Generation Mechanism of Surface Transverse Cracks in Continuous Annealing and Its Control Technology

For the problem of the horizontal stripes defect on the strip surface in the continuous annealing process, fully integrated with equipmental and technological features of the continuous annealing line, and based on such four field trials as the impact test of the rolling speed on the horizontal stripe, the impact test of the speed of strip in furnace on the horizontal stripes, the investigation test of furnace-roller’s surface in annealing furnace and the impact test of the tension in furnace on horizontal stripes, the generation mechanism of horizontal stripes defects of the strip in continuous annealing unit were analyzed in detail, and the comprehensive control measures for horizontal strips was put forward. According to actual situation, the relevant technology was applied to the continuous annealing line, and a detailed technical scheme was worked out. The strip surface quality is improved effectively and larger economic benefits are obtained.