Surface Treatment Process of the Stainless Steel Step Nosing
Stainless steel has excellent characteristics such as unique strength, high wear resistance, superior corrosion resistance and resistance to rust. Therefore, it is widely used in various industries, but its application development largely determines the degree of development of stainless steel surface treatment technology.
In the process of processing, the stainless steel step nosing is processed by coiling, binding, welding or high-temperature annealing to produce black oxide skin. This kind of hard gray-black oxide skin is mainly composed of NiCr2O4 and NiFeO4, but this method is costly, pollutes the environment, and is harmful to the human body. Besides, the corrosion is relatively large, so it is gradually eliminated. At present, there are two kinds of treatment methods for this kind of oxide skin:
(1) Using blaster method
(2) Using chemical methods
To achieve the purpose of whitening the natural color of stainless steel. It basically looks like the color of a glance. This method is more suitable for large and complex products and is worthy of popularization and application.
According to the complexity of the stainless steel step nosing and the different user requirements, mechanical polishing, chemical polishing, electrochemical polishing and other methods can be used to achieve the mirror gloss.
The coloring of the stainless steel step nosing gives stainless steel products a variety of colors, increases the variety of products, and improves the wear resistance of the products.
There are several coloring methods for stainless steel step nosing:
(1) The ion deposition oxide or oxide method is to place the stainless steel step nosing in a vacuum coating machine for vacuum evaporation coating: for example: titanium-coated watch cases and watch bands are generally golden yellow. This method is suitable for mass product processing. Because of the high cost, it is not economical to apply the method on small batch products.
(2) The high-temperature oxidation method is to immerse the workpiece in a specific molten salt to maintain a certain process range, so that the stainless steel step nosing forms a certain thickness of oxide film, and presents a variety of different colors.
(3) The chemical method is to form the color of the film through chemical oxidation in a specific solution. However, if we want to ensure the color of a batch of products is consistent, it must be controlled by a reference electrode.
(4) The electrochemical method is to form the color of the film through electrochemical oxidation in a specific solution.
(5) The gas phase splitting method is more complicated and less used in industry.