Abstract: Scanning electron microscope and metallographic examination were carried out to determine the cause of peeling defect of 65Mn steel during rolling. The results showed that the crack in casting billet was the main reason of strip discontinuous cold rolling. The bubble and pinhole defects were the main causes of peeling defects in cold rolling. After optimizing the continuous casting process, the occurrence of cracks, bubbles and pinholes in the billet was reduced. Finally, the strip discontinuous peeling defect reduced from 1.7% to 0.04%, the spot peeling defects were completely controlled, and product quality was recognized by users.

Key words: 65Mn steel , peeling defect；crack and bubble pinhole defects；production process