2010 年 59 巻 5 号 p. 375-382
For the reliability design of mechanical structures under cyclic loading, S-N properties of the material are essential as the fundamental reference data. From this viewpoint, the Committee on Standardization of Fatigue Reliability Evaluation of Metallic Materials in JSMS has published the “Standard Evaluation Method of Fatigue Reliability for Metallic Materials -Standard Regression Method of S-N Curve-”. In recent years, this standard is applied to various series of industrial materials in the “Database on Fatigue Strength of Metallic Materials” to investigate the fundamental fatigue properties. In this paper, high strength steel is selected as the target material and the rotating bending fatigue test data for JIS-SCM435, SCM440 and SNCM439 were extracted from the Database. Applying the JSMS standard (JSMS-SD-6-04), S-N curves were analyzed on the basis of 8 types of regression models accepted in the standard. From numerical results, it is confirmed that there are distinct correlation between (1) tensile strength of sB and fatigue limit, (2) slope and intercept of inclined part of S-N curve, (3) slope and the critical number of stress cycles giving fatigue limit. It was also found that S-N property of the individual material was well normalized by tensile strength of sB. Based on this aspect, a number of fatigue data extracted were pooled altogether and P-S-N property was also analyzed. As a result, the change of distribution pattern is observed at low stress level. This aspect is considered to be caused by the change of failure mode in this region.