Commonly used stainless steel spring surface treatment technology has the following treatment methods: ① surface whitening treatment; ② surface mirror bright treatment; ③ surface coloring treatment.
Surface whitening treatment: During the processing of stainless steel springs, black oxide skin is produced by rolling, tying, welding or artificial surface fire heating. This hard gray-black oxide scale is mainly composed of two EO4 components, NiCr2O4 and NiF. In the past, hydrofluoric acid and nitric acid were generally used for strong corrosion removal. However, this method has high cost, pollutes the environment, is harmful to human body, and is highly corrosive, and is gradually eliminated. At present, there are two main methods of oxide skin treatment.
(1) Sand blasting (pellet) method: mainly use the method of spraying micro glass beads to remove the black oxide scale 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 dipping. So as to achieve the purpose of whitening the natural color of stainless steel. After processing, it basically looks like a dull color. This method is more suitable for large, complex products.
Mirror bright treatment method of stainless steel surface: According to the complexity of stainless steel products and different user requirements, mechanical polishing, chemical polishing, electrochemical polishing and other methods can be used to achieve mirror luster. The advantages and disadvantages of these three methods are as follows:
Surface coloring treatment: Stainless steel coloring not only gives stainless steel products various colors, increases the variety of products, but also improves the wear resistance and corrosion resistance of products.
Stainless steel spring coloring methods are as follows:
⑴ chemical oxidation coloring method;
(2) Electrochemical oxidation coloring method;
(3) Ion deposition oxide coloring method;
⑷ high temperature oxidation coloring method;
⑸ gas-phase cracking coloring method.
