Causes of grinding residual stress error of cylindrical gear steel

The main causes of grinding residual stress error of cylindrical gear steel are as follows:

(1) Idealized value of material properties in simulation

In the simulation, we assume that the material performance parameters of 30crmnti material are fixed. However, in the grinding process of cylindrical gear steel, due to the increase of surface temperature of cylindrical gear steel, some performance parameters will change significantly at high temperature, such as yield ultimate strength, elastic modulus and thermal expansion coefficient will change nonlinearly with the increase of temperature. Therefore, the idealized value of material performance parameters of cylindrical gear steel is an important reason for error.

(2) Error caused by microstructure transformation of surface layer of cylindrical gear steel

Microstructure transformation is also an important cause of residual stress. On the 30crmnti material, when the grinding surface temperature of the cylindrical gear steel exceeds the transformation temperature of the material, the surface of the cylindrical gear steel will undergo secondary quenching. Due to the short grinding heating time of the cylindrical gear steel and the extremely fine austenite grain size, the microstructure of the grinding surface of the cylindrical gear steel will change into extremely fine acicular martensite, and the specific volume of martensite is relatively large, When martensitic transformation occurs, the surface microstructure volume of cylindrical gear steel will expand, resulting in residual compressive stress. In the simulation process, the influence of microstructure transformation on the grinding surface residual stress of cylindrical gear steel can not be simulated, which leads to the difference between the simulation value and the test value.

(3) Other reasons

In addition to the above two main reasons, there are also the reduction of equivalent diameter and contact arc length caused by grinding wheel wear, and the error caused by test measurement. Therefore, how to comprehensively consider these factors and further improve the simulation accuracy is the next important research direction.

Scroll to Top