用电化学阻抗谱研究提高锆基无铬化学转化膜耐蚀性的方法

摘要

采用含1.4%(质量分数)ZRT-955陶化环保处理剂的水溶液(pH = 4.5),在20 ℃下对Q235钢板表面锆化处理12 min,通过测量所得锆化膜在0.35% (NH4)2SO4+ 0.05% NaCl的模拟汗液中的电化学阻抗谱(EIS),探索了烘干温度和缓蚀处理对膜层耐蚀性的影响.确定最佳烘干温度为180 ℃.采用硅氧烷酮类缓蚀剂对锆基转化膜进行后处理能够有效地提高其防腐性能.%Q235 steel sheets were treated by zirconium-based chemical conversion in an environment-friendly solution containing 1.4wt.% of ZRT-955 zirconization agent at a temperature of 20 ℃ and pH 4.5 for 12 min. The effects of baking temperature and corrosion inhibition treatment on corrosion resistance of the zirconium-based conversion film were studied by electrochemical impedance spectroscopy in an artificial sweat solution composed of 0.35% (NH4)2SO4and 0.05% NaCl. The optimal baking temperature was determined to be 180 ℃. The post-treatment with siloxane ketone inhibitor greatly improves the corrosion resistance of zirconium-based conversion film.