双拉变形对热浸镀铝硅镀层板腐蚀性能的影响

The Effect of Biaxial Stretching on Corrosion Performance of Hot-Dipped Al-Si Coated Material

为了研究热浸镀铝硅镀层材料在应用过程中受到塑性变形作用后腐蚀性能的变化,通过胀型实验对热浸镀铝硅镀层材料进行了双拉变形处理,通过扫描电镜对不同应变量下镀层的微观组织形貌进行了观察,使用交流阻抗、极化曲线和中性盐雾的方法对不同应变量镀层的腐蚀性能进行了测试。微观形貌观察发现,受到双拉变形作用,镀层表面以及内部合金层都出现了裂纹,随着应变量的增加,裂纹逐渐由细小状态聚集形成粗大的裂纹;电化学测试结果表明,双拉变形导致镀层的阻抗值下降,腐蚀电流密度升高;中性盐雾测试结果显示,随着变形量的增加,镀层出现红锈的时间缩短。

In order to investigate the deformation effects on corrosion performance of hot-dipped Al-Si coating during the application,the material was subjected to biaxial stretching through the bulging ex‐periment.Scanning electron microscope(SEM)was used to observe the morphology of the coating un‐der different strains,and the coating corrosion performance under different strains was tested by electro‐chemical impedance spectroscopy(EIS),potentiodynamic polarization and neutral salt spray test(NSST).The SEM results showed that cracks appear in the alloy layer of the coating,with the increase of the amount of strain,the cracks gradually aggregated from small to coarse.The electrochemical test results showed that biaxial stretching leads to a decrease in the resistance value and an increase in the corrosion current density.The NSST results showed that with the increase of deformation,the time for red rust to appear on the coating is shortened.