Effect of Temperature on Hydrogen Assisted Fatigue Crack Growth Rate of an Austenitic Stainless Steel

The fatigue crack growth rate (FCGR) of austenitic stainless steel 1.4404 was measured in uncharged and in gaseous hydrogen precharged conditions, both as a function of temperature. At room temperature and ΔK < 40 MPa m0.5, the FCGR of gaseous hydrogen precharged 1.4404 is by a factor of about 5 higher compared to the uncharged condition. FCGR as a function of temperature revealed a broad maximum at temperatures between 293 and 333 K. The temperature of maximum FCGR does not correlate with the temperature of maximum loss of tensile RA, which is about 220 K. A simplistic interpretation based on the respective governing mechanism, HEDE for FCGR tests and HELP for tensile tests, is proposed.