A Study on Environment-friendly Acid Pickling Solution for Magnesium Alloys

CrO_3 is replaced by conventional acids, such as H_3PO_4 and H_2SO_4.An environment-friendly acid picking solution for magnesium alloys is developed by addition of picking additive and corrosion inhibitor. Effectiveness of acid picking solutions with H_3PO_4 and H_2SO_4 is studied respectively. The results show that the acid pickling solution with H_3PO_4 is better than with H_2SO_4 in pickling effect. Effectiveness of acid pickling solutions with different corrosion inhibitors are analyzed and the results show that the inhibitor (CH_2)_6N_4 has a better pickling quality on the samples. The optimum formula and process are sorted out by orthogonal test. The results also show that solution acidity and inhibitor have a great influence on the pickling effectiveness and suface quality of magnesium alloys. And additive can also improve pickling effectiveness and surface quality of magnesium alloys.