Black Oxidation Treatment Of CNC Machining Gears
The anti rust effect of blackening treatment on gears mainly depends on the strict control of the treatment process and the rationality of parameter settings. The following is a clear answer about the anti rust effect of blackening treatment:
1. Principle and Effect
Principle: Blackening treatment is a chemical method that forms a layer of oxide film on the surface of gears, mainly ferric oxide (Fe2O3). This oxide film can isolate air and water, thus achieving the purpose of rust prevention.
Effect: This oxide film can effectively improve the corrosion resistance of gears and extend their service life. Under appropriate conditions, this oxide film can protect gears from corrosion for a relatively long time.
2. Influencing factors
Processing temperature: Blackening treatment is usually carried out within the temperature range of 135~155 ℃. Low temperature may lead to incomplete formation of the oxide film, while high temperature may damage the formed oxide film.
Processing time: Processing time is also a key factor, usually between 10 and 30 minutes. If the processing time is too short, the oxide film may be too thin and the rust prevention effect may be poor; If the processing time is too long, it may cause the oxide film to be too thick, affecting the accuracy and performance of the gear.
Chemical composition: The main components of the black liquid are sodium hydroxide and sodium nitrite. The concentration and proportion of these chemical components can also affect the quality and rust prevention effect of the oxide film.
3. Post processing and inspection
Post treatment: After blackening treatment, it is usually necessary to apply oil, wax, or paint to further enhance the rust prevention effect.
Inspection: The anti rust effect of blackening treatment can be tested through methods such as copper sulfate droplet method or salt spray test. For example, if there is no obvious rust after 96 hours of salt spray testing, it is considered qualified.
4. Advantages and precautions
Advantages: The cost of blackening treatment is low, the surface of the treated gear is uniform and beautiful, and it is not easy to peel off or peel off.
Attention: Before blackening treatment, it is necessary to ensure that the surface of the gear is clean, free of oil stains and rust; Strict control of temperature, time, and concentration and proportion of chemical components is required during the processing; The post-processing steps are equally important, and appropriate post-processing methods need to be selected based on specific circumstances.
The anti rust effect of Gear’s blackening treatment is significant, but the specific effect depends on the strict control of the treatment process and the rationality of parameter settings. Through reasonable processing procedures and strict quality control, it can be ensured that gears achieve good rust prevention effects and a longer service life.