Brief introduction to stainless steel surface treatment technology: This article introduces stainless steel varieties and various stainless steel surface treatment methods, and analyzes the advantages and disadvantages of various treatment methods. Introduction to stainless steel varieties: Stainless steel generally contains high-quality metal elements such as chromium (CR), nickel (NI), molybdenum (MO), and titanium (TI). Common stainless steels are chromium stainless steels, which contain CR ≥ 12%. Nickel-chromium stainless steel contains CR ≥ 18% and NI ≥ 12%. From the metallographic structure of stainless steel, there are austenitic stainless steels, such as: 1CR18NI9TI, 1CR18NI11NB, CR18MN8NI5. Martensitic stainless steel, such as: CR17, CR28, etc. Commonly referred to as non-magnetic stainless steel and magnetic stainless steel.
Stainless steel surface treatment varieties: stainless steel surface treatment:
(1) The surface is whitened.
(2) Bright treatment of mirror stone on the surface.
(3) Surface coloring treatment: 1. During the processing of stainless steel, black oxide skin is produced by coiling, edging, welding or annealing. This hard gray-black oxide scale is mainly composed of two E04 components, NICR204 and NIF, which were generally removed by strong corrosion methods with hydrofluoric acid and nitric acid. However, this method is costly, pollutes the environment, is harmful to the human body, and is relatively corrosive, and is gradually eliminated.
At present, there are two kinds of treatment methods for this oxide scale:
(1) The sand blasting (shot) method is adopted.
(2) The chemical method is used. That is, 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. Basically it looks like the color of a glance. This method is more suitable for large and complex products and is worth popularizing and applying.
2. 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 stone luster.
Advantages and disadvantages of the three methods:
Mechanical polishing: good flatness, bright, labor-intensive, serious pollution, difficult to process complex parts, decreased gloss, high investment and cost. Simple workpieces, medium and small products and complex parts cannot be processed. The gloss of the whole product is not consistent, and the gloss does not last for a long time.
Chemical polishing: less investment, complex parts can be thrown, high efficiency and fast speed. If the brightness is insufficient, the polishing liquid needs to be humidified, and there is gas overflow, so wind-friendly equipment is required. Complicated products and products with low brightness requirements can be selected, and it is more cost-effective to process small batches.
Electrochemical polishing: mirror gloss, long-term maintenance, stable process, less pollution, low cost, and good anti-pollution. One-time investment is large, complex parts need to be equipped with tooling, auxiliary electrodes, and mass production needs to be cooled. It is necessary to maintain a mirror-bright product for a long time. The process is stable, easy to operate, and can be widely used.
3. Stainless steel coloring increases the color of stainless steel products and improves the wear resistance of products. Stainless steel coloring methods are as follows:
(1) Ion deposition of oxides or oxides.
(2) High temperature oxidation method.
(3) Chemical oxidation method. electrochemical oxidation.
(4) Gas-phase cracking method.
A brief overview of the various methods is as follows:
(1) The ion deposition oxide or oxide method is to place stainless steel workpieces in a vacuum coating machine for vacuum evaporation plating: for example: titanium-plated watch cases and watch straps. Usually golden yellow. This method is suitable for high-volume product processing. Because of the large investment and high cost, small batch products are not cost-effective.
(2) The high-temperature oxidation method is to immerse the workpiece in a specific molten salt and keep it within a certain process range, so that the workpiece forms a certain thickness of oxide film, and presents various colors.
(3) The chemical method is to form the color of the film through chemical oxidation in a specific solution. Generally, the "inco method" is used more, but if the color of a batch of products can be guaranteed to be consistent, it must be controlled by a reference telegraph.
(4) Electrochemical method, which is to form the color of the film by electrochemical oxidation in a specific solution, which is used in this business.
(5) The gas-phase cracking method is more complicated and less used in industry.
