热浸镀锌层表面钛盐转化膜研究

Study of titanium conversion coating on hot-dip galvanized coating

利用钛盐成膜工艺在热镀锌层表面获得了色泽光亮、耐蚀性能优良的银白色转化膜层。采用扫描电镜、能谱仪、电化学极化和盐水浸泡方法研究了钛盐转化膜层的表面形貌、元素组成和耐蚀性能。分析了钛盐溶液成分及工艺参数对热镀锌层表面转化膜的耐蚀性能影响。确定的最佳工艺条件为:Ti(SO4)21g/L,H2O260mL/L,pH0.5～1.0,处理温度25～30°C,处理时间10min。热镀锌层经此工艺处理后,耐蚀性能明显提高。

A bright and silvery white conversion coating with good corrosion resistance was obtained on the surface of hot-dip galvanized coating. The morphology, composition and corrosion resistance of the titanium conversion coating were analyzed by scanning electron microscopy, energydispersive spectroscopy, electrochemical polarization and salt water immersion test. The effects of solution composition and process parameters on the corrosion resistance of the conversion coatings on the surface of hot-dip galvanized coating were analyzed. The optimal process parameters were determined as follows： Ti（SO4）2 1 g/L, H2O2 60 mL/L, pH 0.5-1.0, temperature 25-30 ℃, time 10 min. The corrosion resistance of the hot-dip galvanized coating is greatly improved by the titanium conversion coating.