Effect of Surface Ultrasonic Rolling Treatment on Rolling Contact Fatigue Life of D2 Wheel Steel

• Main Authors: Pengtao Liu, Zilong Lin, Chunpeng Liu, Xiujuan Zhao, Ruiming Ren
• Format: Article
• Language: English
• Published: MDPI AG 2020-11-01
• Series: Materials
• Subjects: surface ultrasonic rolling treatment; D2 wheel steel; rolling contact fatigue life; surface microstructure
• Online Access: https://www.mdpi.com/1996-1944/13/23/5438

A GPM-30 fatigue machine was used to investigate the influence of surface ultrasonic rolling (SURT) on the rolling contact fatigue (RCF) life of D2 wheel steel. The experimental results present that the RCF life of the grinding processing sample is 4.1 × 10⁵ cycles. During the RCF process, the flaking of the fine grain layer and high surface roughness of the grinding processing sample cause the production of RCF cracks. When the samples are treated by SURT with 0.2 MPa and 0.4 MPa, the RCF life is 9.2 × 10⁵ cycles and 9.6 × 10⁵ cycles, respectively. After SURT, the surface roughness of the samples is reduced, and a certain thickness of gradient-plastic-deformation layer and a residual-compressive-stress layer are produced. These factors lead to the improvement of the RCF property. However, when the static pressure increases to 0.6 MPa during SURT, the RCF life of the sample is reduced during RCF testing. The micro-cracks, which are formed during SURT, become the crack source and cause the formation of RCF cracks, decreasing of the RCF life.