车身门框边缘电泳黑色条纹问题的原因分析  

Cause analysis on black stripe defect of electrocoating on door frame edge of car body

作　　者：张涛 董美琛 张焕亮 高丙峰 杨瀛涛 冯岩 ZHANG Tao;DONG Meichen;ZHANG Huanliang;GAO Bingfeng;YANG Yingtao;FENG Yan(Zhejiang Geely New Energy Commercial Vehicle Group Co.,Ltd.,Hangzhou 310000,China;Jiangxi Geely New Energy Commercial Vehicle Group Co.,Ltd.,Shangrao 334000,China)

机构地区：[1]浙江吉利新能源商用车集团有限公司,浙江杭州310000 [2]江西吉利新能源商用车有限公司,江西上饶334000

出　　处：《电镀与涂饰》2023年第6期52-55,共4页Electroplating & Finishing

摘　　要：某冷轧车身钢板经过薄膜前处理、电泳和烘烤工序后,在门框边缘的电泳漆膜表面出现黑色条纹。通过对缺陷区域切片的显微镜和红外光谱分析,以及实验验证,确认这是由于电泳槽液层流表面有涡流,且门框位置开门角度较小加剧了涡流对此位置电泳的影响,因此电泳过程中门框位置局部电流过大,阳离子在迁移及沉积时出现异常,导致漆膜过厚。通过调整电泳槽层流循环设备参数解决了该问题。Some black stripes appeared on the surface of electrocoated film after being baked at the edge of door frame made of cold-rolled steel sheet pretreated by thin film technology.The section of the defective area was analyzed by using electron microscope and micro-infrared analyzer,and the possible causes of this defect were verified experimentally.It was found that there existed a turbulence of surficial laminar flow in electrocoating tank and its effect on electrodeposition at the edge of door frame was enhanced due to the small opening angle of the door.Therefore the electric current was too high at the local area of door frame where the abnormal migration and deposition of cations happened during the electrocoating process,resulting in the excessive thickness of the electrocoated film.This problem was solved by adjusting the operation parameters of circulation equipment.

关 键 词：冷轧钢板 薄膜前处理 电泳 黑色条纹缺陷 槽液循环 故障处理 

分 类 号：TQ639.8[化学工程—精细化工] U466[机械工程—车辆工程]