In September 2022, Vallourec announced the successful completion of tests qualifying the fracture toughness resistance of a selection of steel grades in the presence of pure H2 gas . Since then, Vallourec has expanded its range of validated materials for hydrogen service, solidifying its expertise and product portfolio to assist customers in high-pressure transport and storage of H2. Thanks to its material expertise, Vallourec succeeded in testing higher strength steels that, for certain applications, enable thinner walls, lighter solutions, and reduced resource consumption to its customers.
We are pleased to confirm the excellent performance of our high-strength materials in hydrogen gas. This superior performance not only enhances our product offerings, but also allows us to optimize mid-scale and underground storage solutions for hydrogen, thereby providing higher-end efficient options to our customers.Vincent Designolle Vallourec Hydrogen Director
With the growing number of low-carbon hydrogen production and use projects, ensuring the compatibility of assets for hydrogen storage and transportation is paramount. Vallourec has investigated the fracture toughness resistance and corrosion fatigue behavior of a selection of seamless pipes for OCTG, pipeline, and pressure vessels in pressurized H2 service. The first selection of standard and Vallourec proprietary grades tested in the presence of pure H2 gas back in 2022 included:
Vallourec has now added the following grades to its validated material portfolio:
Validation tests included fracture toughness evaluations conducted using fatigue pre-cracked bolt-load specimens exposed to 100 bar hydrogen gas during 1,000 hours at room temperature. All materials presented hydrogen stress intensity factor thresholds KIH largely above 55 MPa.m1/2, compliant with the ASME B31.12 option B requirement that defines materials requirements for hydrogen service.
Although there were concerns in the industry regarding their potential susceptibility to hydrogen embrittlement, we have always been confident that our metallurgies would enable us to achieve even higher mechanical properties. Our materials benefit from tightly controlled chemistries and undergo precise heat-treatment to achieve the desired microstructures, which is crucial in mitigating hydrogen embrittlement.Florian Thébault Principal Corrosion Engineer at Vallourec
In addition, corrosion fatigue tests were performed on compact tensile specimens prior to pre-cracking. Fatigue crack growth rate measurements were determined from 0.01 to 30 Hz and load ratios at 0.1 or 0.9 for covering applications susceptible to present very different internal pressure variations during service life.
As hydrogen projects gain traction around the world, the ability to safely transport and store hydrogen gas is essential to its development and Vallourec is learning as much as possible about its grades’ behavior to hydrogen to anticipate customers’ future needs and contribute to the industry's success by providing safe and effective solutions.