高铝锌铝镁环保聚酯彩涂板酸碱腐蚀失效机制分析  

Analysis of Acid Alkali Corrosion Failure Mechanism of Environmentally Friendly Polyester Coated High Aluminum Zinc Aluminum Magnesium Color Coated Sheets

作　　者：钱婷婷 施国兰[1] 汤晓东[1] 柴立涛[1] 吴银义 孙霖[1] Qian Tingting;Shi Guolan;Tang Xiaodong;Chai Litao;Wu Yinyi;Sun Lin(Maanshan Iron and Steel Co.,Ltd.,Maanshan,Anhui 243000,China)

机构地区：[1]马鞍山钢铁股份有限公司,安徽马鞍山243000

出　　处：《涂料工业》2023年第11期8-15,共8页Paint & Coatings Industry

基　　金：国家重点研发计划专项资助项目(2017YFB0304300,2017YFB0304305)。

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Mg_(2)Si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。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 were analyzed 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 coating phase of environmentally friendly polyester coated high aluminum zinc aluminum magnesium color coated sheets was continuous gray phase and rich Al phase white rich Zn phase/Zn Mg phase and black Mg_(2)Si phase.Corrosion in the same concentration(5%)medium(hydrochloric acid/sodium hydroxide)for 24 hours,with complete surface coating and visual inspection without visible blistering.Its color loss level and light loss level met the requirements of level 0 in GB/T 1766—2008;after soaking for 144 hours,the degree of foaming on the color coated board soaked in hydrochloric acid solution was more severe than that soaked in sodium hydroxide solution.The reason was both the different molecular penetration abilities of the corrosive solution medium itself and the self-protection mechanism of corrosion product coverage inhibition.The difference lied in the corrosion products.The corrosion products soaked 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.

关 键 词：高铝锌铝镁 环保聚酯彩涂板 酸碱溶液 腐蚀失效 

分 类 号：TQ635.9[化学工程—精细化工]