Have you seen the common appearance quality problems of steel coils? Do you know what causes them?
Overflow edge
Features: Part of the coil layer protrudes or is concave on the end plane of the steel coil.
Cause: During the coiling process of the strip, due to the wedge-shaped gap between the pinch rollers, poor centering when feeding the coiling machine, sickle bends in the strip, and excessive gaps between the auxiliary rolls, part of the coil layer on the inner circle of the steel coil protrudes;
Coil layer dislocation
Features: Part of the coil layer repeatedly protrudes and is concave on the end plane of the steel coil, and is uneven;
Cause: The drive end of the reel is severely worn, and there is a large eccentric difference when rotating; the opening of the guide plate on the front side of the coil is too large, and the strip steel moves back and forth axially;
Inner ring loose coil
Features: The inner ring layer of the steel coil is loose, and there is a large gap between the layers. In severe cases, the belt head can be seen to collapse;
Cause: The winding tension setting is unreasonable; After the winding is completed, the reel reverses;
Outer ring loose coil
Features: The outer ring layer of the steel coil is loose.
Cause: The strapping is broken, and the outer ring is loose; the strapping is not tightened during manual bundling;
Flat roll
Features: The overall shape of the steel roll is oval when observed visually;
Cause: The overall collapse of the steel coil is caused by reasons such as excessively high coiling temperature, long-term horizontal stacking, excessively high horizontal unwinding stacking, low coiling tension, loose coil layers, and large impact during lifting.
The above quality problems will affect the user’s coiling, uncoiling, and lifting. If it is a galvanized and pre-painted steel coil, it will also affect the surface quality of the product and even make it unusable.
