Reasons and solutions for cracked edges of packaging steel strips

1) Defect features: transverse cracks on the edge of the packaging steel strip. Its length varies, resembling a zigzag shape, and mainly appears in steel grades with poor plasticity, such as alloy steel, high-carbon steel, silicon steel, and second-rolled thin packaging steel strips.
　　（2）Causes
　　①The tearing phenomenon of the edge metal of the packaging steel strip under tension rolling conditions.
　　②The plasticity of the packaging steel belt is poor, the reduction ratio is large, and the reduction of each pass is uneven.
　　③The local work hardening of the packaging steel strip is severe.
　　④The cutting quality of the edges of the packaging steel strip after pickling is poor, with large burrs.
　　 (3) Prevention and elimination methods
　　①Choose a reasonable reduction ratio, and reasonably distribute the reduction of each pass. Increase the reduction of the opening pass.
　　②Improve the shear quality after pickling, and trim the edges before the second rolling.
　　(4) Inspection and judgment
　　① Check with the naked eye and measure the length with a tape measure.
　　② The crack on the edge of the packaging steel strip shall not be greater than half of the allowable width deviation, and the width dimension specified in the contract shall be guaranteed.
　　③The board with cracks can be delivered by changing the ruler.