During use, due to the influence of air and environment, a black substance appears on the surface of electric heaters, which requires blackening treatment. Blackening treatment is actually a process of heat treatment for metal objects such as stainless steel. After treatment, a layer of oxide film forms on the surface to achieve anti-corrosion and anti-rust purposes. After heat treatment, the wear resistance of the heater surface is improved, the surface hardness is increased, and it does not affect the internal components of the electric heater.
Under normal working conditions, the simplest method for blackening treatment of electric heater surfaces involves the following steps:
1. First, clean the metal tube surface to keep it clean;
2. Second, perform degreasing treatment on the surface. This process can completely immerse the metal tube in the degreasing solution. The pH value of the degreasing solution should be around 13, and the time should be no less than half an hour. After degreasing, rinse with clean water.
3. Next, pickling can be carried out. The pH value of the pickling solution should be around 3, and the treatment time should not exceed 10 minutes. After pickling, rinse with clean water;
4. Blackening treatment: The pH value of the bath solution should be between 2-4, and the treatment time is about 10 minutes. After blackening, be sure to clean thoroughly;
5. Finally, dry and apply oil;
