Research Progress of Very High Cycle Fatigue for High Strength Steels

In recent years,the core engineering components of high-speed train,automobiles and aircrafts are required to endure fatigue loads up from 108 to 1010 cycles.The present study results show that in the very high cycle fatigue(VHCF)regimes of more than 107 cycles,the fatigue failure of high strength steel materials can occur below the traditional fatigue limit,hence the VHCF investigations of high strength steels not only help to further understand the fatigue essence and mechanism,but also do research on the fatigue design and life assessment method.The background and significance of research on very high cycle fatigue are presented firstly.Then achievements of VHCF researchers for high strength steels,such as the characteristics of S-N curve and crack initiation,crack propagation mechanism,the observations on fish-eye,etc.are summarized.Some possible and prospective aspects of future researches are also proposed.