论文部分内容阅读
利用浸涂法在Q235钢表面制备无铬锌铝涂层,并在涂层中添加TiO2纳米颗粒制备TiO2纳米复合涂层。采用SEM、EDS等测试手段分析两种涂层的组织、形貌和成分,并通过快速硝酸铵腐蚀实验以及电化学实验研究涂层的耐蚀性能。结果表明:涂层呈层片状组织,纳米颗粒部分填充在金属粉的孔隙中。在20%的硝酸铵溶液中腐蚀4 h后,TiO2纳米复合涂层仍维持层片状结构,未出现明显的剥落现象,耐蚀性优于无铬锌铝涂层。在3.5%NaCl溶液中,TiO2纳米复合涂层的自腐蚀电流密度为2.476×10-6A/cm2,低于无铬锌铝涂层的5.015×10-5A/cm2,显著提升了涂层的耐蚀性。
A chromium-free zinc-aluminum coating was prepared on the surface of Q235 steel by dip-coating method and the TiO2 nano-composite was prepared by adding TiO2 nanoparticles in the coating. The microstructure, morphology and composition of the two coatings were analyzed by SEM and EDS. The corrosion resistance of the coatings was also studied by fast ammonium nitrate corrosion test and electrochemical experiment. The results showed that the coating was lamellar and the nanoparticles were partially filled in the pores of the metal powder. After etching for 4 h in 20% ammonium nitrate solution, the TiO2 nanocomposite coating still lamellar structure, no obvious spalling phenomenon and better corrosion resistance than the chrome-free zinc-aluminum coating. In 3.5% NaCl solution, the self-corrosion current density of TiO2 nanocomposite coating is 2.476 × 10-6A / cm2, which is lower than 5.015 × 10-5A / cm2 of zinc-free zinc-aluminum coating, Erosive.