Raising our hydrogen research to the next level

Since 2005, OCAS has been building up hydrogen research competence systematically in order to serve the needs related to modern technological developments, i.e. hydrogen as an energy vector, the industrialisation of ultra high strength metals, etc. The OCAS test facilities therefore included a in-house hydrogen lab to characterise hydrogen solubility, diffusivity and trapping and a dedicated sour lab for standardised NACE testing.

Over the past years, several new methodologies have been developed and the OCAS testing capability has been expanded accordingly:

Deuterium as hydrogen tracer

The major advantage of using deuterium over hydrogen is the absence of background noise during the measurements. The combination of the existing metallurgical lab simulation capabilities and the use of deuterium in liquid (heavy water) or gas, allows OCAS to simulate numerous treatments (thermal treatment or electrochemical treatment) where hydrogen (in this case deuterium) is introduced in the material. This methodology can be applied in fundamental studies to reproduce a complete material process cycle under deuterium. The built-up experience has proven to be beneficial and OCAS is currently using this methodology for advanced characterization of trapping behaviour of different microstructural features in both bcc and fcc structures.

Instrumented NACE testing

There are many methods to test the resistance to Sulphide Stress Cracking in H2S environments according to NACE TM0177. Amongst them, method D using Double Cantilever Beam (DCB) specimens, provides a quantitative sour service resistance assessment. OCAS has been testing materials with this method since 2013. To acquire more information, OCAS is currently implementing an instrumented DCB test which will enable continuous follow-up of crack advancement as function of time. This will permit to determine the crack growth rate for different materials and to interupt the test for a given stress intensity factor in order to study how steel’s metallurgical features affect the SSC resistance. The acquired information will enable to link it with the hydrogen content through hydrogen ingress measurements and diffusion modelling




H permeation in sour environment

The existing hydrogen permeation equipment is used to determine the effective diffusivity, permeation rate and apparent solubility of hydrogen in metals. A new set-up has been installed in the sour lab, allowing to  introduce hydrogen by H2S containing solutions, identical to the ones used for NACE sulfide stress cracking tests. This will provide a much better understanding of NACE testing results on today’s advanced materials. To understand the combined effect of hydrogen permeation and applied stress, the hydrogen permeation cell is incorporated in a tensile setup to perform constant load, step loading or slow strain rate (SSRT) tests.


OCAS is convinced that continuous developments are necessary to realise our ambition to remain a centre of excellence for hydrogen related research. For the same reason, OCAS will continue to organise the SteelyHydrogen conference. The third edition “SteelyHydrogen2018” gathered over 170 worldwide experts on hydrogen in metals  in this international scientific event. OCAS is currently preparing the next edition of SteelyHydrogen2022.