Status of French Fatigue Analysis Procedure

During the past 15 years many works has been done on stainless steel fatigue curves: • in many cases over 10⁵ cycles the RCC-M mean curve has been found un-conservative, in a similar situation than ASME Section III curve [12]; • the fatigue data other 10⁶ cycles can now be done under strain control in a reliable way (improvements in fatigue test machine); • a large test program has been done in Japan and partially in USA; • a limited program has been done in France. This paper presents a new proposal for fatigue stainless steel mean curve in air (the existing ASME curve C seems to cover environmental effect on real structures) and a comparison with the NRC Regulatory Guide 1.207 [14] proposal for new curves. In order to transfer these mean curve data to structures, different complementary tests have been developed, some under air conditions, some under environmental effects. The paper ends with proposed code improvements in fatigue analysis rules in the RCC-M French Code.