不锈钢表面电化学磷化及膜层性能

采用由4.0 g/L ZnO、4 g/L CaCl₂、5%(体积分数)H₃PO₃、4 g/L酒石酸和3 g/L氯酸钠组成的锌钙系磷化液,在温度为70°C和电流密度为4 mA/cm²的条件下对1Cr₁₈Ni₉Ti不锈钢表面进行电化学磷化20 min。对比了所得磷化膜与采用相同磷化液化学磷化2 h所得膜层的表面形貌、相结构和耐蚀性。结果表明,与化学磷化相比,电化学磷化所需时间较短,所得膜层的结晶大小和分布均匀,耐腐蚀性更好。

Electrochemical phosphating of stainless steel and properties of the phosphating film

Electrochemical phosphating was conducted on Cr18Ni9 Ti stainless steel in a zinc–calcium phosphating solution comprising ZnO 4.0 g/L, CaCl2 4 g/L, H3 PO3 5 vol.%, tartaric acid 4 g/L, and sodium chlorate 3 g/L at temperature 70 °C and current density 4 m A/cm2 for 20 min. The surface morphology, phase structure, and corrosion resistance of the phosphating film obtained electrochemically were compared with that prepared chemically in the same solution for 2 h. The results showed that electrochemical phosphating needed less time than chemical phosphating, and produced films with uniform size and distribution of crystals and better corrosion resistance.