单宁酸-磷酸复合转化液pH值对Q235钢锈层结构和防腐蚀性能的影响  

Effects of pH Value of Tannin- Phosphoric Acid Composite Converter on Structure and Corrosion Resistance of the Rust Layer of Q235 Steel

作　　者：虢韬[1] 王伟[1] 赵定义 杨恒[1] 屈中伟 

机构地区：[1]贵州电网公司输电运行检修公司,贵州贵阳550000 [2]武汉科迪奥电力科技有限公司,湖北武汉430000

出　　处：《材料保护》2016年第3期8-11,6,共4页Materials Protection

摘　　要：目前,未见pH值对锈层复合转化膜层结构和性能影响的研究。采用不同pH值的单宁酸-磷酸复合转化液对Q235钢锈层进行了转化处理,并通过扫描电镜、交流阻抗谱和Fe3+溶出试验等研究了不同pH值的转化液对锈层结构和性能的影响。结果表明:复合转化液能够使锈层结构变得致密稳定,从而使带锈试片的耐腐蚀性能提高;当单宁酸浓度为5g/L、复合转化液pH值为2时,锈层结构最为致密平整,基材耐腐蚀性好;复合转化层主要由单宁酸铁和磷酸铁组成。The tannin-phosphoric acid composite converters with different pH values were used for the conversion treatment of the Q235 rust layer.Subsequently,the SEM,EIS and Fe^(3+) dissolution tests were used to investigate the effects of the converters with different pH values on the structure and properties of rust layer.Results showed that the composite converter could make the rust layer denser and more stable,leading to the improved corrosion resistance of rust layer.When the tannic acid concentration was 5 g/L and the pH value of composite converter was 2,the rust layer had the densest and the most uniform structure,and the corrosion resistance of substrate was the optimum.Besides,the composite conversion layer was mainly composed of ferric tannate chelale and FePO_4.

关 键 词：Q235钢 单宁酸 磷酸 复合转化液 锈层转化 耐腐蚀性能 

分 类 号：TG178[金属学及工艺—金属表面处理]