Always find stainless steel products in the use of a period of time, the surface of stainless steel material is not as bright as the new, and even stainless steel will appear black phenomenon, affecting the beauty of stainless steel products at the same time, but also affect the performance of stainless steel products. So what is the reason that causes stainless steel products to become black and oxidized? And how is the brightness of stainless steel products are graded and classified? The point is how to polish stainless steel products to keep the surface brightness of stainless steel products? Here are more knowledge about stainless steel Oh.
The causes of stainless steel oxidation
Stainless steel in hot processing, mechanical processing or placed after a certain period of time its surface will form a layer of black or gray oxide, its main components are Cr2O3, NiO and very insoluble FeO, Cr2O3, their presence on the one hand affects the appearance of quality, on the other hand, also affect the performance of the product, so to take appropriate measures to remove. Stainless steel polishing as a mature surface treatment method, has been widely used, polishing can further improve the corrosion resistance of stainless steel and brightness effect.
Stainless steel brightness grading
Grade 1: white oxide film on the surface, no brightness.
Grade 2: slightly bright, can not see the outline.
Grade 3: brightness is good, can see the outline.
Grade 4: bright surface, more clearly visible contours (equivalent to the surface quality of electrochemical polishing).
Grade 5: mirror-like brightness.
Stainless steel polishing methods
1. Mechanical polishing. Is by cutting, material surface plastic deformation to remove the convex part of the polished and get a smooth surface polishing method, the general use of oil stone bar, wool wheel, sandpaper, etc., mainly by hand, special parts such as the surface of the rotating body, can use the rotary table and other auxiliary tools, the surface quality requirements of the high can be used to ultra-precision research polishing method.
2. Chemical polishing. Is to let the material in the chemical medium surface microscopic convex part than the concave part of the priority dissolution, so as to get a smooth surface.
3. Electrolytic polishing. The basic principle is the same as chemical polishing, that is, by selective dissolution of the material surface micro projection part, so that the surface is smooth. Compared with chemical polishing, can eliminate the influence of cathodic reaction, the effect is better.
4. Ultrasonic polishing. The workpiece into the abrasive suspension and placed together in the ultrasonic field, relying on the ultrasonic oscillation effect, so that the abrasive in the workpiece surface grinding polishing.
5. Fluid polishing. It relies on the high-speed flow of liquid and the abrasive particles it carries to scour the surface of the workpiece to achieve the purpose of polishing. Commonly used methods are: abrasive jet processing, liquid jet processing, hydrodynamic grinding, etc.
6. Magnetic grinding and polishing. Is the use of magnetic abrasives in the magnetic field under the action of the formation of abrasive brush, the workpiece grinding processing. This method has high processing efficiency, good quality, easy to control the processing conditions, and good working conditions.
In fact, stainless steel surface blackening and oxidation is a phenomenon that can not be avoided, because stainless steel products, no matter what field they are used in, will make stainless steel products attached to some pollution and bacteria, so the best way to eliminate the oxidation of stainless steel products, is to do a polishing of stainless steel products, so that not only can oxidation of stainless steel products become clean as new, but also enhance the corrosion resistance of stainless steel products. On the polishing method of stainless steel products small list of several, free to choose the method of polishing stainless steel.
