Fatigue Crack Growth Behavior of Sensitized Type 304 Stainless Steel Under Boiling Water Reactor Conditions

The fatigue crack growth behavior of sensitized Type 304 (UNS S30400) stainless steel (SS) with an electrochemical potentiokinetic reactivation (EPR) value of 30 C/cm² was investigated under boiling water reactor (BWR) conditions at 288°C. Tests were performed under either cyclic or trapezoidal loading conditions. Test environments were high-purity water either with 200 ppb dissolved oxygen (DO) under normal water chemistry (NWC) conditions or with 10 ppb DO plus 160 ppb dissolved hydrogen (DH) under hydrogen water chemistry (HWC) conditions. It was observed that whether the loading waveform was cyclic or trapezoidal, the fatigue crack growth rates (FCGR) could not be reduced by HWC conditions. None of the current FCGR data was encompassed by the reference curves of the ASME Code Section XI, Appendix C (ASME-XI, Appendix C), whereas all of the current data could be bounded by the JSME flaw evaluation code (JSME S NA1-2000). Finally, the examination of the accuracy of the superposition principles indicated that the Argonne National Laboratory (ANL) model was higher than that developed by the General Electric (GE) model.