Very High Cycle Fatigue and Fatigue Crack Growth of Steels: A Review

This review presents a comprehensive examination of the total fatigue life behaviour of high-strength steels (HSS) with particular emphasis on fatigue crack initiation in the very high cycle fatigue (VHCF) regime and crack propagation based on fracture mechanics. The discussion draws on recent advances in experimental techniques, microstructural characterisation, and analytical approaches by reviewing studies conducted over the past few years. Key factors influencing fatigue performance, including loading frequency, specimen geometry, microstructure, and environmental conditions, are critically evaluated. The review concludes by highlighting existing knowledge gaps and outlining directions for future research aimed at improving the understanding and optimisation of fatigue performance in current and next-generation HSS.