TY - GEN
T1 - Micromechanics of hydrogen transport and embrittlement in pipeline steels
AU - Dadfarnia, Mohsen
AU - Sofronis, Petros
AU - Robertson, Ian
AU - Somerday, Brian P.
AU - Muralidharan, Govindarajan
AU - Stalheim, Douglas
PY - 2007
Y1 - 2007
N2 - The technology of large scale hydrogen transmission from central production facilities to refueling stations and stationary power sites is at present undeveloped. Among the problems which confront the implementation of this technology is the deleterious effect of hydrogen on structural material properties, in particular at gas pressure of 1000 psi which is the desirable transmission pressure suggested by economic studies for efficient transport. To understand the mechanisms of hydrogen embrittlement our approach integrates mechanical property testing, TEM observations, and finite element modeling. In this work a hydrogen transport methodology for the calculation of hydrogen accumulation ahead of a crack tip in a pipeline steel is outlined. The approach accounts for stress-driven transient diffusion of hydrogen and trapping at microstructural defects whose density evolves dynamically with deformation. The results are analyzed to correlate the level of load in terms of the applied stress intensity factor with the time after which hydrogen transport takes place under steady state conditions. The transient and steady state hydrogen concentration profiles are used to assess the hydrogen effect on the mechanisms of fracture as they depend on material microstructure.
AB - The technology of large scale hydrogen transmission from central production facilities to refueling stations and stationary power sites is at present undeveloped. Among the problems which confront the implementation of this technology is the deleterious effect of hydrogen on structural material properties, in particular at gas pressure of 1000 psi which is the desirable transmission pressure suggested by economic studies for efficient transport. To understand the mechanisms of hydrogen embrittlement our approach integrates mechanical property testing, TEM observations, and finite element modeling. In this work a hydrogen transport methodology for the calculation of hydrogen accumulation ahead of a crack tip in a pipeline steel is outlined. The approach accounts for stress-driven transient diffusion of hydrogen and trapping at microstructural defects whose density evolves dynamically with deformation. The results are analyzed to correlate the level of load in terms of the applied stress intensity factor with the time after which hydrogen transport takes place under steady state conditions. The transient and steady state hydrogen concentration profiles are used to assess the hydrogen effect on the mechanisms of fracture as they depend on material microstructure.
UR - http://www.scopus.com/inward/record.url?scp=37349130615&partnerID=8YFLogxK
U2 - 10.1115/IMECE2006-16325
DO - 10.1115/IMECE2006-16325
M3 - Conference contribution
AN - SCOPUS:37349130615
SN - 079184773X
SN - 9780791847732
T3 - Proceedings of the Materials Division, The ASME Non-Destructive Evaluation Division and The ASME Pressure Vessels and Piping Division, 2006
SP - 741
EP - 750
BT - Proceedings of the Materials Division, The ASME Non-Destructive Evaluation Division and The ASME Pressure Vessels and Piping Division, 2006
T2 - 2006 ASME International Mechanical Engineering Congress and Exposition
Y2 - 5 October 2007 through 10 October 2007
ER -