Statistical evaluation of ultra-long life fatigue strength and characteristic inclusion size of carburised Cr-Mn steel

Two statistical methods consisting of statistics of generalised extreme values and exponential generalised Pareto distribution were used to evaluate the characteristic inclusion size of carburised Cr-Mn steel, and to predict the fatigue strength of the steel in the ultra-long-life regime (life is larger than 10⁹ cycles). The fatigue strength evaluated by two models is both higher than the experimental value corresponding to the fatigue life of 10⁹ cycles, where fatigue strength evaluated by the exponential generalised Pareto distribution model is lower in comparison with that evaluated by the generalised extreme values model.