Fatigue Crack Growth (14.4)
Criticality: High
Progress: Addressed, Not Adequately
Score: 20
DOT Relevance: §192.501 – §192.517
Description of Key Area
Material testing falls under Subpart J (Test Requirements) of 49
CFR 192. Per the Code, “This subpart prescribes minimum leak-test and
strength-test requirements for pipelines.”
Discussion of Criticality
There is little knowledge other than that fatigue cracks grow 10
to 30 times faster in hydrogen embrittled materials than under the same
conditions in air.
Discussion of Progress
SRNL advises that fatigue crack growth should be identified and
evaluated for materials to be used for hydrogen pipelines.
Recommendations
ASME B31.12 will address this issue within the limits of
available data. Further research is necessary and appropriate fatigue crack
growth testing methods should be identified and documented. A database of
fatigue related incidents should be established. Standards for hydrogen
pipelines should be established and incorporated by reference into the federal
code.
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