What are several methods of surface treatment technology for stainless steel parts? ​

1、 Whitening treatment of surface natural color: during the processing of stainless steel, black oxide skin is generated after rolling, binding, welding or artificial surface fire baking and heating treatment.Previously, hydrofluoric acid and nitric acid were generally used for strong corrosion removal. However, this method costs a lot, pollutes the environment, is harmful to human body, and is corrosive, so it is gradually eliminated.
At present, there are two main methods for oxide skin treatment:
1. Sand blasting (shot) method: it mainly adopts the method of spraying micro glass beads to remove the black oxide skin on the surface.
2. Chemical method: use a pollution-free pickling passivation paste and a non-toxic cleaning solution with inorganic additives at room temperature for leaching. So as to achieve the purpose of whitening the natural color of stainless steel. After treatment, it basically looks matte. This method is suitable for large and complex products.

2、 Surface coloring treatment: Stainless Steel Coloring 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. The methods of stainless steel surface coloring are as follows:
1. Chemical oxidation coloring method: refers to the color of the film formed by chemical oxidation in a specific solution, including dichromate method, mixed sodium salt method, vulcanization method, acid oxidation method and alkaline oxidation method. Generally, "inco" is used more, but if you want to ensure that a batch of products have the same color, you must use the reference electrode to control.
2. Electrochemical oxidation coloring method: it is the color of the film formed by electrochemical oxidation in a specific solution.
3. Ion deposition oxide coloring method: put stainless steel workpiece in vacuum coating machine for vacuum evaporation plating. For example, titanium plated watch cases and watch bands are generally golden yellow. This method is suitable for mass production processing. Because of large investment and high cost, small batch products are not cost-effective.
4. High temperature oxidation coloring method: it is to immerse the workpiece in a specific molten salt and maintain certain process parameters, so that the workpiece forms a certain thickness of oxide film and presents various colors.
5. Gas phase cracking coloring method: it is relatively complex and is rarely used in industry.