How to improve the hardness of powder metallurgy gears

Because powder metallurgy gears are used for transmission, the requirements for strength are very high, so the required density is also very high. Generally, the higher the gear density, the higher the tooth resistance and the better the strength. In other words, the hardness of the gear is closely related to the material, density grade and post-processing of the product.
In order to improve the strength and wear resistance of iron-based powder metallurgy gears, it is necessary to add post-processing engineering after sintering in order to improve the service performance of powder metallurgy gears. Post-processing engineering usually has the following two methods:
1. Carburizing treatment: The same as the carburizing treatment of ordinary machined gears, iron-based powder metallurgy gears currently adopt carbonitriding, integrated quenching treatment, and the hardness range is the same as above.
2. Surface water vapor treatment: In a high temperature environment, water vapor reacts with Fe on the surface of the gear to form a dense substance Fe3O4. Fe3O4 has a higher hardness, which can increase the wear resistance and surface hardness of iron-based powder metallurgy gears.