冲压“积瘤”对汽车外板涂装影响及对策分析

评价热镀锌汽车外板表面质量的参数包括粗糙度、波纹度和PC值，而评价汽车板涂装后表面质量的重点参数包括桔皮、鲜映性、长波、短波等。冷轧钢板表面粗糙度的波长在油漆前后有明显的差别，油漆前冷轧钢板表面的起伏以短波长的比例占优势，而油漆后短波长的部分几乎消失，长波长部分仍然保留并且占优势。以汽车公司反映最为强烈的影响涂装的表面积瘤缺陷为切入点，全面分析了积瘤的类别及缺陷形成的根本原因，重点制定了包括降低入锌锅板温，优化入锌锅板温与锌锅温度的匹配，通过提高锌锅铝含量来抑制锌锅中的铁，保持铁含量在极低的范围内，从根本上抑制锌粒的形成，从而达到有效降低锌粒缺陷比例，降低汽车公司返修率，满足2C1B涂装工艺要求的目的。

Impact of stamping on automobile outer panel coating and analysis of countermeasures

The parameters for evaluating the surface quality of cold rolled automobile plate includes roughness, waviness and PC values. And the main parameters for evaluating the surface quality of the car plate after coating are orange peel, bright mirror, long wave and short wave, etc. The wavelength of the surface roughness of cold rolled steel sheet is obviously different before and after painting. The percentage of the short wavelength of the surface roughness of cold rolled steel sheet is in a dominant position before painting, which is almost disappeared after painting. While the long wavelength parts still remain and dominate. According to the surface accumulated burl defects strongly affecting the coating reflected by car companies, the accumulated burl type and the root cause of defect formation were comprehensively analyzed. Through lowering into the zinc pot plate temperature, the matching of the zinc pot and zinc pot temperature was optimized. By improving the zinc aluminum content, the Fe content in zinc pot was controlled in a very low scope, which radically suppressed the formation of the zinc granule. And therefore, the defect ratio of zinc grain was effectively reduced, the repair rate of motor corporations was decreased, the requirement of the dragon 2C1B coating process was satisfied.