Chemical heterogeneity enhances hydrogen resistance in high-strength steels

Abstract

The antagonism between strength and resistance to hydrogen embrittlement in metallic materials is an intrinsic obstacle to the design of lightweight yet reliable structural components operated in hydrogen-containing environments. Economical and scalable microstructural solutions to this challenge must be found. Here, we introduce a counterintuitive strategy to exploit the typically undesired chemical heterogeneity within the material’s microstructure that enables local enhancement of crack resistance and local hydrogen trapping. We use this approach in a manganese-containing high-strength steel and produce a high dispersion of manganese-rich zones within the microstructure. These solute-rich buffer regions allow for local micro-tuning of the phase stability, arresting hydrogen-induced microcracks and thus interrupting the percolation of hydrogen-assisted damage. This results in a superior hydrogen embrittlement resistance (better by a factor of two) without sacrificing the material’s strength and ductility. The strategy of exploiting chemical heterogeneities, rather than avoiding them, broadens the horizon for microstructure engineering via advanced thermomechanical processing.

Atomic-scale insights on hydrogen trapping and exclusion at incoherent interfaces of nanoprecipitates in martensitic steels

“…The pledge of zero carbon dioxide emission has provoked an increasing demand on clean hydrogen to reduce the use of fossil fuels. However, hydrogen poses detrimental effects on the mechanical properties of metallic materials 1 – 6 , commonly known as hydrogen embrittlement (HE), which endangers the safe operation of structural materials such as high-strength alloys in energy-efficient vehicles 7 and hydrogen storage tanks 8 . Generally, hydrogen embrittlement sensitivity increases with the material strength, being a major concern in the development and practical application of high strength alloys.…”

Probing the Damage Recovery Mechanism in Irradiated Stainless Steels Using In-Situ Microcantilever Bending Test

“…The crack blunting behavior is illustrated schematically in Figure 7, which shows ductile behavior in the plastic zone under the crack tip with a localized region of stress concentration immediately ahead of the crack. Dislocations likely nucleate or glide towards the crack tip-cross-slip driven or dislocation multiplication mechanism (Bitzek and Gumbsch, 2013;Daly et al, 2017;Ast et al, 2019) as well as active sources such as heterogeneities generated by extreme conditions (Lucas, 1993;Sun et al, 2021). In the base metal (Figure 7A), the existence of radiation-induced cavities could activate the martensitic transformation near cavities through shear deformation (Yang et al, 2022).…”

Increasing anhydrous chromium chloride concentration in AlCl3–EMIC ionic liquid: a step towards non-hydrogen-embrittlement chromium electroplating

“… 4 High-strength steels are particularly prone to hydrogen embrittlement, as less than 1 ppm of hydrogen is sufficient to result in a dramatic degradation of their mechanical properties. 5 …”