中温锌-锰系黑磷化液的制备及研究

Study and Preparation of Zn-Mn Series Black Phosphating Solution at Middle Temperature

研究了一种中温锌-锰系黑磷化配方及工艺。通过正交试验法确定了最佳黑磷化液配方及工艺:马日夫盐60.0g/L,硝酸锌35.0g/L,硝酸镍20.0g/L,氯酸钾6.0g/L,柠檬酸1.0g/L,硝酸锰20.0g/L,十二烷基苯磺酸钠为0.4g/L,施镀时间为30min,温度为60℃,pH为2.5。并考察了镀层的形貌、硬度、厚度以及耐蚀性能。该工艺用于钢铁件涂装前的表面预处理,具有溶液稳定、附着力强、耐蚀性好等特点。

A kind of Zn-Mn black phosphating formula and process at medium temperature was studied. The best black phosphating solution formula and process conditions were obtained by using the orthogonal test method as follows： manganous dihydrogen phosphate 60. 0 g/L, zinc nitrate 35. 0 g/L, nickel nitrate 20. 0 g/L, potassium chlorate 6.0 g/L, citric acid 1. 0 g/L, manganese nitrate 20. 0 g/L, sodium dodeeyl benzene sulfonate 0. 4 g/L, temperature 60 ℃, pH 2. 5 and plating time 30 min. Corrosion resistance, hardness, thickness and morphology of the coating were investigated. The process is used for pretreatment of steel and iron surfaces before coating process, it has the characteristics of stable solution, strong adhesion,good corrosion resistance etc.