Commonly used stainless steel surface treatment techniques include the following treatment methods:
① surface natural color whitening treatment;
② surface mirror brightening treatment;
③ surface coloring treatment.
Surface natural color whitening treatment:
During the processing of stainless steel, black oxide skin is produced after coiling, edge binding, welding or artificial surface heating. This hard gray-black oxide scale is mainly composed of two kinds of EO4, NiCr204 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.
At present, there are two main methods of oxide skin treatment:
(1) sandblasting (shot) method: mainly using 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. After processing, it basically looks like a matte color. This method is more suitable for large and complex products.
Stainless steel surface mirror bright treatment method:
According to the complexity of stainless steel products and user requirements, methods such as mechanical polishing, chemical polishing, and electrochemical polishing can be used to achieve mirror gloss.
The advantages and disadvantages of these three methods are as follows:
Surface coloring treatment: stainless steel coloring not only endows stainless steel products with various colors, increases the variety of designs and colors 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;
(2) electrochemical oxidation coloring method;
(3) ion deposition oxide coloring method;
(4) high temperature oxidation coloring method;
(5) gas phase cracking coloring method.
