Investigation and improvement of tiny spot defects on hot-dip galvanized automotive steel sheets  

作　　者：GE Zhiyong YANG Bo YANG Jiwu 

机构地区：[1]Baosteel Zhanjiang Iron&Steel Co.,Ltd.,Zhanjiang 524072,Guandong,China

出　　处：《Baosteel Technical Research》2024年第2期32-38,共7页宝钢技术研究（英文版）

摘　　要：The causes of tiny spot defects on the surface of hot-dip galvanized automotive steel sheets were studied using scanning electron microscopy(SEM)and energy dispersive spectrometer(EDS),and effective control measures were introduced.The results show that rubbing against the top roller after galvanizing is easy due to the local thickness of tiny spot defect location coating;therefore,the surface morphology is different from the normal part.Three kinds of defects,namely zinc slag,small slivers,and pitting,are likely to cause local thickening of the coating after galvanizing,leading to the formation of tiny spots.Therefore,resolving the three types of defects can effectively control the generation of tiny spot defects.Among them,due to the hereditary nature of the small sliver defect,focusing on its control and supervision is necessary.

关 键 词：hot-dip galvanizing tiny spot zinc slag PITTING small sliver 

分 类 号：TG174.4[金属学及工艺—金属表面处理] U465.11[金属学及工艺—金属学]