EN ISO 17081:2014 PDF

Overview - EN ISO 17081:2014 (ISO 17081:2014)

EN ISO 17081:2014 specifies a laboratory electrochemical technique for measuring hydrogen permeation, and for determining hydrogen uptake and transport in metals (including alloys). The method is based on measuring the steady‑state hydrogen flux through a metal specimen and analyzing the permeation transient to obtain effective diffusivity and to distinguish reversible and irreversible trapping. The standard covers specimen preparation, apparatus (charging and oxidation cells), control and monitoring of test environment, test procedures and result analysis.

Key topics and technical requirements

• Measurement principle: place a metal sample between a charging cell (environment of interest) and an oxidation cell; hydrogen atoms generated at the charging surface diffuse through and are oxidized on exit, producing a measurable permeation current.
• Outputs and analysis:
  • Steady‑state hydrogen flux and permeation current.
  • Effective hydrogen diffusivity (from permeation transient and lag time).
  • Identification of reversible vs irreversible traps in the metal.
• Specimen requirements: dimensions, surface preparation and optional coatings (e.g., palladium) that can affect subsurface hydrogen concentration.
• Environmental control: requirements for aqueous and gaseous charging, use of recombination poisons where applicable, and monitoring of electrical and chemical test conditions.
• Data treatment: normalization of flux, extrapolation methods for lag time, and standardized reporting of test conditions and results.
• Normative reference: ISO 17475 (guidelines for potentiostatic and potentiodynamic measurements) is referenced for electrochemical practice.

Practical applications and users

This standard is widely used by:

• Corrosion engineers and materials scientists assessing hydrogen embrittlement risk.
• R&D labs characterizing hydrogen diffusion and trapping in steels, titanium, nickel alloys and other metals.
• Coating and surface‑treatment developers evaluating how treatments affect hydrogen uptake.
• Failure analysis and quality control teams ranking the aggressivity of environments (gaseous or aqueous) with respect to hydrogen uptake.
• Standards bodies and test laboratories requiring reproducible, comparable hydrogen permeation data.

Practical benefits:

• Quantitative comparison of environments and materials for hydrogen susceptibility.
• Data to inform material selection, heat treatment, and protective measures against hydrogen‑induced failures.

Related standards and context

• EN ISO 17081:2014 supersedes the 2008 edition and was prepared by ISO/TC 156 (Corrosion of metals and alloys) and adopted by CEN.
• Related reference: ISO 17475 for electrochemical measurement techniques.

Keywords: EN ISO 17081:2014, hydrogen permeation, hydrogen uptake, electrochemical technique, hydrogen diffusion, permeation current, effective diffusivity, reversible trapping, irreversible trapping, specimen preparation, corrosion testing.