【摘要】 渗锌钢不耐冲刷腐蚀 ,其应用受到了限制。在料浆渗锌涂层上采用溶胶 -凝胶法研究了制备SiO2 涂层的过程 ,获得了具有优异抗蚀性能的Zn -SiO2 复合涂层的新技术。EDS和XRD分析证明 ,Zn -SiO2 复合涂层的外层是一层较薄的非晶态SiO2 薄膜 ,内层是与基体结合紧密的由FeZn11,FeZn9,FeZn7相组成的Zn -Fe合金层。在 4 0℃自来水中冲刷腐蚀 10 0h后 ,Zn -SiO2 复合涂层的腐蚀速率约是渗锌层的 1/ 2 0 ,2 0钢的 1/ 170。在 4 0℃ ,3.5 %NaCl溶液中冲刷腐蚀 10 0h后 ,Zn -SiO2 复合涂层仍然保持光泽的表面。电化学测试结果表明 ,渗锌涂层涂覆一层SiO2 薄膜后电极电位大幅度向正方向移动 ,是Zn -SiO2 复合涂层提高抗腐蚀性能的主要原因。更多还原

【Abstract】 Application of sherardizing steel is limited for bad erosion - corrosion resistance. A thin SiO 2 film was deposited on the sherardizing coating by sol-gel method. By the way, Zn - SiO 2 composite coating with excellent corrosion resistance was prepared. EDS and XRD analysis demonstrate that Zn - SiO 2 composite coating has a double - layer structure that the outside layer is a thin amorphous SiO 2 film and inside layer is a Zn- Fe alloy layer composed of FeZn 11 , FeZn 9 and FeZn 7 phases. After erosion- corrosion in water at 40 ℃ for 100 h, the erosion - corrosion rate of specimen with Zn-SiO 2 coating is about 1/170 and 1/20 as that of carbon steel and sherardizing coating respectively. After erosion - corrosion in 3. 5% NaCl solution at 40℃ for 100 h, the surface of Zn - SiO 2 composite coating still keeps bright. Electrochemical results show that the potential of sherardizing coating shifts markedly to positive with SiO 2 deposit, which is the main reason for increasing corrosion resistance of Zn-SiO 2 composite coating.更多还原