Wire Surface Defects - Folding

The surface of the wire along the rolling direction is straight or jagged unwelded gap, in the cross-section presents folding defects called folding, generally along the rolling direction is continuous or intermittent distribution. Folded sides are often accompanied by decarburisation layer or part of the decarburisation layer, folding seam in the middle of iron oxide inclusions. With folded wire in deep processing, very easy to burr or fracture.

The causes of folding defect are

1.The raw material itself exists folding;2.Improper cleaning of the surface of the billet, sharp edges and corners, or cleaning the depth to width ratio does not meet the requirements, the formation of folding when rolling;

2.Non-finished hole rolled pieces produce obvious ears (single folding side ears, bilateral ears, wrong side ears, etc.), when the rolled pieces turned 90 ° into the next hole type, the ears were overwhelmed and formed folding;

3.Deeper scratches on the surface of the wire, and folding is formed after re-rolling;

4.Deep grooves left by improper handling of defects on the continuous casting billet, forming folds when rolling.

Prevention methods from folding defect

1 Strictly prohibit to roll the wires with poor surface of billets;

2 To keep the rolling temperature normal; 

3 To avoid a certain pass making lugs and rolling scraping through regulating the operation.