Effects of Temperature and Stress Concentration Factor on High Cycle Fatigue Properties of Engineering Steels
1988 Volume 37 Issue 414 Pages 254-260
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1988 Volume 37 Issue 414 Pages 254-260
National Research Institute for Metals has proceeded the fatigue data sheet project, in which fatigue properties have been examined systematically for engineering materials manufactured in Japan. The results obtained have been published as NRIM Fatigure Data Sheets.
In this paper, the effects of temperature and stress concentration factor on high cycle fatigue properties were summarized for nine kinds of engineering steels, fatigue data of which were published in NRIM Fatigue Data Sheets.
The conclusions obtained were as follows:
(1) The ratio of the fatigue strength of the smooth specimens at 108 cycles to the tensile strength at the same temperature varied a little ranging from 0.4 to 0.6 depending on temperature and material conditions. The mean value was about 0.5.
(2) The notch effect on fatigue strength varied depending on temperature and material conditions. The reason is considered as that the fatigue strength of the notched specimens for failure has a tendency to become larger than that for crack initiation at high temperatures.
(3) The fatigue strength of the notched specimens at 108 cycles for crack inititation corresponded well to the tensile strength independent of temperature and material conditions.
(4) The notch sensitivity index η had a tendency to become small with increasing stress concentration factor or with decreasing tensile strength.
