1989 Volume 38 Issue 435 Pages 1402-1408
In order to obtain the fundamental information on the remaining life evaluation of high temperature components, the high cycle fatigue strength of austenitic stainless steel used in service for a long time in fossil fuel power plant was investigated at 873K, and it was compared with that of the virgin material. The fatigue strength of the postservice material was significantly lower than that of the virgin material, and the carbide precipitation in the postservice material played an important role in fatigue crack initiation. The small fatigue crack growth behavior in both materials was also studied. Small cracks in both materials propagated even in the region of lower J-integral range than the long crack threshold ΔJth of the virgin material. In addition, the small crack growth rate of the postservice material was several times faster than that of the virgin material. It was concluded that the information on crack growth in the virgin material is not always justifiable to the safety assessment of high temperature long term service components.
