Abstract: The surface morphology，composition，and chemical composition of corrosion products of environmentally friendly polyester coated high aluminum zinc aluminum magnesium color coated sheets soaked in hydrochloric acid and sodium hydroxide wereanalyzed by using scanning electron microscopy and X-ray instrument. The acid alkali corrosion mechanism of environmentally friendly polyester coated high aluminum zinc aluminum magnesium color coated sheets was explored. The results showed that the coatingphase of environmentally friendly polyester coated high aluminum zinc aluminum magnesiumcolor coated sheets was continuous gray phase and rich Al phase white rich Zn phase/Zn Mg phase and black Mg₂Si phase. Corrosion in the same concentration（5%）medium（hydrochloric acid/sodium hydroxide） for 24 hours，with complete surface coating and visual inspectionwithout visible blistering. Its color loss level and light loss level met the requirements of level 0in GB/T 1766—2008；after soaking for 144 hours，the degree of foaming on the color coatedboard soaked in hydrochloric acid solution was more severe than that soaked in sodiumhydroxide solution. The reason was both the different molecular penetration abilities of thecorrosive solution medium itself and the self-protection mechanism of corrosion productcoverage inhibition. The difference lied in the corrosion products. The corrosion productssoaked in hydrochloric acid were mainly composed of ZnO and Fe，while the corrosion products soaked in sodium hydroxide were mainly composed of Al（OH）₃，Zn，and Fe. The similarity lied in the surface scanning results of the coating cross-section，which indicated that whether it was hydrochloric acid or sodium hydroxide corrosion，the white rich Zn phase/Zn Mg phase was significantly reduced，followed by the continuous gray rich Al phase. 

Key words: high aluminum zinc aluminum magnesium, environmental protection polyester color coated sheets, acid and base solution, corrosion failure

摘要： 为探究高铝锌铝镁环保聚酯彩涂板酸碱腐蚀机制，使用扫描电镜及 X射线衍射仪分析了经盐酸和氢氧化钠浸泡腐蚀后的高铝锌铝镁环保聚酯彩涂板的表面形貌、成分及腐蚀产物的化学组成。结果表明：高铝锌铝镁环保聚酯彩涂板的镀层相为连续灰色富 Al相、白色富 Zn相/Zn-Mg相以及黑色 Mg₂Si相。在 5%盐酸 /氢氧化钠溶液中腐蚀 24 h，表面涂层完整，目视无可见起泡，失色和失光等级均满足 GB/T 1766—2008的 0级的规定；浸泡 144 h后，经盐酸溶液腐蚀的彩涂板起泡程度比经氢氧化钠溶液腐蚀的程度更重。其原因既有腐蚀介质本身穿透能力不同又有腐蚀产物覆盖抑制的自我保护机制。不同之处在于，经盐酸浸泡后的腐蚀产物主要由 ZnO和 Fe组成，经氢氧化钠浸泡后的腐蚀产物主要由 Al（OH）₃、Zn以及 Fe组成；相同点在于，无论是盐酸还是氢氧化钠腐蚀，都是白色富 Zn相/Zn-Mg相明显减少，其次是连续灰色富 Al相。

关键词: 高铝锌铝镁, 环保聚酯彩涂板, 酸碱溶液, 腐蚀失效

CLC Number: 

• TQ635. 9