TY - EJOU
AU - Toribio, J.
AU - Kharin, V.
TI - On the Validity of the Fracture Mechanics Approach to Hydrogen Assisted Cracking
T2 - The International Conference on Computational \& Experimental Engineering and Sciences
PY - 2008
VL - 7
IS - 3
SN - 1933-2815
AB - This paper deals with the meaning and significance of the fracture mechanics
approach to hydrogen assisted cracking, analyzing the question of K-dominance not
only over the purely mechanical aspects, but also over the environmental (physicochemical) events. Two key factors able to violate the uniqueness of the crack
growth kinetics curve v = v(K) are discussed: the role of far field (the stress-strain
field which is not K-dominated) and the effect of the history of hydrogenation and
crack growth. The far field is shown to have a minor effect on near-tip hydrogen diffusion, and thus it can only widen the scatter band of crack growth rates in
the near-threshold portion of the v(K)-curve. With regard to the effect of history,
the study reveals that hydrogenation and crack growth are coupled processes, one
influencing the other, so the crack growth kinetics curve v = v(K) is not unique,
although a special regime of steady-state crack growth is seen to exist in which
hydrogen assisted cracking turns out to be a K-dominated process, and the corresponding plot of the steady-state v against K acquires the uniqueness of a material’s
characteristic curve useful in engineering.
KW -
DO - 10.3970/icces.2008.007.135