Cleavage failure in pipeline steel (7251418220)

Scanning electron microscope images of a test section of X100 alloy pipeline steel shows the effects of a hydrogen-induced crack at the surface. Image shows an area roughly 21.5 micrometers across. Color added for clarity.
See also www.nist.gov/mml/nist-hydrogen-fuel-materials-test-facili...
Credit: NIST
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