What effect does nitriding treatment have on the dimensional accuracy of the DCYK315-28-I gear reducer housing?

The effect of nitriding treatment on the dimensional accuracy of the DCYK315-28-I gear reducer housing is as follows:

The reason for the size change: During the nitriding process, nitrogen atoms will infiltrate the surface of the box, generating various nitrides and increasing the lattice constant of the original structure on the surface of the workpiece. Macroscopically, this is manifested as a slight increase in surface volume, leading to the phenomenon of "swelling" in the box.

Factors affecting size changes:

Material factor: If the alloy element content of the box material is high, the "swelling" after nitriding may be greater. For example, steel containing alloy components with strong affinity for nitrogen has a stronger ability to absorb nitrogen atoms during nitriding, which can affect the thickness and nitrogen concentration of the nitriding layer, resulting in more significant size changes.

Process factors: The higher the nitriding temperature and the longer the time, the more obvious the "swelling" of the parts after nitriding. In addition, different nitriding atmospheres can also have an impact on "swelling". The higher the nitrogen potential, the greater the "swelling" of the box after nitriding.

Structural factors of parts: Complex box structures may result in uneven size changes due to differences in heat dissipation conditions and nitrogen atom diffusion paths in various parts.

The manifestation of size change: Generally speaking, the size change caused by nitriding treatment is relatively small. If ion nitriding is used, due to the effect of "cathode sputtering" on reducing the size, it can offset some of the "swelling" of nitriding, and the size change will be relatively smaller. However, for the DCYK315-28-I gear reducer housing with high dimensional accuracy requirements, such small changes may still exceed the tolerance range, affecting its fitting accuracy with other components.

However, some measures can be taken to control the size changes, such as conducting reasonable pre heat treatment and "stabilization" treatment on the box before nitriding, appropriately reducing the nitriding temperature and shortening the nitriding time under the premise of process permission, and adjusting the nitriding atmosphere while ensuring the performance of the nitriding layer. In the final processing step before nitriding treatment, the workpiece size can be adjusted to a negative deviation based on the expected amount of "swelling" to ensure that the size after nitriding is within the required tolerance range.