Improvement of the Mechanical Properties of 30CrNi2MoVA through Ultrasonic-Milling in Certain Key Components

To improve the fatigue life of the key component and the surface properties of the 30CrNi2MoVA steel material, advanced ultrasonic-milling composite superficial treatment was performed. The microstructure, surface roughness, friction and wear performance, surface hardness, fatigue life and environmental experiments of the steel with and without ultrasonic-milling have been carried out in detail. In comparison with those of the traditional dry cutting, the results show that the surface roughness of the samples after the advanced ultrasonic-milling surface modification fluctuates about 0.32 μm, and the surface hardness is increased by about 40% compared with the matrix hardness, and the fatigue life of the pump head connection shaft has been increased by more than 11 times. Advanced ultrasonic-milling surface modification technology can increase the local residual compressive stress and wear resistance on the material surface, which can make the material have better surface properties.