Abstract: To understand thoroughly the mechanisms of the disc slitting process and improve the slitting quality, the slitting surface morphology of galvanized steel sheet is numerically analyzed by using the DEFORM-2D finite element analysis software, and the formation mechanism of the slitting surface morphology is clarified. The numerical simulation results are in good agreement with the experimental results. The formation of the morphology characteristics is closely related with the stress-strain distribution of the sheet metal in the disc slitting process. The widths of the rollover and compressive area can be predicted by tracking the history of the maximum shear stress on the sheet surface, and the cutter travel between the beginning and ending of the forming of the rollover is proposed to estimate the change tendency of the rollover’s height. With the increase of the distance from the edge of the disc cutter, the shear stress of the points on the rollover area increases at first and then decreases, while that on the compressive area decreases gradually. When the disc cutter cuts into the sheet metal, the shear force increases rapidly at first, then ascends slowly to a peak, next decreases slowly, and reduces sharply after the cracks appear. The slitting clearance between the neighboring disc cutters determines the stress-strain distribution of the sheet metal and the occurring and propagating of the crack, thus influences the shear force and the slitting surface morphology. A large clearance can promote crack propagation.

Key words: disc slitting;slitting surface morphology;formation mechanism;numerical simulation;clearance