Effects of Various Shot Peening Parameters on the Distribution of Residual Stresses and Microstructures of an 18CrNiMo7-6 Steel

摘要

Effects of shot peening (SP) parameters on the structure and residual stress of 18CrNiMo7-6 steel have been investigated using X-ray diffraction (XRD) analysis method. XRD pattern reveals that SP can induce the phase transformation from austenite to martensite. Results show that multi-step SP can significantly improve the compressive residual stress (CRS) and refine the domain size. After multi-step shot peeing with optimal intensities, CRS (martensite) at top surface attains 1,256 MPa, and maximum CRS of 1463 MPa is located at depth of 20 μm; maximum CRS and top-surface CRS (austenite) attains values of 1,039 MPa and 766 MPa, respectively. Obviously, domain sizes are decreased after SP.