journal article·2026-03Open access

The effects of dislocation density and configuration, and grain boundary properties on hydrogen induced stress cracking of conventionally processed and additively manufactured Inconel 625

Alex Kovacs, Mobin Salasi, Zakaria Quadir, Christopher Hutchinson, Thaneshan Sapanathan

Corrosion Science· Volume 260

Abstract

This study examined the hydrogen embrittlement properties of both conventional and additively manufactured (AM) Nickel Alloy 625. The conventional Nickel Alloy 625 samples were prepared to contain altered grain boundary properties and dislocation densities and were evaluated in relation to AM 625 specimens which displayed distinct dislocation configurations and columnar grain structures. Step loading and slow strain-rate tensile tests with hydrogen charging, fractography, crack analysis and hydrogen desorption tests were performed to determine the hydrogen effects in the wrought material in “as received”, “annealed” and “annealed & pre-strained” conditions and AM 625. The hydrogen embrittlement resistance of as-received wrought 625 (W625) and annealed (ANN) wrought 625 (ANN W625) showed no comparative difference between their hydrogen charged condition and their baseline uncharged Fast Fracture Strength (FFS) tests, both failing at 12 incremental steps despite the removal of grain boundary precipitates and the larger grain size in the annealed condition. Annealed & pre-strained wrought (ANN W625_S), with similar flow stress and dislocation density as AM 625, showed an increased HE resistance compared to W625 and ANN W625 which was attributed to a reduction in the mobile hydrogen due to trapping at the random dislocation arrangement. W625, ANN W625, and AM 625 showed higher mobile hydrogen concentrations through hydrogen desorption tests, however the AM 625 material still maintained a higher threshold stress and higher ductility compared to W625 and ANN W625. This work suggests that the dislocation density and arrangement are important contributors to the increase in hydrogen embrittlement resistance of AM 625 compared to W625 and ANN W625, which is supported by the fractography and crack analysis. • AM 625 shows higher HE resistance than wrought forms under hydrogen charging. • Pre-strained wrought alloy mimics AM 625 dislocation density and strength. • Dislocation density and arrangement enhance HE resistance in AM 625. • Increased dislocation density in Annealed W625 provided increased hydrogen traps. • Fractography and desorption confirm role of dislocations in HE resistance.
Source: openalex_inverted_index · Quality: baseline

Research context

OpenAlex topics: Hydrogen embrittlement and corrosion behaviors in metals · Additive Manufacturing Materials and Processes · Cellular and Composite Structures

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

References (80)

Show source-provided references
1. N. Institute. "Nickel alloys in energy and power." 〈https://nickelinstitute.org/en/about-nickel-and-its-applications/nickel-alloys-in-energy-and-power/〉 (accessed 2023).
2. "High performance corrosion resistant stainless steels and nickel alloys for oil & gas applications,"
3. "Hydrogen stress cracking of Alloy 716 under cathodic protection—Root cause analysis, and an evaluation of quality control methods10.5006/4128 ↗
4. "Hydrogen effect on dislocation nucleation in a vanadium (100) single crystal as observed during nanoindentation10.1016/j.scriptamat.2010.07.039 ↗
5. "A mechanistic theory of hydrogen embrittlement of steels10.1002/bbpc.19720760864 ↗
6. "The role of hydrogen and other interstitials in the mechanical behavior of metals10.1007/s13632-016-0319-4 ↗
7. "A new model for hydrogen-assisted cracking (hydrogen “embrittlement”)10.1007/BF02642048 ↗
8. "An HVEM study of hydrogen effects on the deformation and fracture of nickel10.1016/0001-6160(86)90071-4 ↗
9. "Mechanisms of hydrogen assisted cracking - A review
10. "Hydrogen embrittlement of magnesium and magnesium alloys: a review10.1149/2.023304jes ↗
11. "Hydrogen related failure of steels - A new aspect10.1179/026708304225019687 ↗
12. "The predominant role of strain-induced vacancies in hydrogen embrittlement of steels: Overview10.1016/j.actamat.2018.12.013 ↗
13. "Revisiting hydrogen embrittlement models and hydrogen-induced homogeneous nucleation of dislocations10.1016/j.scriptamat.2009.09.037 ↗
14. "Influence of hydrogen-enhanced plasticity and decohesion mechanisms of hydrogen embrittlement on the fracture resistance of steel10.1016/j.engfailanal.2021.105312 ↗
15. "The synergistic action and interplay of hydrogen embrittlement mechanisms in steels and iron: Localized plasticity and decohesion10.1016/j.engfracmech.2019.106528 ↗
16. "Hydrogen-assisted failure of laser melting additive manufactured IN718 superalloy10.1016/j.corsci.2019.108171 ↗
17. "Effect of Microstructure and Alloy Chemistry on Hydrogen Embrittlement of Precipitation-Hardened Ni-Based Alloys10.1007/s11661-018-4483-9 ↗
18. "The role of nano-sized intergranular phases on nickel alloy 725 brittle failure10.1038/s41529-021-00185-2 ↗
19. "On the hydrogen embrittlement behavior of nickel-based alloys: Alloys 718 and 72510.1016/j.msea.2020.139785 ↗
20. "Hydrogen trapping in work-hardened alloys10.1016/0956-7151(91)90180-9 ↗
21. "Evaluation of hydrogen diffusion and trapping in nickel Alloy 625 by thermal desorption spectroscopy10.1016/j.ijhydene.2022.07.094 ↗
22. "Grain size and grain-boundary effects on diffusion and trapping of hydrogen in pure nickel10.1016/j.actamat.2012.09.004 ↗
23. "Grain boundary carbides as hydrogen diffusion barrier in a Fe-Ni alloy: a thermal desorption and modelling study10.1016/j.matdes.2018.10.012 ↗
24. "Determination of the critical plastic strain-induced stress of X80 steel through an electrochemical hydrogen permeation method10.1016/j.electacta.2016.08.026 ↗
25. "Effect of shot peening coverage on hydrogen embrittlement of a ferrite-pearlite steel10.1016/j.ijhydene.2020.01.021 ↗
26. Department of material science and technology norwegian university of science and technology
27. "The trapping and transport phenomena of hydrogen in nickel10.1007/BF02643893 ↗
28. "Observation of hydrogen trapping at dislocations, grain boundaries, and precipitates10.1126/science.aaz0122 ↗
29. P. Metalnikov, G. Ben-Hamu, and D. Eliezer, "Hydrogen Trapping in Laser Powder Bed Fusion 316L Stainless Steel," Metals, vol. 12, no. 10, doi: 10.3390/met12101748.10.3390/met12101748 ↗
30. "Dislocation pipe diffusion10.1016/0001-6160(64)90220-2 ↗
31. "Influence of deformation on the hydrogen behavior in iron and nickel base alloys: a review of experimental data10.1016/S0921-5093(97)00523-6 ↗
32. "The effect of plastic deformation on hydrogen diffusion in nickel Alloy 62510.1016/j.scriptamat.2022.115210 ↗
33. "Hydrogen embrittlement of 3-D printing manufactured austenitic stainless steel part for hydrogen service10.1016/j.scriptamat.2016.11.020 ↗
34. "Comparative study of hydrogen embrittlement resistance between additively and conventionally manufactured 304L austenitic stainless steels10.1016/j.msea.2020.140499 ↗
35. "Influence of dislocation cells on hydrogen embrittlement in wrought and additively manufactured Inconel 71810.1038/s43246-024-00654-6 ↗
36. "Formation of metastable cellular microstructures in selective laser melted alloys10.1016/j.jallcom.2016.12.209 ↗
37. "About metastable cellular structure in additively manufactured austenitic stainless steels
38. "Additive manufacturing of metals: a brief review of the characteristic microstructures and properties of steels, Ti-6Al-4V and high-entropy alloys10.1080/14686996.2017.1361305 ↗
39. "Defect formation mechanisms in selective laser melting: a review10.1007/s10033-017-0121-5 ↗
40. "Stress corrosion cracking of additively manufactured Alloy 62510.3390/ma14206115 ↗
41. "Hydrogen Embrittlement of Ni-Based Superalloy Inconel 625 Fabricated by Wire Arc Additive Manufacturing: The Role of Laves Phase10.1007/s12540-023-01546-z ↗
42. "Hydrogen embrittlement susceptibility of additively manufactured 316L stainless steel: Influence of post-processing, printing direction, temperature and pre-straining
43. "Hydrogen uptake and its influence in selective laser melted austenitic stainless steel: A nanoindentation study10.1016/j.scriptamat.2020.113718 ↗
44. "A comparative study of microstructure and hydrogen embrittlement of selective laser melted and wrought 17–4 PH stainless steel10.1016/j.msea.2020.139363 ↗
45. "High susceptibility of 3D-printed Ti-6Al-4V alloy to hydrogen trapping and embrittlement10.1016/j.matlet.2021.130334 ↗
46. "Influence of additive manufacturing by laser powder bed fusion on the susceptibility of Alloy 718 to hydrogen embrittlement10.1080/1478422X.2021.1921336 ↗
47. "Hetero-deformation-induced stress in additively manufactured 316L stainless steel10.1080/21663831.2020.1775149 ↗
48. "Formation of strain-induced martensite in selective laser melting austenitic stainless steel10.1016/j.msea.2018.10.121 ↗
49. "Three-dimensional maps of geometrically necessary dislocation densities in additively manufactured Ni-based superalloy IN71810.1016/j.ijplas.2020.102709 ↗
50. "Hydrogen permeation behavior and hydrogen-induced defects in 316L stainless steels manufactured by additive manufacturing10.1016/j.matchemphys.2020.123038 ↗
51. "The effect of pre-strain on hydrogen embrittlement in 310S stainless steel10.1016/j.jallcom.2014.02.038 ↗
52. "On the role of precipitates in hydrogen trapping and hydrogen embrittlement of a nickel-based superalloy10.1016/j.corsci.2018.10.019 ↗
53. "Dislocations generated by pre-strain dominate the subsequent plastic deformation10.1016/j.msea.2023.145716 ↗
54. 2022, ASTMStandard Test Methods for Tension Testing of Metallic Materials, ASTM, 2022. [Online]. Available: https://compass.astm.org/document/?contentCode=ASTM%7CE0008_E0008M-22%7Cen-US.
55. 2018, ASTMStandard Test Method for Measurement of Hydrogen Embritttlement Threshold in Steel by the Incremental Step Loading Technique, ASTM, 2018. [Online]. Available: https://compass.astm.org/document/?contentCode=ASTM%7CF1624-12R18%7Cen-US.
56. 2021, Standard Practice for Slow Strain Rate Testing to Evaluate the Susceptibility of Metallic Materials to Environmentally Assisted Cracking, ASTM, 2021. [Online]. Available: https://compass.astm.org/document/?contentCode=ASTM%7CG0129-21%7Cen-US.
57. 2021, Standard Practice for Preparation of Substitute Ocean Water, ASTM, 2021. [Online]. Available: https://compass.astm.org/document/?contentCode=ASTM%7CD1141-98R21%7Cen-US.
58. "The activity of NaCl in seawater of 10–40‰ salinity and 5–25°C at 1 atmosphere10.1016/0304-4203(81)90024-4 ↗
59. "Hydrogen determination in welded specimens by carrier gas hot extraction—a review on the main parameters and their effects on hydrogen measurement10.1007/s40194-018-0664-9 ↗
60. "Application of a new method for accurate determination of α and β texture in Ti-6Al-4V from synchrotron diffraction intensities10.1016/j.matchar.2023.112769 ↗
61. "A preferred orientation correction to describe a fiber texture under glancing incidence10.1107/S0021889812045736 ↗
62. "Hydrogen diffusion and trapping in nickel-based Alloy 625: an electrochemical permeation study
63. "The Metallurgy of Alloy 625,"
64. Shoemaker · Alloy. 625 725 Trends Prop. Appl. · 2005 · 409
65. 2019, Standard Specification for Nickel-Chromium-Molybdenum-Columbium Alloy (UNS N06625), Nickel-Chromium-Molybdenum-Silicon Alloy (UNS N06219), and Nickel-Chromium-Molybdenum-Tungsten Alloy (UNS N06650) Rod and Bar, ASTM, 2019. [Online]. Available: https://compass.astm.org/document/?contentCode=ASTM%7CB0446-19%7Cen-US.
66. "Hydrogen-assisted failure in Ni-based superalloy 718 studied under in situ hydrogen charging: The role of localized deformation in crack propagation10.1016/j.actamat.2017.02.059 ↗
67. "Effect of powder layer thickness on the microstructure and properties of Inconel 625 superalloy manufactured by selective laser melting10.1016/j.jallcom.2025.179465 ↗
68. "Effect of solution heat treatment on the microstructure and mechanical properties of Inconel 625 superalloy fabricated by laser solid forming10.1016/j.jallcom.2018.07.087 ↗
69. "Evaluation of microstructure heterogeneity in INCONEL 625 thin-wall fabricated by Laser Powder Bed Fusion additive manufacturing10.1016/j.mtla.2024.102126 ↗
70. "Hydrogen assisted crack initiation and propagation in a nickel-based superalloy10.1016/j.actamat.2016.05.003 ↗
71. "On the formation and nature of quasi-cleavage fracture surfaces in hydrogen embrittled steels10.1016/j.actamat.2010.11.024 ↗
72. Fiji Software Download (2024). Accessed: 26/09/2024. [Online]. Available: 〈https://imagej.net/software/fiji/〉.
73. "Hydrogen embrittlement of the Ni-base Alloy 600 correlated with hydrogen transport by dislocations10.1016/S0921-5093(98)01006-5 ↗
74. "Assessment of the Hydrogen Induced Stress Cracking Resistance of Precipitation Hardened Nickel-Based Alloys Using the Slow Strain Rate Tensile Test Method: Influence of Microstructure
75. "Assessment of the Hydrogen Induced Stress Cracking Resistance of Precipitation Hardened Nickel-Based Alloys Using the Slow Strain Rate Tensile Test Method – Review of a Three Years Test Program
76. "Multi-scale and spatially resolved hydrogen mapping in a Ni–Nb model alloy reveals the role of the δ phase in hydrogen embrittlement of alloy 71810.1016/j.actamat.2016.02.053 ↗
77. "The diffusion and trapping of hydrogen along the grain boundaries in polycrystalline nickel10.1016/j.scriptamat.2011.09.036 ↗
78. "2D modelling of the effect of grain size on hydrogen diffusion in X70 steel10.1016/j.commatsci.2012.01.003 ↗
79. "Characterising hydrogen induced cracking of alloy 625+ using correlative SEM - EDX and NanoSIMS10.1016/j.corsci.2020.109228 ↗
80. "Effect of electrochemical charging on the hydrogen embrittlement susceptibility of alloy 71810.1016/j.actamat.2019.08.020 ↗