8Cr4Mo4V steel is mainly used to the aero-engine bearings manufacture. The service environment is complex and the working conditions are harsh. In order to meet the requirements of fatigue performance and surface state

some parts of the bearings need sand blasting treatment. In this paper

the surface of 8Cr4Mo4V steel was sand-blasted under various conditions. The residual stress on the surface of 8Cr4Mo4V steel was measured by X-ray residual stress tester after sand blasting under various conditions. The surface morphology was observed by SEM

and the variation of dimension and surface roughness were measured after sand blasting. The results show that the residual compressive stress on the surface of 8Cr4Mo4V steel is generated by sand blasting

and the maximum residual compressive stress can reach –1576MPa. The value of residual compressive stress is proportional to the pressure and time of sand blasting

and inversely proportional to the particle size of sand. After sand blasting treatment

a compact layer was formed on the surface of 8Cr4Mo4V steel. The thickness of the compact layer was mainly affected by sand blasting pressure and increased with the sand blasting pressure raising. Sand blasting has a stripping effect on the surface layer of 8Cr4Mo4V steel. The amount of surface layer stripped increases with the increase of sand blasting pressure and time

and the decrease of sand particle size. The main factor is the sand particle size which affects the surface roughness of 8Cr4Mo4V steel after sand blasting. When the sand particle size is small

the roughness value is the lowest after sand blasting.