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Hydrogen cracking in metastable austenitic stainless steels

3,071 views · Published 22 November 2018 · 1:13 · Indexed 15 October 2026

Channel: bhadeshia123 · 2018 · Education

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An illustration of cracking associated with the hydrogen embrittlement of austenitic stainless steel that is pulled in tension. It is clear that in both cases, cracking occurs at many locations other than at the artificial  notch (stress concentration) at the centre. This is because of thermal-induced, deformation-induced martensite and deformation bands. 
Koyama M, Ogawa T, Yan D, Matsumoto Y, Tasan CC, Takai K, Tsuzaki K. Hydrogen desorption and cracking associated with martensitic transformation in Fe-Cr-Ni-Based austenitic steels with different carbon contents. International Journal of Hydrogen Energy. 2017 Oct 19;42(42):26423-35.
Abstract: The hydrogen embrittlement behavior of Fe-19Cr-8Ni-0.05C and Fe-19Cr-8Ni-0.14C metastable austenitic steels was investigated using tensile tests under hydrogen-charging, cryogenic thermal desorption spectroscopy, and in situ deformation experiments. Coupled with post-mortem microstructure characterization, the cracking paths were clarified to be transgranular along {110}α and {100}α in the Fe-19Cr-8Ni-0.05C steel and {100}α in the Fe-19Cr-8Ni-0.14C steel. Intergranular cracking also occurred in the Fe-19Cr-8Ni-0.05C steel when α′-martensite thoroughly covered the grain boundaries. Occurrence of the transgranular and intergranular hydrogen-assisted cracking in the steels is assisted by (1) an increase in the hydrogen-affected zone associated with presence of thermally induced α′-martensite, and (2) an increase in the local mobility of hydrogen that occurs with the deformation-induced α′-martensitic transformation. Additionally, (3) the transgranular hydrogen-assisted cracking is assisted by the intersection of deformation bands driven by the maximum Schmid factor and the stress concentration at the crack tip.

http://www.phase-trans.msm.cam.ac.uk/2014/hydrogen.html

Video courtesy of Professor Kaneaki Tsuzaki

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