Steel is very easy to be oxidized to form red rust in its natural state. If it is not oiled, it can hardly meet the requirements of storage, transportation and indoor use. On the one hand, zinc can have better corrosion resistance than iron without passivation. After passivation, it can be used indoors for a long time without rusting. On the other hand, zinc on the surface of steel can sacrifice itself to protect the steel, which can greatly extend the time of red rust. In addition, chromium plating generally has longer corrosion resistance than zinc plating. This is also the role of steel corrosion resistance.
Galvanizing is divided into hot-dip galvanizing and cold-dip galvanizing. The main raw material is zinc ingots. Whether hot-dip or cold-dip galvanizing can be used to achieve the color effect, the anti-corrosion effects of the two are quite different.
Cold galvanizing is also called electro-galvanizing. It uses electrolysis equipment to put the workpiece in a solution of zinc salt after degreasing and pickling, and connect it to the negative electrode of the electrolysis device; place a zinc plate on the opposite side of the workpiece and connect it to the electrolysis device The positive pole, turn on the power, use the directional movement of the current from the positive pole to the negative pole, and a layer of zinc will be deposited on the workpiece.
With the development of industry, hot-dip galvanizing products have been used in many fields. The advantage of hot-dip galvanizing is that it has a long anti-corrosion period. It has been a popular anti-corrosion treatment method to adapt to a wide range of environments. It is widely used in electric power towers, communication towers, railways, highway protection, street lamp poles, marine components, building steel structural components, substation ancillary facilities, light industry, etc.
The anti-corrosion period of hot-dip galvanizing is long, but the anti-corrosion period is different in different environments: 13 years in heavy industrial areas, 50 years in the ocean, 104 years in the suburbs, and 30 years in the city.
The thickness of the hot-dip galvanized alloy layer mainly depends on the chemical composition such as the silicon content of the steel, the cross-sectional area of the steel, the roughness of the steel surface, the temperature of the zinc pot, the galvanizing time, cooling speed, cold rolling deformation, etc.
