material question Explain the cause for the following defect

material question

Explain the cause for the following defects and provide remedies to prevent the defects

6. Explain the causes for the following defects (a to d) and provide remedies to prevent the defects (a) (c) (b) (d)

Solution

causes:

a. due to improper roller speeds and roll bending called waviness

b.too much rolling pressure in center called zipper cracks

c. too much rolling pressure at edges called edge cracks

d. due to non-uniform deformation or defects in the initial workpiece only called alligatoring.

remedies:

a. roller speed is to maintained constant throught out the operation

b and c. rolling pressure is to maintained constant through out width of the sheet/plate.

d. initial workpiece should be defect free to prevent this defect.