铝锌硅合金镀层的耐热性研究

Research on heat resistance of aluminum-zinc-silicon plating sheet

为了解决铝锌硅合金镀层在不同环境中的极限使用温度,研究镀层的耐热性,在200~500℃保温不同时间后,观察表面外观形貌变化,采用SEM和EDS分析镀层截面组织演变和元素成分变化规律。研究表明:铝锌硅合金镀层板在不超过300℃环境中,可以长期使用,镀层组织无明显变化,可以保证镀层的耐腐蚀性能;使用环境温度超过300℃后,铝锌硅合金镀层中的Fe含量直线上升,形成Al-Zn-Fe金属化合物,镀层组织合金化,表面裂纹、鼓泡明显,导致镀层失效。

In order to solve the limited service temperature of Al-Zn-Si alloy coating in different environments and study the heat resistance of the coating,the change of surface appearance after heating at 200-500℃for different time was observed,and the evolution of microstructure and element composition of the coating section were analyzed by SEM and EDS.The results show that the aluminum zinc-silicon alloy coating plate can be used for a long time in the environment of not more than 300℃,and the coating structure has no obvious change,which can ensure the corrosion resistance of the coating.However,when the ambient temperature exceeds 300℃,the Fe content in the aluminum-zincsilicon alloy coating increases linearly,forming an Al-Zn-Fe metallic compound.The coating microstructure alloying,surface cracks and bubbling are obvious,leading to the failure of the coating.