And due to the iron content, the pure zinc layer on the surface after galvanizing will appear gray, causing color difference. The specific reason: d The material of the electroplated parts contains more carbon, silicon, sulfur and phosphorus elements. The electrochemical reaction between iron and zinc is attributed to the inert electricity formed by these elements, and the relative potential becomes higher, which causes the iron and zinc reaction to intensify.
The content of metallic elements such as aluminum in the zinc bath is relatively small. For galvanizing of active steel and other materials, the iron-zinc reaction cannot be effectively inhibited, and the iron content in the zinc solution increases, which reduces the quality of the zinc solution. Improvement measures: select the appropriate zinc plating temperature according to the material and adjust the zinc solution Composition to control the content of aluminum and nickel within an appropriate range.
Shorten the time for dipping zinc as much as possible; after getting out of the pot, please cool down in water as soon as possible. Purify the zinc liquid in time to ensure the quality of the zinc liquid.