Features: Within 20mm of the front and back sides of the steel coil from the edge of the hot-rolled coil, continuous and intermittent linear defects are generated on the entire length of the coil, and the hot-rolled upper surface is wider.
Cause: In the hot rolling process, the side compression marks caused by rolling are transferred to the wide surface, and the hot rolled coil is manufactured by shrinking and rolling, and the width of the steel strip is unchanged when the strip is extended.
Production process: hot rolling
