A groundbreaking achievement in the realm of stainless steel has been realized by a team led by Professor Mingxin Huang from the University of Hong Kong’s Department of Mechanical Engineering. The latest innovation, known as SS-H2, is a stainless steel specifically designed for hydrogen applications, marking a significant advancement in the ‘Super Steel’ Project helmed by Professor Huang.

This achievement builds upon the project’s earlier milestones, including the creation of anti-COVID-19 stainless steel in 2021 and the development of ultra-strong and ultra-tough Super Steel in 2017 and 2020. The newly developed SS-H2 showcases exceptional corrosion resistance, opening the door to potential applications in green hydrogen production from seawater, addressing the need for sustainable solutions.

Published in the journal Materials Today, the research findings are currently in the process of obtaining patents in multiple countries, with two already authorized. The breakthrough in stainless steel is a departure from conventional methods, providing a cost-effective alternative for industrial applications.

The research team’s sequential dual-passivation strategy led to the creation of SS-H2, demonstrating superior corrosion resistance. Unlike traditional stainless steel, the SS-H2 forms a secondary Mn-based layer in addition to the Cr2O3-based passive layer. This innovative mechanism prevents corrosion in chloride media up to an ultra-high potential of 1700 mV, surpassing the limitations of conventional stainless steel.

Dr. Kaiping Yu, the first author of the article, expressed initial disbelief at the counter-intuitive discovery involving Mn-based passivation. The unexpected breakthrough took nearly six years of dedicated work, from the initial discovery to scientific understanding and preparation for industrial application.

Professor Huang highlighted the team’s focus on developing high-potential-resistant alloys, overcoming fundamental limitations and establishing a new paradigm for alloy development at elevated potentials. The breakthrough holds promise for practical applications, particularly in water electrolyzers, where expensive components like Au- or Pt-coated Ti are currently required.

The cost-cutting potential of SS-H2 is substantial, with an estimated 40-fold reduction in the cost of structural material. This breakthrough paves the way for industrial applications, with the team already producing tons of SS-H2-based wire in collaboration with a mainland factory. As Professor Huang noted, the team is progressing toward applying the more economical SS-H2 in hydrogen production from renewable sources, showcasing the exciting prospects of this innovative stainless steel.

By Impact Lab