两种电弧喷涂涂层在中性盐雾环境下的耐蚀性能对比研究  

Corrosion Resistance of Two Arc Spraying Coatings on EH36 Steel in Neutral Salt Spray Environment

作　　者：肖文涛[1] 刘静[1] 彭晶晶 张弦 吴开明[1,2] XIAO Wentao;LIU Jing;PENG Jingjing;ZHANG Xian;WU Kaiming(Collaborative Innovation Center for Advanced Steels,The State Key Laboratory of Refractory Material and Metallurgy,Hubei Province Key Laboratory of Systems Science in Metallurgical Process,Wuhan University of Science and Technology,Wuhan 430081,China;Metals Valley&Band(Foshan)Metallic Composite Co.Ltd.,Foshan 528000,China)

机构地区：[1]武汉科技大学高性能钢铁材料及其应用、省部共建协同创新中心耐火材料与冶金省部共建国家重点实验室、冶金工业过程系统科学湖北省重点实验室,武汉430081 [2]材谷金带(佛山)金属复合材料有限公司,佛山528000

出　　处：《中国腐蚀与防护学报》2023年第5期1003-1014,共12页Journal of Chinese Society For Corrosion and Protection

基　　金：湖北省教育厅科学技术研究计划重点项目(D20221103);冶金工业过程系统科学湖北省重点实验室开放基金(Y202204)。

摘　　要：采用电弧喷涂技术在EH36钢表面制备了5083铝合金涂层和Zn15Al涂层,结合扫描电子显微镜(SEM)、X射线衍射仪(XRD)、电化学测试和腐蚀失重等方法对比研究了两种涂层在中性盐雾环境下的耐蚀性能。结果表明,随着腐蚀的进行,两种涂层的腐蚀速率均逐渐下降,且5083Al合金涂层的腐蚀速率明显低于Zn15Al涂层。形貌观察结果表明,5083铝合金涂层的腐蚀产物呈致密块状,Cl-无明显渗入;而Zn15Al涂层的腐蚀产物呈疏松的细针状,盐雾腐蚀10 d后有Cl-沉积在腐蚀产物层中并逐渐渗入至涂层基体。5083铝合金涂层的腐蚀产物主要为Al(OH)3,Zn15Al涂层腐蚀产物主要由Zn(OH)_(2)和Zn_(5)(OH)_(8)Cl_(2)·H_(2)O组成。结合溶度积常数K_(sp) 和过饱和度的理论计算,Al(OH)_(3)沉积所需Al^(3+)浓度更低、沉积速度更快,因此5083铝合金涂层更倾向于形成致密的腐蚀产物层。这一结果与电化学阻抗谱(EIS)测试结果相吻合,随腐蚀时间延长,两种涂层的极化电阻逐渐增大,且5083铝合金涂层的极化电阻高于Zn15Al涂层,说明腐蚀产物致密性是影响两种涂层耐蚀性能的主要原因。The 5083 Al-alloy coating(5083 coating)and Zn15Al coating were prepared on the surface of EH36 steel by arc spraying technology,and the corrosion resistance of the two coatings in neutral salt spray environment was comparatively studied by means of mass loss method,electrochemical tests,SEM and XRD etc.The results show that,with the progress of corrosion,the corrosion rate of the two coatings gradually decreases,and the corrosion rate of 5083 Al-alloy coating is significantly lower than that of Zn15Al coating.The morphological observations show that the corrosion products of 5083 Al-alloy coatings are dense and blocky,and there is no obvious infiltration of Cl-.However,the corrosion products of Zn15Al coatings are loose and fine needle-like,and Cl-is deposited in the corrosion product layer after 10 d of salt spray corrosion and then gradually penetrates into the coating matrix.The corrosion products of 5083 Al-alloy coating are mainly Al(OH)_(3),and those of Zn15Al coating composed mainly of Zn(OH)_(2) and Zn_(5)(OH)8Cl_(2)·H_(2)O.Taking the calculation results of the solubility product constant K_(sp) and supersaturation into consideration,it follows that the deposition of Al(OH)_(3) requires a lower Al^(3+)concentration and presents a faster deposition rate.Therefore,the 5083 coating is more inclined to form a dense layer of corrosion products.This result is verified by the EIS test results.As corrosion time prolongs,the polarization resistance of the two coatings gradually increases,and the polarization resistance of the 5083 Al-alloy coating is higher than that of the Zn15Al coating,indicating that the densification of corrosion products is the main reason affecting the corrosion resistance of the two coatings.

关 键 词：电弧喷涂 5083Al涂层 Zn15Al涂层 盐雾腐蚀性能 

分 类 号：TG174[金属学及工艺—金属表面处理]