Effect of Loading Frequency on the Fatigue Strength of Steels at Elevated Temperatures

抄録

The results of cantilever type rotating beam fatigue tests on low carbon steel and Cr-Mo-V steel at room temperature, 300°C and 500°C in a wide frequency range from 775 to 15000 rpm were summarized and examined in detail. From S-N diagrams it was found that the highest fatigue strength cccurred at 7500 rpm for both steels at elevated temperatures, whereas from S-t diagrams in which abscissa was time to failure instead of number of stress cycles, it was found that the life time gradually decreased with an increase of frequency. Some irregularities were observed in the strength of low carbon steel at 300°C. It should be noted that the fatigue strength for the frequency higher than 10000 rpm decreases rather rapidly at elevated temperatures.