Understand hydrogen interactions

Significant efforts are being made to design steel grades that can be used to safely generate, store and transport hydrogen. However, to develop new materials with the necessary resistance to hydrogen, it’s crucial to understand the mechanisms of hydrogen embrittlement and the interactions with the microstructure.

Over the past few years, OCAS has developed a great deal of competence in terms of methodology, knowledge building, modelling and understanding the hydrogen embrittlement phenomenon. Plus, OCAS organised the very first European conference dedicated to hydrogen and steel. Thanks to the huge success of SteelyHydrogen2011, we’ve decided to launch the second International Conference on Metals & Hydrogen “SteelyHydrogen2014”. Again, feedback from the more than 140 participants was highly positive. For its 3rd edition in 2018, the scope was extended to non-ferrous alloys. SteelyHydrogen 2018 attracted 180 internatioal participants. OCAS is pleased to announce that we are currently preparing the 4th edition of “SteelyHydrogen2021”. The call for papers will open soon.

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Fully equipped for the future

To be prepared for future challenges, OCAS developed a new approach to thoroughly analyse the results of thermal desorption spectroscopy (TDS). During the past year, we developed a trapping-desorption model for hydrogen and adopted the use of deuterium as hydrogen tracer. So, OCAS is now equipped with electrochemical permeation, TDS (hydrogen and deuterium), determination of hydrogen concentrations, disk rupture tests, tensile tests with in situ hydrogen charging, and equipment that allows hydrogen charging at high temperatures and/or pressures.

In-house models add value

In addition, the in-house models we have developed for hydrogen trapping and diffusion bring added value to our work: they enable us to better understand the hydrogen-microstructure interactions and to optimise the testing that must be performed.

A good example of the contribution our knowledge can make was determining the amounts of hydrogen pick-up during the various processing steps of high-strength steels. During austenitisation at different atmospheres, we found hydrogen in sufficient quantity to cause hydrogen-induced cracking of the steels. This finding will allow us to develop better hydrogen embrittlement resistant high-strength grades by modifying the process cycle.

“The equipment and the models we’ve developed on hydrogen diffusion and trapping have given us a better understanding of hydrogen embrittlement mechanisms and hydrogen-microstructure interactions.”

Laura Moli Sanchez, Research Engineer Metallurgy, OCAS