Understanding material variability. Predicting hydrogen damage. Designing reliable steel for a circular industrial future.
Watch a short introduction to CIRHY and see how the project brings together multiscale materials research, digitalisation, experimental validation and industrial demonstration to develop hydrogen-resistant circular steels.
CIRHY is a six-year research and innovation project focused on enabling circular steels to operate safely in hydrogen environments. The project was granted by the Dutch national funding agency NWO in 2025 under project number P24.058.
Hydrogen can penetrate steel and cause embrittlement, reducing ductility and potentially leading to cracking and structural failure. At the same time, the shift towards circular steels produced from recycled materials is essential to reduce CO₂ emissions and reliance on primary resources.
CIRHY brings these challenges together. The inherent variability of recycled steel, including the presence of residual elements, is investigated as a potential design lever. Understanding these elements could reveal ways to improve resistance to hydrogen damage, for example through beneficial hydrogen-trapping mechanisms.
The project combines advanced experiments with physics-based modelling across atomistic, mesoscopic and macroscopic scales. It connects microstructural features and residual elements to mechanical performance, translating fundamental knowledge into predictive design capabilities.
CIRHY builds on initiatives such as DEPMAT and Growing with Green Steel. It complements their work on recycled materials by addressing the impact of hydrogen on steel performance in the presence of residual elements.
The hydrogen economy depends on reliable materials. Failures in hydrogen-exposed steel structures can have serious safety, environmental and economic consequences. Circular steel offers an opportunity to reduce the steel industry's carbon footprint, provided its performance can be assured under demanding conditions.
CIRHY aims to redefine how circular steel is designed and used. Its ambition is a predictive, digital twin-based approach in which performance can be designed, assessed and validated before production and deployment.
By reducing reliance on trial-and-error development, CIRHY seeks to accelerate materials innovation, support safe infrastructure and strengthen sustainable, digitalised industry in the Netherlands and Europe.
Fundamental understanding and predictive modelling come together with industrial validation.
Optimise residual (tramp) elements and precipitates to turn recycling-induced microstructural variability into a strength. Dual-phase or complex-phase steels will be selected at the start of the project, with simpler ferritic or martensitic microstructures supporting fundamental mechanistic understanding.
Integrate atomistic, mesoscopic and macroscopic models to predict mechanical behaviour, material properties and hydrogen embrittlement, enabling reliable simulation and optimised steel design.
Deepen understanding of how hydrogen interacts with dislocations, grain boundaries and precipitates in the presence of residual elements.
Develop physics-based models requiring minimal experimental input, reducing reliance on physical testing and accelerating the design of circular steels for hydrogen-exposed conditions.
Validate the framework through industrial demonstrators, including energy infrastructure and transportation applications, to guide material selection, performance assessment and next-generation steel design.
CIRHY connects advances in materials science with tools and applications that industry can use.
The project aims to enable steel producers to use advanced digital tools for designing and optimising circular steels under hydrogen exposure, reducing costly testing and accelerating innovation.
Industrial partners will test and apply validated circular steels across infrastructure, transport and energy. Integration of the modelling framework into commercial software platforms is intended to make these tools accessible to a wider industrial community.
CIRHY aims to support large-scale adoption of hydrogen-resistant circular steels, reduce material failure risks and enable safer infrastructure.
Its long-term ambition includes further digitalisation of steel development, new data-driven alloy design approaches and stronger international collaboration and industrial competitiveness in sustainable materials and hydrogen technologies.
An expert in hydrogen–material interactions and multiscale modelling of metallic systems, Dr. Dey leads the scientific direction of CIRHY, integrating fundamental research, modelling and experimental validation.
Dr. Sedighiani represents industrial end-users and bridges academic and industrial research, aligning the programme with real-world challenges in steel production and application.
Together, they coordinate academic and industrial collaboration, guiding CIRHY from fundamental insights to practical solutions for hydrogen-resistant circular steels.
CIRHYCircular steel