Study on technical properties of cyanide-free alkaline galvanizing
The dispersing ability and deep plating ability of the cyanide-free galvanizing plating solution used in this time were good.When the current density was 1.70-2.00 A/dm2 and the bath tem-perature is 21-22℃,the deposition rate of zinc layer was about 20 μm/h,and the concentration of zinc ions had a great influence on the deposition rate.The zinc layer had a uniform and fine silver-gray or silver-white appearance,with iridescent colors of green,yellow and purple after passivation.The binding force,corrosion resistance and hydrogen brittleness of the zinc layer met the requirements of HB5035-1992.The oxidation phosphating film was prepared on zinc layer,and the appearance and corrosion resistance of the film met the technological requirements.By adjusting the concentration of zinc ions in the plating solution according to the Hall bath test,the appearance of zinc layer and the change of deposition rate,the zinc ions in the plating solution could be supplemented by increasing the area of zinc plate anode or adding concentrated liquid.The test plating effect of small parts was good and met the delivery standard.
万方数据
维普
