深海静水压力对环氧涂层/907A低合金钢体系失效行为的影响  

Effect of Deep-sea Hydrostatic Pressure on Failure Behavior of Epoxy Coating/907A Low Alloy Steel System

作　　者：景超杰 方博 赵方超[1] 赵阳 杨小奎[1] 陈雪晴 周堃[1] 刘杰 JING Chaojie;FANG Bo;ZHAO Fangchao;ZHAO Yang;YANG Xiaokui;CHEN Xueqing;ZHOU Kun;LIU Jie(Weathering Test and Research Center of Science Technology and Industry for National Defense,Southwest Institute of Technology and Engineering,Chongqing 400039,China;School of Chemistry and Chemical Engineering,Yantai University,Shandong Yantai 264005,China;AVIC China Aero-Polytechnology Establishment,Beijing 100028,China)

机构地区：[1]西南技术工程研究所国防科技工业自然环境试验研究中心,重庆400039 [2]烟台大学化学化工学院,山东烟台264005 [3]中国航空综合技术研究所,北京100028

出　　处：《表面技术》2024年第16期68-77,102,共11页Surface Technology

基　　金：重庆市技术创新与应用发展专项重点项目(KJJ202105);国家自然科学基金(51971192);山东省泰山学者工程(tsqn202306160);江苏省卓越博士后计划(338057)。

摘　　要：目的探究深海静水压力作为单一因素影响涂层/金属体系的失效过程。方法在深海环境模拟实验装置中开展环氧涂层/907A低合金钢体系的浸泡实验,从电化学阻抗谱、涂层湿附着力、涂层微观形貌及其化学结构等方面分析涂层的失效机理。结果当静水压力为0.1 MPa和15 MPa时,涂层阻抗值分别下降至3.83×10^(6)Ω·cm^(2)和6.28×104Ω·cm^(2),涂层湿附着力分别下降至2.76 MPa和2.31 MPa。在不同静水压力下,水在涂层中的前期扩散形式均符合Fick扩散定律,而涂层下水的扩散系数从1.05×10^(-9) cm^(2)/s增加至2.39×10^(-9) cm^(2)/s。随着静水压力的升高,环氧涂层表面的孔隙以及裂纹不断发展并出现了鼓泡。在静水压力为0.1 MPa条件下腐蚀产物以γ-FeOOH为主,静水压力升高后腐蚀产物Fe_(3)O_(4)含量明显增加,除锈后的腐蚀坑直径由15μm增加至25μm。结论高静水压力可以加速腐蚀性介质向涂层内部以及涂层/金属界面的渗透,涂层湿附着力迅速下降,涂层失效更加严重。高静水压力能够促进腐蚀产物中高电化学活性Fe_(3)O_(4)的生成。此外,静水压力下涂层失效的主要原因是物理结构受到破坏。Applying coatings on metal surfaces is one of the most effective ways to protect metals.In the field of marine corrosion protection,epoxy glass flake coatings with lamellar structures that hinder the transmission of corrosive media have been extensively explored and used.The work aims to investigate the failure behavior and failure mechanism of the coatings under deep-sea hydrostatic pressure.The epoxy glass flake coating/907A low alloy steel system was immersed by the simulation test device of the deep-sea environment.The failure mechanism of the coating/metal system was analyzed from the perspectives of EIS,wet adhesion,cathodic delamination diameter,chemical structure and microscopic morphology of the coatings,microscopic morphology of the metal surface before and after rust removal,and corrosion products of the metal.EIS was used to test the anti-corrosion properties of the coatings.Following the ASTM D4541,a pull-off adhesion tester was used to test wet adhesion,and the diameter of the alloy was 20 mm.At the end of the test,the impedance values of the coatings decreased to 3.83×106Ω·cm^(2) and 6.28×10^(4)Ω·cm^(2) at 0.1 MPa and 15 MPa hydrostatic pressure,respectively.The wet adhesion of the coatings from original 6.52 MPa decreased to 2.76 MPa and 2.31 MPa and the wet adhesion loss values were 57.67%and 64.57%,respectively.The cathodic delamination diameter of the coatings increased by 1.2 mm and 1.5 mm under 0.1 MPa and 15 MPa hydrostatic pressure,respectively.At the initial stage of immersion,the diffusion process of water in the coatings conformed to Fick's diffusion law,and the diffusion coefficients of water in the coating increased from 1.05×10^(-9) cm^(2)/s to 2.39×10^(-9) cm^(2)/s under 0.1 MPa and 15 MPa hydrostatic pressure.Small pores and cracks appeared on the coating surface under 0.1 MPa hydrostatic pressure,while the pores on the coating surface were more obvious and small bubbles appeared on the coating surface under 15 MPa hydrostatic pressure.Uniformly distributed corrosion produ

关 键 词：环氧涂层 深海静水压力 水传输行为 失效行为 电化学阻抗谱 

分 类 号：TG171[金属学及工艺—金属表面处理]