What is the relationship between rolling mill bearings and carbonitriding?

Dec 09, 2024

The relationship between rolling mill bearings and carbonitriding is mainly reflected in the application of carbonitriding technology in the manufacturing of rolling mill bearings. Here is a detailed explanation of this relationship:

1. Overview of rolling mill bearings

Rolling mill bearings are used in the rolling industry, such as the rolling of non-ferrous metals, ferrous metals and non-metallic products. These bearings are usually subjected to huge radial and axial loads and, therefore, require high strength, wear resistance and fatigue resistance.

2. Introduction to carbonitriding technology

Carbonitriding is a chemical surface heat treatment process that simultaneously infiltrates carbon and nitrogen elements into the surface of steel parts to form a carbonitride layer. This technology can significantly improve the material's hardness, wear resistance and fatigue resistance. The color and form of this layer of compounds may vary depending on processing conditions (such as temperature, time, atmosphere, etc.).

When observed under a microscope, the carbonitrided layer may show different metallographic structures. For example, nitrogen-containing martensite retained austenite, and carbonitride particles may be seen. The morphology and distribution of these tissues can also be affected by processing conditions.

In some cases, black tissue may appear in the carbonitrided layer. These black structures may be caused by decarburization or carburization during the quenching process, which may reduce the hardness and fatigue strength of the material. Therefore, various parameters need to be strictly controlled during the carbonitriding process to avoid the generation of such undesirable structures.

3. Application of carbonitriding in rolling mill-bearing manufacturing

Improved performance: Carbonitriding technology can significantly improve the surface hardness and wear resistance of rolling mill bearings, thereby extending the service life of the bearings. It is particularly important for rolling mill bearings, which are subject to high pressures, high-speed rotations and heavy loads.

Optimized process: Carbonitriding technology simplifies the production process, saves energy, and reduces the deformation of bearing parts, which is because the carbonitriding temperature is lower than the carburizing temperature, and the austenite grains are smaller during the carburizing process. Generally, it can be quenched directly after co-carburizing.

Enhanced fatigue resistance: Carbonitriding technology can form a hard carbonitride layer on the surface of the bearing. This layer of compound can effectively resist the expansion of cracks and improve the fatigue resistance of the bearing.

4. Specific requirements for carbonitriding treatment

During the carbonitriding process of rolling mill bearings, various parameters need to be strictly controlled to ensure the treatment effect. These parameters include co-infiltration temperature, time, atmosphere composition, etc. At the same time, it is also necessary to control the co-infiltration layer thickness, carbide morphology, etc., to meet the requirements of subsequent processing and use.

In summary, carbonitriding technology plays an important role in rolling mill-bearing manufacturing. By applying this technology, the performance and service life of bearings can be significantly improved, thus meeting the demand for high-quality bearings in the calendering industry.