Elucidating the loading rate dependence of hydrogen environment-assisted cracking in a Ni-Cu superalloy

Abstract

Abstract The effect of loading rate (dK/dt) on the hydrogen environment-assisted cracking (HEAC) behavior of Monel K-500 immersed in 0.6 M NaCl and polarized to -950 and -1200 mVSCE was assessed via a slow-rising stress intensity (K) testing framework at dK/dt ranging from 0.2 to 20 MPa√m/hr. Comparative testing on Monel K-500 in an inert environment (dry N2 with RH 8 MPa√m/hr and (2) a ‘linear’ regime where log(da/dt) linearly scales with log(dK/dt) was observed for dK/dt 10 MPa√m/hr at -950 mVSCE and all evaluated dK/dt at -1200 mVSCE, while mechanics-based factors govern the da/dt response for dK/dt