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在低温磷化条件下,在磷化液中加入Ca~(2+)并以臭氧作为促进剂,在A3碳钢表面制备了磷化膜。通过SEM、XRD、EDS、FT-IR以及腐蚀电化学测试等手段对磷化膜进行表征,研究了Ca~(2+)和臭氧对磷化膜的结构和性能的影响。结果表明,在磷化液中添加Ca~(2+)所得磷化膜的质量随着Ca~(2+)浓度的提高而减小,添加Ca~(2+)可细化磷化膜的晶粒、提高磷化膜的致密度和耐蚀性能;溶解在磷化液中的臭氧具有细化磷化膜晶粒和促进晶粒生长的作用,能大幅提高磷化膜晶粒的形核率和磷化膜的主体形成速度。当磷化液的pH=2.70、Ca~(2+)浓度为1.8 g/L、臭氧含量为2.50 mg/L时,磷化膜的质量为5.46 g/m~2,其耐硫酸铜点滴腐蚀时间超过122 s,在5%NaCl溶液中的腐蚀电流为0.50μA/cm~2。
Under the condition of low temperature phosphating, the phosphating film was prepared on the surface of A3 carbon steel by adding Ca2 + into the phosphating solution and using ozone as accelerator. The phosphate coatings were characterized by SEM, XRD, EDS, FT-IR and electrochemical corrosion tests. The effects of Ca 2+ and ozone on the structure and properties of the phosphate coatings were investigated. The results showed that the mass of phosphating film with Ca2 + added to the phosphating solution decreased with the increase of Ca2 + concentration. The addition of Ca2 + could refine the phosphating film Grains, and improve the density and corrosion resistance of the phosphate coating; the dissolved ozone in the phosphating solution has the function of refining the crystal grains of the phosphate coating and promoting grain growth, and can greatly improve the nucleation of the phosphate coating crystal grains The rate of formation of the phosphating film and the bulk. When the pH value of the phosphating solution is 2.70, the concentration of Ca 2+ is 1.8 g / L and the content of ozone is 2.50 mg / L, the mass of the phosphating film is 5.46 g / m 2, The time exceeds 122 s, and the corrosion current in 5% NaCl solution is 0.50 μA / cm ~ 2.