How to prevent aging and corrosion of screws

Galvanizing, screws and zinc coatings during production, storage, and transportation may appear white, black, black, etc., which are mainly caused by the exposure of the galvanized layer and corrosive media and atmospheric moisture, oxygen, and carbon dioxide corrosion.

In order 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. 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 the best. The box can be placed in a desiccant with an appropriate amount of humidity to reduce relative humidity. Prevent the warehouse from corroding harmful gases. The so-called metal surface treatment of screws and nuts is currently on the market LONGZINC.

In order to prevent the non-standard screw anti-corrosion treatment has been degreasing, and the anti-rust screw and nut in the rust and anti-rust agent water tank, or use the zinc and chromium compound to form a protective film on the metal surface, form a spray method, and perform 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. This baking plant is covered with zinc chromate coating treatment, with high-strength steel bolt test, after two years of good results. (Guide: Regarding the general problems of fastener grinding prevention)

Phosphate treatment is a phosphate chemical treatment containing metal to the metal surface to form a phosphate protective film. Phosphating treatment solution is insoluble in water and has excellent adhesion of the phosphate film as its main purpose. The layer and paint cold adsorb the metal layer of the 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 a good absorption, adsorption coating or a large amount of lubricant , So it is often used as a primer, or cold stamping to reduce friction and steel, cold drawn steel wire lubrication layer.

The oxidized steel parts will be immersed in alkaline treatment solution containing oxidizing agent, such as potassium hydroxide or sodium hydroxide solution of nitric acid, and keep its boiling point at about 140°C, or nitric acid and sodium hydrogen nitrate salt impregnated steel It is pleasant to remove the surface layer of molten salt, and the eyes with the black iron oxide film in the composition of the mixture of ferrous oxide and iron oxide can be obtained and then quenched in water, which is to improve the corrosion ability of ferrous metals. Easy and economical method.

More related galvanized stamping parts industry news: