连退板冲压后纵向条纹缺陷成因分析

Cause Analysis of Longitudinal Streak Defects after Stamping of Continu⁃ous Annealing Strip

通过扫描电镜及能谱分析研究了国内某车型前罩外板冲压后纵向条纹缺陷的表观形貌及内部金相组织,探讨了连退板冲压后纵向条纹缺陷的形成原因与改善措施。研究表明钢板表层存在一层厚度5~15μm的未回复再结晶层,冲压后因表层未回复再结晶层与内部组织存在差异从而影响变形,打磨零件表面表现为延轧制方向的条纹状缺陷,连退机组生产时可通过提高清洗段清洗效果,提高带钢板面清洁度来改善。

The apparent morphology and internal metallurgical organization of the longi⁃tudinal streak defects after stamping of the front cover outer plate of a domestic model were studied by scanning electron microscopy and energy spectrum analysis,and the causes and improvement measures of the longitudinal streak defects after stamping of the continuous an⁃nealing strip were discussed.Research shows that there is a 5~15μm layer without recov⁃ery and recrystallization on the surface of the steel plate,the difference between this layer and the internal organization after stamping affects the deformation.The surface of the pol⁃ished parts shows streak-like defects in the direction of rolling,which can be improved by improving the cleaning effect of the cleaning section,that is,improving the cleanliness of the surface of the strip steel plate during the production of the continuous annealing unit.