The principle of hot dip galvanization

The principle of hot dip galvanizing is simply that the cleaned iron parts are soaked in zinc bath through the wetting action of the coplating agent to make the steel react with the molten zinc to form a alloyed leather film. Good hot dip galvanizing operations should be under strict control of all processes, fully play the function of the process. And if the operation of the previous process is not good enough, it will cause a chain of adverse reactions to the subsequent process, and a large increase in the cost of operation or cause bad hot dip galvanizing products. If the pretreatment is not good, the molten zinc can not fully react with the steel to form the most perfect galvanized film. If the post-treatment is not good, it will damage the appearance of the galvanized film and reduce the value of the goods.

advantages

1. The entire steel surface is protected, and it is easy for the dissolved zinc to be covered uniformly, no matter in the inner part of the pipe in the depression or any other corner where the coating is difficult to enter.

2. The hardness of galvanizing layer is greater than that of steel. The top-layer Eta layer has only 70 DPN hardness, so it is easy to be dented by collision. However, the lower Zeta layer and delta layer have 179 DPN hardness values and 211 DPN hardness values, respectively, which are higher than the 159 DPN hardness values of iron, so its impact resistance and abrasion resistance are quite good.

3. In the corner area, the zinc layer is often thicker than other areas, and has good toughness and abrasion resistance. And other coating is in this corner place, often be the thinnest the least easy to construct, the most vulnerable injury, therefore often must maintain again.

4. Even if it is due to heavy mechanical injury or other reasons. When a small part of the zinc layer falls off and the iron base is exposed, the surrounding zinc layer ACTS as a sacrificial anode to protect the steel here from erosion. Other coatings, on the other hand, are just the opposite, rust will be generated immediately and quickly spread below the coating, causing the coating to peel off.

5. The depletion of zinc layer in the atmosphere is very slow, about 1/17 to 1/18 of the corrosion rate of steel, and can be estimated. Its life is much longer than any other coating.

6. Coating life in a specific environment depends mainly on the thickness of the coating. The thickness of the plating layer is determined by the thickness of the steel, that is, the thicker the steel is easier to get the thicker the plating layer, so the thicker steel part in the same steel structure must also get the thicker the plating layer, so as to guarantee the longer life.

7. Due to aesthetics, art, or the use of a certain serious corrosive environment, the galvanized coating can be applied to deal with the duplex system again. As long as the paint system is correctly selected and easy to be constructed, the anticorrosion effect is 1.5~2.5 times better than that of the single painting and hot dip zinc combined.

8. To protect steel with zinc coating, there are several other methods besides hot dip galvanizing. Generally, hot dip galvanizing method is the most widely used, has the best corrosion protection effect and has the best economic benefits.