Why does hot-dip galvanized seamless steel pipe cause chromatic aberration?
Mainly due to the violent reaction of iron and zinc. The violent reaction of Fe-Zn makes the original complete coating composed of alloy layer and pure zinc layer become the phenomenon of only alloy layer and no pure zinc layer. Gray or dark gray is the color of iron-zinc alloy. In addition, if the quality of the zinc solution deteriorates, the iron content in the zinc solution will increase, and the pure zinc layer on the surface after galvanizing will appear gray due to iron content, causing color difference.
Specific reasons:
(1) The material of the plated parts contains more elements such as carbon, silicon, sulfur, and phosphorus. The electrochemical reaction between iron and zinc is due to the inert electrode formed by this type of element, and the relative potential becomes higher, which causes the iron and zinc reaction to intensify.
(2)The content of aluminum and other metal elements in the zinc solution is too small, and for active steel and other materials galvanizing, the iron-zinc reaction cannot be effectively inhibited.
(3) The increase in iron content in the zinc liquid deteriorates the quality of the zinc liquid.
Improvement measures:
⑴ According to the material, choose the appropriate galvanizing temperature;
⑵ Adjust the composition of zinc liquid to control the content of aluminum and nickel in an appropriate range;
⑶ Shorten the zinc immersion time as much as possible;
⑷ After being out of the pot, add water as soon as possible to cool down.
⑸ Purify the zinc liquid in time to ensure the quality of the zinc liquid.
没有评论:
发表评论