TY - JOUR
T1 - Role of hydrogen on the incipient crack tip deformation behavior in α-Fe
T2 - An atomistic perspective
AU - Adlakha, I.
AU - Solanki, Kiran
N1 - Funding Information:
The authors gratefully acknowledge support from the Office of Naval Research under Contract N00014-16-1-2174.
Publisher Copyright:
© 2018 Author(s).
PY - 2018/1/7
Y1 - 2018/1/7
N2 - A crack tip in α-Fe presents a preferential trap site for hydrogen, and sufficient concentration of hydrogen can change the incipient crack tip deformation response, causing a transition from a ductile to a brittle failure mechanism for inherently ductile alloys. In this work, the effect of hydrogen segregation around the crack tip on deformation in α-Fe was examined using atomistic simulations and the continuum based Rice-Thompson criterion for various modes of fracture (I, II, and III). The presence of a hydrogen rich region ahead of the crack tip was found to cause a decrease in the critical stress intensity factor required for incipient deformation for various crack orientations and modes of fracture examined here. Furthermore, the triaxial stress state ahead of the crack tip was found to play a crucial role in determining the effect of hydrogen on the deformation behavior. Overall, the segregation of hydrogen atoms around the crack tip enhanced both dislocation emission and cleavage behavior suggesting that hydrogen has a dual role during the deformation in α-Fe.
AB - A crack tip in α-Fe presents a preferential trap site for hydrogen, and sufficient concentration of hydrogen can change the incipient crack tip deformation response, causing a transition from a ductile to a brittle failure mechanism for inherently ductile alloys. In this work, the effect of hydrogen segregation around the crack tip on deformation in α-Fe was examined using atomistic simulations and the continuum based Rice-Thompson criterion for various modes of fracture (I, II, and III). The presence of a hydrogen rich region ahead of the crack tip was found to cause a decrease in the critical stress intensity factor required for incipient deformation for various crack orientations and modes of fracture examined here. Furthermore, the triaxial stress state ahead of the crack tip was found to play a crucial role in determining the effect of hydrogen on the deformation behavior. Overall, the segregation of hydrogen atoms around the crack tip enhanced both dislocation emission and cleavage behavior suggesting that hydrogen has a dual role during the deformation in α-Fe.
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U2 - 10.1063/1.5001255
DO - 10.1063/1.5001255
M3 - Review article
AN - SCOPUS:85040189326
SN - 0021-8979
VL - 123
JO - Journal of Applied Physics
JF - Journal of Applied Physics
IS - 1
M1 - 014304
ER -