Effects of LWR environments on fatigue life of carbon and low-alloy steels

Abstract

The ASME Boiler and Pressure Vessel Code provides rules for the construction of nuclear power plant components. Section of the Code specifies fatigue design curves for structural materials. While effects of reactor coolant environments are not explicitly addressed by the design curves, test data suggest that the Code fatigue curves may not always be adequate in coolant environments. This paper reports the results of recent fatigue tests that examine the effects of steel type, strain rate, dissolved oxygen level, strain range, loading waveform, and surface morphology on the fatigue life of A106-Gr B carbon steel and A533-Gr B low-alloy steel in water.

Effects of LWR Coolant Environments on Fatigue Lives of Austenitic Stainless Steels

“…All tests were conducted at 288°C with fully reversed axial loading (i.e., R = -1) and a triangular or sawtooth waveform. Details about the test facility and procedure have been described by Chopra et al (1995). Tests in water were conducted in a small autoclave under stroke control where the specimen strain was controlled between two locations outside the autoclave.…”

Effects of LWR coolant environments on fatigue lives of austenitic stainless steels

“…Information from the air tests was used to determine the stroke required to maintain constant strain in the specimen gage length for tests in water; the stroke is gradually increased during the test to account for cyclic hardening of the material and to maintain constant strain in the specimen gage section. Details regarding the test facility and procedure have been described elsewhere [2]. The fatigue test data from the present study and those obtained previously [6] on Type 316NG in air and high-DO water are listed in Tables 2 and 3.…”