What is Nitrocarburization?

This process, called nitrocarburization, is actually a thermochemical diffusion process. During this process, nitrogen, carbon and a very small number of oxygen atoms are spread on the surface of steel or other iron alloys. This forms a surface compound layer and forms a diffusion layer. There are two types of nitrocarburizing processes. Both types occur at low temperature, which falls somewhere between 490°C and 580°C. Normally this is below the tempering temperature of steel above 600°C. These processes either cause little or no deterioration. The nitrocarburization process is more commonly used in low alloy steels, mild steels and cast irons. However, it can be applied equally to any steel that is thermally stable at the temperatures of the process.
Austenitic and Ferritic Nitrocarburization
There are two types of nitrocarburization and the first of these types is austenitic. Austenitic nitrocarburization occurs at the upper end of the temperature range and has some advantages. These advantages; These can be listed as increasing surface hardness, high wear resistance, excellent fatigue resistance, and improved corrosion resistance. The second type is the ferritic nitrocarburization process. This process is performed at a lower temperature and is often used instead of chrome plating. The case depth is generally less than austenitic nitrocarburization. Ferritic nitrocarburizer solves most of the dimensional change and distortion problems seen in high temperature operations. Both types of nitrocarburization are used with steel and other ferrous metals in a salt bath. Despite its name, the process is really a modified form of carbon-addition nitriding.
Nitriding and Nitrocarburization
Nitriding is the name for another low-temperature process in which nitrogen is transported and removed by the steel and occurs around 510 °C. Most commonly, the term nitriding refers to steel heated in ammonia gas. The term nitrocarburization means steel that has been treated with salt or exhausts. The process is carried out in a closed retort furnace at temperatures between 490°C and 530°C for up to 120 hours in a flowing ammonia atmosphere. Unlike nitrocarburization, only nitrogen is transferred in nitriding. Nitriding processes give surface hardness and a distinct microstructure. However, the nitriding process can take tens of times longer than nitrocarburization to achieve the same case depth. https://www.aht.com.tr/