Brief Analysis Surface Defects of Steel

1.Crack

A.Defect characteristics:Cracks are generally linear,Sometimes "Y" shape,Its direction usually consistent with the rolling direction,but also But there are other directions,General opening for the acute Angle

B.Causes：steel ingot bubble,Uncovered cracks and nonmetallic inclusions formed crack during rolling by rupture and extend. The crack can cause of the internal crack of steel ingot extend during rolling.Steel ingot, billet heating uneven or steel temperature is too low and rolling is not correct, the extension of each part is inconsistent, will produce cracks

2.Scratched

A.Feature:Longitudinal slender concave defects along the rolling direction,Its shape and depth, width is different for the cause

B.Causes:It is due to the iron oxide of steel,metal particles or other impurities accumulate in the guards,scratch by high temperature and high speed rolling contact.Or due to improper installation of the guide plate and its abnormal loss, poor maintenance and so on

3.End burr

A.Feature:Generally appearing in the steel both ends,flash-like, burr-like, irregular distribution of the end of steel.

B.Causes:Rolling material sawing due to serious wear or saw blade improper adjustment .