热浸镀铝锌硅镀层云纹缺陷的分析及抑制

 对采用薄板坯连铸连轧工艺生产的热浸镀铝锌硅产品镀层横向云纹缺陷和纵向云纹缺陷进行了表面和截面结构的分析。结果表明，产生的云纹缺陷与气刀工作压力、气刀工作距离、气刀喷吹角度、锌液温度和钢板入锌锅温度有关；气刀工作压力过低及锌液温度过高时，易形成纵向云纹缺陷。气刀工作压力过大，气刀间距相应变大，形成镀层横向云纹缺陷；在一定温度下，调整各项参数将钢带抖动控制在3mm以下时，可以获得均匀的镀层厚度、表面锌花尺寸和色泽。

Analysis and Control of Coating Ripple on the Hot-Dip Galvalume Coating

The defects of transverse coating ripple and longitude coating ripple on the hot-dip galvalume coating produced by thin slab continous casting-rolling process were analyzed by using OM and SEM-EDS.Comprehensively,air knife-pressure,gap of air knife,angle of air knife,the temperature of zinc liquid,the temperature of steel strip in zinc pot are the main reasons of coating ripple on the galvalume coating.Longitude coating ripple is caused by lower air knife pressure and higher temperature of zinc liquid.Higher air knife pressure and wider gap of air knife lead to transverse coating ripple.The homogeneity coating thickness,spangles and shine can be achieved by means of controlling the process parameters to ensure the shake of strip steel under 3 mm at certain temperatre.