Hydrogen Permeation
Hydrogen uptake and permeation during electrochemical processes has a critical effect on the mechanical stability of some metals, especially iron- and copper-based materials.
Today, production- and operation-related material embrittlement caused by hydrogen confronts designers and process operators with unexpected challenges. The starting point for hydrogen-induced material embrittlement can be coating processes and their pretreatment as well as corrosion processes during component operation under mechanical load.
In recent years, the measurement method of hydrogen permeation has been established for the investigation of phase boundary reactions with special consideration of hydrogen formation. Existing measuring systems are characterised by a complex setup according to Devanathan and Stachurski. With ElyFlow and the Gaskatel control box, Gaskatel is launching a complete and robust measuring system for the determination of hydrogen permeation, which performs its electrochemical measuring service without the use of expensive potentiostats. When examining steel foils, a Pd coating on the oxidation side of the sample can also be omitted. In doing so, you can perform a wide range of electrochemical measurement and control tasks:
- In situ monitoring of hydrogen evolution during electrochemical coating, including monitoring of the potential at the phase boundary.
- In situ monitoring of hydrogen evolution in pretreatment processes, such as pickling processes, in conjunction with monitoring of the electrochemical potential at the phase boundary.
- Monitoring of production process parameters with regards to hydrogen embrittlement.
- Determination of material embrittlement during transport and storage of hydrogen in tank lines and storage systems.
- Determination of H-diffusion coefficients in metallic materials in dependence of the morphological material properties.
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Basics about Hydrogen Permeation
Here you will find an overview of typically used terms and some useful basics for hydrogen permeation measurements.
How to Measure Hydrogen Permeation
Our concept is characterised by less technical equipment. The measuring cell consists of a reduction cell (charging cell) and an oxidation cell (fuel cell). The test piece is located between these two subcells. To detect the permeation current, an oxygen consumption electrode (oxygen gas diffusion electrode O2-GDE) is used on the oxidation side of the test piece.
Evaluation of the Measurement
The passivation current at the beginning of the measurement decreases to a small constant offset. For an exact calculation of the permeation current, you have to correct the measured current by this offset.