1. Galvanizing, screws, and zinc coatings during pro […]
1. Galvanizing, screws, and zinc coatings during production, storage, and transportation may appear white, black, black, etc., mainly the galvanized layer, corrosive media, and atmospheric moisture, oxygen, and carbon dioxide. Corrosion caused by exposure. To prevent this phenomenon, you can try to use the surface condition of the good material before the screw is processed. Due to the galvanizing process, the surface of the defective screw is easy to penetrate the corrosive medium such as acid, alkali, salt, etc., which is difficult to clean and causes corrosion.
The reasonable choice of packaging materials avoids the use of plastic products that are not compatible with zinc. Packaging materials such as galvanized iron sheet metal are good. The box can be placed in a desiccant with an appropriate amount of humidity to reduce relative humidity and reduce compatibility and prevent harmful gases. Treasury erosion.
To prevent the anti-corrosion treatment of China fasteners, the anti-corrosion treatment has been degreased, and the anti-rust screw and nut in the NASDAQ rust-removing and anti-rust agent water tank, or the use of zinc and chromium compounds to form a protective film on the metal surface, forming a spray method, and proceed Dry, cool, and then repeat the process once. The resulting thickness of about 5-8μ(, silver-gray, based on the information provided by the manufacturer of the display is said to have good rust and corrosion resistance. Lao plants are baked in this way. Covered with zinc chromate coating treatment, with high-strength steel bolt test, after two years of good results.
Phosphate treatment is a phosphate chemical treatment containing metal to the metal surface to form a phosphate protective film. The phosphating treatment solution is insoluble in water and has excellent adhesion to the phosphate film. It is the main purpose of the bottom layer and coating. Metal layer for cold adsorption of lubricant. Since the phosphate film is composed of a series of zinc, manganese, hydrogen phosphate, and iron phosphate crystals of different sizes, the film is porous, has a large specific surface area, has good absorption, and has a coating that is adsorbed by extra-long screws or a large number of Lubricant, so it is often used as a primer, or cold stamping to reduce friction and steel, cold drawn steel wire lubricating layer.
2. The oxidized steel parts will be immersed in an alkaline treatment solution containing an oxidant, such as potassium hydroxide or sodium hydroxide solution of nitric acid, and keep its boiling point at about 140℃, or nitric acid and sodium hydrogen nitrate impregnated steel parts Molten salt is pleasant to remove its surface layer. Eyes with a black iron oxide film in the composition of a mixture of ferrous oxide and iron oxide can be obtained and then quenched in water, which improves the corrosion ability of iron metals and is an easy And economical method.