Solute hydrogen and deuterium observed at the near atomic scale in high-strength steel

Breen AJ, Stephenson LT, Sun B, Li Y, Kasian O, Raabe D, Herbig M, Gault B (2020)

Publication Type: Journal article

Publication year: 2020

Journal

Acta Materialia Elsevier

Book Volume: 188

Pages Range: 108-120

DOI: 10.1016/j.actamat.2020.02.004

Abstract

Observing solute hydrogen (H) in matter is a formidable challenge, yet, enabling quantitative imaging of H at the atomic-scale is critical to understand its deleterious influence on the mechanical strength of many metallic alloys that has resulted in many catastrophic failures of engineering parts and structures. Here, we report on the APT analysis of hydrogen (H) and deuterium (D) within the nanostructure of an ultra-high strength steel with high resistance to hydrogen embrittlement. Cold drawn, severely deformed pearlitic steel wires (Fe–0.98C–0.31Mn–0.20Si–0.20Cr–0.01Cu–0.006P–0.007S wt%, ε=3.1) contains cementite decomposed during the pre-deformation of the alloy and ferrite. We find H and D within the decomposed cementite, and at some interfaces with the surrounding ferrite. To ascertain the origin of the H/D signal obtained in APT, we explored a series of experimental workflows including cryogenic specimen preparation and cryogenic-vacuum transfer from the preparation into a state-of-the-art atom probe. Our study points to the critical role of the preparation, i.e. the possible saturation of H-trapping sites during electrochemical polishing, how these can be alleviated by the use of an outgassing treatment, cryogenic preparation and transfer prior to charging. Accommodation of large amounts of H in the under-stoichiometric carbide likely explains the resistance of pearlite against hydrogen embrittlement.

Involved external institutions

Max-Planck-Institut für Eisenforschung GmbH (MPIE) / Max Planck Institute for Iron Research DE Germany (DE) Ruhr-Universität Bochum (RUB) DE Germany (DE)

How to cite

APA:

Breen, A.J., Stephenson, L.T., Sun, B., Li, Y., Kasian, O., Raabe, D.,... Gault, B. (2020). Solute hydrogen and deuterium observed at the near atomic scale in high-strength steel. Acta Materialia, 188, 108-120. https://doi.org/10.1016/j.actamat.2020.02.004

MLA:

Breen, Andrew J., et al. "Solute hydrogen and deuterium observed at the near atomic scale in high-strength steel." Acta Materialia 188 (2020): 108-120.

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