Mg含量对于高铝锌铝镁镀层组织及耐蚀性的影响  

Effect of Magnesium Content on the Microstructure and Corrosion Resistance of High Aluminum Zinc⁃Aluminum⁃Magnesium Coating

作　　者：孙霖[1] 钱婷婷 李超[1] SUN Lin;QIAN Tingting;LI Chao(Technical Center of Ma'anshan Iron and Steel Co.,Ltd.,Ma'anshan 243000,Anhui,China)

机构地区：[1]马鞍山钢铁股份有限公司技术中心,安徽马鞍山243000

出　　处：《焊管》2023年第6期21-25,共5页Welded Pipe and Tube

基　　金：十三五国家重点研发计划“资源节约型高耐蚀镀层技术与除雾霾抗菌涂层技术开发”(项目编号2017YFB0304305)。

摘　　要：为了探究Mg含量对高铝锌铝镁镀层耐蚀性能的影响,采用显微组织分析、电化学试验以及中性盐雾试验等方法,对三种不同Mg含量的高铝锌铝镁镀层组织及耐蚀性进行了研究。结果显示,1.2%Mg和1.8%Mg镀层已形成较为明显的富Al枝晶相和富Zn枝晶相的典型高铝锌铝镁镀层结构,而0.6%Mg镀层Zn、Mg元素分布较为分散;电化学试验中,1.2%Mg和1.8%Mg镀层与0.6%Mg镀层相比,腐蚀电流更低,耐蚀性更好;1 000 h中性盐雾试验后,1.8%Mg镀层表面仍保持较为平整的镀层形貌,镀层成分中O元素含量较低,Cl元素含量较高,处于腐蚀初期阶段,氧化腐蚀程度较低,而0.6%Mg和1.2%Mg镀层表面呈现颗粒状腐蚀产物,镀层成分中O元素含量偏高,Cl元素含量偏低,处于腐蚀后期阶段,氧化腐蚀程度较高。In order to investigate the effect of Mg content on the corrosion performance of high aluminum zinc⁃aluminum⁃magnesium coatings,microstructure analysis,electrochemical testing and neutral salt spray testing were used to study the microstructure and corrosion resistance of three different Mg content high aluminum zinc⁃aluminum⁃magnesium coatings.The results show that the 1.2%Mg and 1.8%Mg coatings have formed typical high aluminum zinc⁃aluminum⁃magnesium coating structures with rich Al dendrite and Zn dendrite phases,while the distribution of Zn and Mg elements in the 0.6%Mg coating is relatively dispersed.Electrochemical tests further showed that the 1.2%Mg and 1.8%Mg coatings had lower corrosion current and better corrosion resistance compared to the 0.6%Mg coating.After 1000 hours of neutral salt spray test,the surface of 1.8%Mg of the coating still maintains a relatively flat coating morphology.The composition of the coating is low in O element and high in Cl element,which is in the early stage of corrosion and has a low degree of oxidation corrosion.However,the surfaces of 0.6%Mg and 1.2Mg%coatings present granular corrosion products.The composition of the coating is relatively high in O element and low in Cl element,which is in the later stage of corrosion and has a high degree of oxidation corrosion.

关 键 词：锌铝镁 镁含量 镀层结构 耐蚀性 

分 类 号：TG174.44[金属学及工艺—金属表面处理]