What should I do if the conductor of copper braided wire is black after annealing?

The figure of copper braided wire can be seen everywhere in daily life, because it really has a lot of uses, but the premise is that the quality of copper braided wire should meet the corresponding standards, if the copper braided wire is black, it should be used with caution, and it must be qualified after improvement.

When processing copper braided wire, surface discoloration and blackening occur immediately after annealing or after a period of time, we can consider this phenomenon to be a corrosion process, and it is a chemical corrosion beginning, and then electrochemical corrosion may occur.

Since it is corrosion, there are many factors related to it, including the composition of the environmental medium, temperature, properties, the surface state of the metal, chemical composition, organizational structure, stress state, etc., for example, the oxidation of copper in the air can be carried out at room temperature, and a thin oxide film can be generated on the surface of copper.

In order to avoid similar phenomenon in the wire and improve the quality of copper braided wire, the protective gas should be purified to avoid harmful gases such as oxygen and water vapor entering the annealing tank; At the same time, during the air cooling process of the annealing tank, the protective gas is filled into the tank, and the pressure in the tank is more than 1 atmosphere.

The annealing wire should be treated with corrosion inhibition. Replace the damaged die in time to prevent the surface of the wire from being scratched due to the damage of the die, resulting in more lubricating oil remaining in the scratch and causing product discoloration and blackening. In addition, the annealing tank should be washed with high pressure water regularly, dried and cleaned to keep the tank clean.

In addition, when processing copper braided wires, N2 gas is used as far as possible to replace compressed air to test the air tightness of the annealing tank, and continuous pumping is carried out during the process of heating the annealing tank to 200 ° C to eliminate all adverse factors.