摘要
为研究高Cl^(-)环境对富铝磷酸盐涂层腐蚀的影响,采用开路电位、动电位极化、电化学阻抗谱等电化学测试方法,并结合扫描电镜、激光共聚焦显微镜,分析了磷酸盐涂层在高Cl^(-)环境下的腐蚀行为。结果表明:富铝磷酸盐涂层具有双层结构,涂层内磷酸盐包裹Al粉使其具有良好的屏蔽性能;随着溶液中Cl^(-)浓度的升高,其腐蚀倾向和腐蚀速率均增大,涂层的耐蚀性下降;富铝磷酸盐涂层在低浓度Cl^(-)时首先在裂纹和缺陷处发生腐蚀,随着Cl^(-)浓度的升高磷酸盐发生腐蚀时,外表面和涂层中的Al粉发生脱落并形成腐蚀坑,腐蚀坑趋于向外扩展并增大,加速涂层和基体的腐蚀。
To study the effect of high Cl^(-)environment on the corrosion of aluminum rich phosphate coatings,the corrosion behavior of phosphate coatings in high Cl^(-)environments was analyzed using electrochemical testing methods such as open circuit potential,potentiodynamic polarization and electrochemical impedance spectroscopy,combined with scanning electron microscopy and laser confocal microscopy.Results showed that the aluminum-rich phosphate coating had a double-layer structure.Phosphate coated Al powder inside the coating provided excellent shielding performance.With the increase of Cl^(-)concentration in the solution,the corrosion tendency and corrosion rate increased,and the corrosion resistance of the coating decreased.Moreover,aluminum-rich phosphate coatings corroded first at cracks and defects when the concentration of Cl^(-)was low.With the increase of Cl^(-)concentration,the corrosion of phosphate would cause the Al powder in the outer surface and the inner of coatings to fall off,and then the corrosion pits were formed.Furthermore,the corrosion pits tended to expand outward and increase in size,accelerating the corrosion of the coating and the substrate.
作者
胡红旺
李全德
郭维华
郭龙蔚
戴君
李定骏
倪荣
隆彬
巩秀芳
孟惠民
HU Hongwang;LI Quande;GUO Weihua;GUO Longwei;DAI Jun;LI Dingjun;NI Rong;LONG Bin;GONG Xiufang;MENG Huimin(Institute of Advance Materials and Technology,University of Science and Technology Beijing,Beijing 100083,China;State Key Laboratory of Clean and Efficient Turbomachinery Power Equipment,Deyang 618000,China;Dongfang Turbine Co.,Ltd.,Deyang 618000,China)
出处
《材料保护》
CAS
CSCD
2023年第11期13-22,148,共11页
Materials Protection
关键词
磷酸盐涂层
富铝
高Cl^(-)环境
腐蚀行为
电化学腐蚀
phosphate coating
aluminum rich
high Cl^(-)environment
corrosion behavior
electrochemical corrosion
