Causes of longitudinal surface cracks on wide continuous casting slab and control measures

In light of the actual conditions that longitudinal surface crack on the wide CC slab as well as the longitudinal crack on the rolled sheet products frequently occur in the wide continuous caster of the No.3 Steel-making Plant of Shaoguan Iron Steel Co.,Ltd.,the present paper analyzes the real causes to the formation of those defects.The longitudinal surface cracks on the slab have been improved significantly and the occurrence rate of the longitudinal surface crack on the slab is reduced to 0.46 % from original 4.98 % and the comprehensive qualified rate of the rolled stock raised to 99 % from 87.5 % since appropriate counter measures were taken in the plant.