In the process of transportation, the screw and zinc coating often appear white, black and black phenomena, mainly galvanized layer and corrosive medium and atmospheric water, oxygen, carbon dioxide exposure caused by corrosion.

In order to prevent this phenomenon, we can try to use the good material surface condition before the screw processing. Because of galvanizing process, the defective screw surface is easily penetrated by acid, alkali, salt and other corrosive media, so it is difficult to clean and cause corrosion.

The reasonable selection of packaging materials avoids the use of plastic products that are not zinc. Packaging materials, such as galvanized iron sheet metal, are the best, and can be placed in the box in a proper amount of humidity desiccant to reduce relative humidity compatibility and prevent harmful gas warehouse erosion. The so-called screw and nut metal surface treatment market LONGZINC (Nasdaq stock code rusty).

In order to prevent the non-standard screws from being degreased, they are degreased, and swim on the rust preventive screws and nuts of the rust removal and rust preventive agent, or use zinc and chromium compounds to form protective films on the metal surface. Spray method is formed and dried and cooled. Then the process is repeated once, and the obtained information is about 5? 8, silver gray, based on the information thickness provided by the manufacturer of the display. Good rust and corrosion resistance.

Phosphate treatment is a phosphate chemical treatment containing metal to metal surface to form phosphate protective film phosphating treatment solution, insoluble in water, and has excellent phosphate film tightness, as its main purpose of the bottom layer and coating cold adsorption lubricant metal layer. Because phosphate coating is composed of a series of zinc, manganese, hydrogen phosphate and iron phosphate crystals of different sizes, it is porous, has large specific surface area, has good absorption, adsorbed coating or a large number of lubricants, so it is often used as a bottom coating, or cold stamping to reduce friction and steel, cold drawing steel wire lubrication layer.

The oxidized steel parts will be impregnated in the alkali treatment solution containing oxidants, such as potassium hydroxide or sodium hydroxide solution of nitric acid, and keep its boiling point at about 140 C, or molten salts of steel parts impregnated with nitric acid and sodium hydroxide and nitrate. The removal of the surface layer is pleasant. The eyes with black iron oxide film in the composition of ferrous oxide and iron oxide can be obtained and then cooled suddenly in water. Corrosion of Raising Iron Metals