热喷涂高铝含量Zn-Al合金涂层热带岛礁大气环境腐蚀行为研究  

Corrosion Behavior of Thermal Sprayed Zinc-Aluminum Alloy Coating with High Aluminum Content in Tropical Island-reef Atmospheric Environment

作　　者：郭强 赵巍 张冲[1] GUO Qiang;ZHAO Wei;ZHANG Chong(Beijing Institute of Machinery and Equipment,Beijing 100854,China;First Military Representative Office of Air Force Equipment Department in Beijing,Beijing 100854,China)

机构地区：[1]北京机械设备研究所,北京100854 [2]空军装备部驻北京地区第一军事代表室,北京100854

出　　处：《装备环境工程》2024年第3期129-137,共9页Equipment Environmental Engineering

摘　　要：目的 研究Zn-Al合金涂层在热带海洋大气环境中的腐蚀行为,为低合金钢长效防护涂层的选用提供依据。方法 采用电弧热喷涂和高铝合金丝制备高铝含量Zn-Al合金涂层,通过户外暴露试验,采用目视、扫描电镜及能谱仪、金相显微镜、XRD、电化学交流阻抗谱和动电位极化曲线等方法,对不同暴露周期的涂层宏观、微观表面形貌、成分组成、截面形貌、腐蚀产物组成、电化学性能和腐蚀速率等进行观察、测试。结果Zn-Al合金涂层是以质量比为50%:50%的Zn/Al合金组成。在0~540 d周期内,涂层腐蚀产物主要由碱式锌铝碳酸盐化合物Zn_(6)Al_(2)(OH)_(16)CO_(3)·H_(2)O和羟基锌铝碳酸盐化合物Zn_(0.70)Al_(0.30)(OH)_(2)(CO_(3))_(0.15)·x H_(2)O、Zn_(0.71)Al_(0.29)(OH)_(2)(CO_(3))_(0.145)·x H_(2)O等组成,其对涂层孔隙进行填充。相对于初始涂层,180、360、540 d腐蚀后,涂层的极化电阻增加1个数量级,自腐蚀电位增加了约200 m V,自腐蚀电流密度降低至30%左右。结论 该Zn-Al合金涂层在腐蚀后保持较低且稳定的腐蚀速率,具有较好的耐腐蚀性能,致密且黏性的腐蚀产物对涂层孔隙起到了自封闭作用,显著提高了涂层的耐蚀性。The work aims to investigate the corrosion behavior of thermal sprayed Zn-Al alloy coatings with high aluminum content in the tropical marine atmospheric environment,so as to provide selection evidence of long-term protective metal coatings on low alloy steel.An outdoor exposure test in a tropical island-reef atmospheric environment was conducted to research the corrosion behavior of Zn-Al alloy coatings with high content of Al on low alloy steel.By the means of visual observation,scanning electron microscope (SEM),energy diffraction spectrum (EDS),optical microscope,X-ray diffraction,electrochemical impedance spectroscopy (EIS) and potential-dynamic polarization curve,et al,the macroscopic and microscopical surface morphology,chemical composition,section morphology,corrosion product composition,electrochemical properties and corrosion rate were observed and tested.The weight ratio of Zn and Al in Zn-Al alloy coatings was 50%:50wt%.The corrosion product layer on the Zn-Al alloy coating mainly consisted of basic zinc aluminum carbonate compound Zn_(6)Al_(2)(OH)_(16)CO_(3).H_(2)O,and hydroxy zinc aluminum carbonate compounds such as Zn_(0.70)Al_(0.30)(OH)_(2)(CO_3)_(0.15)·x H_(2)O and Zn_(0.71)Al_(0.29)(OH)_2(CO_(3))_(0.145)·x H_(2)O,which sealed the pores in the Zn-Al alloy coating.Compared with the uncorroded coating,the coating after 180 d,360 d and 540d exposure increased by an order of magnitude,and the free corrosion potential increased about 200 m V,and the self-corrosion current density decreased to about one-third of the uncorroded coating.After corrosion,the Zn-Al alloy coating shows low and stable corrosion rate,which shows excellent anti-corrosion properties.Dense and viscous corrosion products seal the pores of the coating,improving the corrosion resistance of the Zn-Al alloy coating.

关 键 词：电弧热喷涂 高铝锌基合金 涂层 热带岛礁 大气腐蚀 腐蚀规律 

分 类 号：TG172[金属学及工艺—金属表面处理]