Hydrogen in carbon steels at high pressures up to 1000 bar

Johann Pengg

Research output: ThesisMaster's Thesis

Abstract

Autoclave tests were performed to determine the amount of hydrogen absorbed by two casing and tubing steel grades, a OCTG grade comparable to the API grade L80 (Steel A) and a high strength sour gas resistant steel grade (Steel B), under high hydrogen partial pressures up to 1000 bar and high temperatures up to 200 °C. Steel samples were charged with pressurized pure hydrogen gas for different times to obtain the saturation concentration of hydrogen under these conditions as well as the relationship between hydrogen uptake and charging time.
Furthermore, electrochemical permeation experiments were conducted. Those were done in an electrochemical double cell as first proposed by Devanathan and Stachursky. Data gathered by these measurements were used to calculate the effective diffusion coefficient of the tested material. Additionally, the effective diffusion coefficient was determined by fitting Fick’s second law to hydrogen charging data. By comparing both diffusion coefficients it seems likely that the hydrogen absorption process is not controlled by diffusion under the applied conditions.
The results of the charging experiments showed that even though Steel B is the higher strength steel grade the amount of hydrogen the material absorbed was similar to the lower strength Steel A. Furthermore, it was found that the sample geometry as well as the surface finish and roughness of the samples severely affected the amount of hydrogen the material absorbed.
Translated title of the contributionWasserstoff in Kohlenstoffstählen bei hohen Drücken bis 1000 bar
Original languageEnglish
QualificationDipl.-Ing.
Awarding Institution
  • Montanuniversität
Supervisors/Advisors
  • Mori, Gregor Karl, Supervisor (internal)
Award date15 Dec 2023
DOIs
Publication statusPublished - 2023

Bibliographical note

embargoed until 22-11-2028

Keywords

  • Carbon steel
  • Hydrogen
  • High pressure hydrogen
  • Hydrogen charging
  • Hydrogen permeation

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