The high-cycle fatigue behavior of carburized M50NiL steel with high-energy modification and compound infiltration: A comparative study

• Published in: Surface & coatings technology Vol. 451; p. 129009
• Main Authors: Li, Shaolong, Liang, Yilong, Yu, Jiabang, Liu, Dan, Chen, Jian, Zeng, Guangwei
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.12.2022
• Subjects: Plasma nitriding; Residual compressive stress; Tension–compression fatigue; Ultrasonic surface rolling process; Vacuum carburizing; Residual compressive stress; Ultrasonic surface rolling process; Plasma nitriding; Tension–compression fatigue; Vacuum carburizing
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2022.129009

In this study, ultrasonic rolling (C + USRP) and plasma nitriding (C + N) is performed on the surface of M50NiL steel after carburizing， the tension-compression fatigue test of R = −1 on different samples. The results show that the maximum fatigue limit of C + N, C + USRP, and single carburizing are 770 MPa, 676 MPa, and 412 MPa, respectively. The residual stress relaxation in the fatigue process of C + N and C + USRP is tested and found that the initial residual compressive stress of C + N is lower than that of C + USRP, but its attenuation value is considerably smaller. The microscopic characterization of samples is conducted after the fatigue tests. The nanometer nitrogen compounds in the composite permeability layer showed a strong pinning effect, however, microplastic deformation limits the fatigue process. The C + N demonstrates a much lower residual compressive stress relaxation, consequently, the C + N short crack propagation effective driving force ΔKeff value decreases. As a result, due to the higher crack closure effect, the C + N fatigue limit is observed higher than the C + USRP. •The fatigue properties of carburized M50NiL steel were improved after surface ultrasonic rolling and plasma nitriding (C + N), respectively•The residual compressive stress of C + N is more stable, because of the pinning effect of nitride on dislocation.