Presence of hydrogen in nickel alloys can lead to embrittlement, causing catastrophic failure [a,b] One way to circumvent this is by designing alloys with features that traps hydrogen[c]. Most of the phases formed in Nickel alloys lead to an increase in hydrogen embrittlement [d,e]. However, γ’ precipitates with high γ/ γ’ lattice misfit and MC carbides have been evidenced to trap hydrogen in austenitic steels[f,g]. To experimentally study this in nickel alloys, nickel alloys containing only γ’ precipitates with tailored γ/ γ’ lattice misfit or MC carbides were designed using a combination of computational thermodynamics, genetic algorithm multi-objective optimization, and physical models. These alloys were designed such that the phases can be dissolved at high temperatures and precipitated by heat treatment. After designing, the alloys were fabricated in the laboratory. These alloys were studied with and without the presence of precipitates using hydrogen electrochemical permeation and thermal desorption spectroscopy. Finally, the efficiency of the designed model alloys to control hydrogen trapping will be discussed in the context of experimental results.

References:

[a] Huizinga, Sytze, Like, Willem E., McLoughlin, Brian, and Jan De Jong  CORROSION 2003, San Diego, California, March 2003.
[b] Shademan, Steven S., Martin, John W., and Al P. Davis  CORROSION 2012, Salt Lake City, Utah, March 2012.
[c] Pressouyre, G.M., Bernstein, I.M.. Metall Mater Trans A 835-844 (1981)
[d] Liufa Liu, Katsumi Tanaka, Akio Hirose, Kojiro F Kobayashi,  Science and Technology of Advanced Materials, Volume 3, Issue 4, 335-344 (2002)
[e] Xu Lu, Yan Ma, Dong Wang, Materials Science and Engineering: A, Volume 792,2020,
[f] Pressouyre, G.M., Bernstein, I.M.. Metall Mater Trans A 9, 1571–1580 (1978).
[g] A. W. Thompson, Met. Trans. 7A, 315-318 (1976).