In most cases, blackening treatment on steel, also known as black oxidation, can enhance corrosion resistance to a certain extent. However, the protective effect remains somewhat limited. To significantly improve both corrosion resistance and lubrication of the blackened layer, additional measures like oil immersion or subsequent rust prevention treatment are still necessary.

Generally, the steel blackening (black oxidation) treatment can effectively improve the corrosion resistance, but the protective effect is still quite limited. Oil immersion or subsequent rust prevention treatment is still required to really improve the corrosion resistance and lubricity of the blackened layer.