Effect of shot peening coverage on hardness, residual stress and surface morphology of carburized rollers

• Published in: Surface & coatings technology 2020-02, Vol.384, p.125273, Article 125273
• Main Authors: Wu, Jizhan, Liu, Huaiju, Wei, Peitang, Zhu, Caichao, Lin, Qinjie
• Format: Article
• Language: English
• Subjects: Carburizing; Compressive properties; Coverage; Fatigue life; Grain refinement; High strength steels; Martensite; Martensitic transformations; Microhardness; Microstructure; Morphology; Residual stress; Retained austenite; Rollers; Shot peening; Surface hardness; Surface layers; Surface roughness
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2019.125273

Shot peening is currently becoming a widely used surface strengthening technique that can refine the material grain, increase the hardness and introduce a certain depth of residual compressive stress layer. At the same times it changes the surface topography which may have a deleterious effect on the contact fatigue life. A fully understanding on the mechanism of shot peening for high-strength steels is to be explored. In this paper, the effect of shot peening coverage on residual stress, surface roughness, microhardness and microstructure of rollers are experimentally investigated. Experimental results show that the shot peening leads to a slight increase of surface and near-surface hardness from 690 HV to 740 HV, and an appreciably increasing of the subsurface maximum compressive residual stress. Moreover, some retained austenite in the the near-surface layer are transformed to martensite after shot peening, and wherein the grain refinement occurs. •Carburized steel rollers were shot peened using coverages of 100% and 200%.•Effect of shot peening coverage was investigated.•Shot peening led to an appreciable increase in subsurface maximum residual stress.•Shot peening promoted grain refinement and enhanced surface hardness.•Shot peening transformed some of the near-surface retained austenite to martensite.