Parameter Analysis for Time-Dependent Low-Cycle Fatigue Life

Temperature and strain rate dependences of low-cycle fatigue life can be represented by a modified Larson-Miller parameter. The parameter P is written by P=T(logN₂₅−Alog ε˙ + B), where T is temperature, N₂₅ is fatigue life, ε˙ is strain rate, and A and B are constants. In the analysis, each data of several kinds of engineering materials from ferritic steels to austenitic stainless steels are used. These are the authors original data published in the documents of NRIM Fatigue Data Sheets. The result of 304 stainless steel has been compared with statistical analysis result by Diercks adopted in a design code. The fatigue life curves represented by the proposed parameter analysis fitted well test data in high-cycle region as well as ones in low-cycle region.