Apparatus and method for the non-destructive measurement of hydrogen diffusivity

Patent metadata

Field	Value
Publication number	US-2020200727-A1
Application number	US-202016805126-A
Country	US
Kind code	A1
Filing date	Feb 28, 2020
Priority date	Apr 28, 2017
Publication date	Jun 25, 2020
Grant date	—

Abstract

Apparatuses and methods of measuring a hydrogen diffusivity of a metal structure including during operation of the metal structure, are provided. A hydrogen charging surface is provided at a first location on an external surface of the structure. In addition, a hydrogen oxidation surface is provided at a second location adjacent to the first location on the external surface of the structure. Hydrogen flux is generated and directed into the metal surface at the charging surface. At least a portion of the hydrogen flux generated by the charging surface is diverted back toward the surface. A transient of the diverted hydrogen fluxes measured, and this measurement is used to determine the hydrogen diffusivity of the metal structure in service.

First claim

1 .- 21 . (canceled)

22 . A method of measuring a hydrogen diffusivity of a metal structure comprising:
providing a hydrogen charging surface at a first location on an external surface of the structure; providing a hydrogen oxidation surface at a second location adjacent to the first location on the external surface of the structure; generating a hydrogen flux directed into the metal surface at the charging surface; detecting at least a portion of the hydrogen flux generated by the charging surface diverted back toward the surface; measuring a transient of the diverted hydrogen flux; and determining the hydrogen diffusivity of the metal structure based on the measured transient.

23 . The method of claim 22 , wherein the hydrogen diffusivity is determined from the measured transient using a direct simulation technique based on a Fickian diffusion model that uses initial conditions based on an experimental apparatus.

24 . The method of claim 23 , further comprising:
setting a value for the hydrogen diffusivity; executing the diffusion model using the set value of hydrogen diffusivity; comparing results of the Fickian diffusion model to results using the experimental apparatus; and repeating the previous steps with different values of hydrogen diffusivity until a closest match between the results of the diffusion model and the results using the experimental apparatus is reached.

25 . An apparatus for measuring a hydrogen diffusivity of a metal structure comprising:
a first chamber positioned on an external surface of the metal structure, the first chamber including a hydrogen flux sensor; and a second chamber separated by a wall from and adjacent to the first chamber and positioned on the external surface of the metal structure, the second chamber including a hydrogen charging cell for generating hydrogen and inducing a hydrogen flux into the external surface of the metal structure; wherein a portion of the hydrogen flux is diverted out of the metal surface toward the first chamber, where the hydrogen flux is measurable by the hydrogen flux sensor.

26 . The apparatus of claim 25 , wherein the second chamber includes an electrolyte solution in contact with the external surface of the metal structure.

27 . The apparatus of claim 26 , further comprising a counter electrode and reference electrode position in the electrolyte solution.

28 . The apparatus of claim 27 , further comprising an electric power supply coupled to the external surface of the metal structure, the counter electrode and the reference electrode, the power supply being operative to provide a constant current between the counter electrode and the external surface of the metal structure to provide cathodic polarization of the metal surface.

Assignees

• Saudi Arabian Oil Co

Inventors

• Traidia Abderrazak
• Alshahrani Mohammed
• Duval Sebastien A

Classifications

• C25B1/02

  Hydrogen or oxygen · CPC title

• G01N33/2025 Primary

  Gaseous constituents · CPC title

• G01N2013/003

  Diffusion; diffusivity between liquids · CPC title

• G01N2001/2241

  purpose-built sampling enclosure for emissions · CPC title

• G01N27/413

  Concentration cells using liquid electrolytes {measuring currents or voltages in voltaic cells} · CPC title