590 MPa级合金化热镀锌双相钢剪边断面色差分析及改善  

Analysis and improvement of color difference on trimming surface of 590 MPa galvannealed dual phase steel

作　　者：赵川翔 吴科 谢福永 刘庆均 ZHAO Chuan-xiang;WU Ke;XIE Fu-yong;LIU Qing-jun(Guangzhou JFE Steel Sheet Co.,Ltd.,Guangzhou 511464,China)

机构地区：[1]广州JFE钢板有限公司,广东广州511464

出　　处：《塑性工程学报》2023年第8期235-241,共7页Journal of Plasticity Engineering

摘　　要：采用扫描电镜、激光共聚焦显微镜和金相显微镜分析了590 MPa级合金化热镀锌双相钢剪边断面色差的微观组织和形貌。结果表明,双相钢剪边断面主要由塌角、剪切带、断裂带、毛刺和挤压带构成。在剪切应力作用下,剪切带和断裂带金相组织有明显沿剪切方向的弯曲和拉伸变形,挤压带组织有压缩变形。塌角边缘镀锌层由于塑性变形产生了网状龟裂纹,且部分裂纹向下扩展至剪切带上沿镀锌层区域。剪切形成的断裂带为典型延性断裂,挤压带位置的镀锌层完整。不同卷取方向材料落料后光亮剪切带方向相反,对光线反射角度的差异造成了剪边断面明暗色差。减少剪边机刀片侧向间隙可以防止剪边断面色差。The microstructure and morphologies of color difference on trimming surface of 590 MPa galvannealed dual phase steel were investigated by scanning electron microscopy(SEM),laser scanning confocal microscopy(LSCM)and metalloscope.The results show that the trimming surface is composed of corner collapse,shear band,fracture band,burr and compressive band.The metallographic structure of shear band and fracture band is bent and stretched along the shear direction,and the compressive band microstructure is compressed under the shear stress.The net turtle cracks generate in the zinc coating at the edge of corner collapse due to plastic deformation and a proportion of cracks propagate downward into the zinc coating zone at the upper shear band.The fracture band formed by shear is typical ductile fracture and the zinc coating at compressive band is complete.After blanking of the materials in different reeling directions,the directions of light shear bands are opposite,and the color difference on trimming surface is caused by the difference of light reflection angle.Reducing the lateral clearance of blade of trimming machine can prevent the color difference on trimming surface.

关 键 词：双相钢 合金化热镀锌 圆盘剪 色差 微观组织 

分 类 号：TG386[金属学及工艺—金属压力加工]