热镀锌板的镀层成分对其表面电泳漆膜抗石击腐蚀性能的影响

研究了热镀锌板的镀层成分对其表面电泳漆膜抗石击腐蚀性能的影响。结果表明,经过合金化退火得到的GA板镀层中含有一定量的Fe,镀层较未经合金化退火的GI板硬。GA板镀层表面疏松多孔,电泳漆膜能够充满其缝隙或凹陷之处,固化后在界面区产生了类似勾键作用的机械作用力。因此,GA板与电泳漆膜的附着力优于GI板,石击处的扩蚀速率小于GI板。

Effect of the composition of hot-dip galvanized coating on steel sheet on corrosion resistance of electrophoretic coating thereon after stone chipping

The effect of the coating composition of hot-dip galvanized steel sheet on corrosion resistance of the subsequent electrophoretic coating painted on it after being chipped by stone was studied.The results showed that the coating formed on GA sheet by alloying after being annealed contained a certain amount of Fe,and had a higher microhardness than the GI sheet without annealing.The hot-dip coating on GA sheet was loose and porous,so that the electrophoretic paint could fill the cracks or depressions on it,generating a mechanical force similar to hook bond at the interface after curing.Therefore,the adhesion of electrophoretic coating on GA sheet was stronger than that on GI sheet,and the propagation rate of corrosion at stone chipped position on GA sheet was lower than that on GI sheet.