The difference between galvanizing and hot-dip galvanizing

The differences between electroplating galvanization and hot-dip galvanization are as follows:

1. Different concepts:

Hot-dip galvanization, also known as hot-dip zinc coating, is an effective method of metal corrosion protection, mainly used in various industries' metal structure facilities. It involves immersing rust-free steel components into molten zinc at around 500°C to achieve a zinc coating on the surface of the steel, thus providing corrosion resistance.

Electroplating galvanization, also known as cold galvanization, is the process of forming a uniform, dense, and well-bonded metal or alloy deposition layer on the surface of a workpiece through electrolysis. Compared to other metals, zinc is relatively inexpensive and easy to plate, making it a low-cost corrosion-resistant plating layer. It is widely used in the protection of steel and iron parts, especially for preventing atmospheric corrosion, as well as for decoration.

2. Different processes:

Hot-dip galvanization process: pickling of the finished product - rinsing with water - adding flux - drying - hanging for galvanization - cooling - passivation - cleaning - polishing - completion of hot-dip galvanization.

Electroplating galvanization process: chemical degreasing - hot water rinsing - water rinsing - electrolytic degreasing - hot water rinsing - water rinsing - strong corrosion - water rinsing - electroplating with zinc-iron alloy - water rinsing - water rinsing - brightening - passivation - water rinsing - drying.

3. Different techniques:

Hot-dip galvanization involves multiple processing steps. The workpiece needs to go through degreasing, pickling, flux immersion, drying, etc., before it can be immersed in the molten zinc bath for a certain period of time. This is the process of hot-dip galvanization. For example, hot-dip galvanized pipes are processed in this way.

Electroplating galvanization is processed using electrolytic equipment. After degreasing and pickling, the workpiece is immersed in a solution containing zinc salt and connected to the electrolytic equipment. Zinc is deposited on the workpiece through the directional movement of the positive and negative poles' electric current.

4. Different appearances:

The overall appearance of hot-dip galvanization is slightly rougher, with visible process watermarks and drips, especially at one end of the workpiece. The overall color is silver-white. On the other hand, the surface of electroplating galvanization is smoother, mainly in yellow-green color, but it can also appear in various colors such as blue-white and white with green light. The workpiece is generally free from zinc tumors or agglomerations.