Research Environmentally Friendly Liquid Silicate Passivation And Corrosion Resistance

Traditional chromate passivation is widely applied to the galvanized layer of protection, but traditional chromate passivation will produce hexavalent chromium compounds, because it has high toxicity and carcinogenicity, and serious environmental pollution and harm to human body, in the process of practical production, it caused the social harm and economic loss. So, therefore, the development of green environmental protection of the passivation process to replace the traditional chromate passivation process. Silicate passivation technology for small non-toxic, pollution, low cost, it will get the researchers’ attention and research.In this paper, we study the technology, green environmental protection silicate passivation solution used instead of toxic chromate passivation process. The silicate passivation form passivation film has good appearance, compactness and corrosion resistance. The passivation solution is given priority to with sodium silicate film-former; Contains effective material such as tannic acid and hydrogen peroxide. Through orthogonal experiments and single factor experiments, discussed the influence of each component of galvanized passivation membrane, and discusses the various process conditions (passivation passivation temperature and time, pH value, etc.) on the influence of formation and corrosion resistance of passivation film. The composition of the passivation solution and process conditions for:35 g/LNa2SiO3,10 mL/LH2O2 (30%),5mL/LH2SO4 (98%),2 g/L CuSO4,5 g/L tannins,10 g/L NaNO3, pH value of 2.0, passivation temperature is 50 ℃, passivation time for 30 s,60～ 70 ℃ ageing 5～10 min. The experimental materials for hot-dip zinc steel, the passivation film by lead acetate drop experiment, brine immersion test, salt spray test and chemical test methods such as research on the corrosion resistance of passivation samples, and the industrial expansion of silicate passivation technology experiment and the application prospect of research and analysis.Through the research, the silicate passivation solution can form uniform appearance, corrosion resistance, good colour passivation membrane, possesses the advantages of non-toxic, low pollution, low cost, can replace traditional pollution chromate passivation, can solve the problem of environmental pollution in the industry, it has good development prospects.