Commonly used surface treatment technologies for stainless steel pipes include the following treatment methods: ① surface natural color whitening treatment; ② surface mirror bright treatment; ③ surface coloring treatment.
1. Natural color whitening treatment on the surface of stainless steel pipe:
During the processing of stainless steel pipes, black oxide scales are produced after coiling, edge binding, welding or artificial surface heating. This hard gray-black scale is mainly composed of two kinds of EO4, NiCr2O4 and NiF. In the past, hydrofluoric acid and nitric acid were generally used for strong corrosion removal. However, this method costs a lot, pollutes the environment, is harmful to the human body, and is highly corrosive, so it is gradually eliminated.
There are two main methods of oxide scale treatment:
⑴Sandblasting (shot) method: mainly uses the method of spraying glass beads to remove the black oxide skin on the surface.
(2) Chemical method: Use a non-polluting pickling passivation paste and a non-toxic cleaning solution with inorganic additives at room temperature for immersion. So as to achieve the purpose of whitening the natural color of stainless steel pipes. After processing, it basically looks like a matte color.
2. Stainless steel tube surface mirror bright treatment:
According to the different requirements of stainless steel pipes, mechanical polishing, chemical polishing, electrochemical polishing and other methods can be used to achieve mirror gloss.
3 surface coloring treatment:
The coloring of stainless steel pipes not only endows stainless steel products with various colors, increases the variety of products, but also improves the wear resistance and corrosion resistance of products.
Stainless steel coloring methods are as follows:
(1) chemical oxidation coloring method;
⑵ Electrochemical oxidation coloring method;
(3) Ion deposition oxide coloring method;
⑷ high temperature oxidation coloring method;
⑸ gas phase pyrolysis coloring method.
Tips: According to the production method, stainless steel pipes are divided into two categories: seamless pipes and welded pipes. Seamless steel pipes can be divided into hot-rolled pipes, cold-rolled pipes, cold-drawn pipes and extruded pipes, etc. Cold-drawn and cold-rolled pipes are the secondary processing of steel pipes. Welded pipes are divided into straight seam welded pipes and spiral welded pipes.