Rolling Defects

In this blog we are going to learn about different type of surface defects that arise in rolling of sheet metal

There are two types of Defects 

1. Surface Defects
2. Internal Structural Defects

Surface Defects : As it name suggest these kind of defects on the surface of metal . These defects include scale, rust,scratches,cracks etc. There many reasons to arise these kind of defects like impurities in material ,rolling is done inadequate temperature and much more

Internal Structure Defects: These defects include 

Wavy edges:

Wavy Edges

Zipper Cracks

Zipper Cracks

Edge Cracks

Edge Cracks

Defects due to bending of rolls: Bending Rolls produce wavy edges and zipper cracks lets try to understand why these defects arise in the first place

Bending of Rolls (crown defects): when the sheet metal is inserted into the rolls.Rolls experience two force rolling and transversal load due to sheet because of that roll metal bends in the middle of it. It also causes unwanted result in sheet metal like the thickness of metal increase at the centre of the sheet but the thickness at the edges decrease. These defects also arise wavy edges and zipper cracks

Folds: These defects when the reduction per rolls is very small

Lamination Defects: These defects arise due to incomplete welding and blow holes defects during rolling.This defects decrease the strength of the material along the thickness direction drastically