环保型常温锌钙系磷化工艺

Environment-friendly Zn–Ca phosphating process at room temperature

研究了(NH4)2MoO4、Ca(NO3)2、硫脲、柠檬酸、温度、时间和pH等工艺条件对磷化膜层的耐蚀性和表面状况的影响。通过正交试验法确定的最佳工艺配方为:氧化锌4.5g/L,磷酸11.25mL/L,硝酸钙8g/L,钼酸铵4.0g/L,硫脲1.5g/L,柠檬酸1.4g/L,温度25～35°C,时间20min以上,pH2.5～3.0。该磷化工艺操作简单,清洁环保,常温即可磷化,使用周期较长,易维护。

The effects of （NH4）/MoO4, Ca（NO3）2, thiourea, citric acid, temperature, time and pH on the corrosion resistance and surface conditions of phosphating film were studied. The optimal process conditions determined by orthogonal test are as follows： ZnO 4.5 g/L, HaPO4 11.25 mL/L, Ca（NO3）2 8 g/L, （NH4）2MoO4 4.0 g/L, thiourea 1.5 g/L, citric acid 1.4 g/L, temperature 25-35 ℃, pH 2.5-3.0, and time 〉20 min, and. The phosphating process has features of simple operation, environmental friendliness, phosphating at room temperature, long service life and easy maintenance.