1989 Volume 38 Issue 435 Pages 1395-1401
Fatigue crack growth and crack closure at moderately elevated temperatures were investigated in low carbon steel (SM41A), Cr-Mo-V steel and type 304 stainless steel (SUS304). A critical experiment was made to examine the cause of increase in fatigue threshold at elevated temperatures in air environment. Samples of low carbon steel and type 304 stainless steel were tested in argon gas at 300°C. The fatigue threshold and crack closure were compared with those in air at the same temperature. It was concluded that the oxidation at elevated temperatures would contribute to the increase in fatigue threshold through the double effects of the enhanced crack closure and the increased fatigue crack growth resistance.