The surface treatment process of the common stainless steel plate mainly consists of three aspects: the surface whitening treatment, the surface mirror bright treatment and the surface coloring treatment.
Whitening treatment of stainless steel plate’s surface
The surface of the stainless steel color bleaching treatment, refers to the process of stainless steel processing, scroll plate, rolling edge, welding or by artificial surface fire heating treatment, stainless steel plate surface black oxide. The hard black oxide is mainly two components of EO4 NiCr2O4 and NiF, was removed with hydrofluoric acid and nitric acid and other strong corrosive methods. But this method is costly, environmental pollution, harmful to human health, and corrosive, so it is being eliminated.
Now there are two ways to deal with the oxide skin. The first is sand blasting (pellet) method, that is, the method of spraying micro glass beads is used to remove the black oxide surface. The second is the chemical method of cleaning liquid is a pollution-free pickling passivation cream and non-toxic inorganic additives at room temperature with the immersion, and natural whitening processing of stainless steel plate. After processing, the stainless steel plate appears to be matt. The method is applicable to large and complex products.
Bright mirror finish on stainless steel plate’s surface
Depending on the complexity of the stainless steel plate and the user’s requirements, mechanical polishing, chemical polishing and electrochemical polishing can be used to achieve mirror gloss.
Coloring treatment of stainless steel plate’s surface
Stainless steel plate coloring treatment can not only increase the color of the surface of the product, but also increase the variety of color and variety, and also increase the wear resistance and corrosion resistance of the stainless steel products.
The main methods of coloring treatment of stainless steel are: oxidation dyeing, electrochemical oxidation coloring, ion deposition, oxide coloring, high temperature oxidation coloring, and gas phase cracking coloring.
The following brief comment on these methods, the first is the chemical oxidation coloring is in a specific solution, forming a film color by chemical oxidation, a mixture of sodium dichromate method, method, curing method, acid oxidation and alkaline oxidation; second is the electrochemical coloring method, which is in a specific solution. The formation of surface film on stainless steel color by electrochemical oxidation; third is the deposition of oxide ion chemical coloring method, method of the stainless steel workpieces on the vacuum coating machine for vacuum evaporation plating; fourth is the high temperature oxidation coloring in molten salt in particular, immersed in the workpiece is maintained in a certain process parameters, make the workpiece the formation of a certain thickness of oxide film, while showing a different color. The final method is gas phase cracking staining, which is more complex and is less used in industry.
The above three kinds of stainless steel plate surface treatment process each has advantages, choose which method, need according to the stainless steel products of the structure, material, and the surface of the different requirements, adopt the appropriate method for processing.
Source: China Stainless Steel Plate Manufacturer – Yaang Pipe Industry Co., Limited (www.yaang.com)