Anti-corrosion method of hexagon bolts

For people who use hexagonal bolts, anti-corrosion treatment is an important part. According to different corrosion conditions, different treatment methods can be used. The following briefly introduces several anti-corrosion treatment methods for hexagonal bolts.

1. Oxidation
Since the hexagonal bolts will not have the ability to prevent rust due to blackening, they will quickly rust after no oil. The torque preload consistency of the blackened square column template is also poor. If improvement is needed, grease can be applied to the internal thread during assembly and then tightened.

2. Sherardizing
Sherardizing is a solid metallurgical thermal diffusion coating of zinc powder. It has good uniformity, can obtain a uniform layer in the threads and blind holes of hexagon bolts, and its processing process is pollution-free and environmentally friendly.

3. Electro-galvanized
The electro-galvanizing process is prone to hydrogen embrittlement and has poor consistency. Connect it with a square column template with a height of 500, and pay attention to the coincidence of the card slot interface during the docking assembly process.

4. Cadmium plating
The corrosion resistance of cadmium coating is very good, especially in the marine atmosphere, its corrosion resistance is better than other surface treatments. The waste liquid treatment in the cadmium electroplating process is expensive, and its price is about 15-20 times that of electro-galvanized zinc. Therefore, it is not suitable for general industries, and is suitable for hexagonal bolts for oil rigs and HNA aircraft.

5.Chrome plating
The chromium coating is very stable in the atmosphere, is not easy to change color and lose luster, has high hardness and good wear resistance. Chrome plating on hexagon bolts is usually used for decorative purposes.

6. Phosphating
Two commonly used hexagonal bolt phosphating: zinc phosphating and manganese phosphating. Zinc-based phosphating has better lubricating properties than manganese-based phosphating, while manganese-based phosphating has better corrosion resistance and wear resistance. Many industrial fasteners are treated with phosphating oil. Because it has good torque pre-tightening force consistency, it can guarantee to meet the tightening requirements expected by the design in the assembly process, so it has been widely used in the industry, especially in the connection of some important parts.

7. Silver-plated, nickel-plated
The silver coating can not only prevent corrosion, but also can be used as a solid lubricant for hexagonal bolts. For cost reasons, nuts are silver-plated, bolts are not used, and sometimes small bolts are also silver-plated. Hexagon bolts are plated with nickel and are mainly used in places that require corrosion resistance and good conductivity, such as the lead-out terminals of car batteries.