ABSTRACT This study investigated the high‐cycle fatigue (HCF) behavior of 300M steel with shot peening (SP) followed by surface coatings (Cd/Ti plating, Cr plating, HVOF spraying) under axial stress control. Axial fatigue tests revealed that Untreated specimens exhibited the highest fatigue limit (845 MPa). SP alone slightly reduced the limit (−0.84%) due to the competing effects of surface roughness and compressive residual stress. SP + Cd/Ti minimally impacted HCF, while SP + Cr and SP + HVOF reduced fatigue limits by 7.12% and 6.73%, respectively. Post‐HVOF grinding restored fatigue strength by 20 MPa. The S‐N curves further highlighted that SP and Cd/Ti plating enhanced medium‐to‐high‐cycle fatigue life, but coatings like Cr plating and HVOF accelerated crack initiation. Fracture analysis showed SP shifted crack initiation to internal inclusions, while coatings induced interface cracks. A multifactor life prediction framework integrating surface treatment coefficients, roughness, and residual stress was developed, achieving predictions within ± 2.5 scatter bands.
Tang et al. (Wed,) studied this question.