The difference between electro-galvanizing and hot-dip galvanizing of steel castings

Electro-galvanizing and hot-dip galvanizing are commonly used surface treatments for precision castings

1. Electro-galvanizing: Electro-galvanizing is a commonly used galvanizing process. It can form a uniform, dense and corrosion-resistant zinc layer on the surface of precision castings. The advantages of electro-galvanizing are uniform coating thickness, beautiful appearance, and good corrosion resistance. It is suitable for surface protection in the manufacture of precision castings and is often used in the manufacture of furniture, electrical appliances, auto parts, etc.

2. Hot-dip galvanizing: Hot-dip galvanizing is a galvanizing process in which the steel surface is immersed in molten zinc, causing a chemical reaction between the zinc and the steel surface to form a zinc-iron alloy layer. The advantages of hot-dip galvanizing are large coating thickness, good corrosion resistance and high mechanical properties. It is suitable for manufacturing heavy-duty components of precision castings and components with high corrosion resistance requirements. It is widely used in construction, bridges, automobiles, ships and other fields. . It should be noted that the selection of the appropriate galvanizing process should be determined based on the specific requirements of the precision castings and the use environment. At the same time, in order to ensure the galvanizing effect, a regular galvanizing manufacturer should be selected for galvanizing treatment, otherwise the castings may rust and be scrapped during shipping.

Little knowledge: In addition to electro-galvanizing and hot-dip galvanizing, there are two other galvanizing processes, mechanical galvanizing and spray zinc.

So what are the advantages and disadvantages of the electro-galvanizing and hot-dip galvanizing processes commonly used for precision castings? Advantages of electrogalvanizing:

1. Thin layer: The zinc layer of electro-galvanized is thinner than hot-dip galvanized, usually between 5-20 microns, so the surface of electro-galvanized is smooth and will not change the size and shape of the steel.

2. Uniformity: The zinc layer of electroplated zinc is uniform and can be coated on the surface of complex-shaped objects, such as screws and nuts.

3. Low cost: The production cost of electro-galvanizing is relatively low because it does not require heating and cooling like hot-dip galvanizing.

4. Environmental protection: The production process of electro-galvanizing does not produce waste gas and waste water, so it has less impact on the environment.

Disadvantages of electrogalvanizing:

1. Poor corrosion resistance: The zinc layer of electro-galvanized steel is thinner than that of hot-dip galvanized steel, so its corrosion resistance is relatively poor, especially in humid and corrosive environments, it is easy to rust.

2. Poor wear resistance: The zinc layer of electro-galvanized steel is thinner than that of hot-dip galvanized steel, so its wear resistance is relatively poor and it is easy to be scratched and worn.

3. Limited scope of application: Electro-galvanizing is usually used for steel products indoors and in mildly corrosive environments, such as furniture, electrical appliances, auto parts, etc.

Advantages of hot dip galvanizing:

1. Strong corrosion resistance: The zinc layer of hot-dip galvanizing is thicker than that of electro-galvanizing, usually between 45-100 microns, so its corrosion resistance is relatively strong, especially in humid and corrosive environments, it is not easy to rust.

2. Strong wear resistance: The zinc layer of hot-dip galvanizing is thicker than that of electro-galvanizing, so its wear resistance is relatively strong and is not easily scratched and worn.

3. Wide scope of application: Hot-dip galvanizing is usually used for steel products outdoors and in severely corrosive environments, such as buildings, bridges, pipelines, etc.

Disadvantages of hot dip galvanizing:

1. High cost: The production cost of hot-dip galvanizing is relatively high because it requires heating and cooling.

2. Not suitable for complex shapes: The zinc layer of hot-dip galvanizing is not very uniform and is not suitable for complex-shaped surfaces, such as screws and nuts.

3. Environmental issues: The production process of hot-dip galvanizing will produce waste gas and waste water, which will have a greater impact on the environment.