What is the nitrocarburizing process

What is the nitrocarburizing process

        The method of simultaneously infiltrating carbon elements in a process based on nitriding is called nitrocarburizing. Commonly known as nitrocarburizing. But for the hardness of the nitrocarburized layer of most alloy steels, soft nitriding is not soft.

        The so-called nitrocarburizing is not only to highlight the characteristics of nitriding, but also to distinguish carbonitriding.

        The mechanism of co-infiltration is similar to that of nitriding. As time goes by, the concentration of surface nitrogen and carbon continues to increase, causing reaction and diffusion to form a white layer and a diffusion layer.

        The medium used for nitrocarburizing must be able to decompose active nitrogen and carbon atoms at its process temperature. When the medium is ammonia and the exothermic or endothermic atmosphere is added to form a mixed atmosphere at the same time, the following decomposition reaction will occur, which can provide both active nitrogen atoms and active carbon atoms, thereby realizing nitrogen and carbon atoms at the same time Infiltrate.

        Due to the infiltration of carbon, the phase of the nitrocarburizing surface layer is more complicated. For example, when the nitrogen content is (w) 1.8% and the carbon content is (w) 0.35%, an eutectoid reaction occurs at 560°C to form a mechanical mixture of α+γ´+z. It should be pointed out that carbon mainly penetrates into the compound layer, but hardly penetrates into the diffusion layer, because the solubility of carbon is extremely low at the temperature of nitrocarburizing.