processed so that the angle of the casting slab is close to the arc， and the defect can be reduced. Meanwhile， according to the product specification， reasonable arranged the slab section，broadening ratio can be designed to a minimum as far as possible，in order to removed the defect by the normal steel plate edge trimming.