Abstract
SCM420H has been used for rolling bearings, linear bearings and ball screws, etc. It is thought that for this material when the fatigue test is carried out, in the domain of high cycle fatigue of the S-N curve so-called the Wohler curve, a fatigue limit appears. This type of fatigue limit has been used in the ISO-2007 with a life modification factor a_<ISO> for rolling bearings. However, at present even in the life test of bearing or S-N fatigue test of material, the experimental data does not show any apparent sign of the fatigue limit. In this paper, alternating torsion fatigue test for probabilistic stress-life (P-S-N) evaluation is carried out under standard stress values, from τ = 0.93 GPa to τ = 0.53 GPa for five lots made up of a total of 108 samples, and P-S-N curves were determined based on the three-parameter Weibull and the log-normal distribution function.
