The Korea Institute of Materials Science (KIMS) has developed a next-generation material that can withstand ultra-high temperatures and radiation with enhanced fracture resistance and irradiation resistance through the addition of small amounts of titanium (Ti) and optimized heat treatment, and expectations are high that it can be applied as a core steel material for nuclear fusion power generation.

The Korea Institute of Materials Science has developed, for the first time in Korea, the next-generation low-activation steel 'K-RAFM' (Reduced Activation Ferritic/Martensitic) that can withstand ultra-high temperatures of 100 million degrees Celsius and high-energy neutron environments.

The results of a joint research project between Dr. Lee Chang-hoon's team, Changwon National University, and Myongji University are evaluated as a step closer to domestic production of key structural materials for nuclear fusion power plants.

K-RAFM has overcome two limitations of foreign RAFM steels at the same time. The research team suppressed the formation of chromium-based large carbides by adding a small amount of titanium, and further refined the carbide particles by lowering the heat treatment temperature to 730-740℃.

As a result, the internal structure of the material became dense and uniform, greatly improving fracture resistance and minimizing deterioration of mechanical properties even after high-energy neutron irradiation. It has achieved world-class levels in both key indicators of ‘unbreakable strength’ and ‘radiation resistance.’

This steel can be applied to core components of nuclear fusion reactors, such as blankets, diverters, and inner vessels, and is expected to expand to future industries that require high temperature and extreme radiation environments, such as small modular reactors (SMRs) and spacecraft structures.

The research team has already registered two patents and the 'K-RAFM' trademark, and is speeding up verification research to secure a mass production process.

Lee Chang-hoon, head researcher, said, “Commercialization of K-RAFM is a critical key to simultaneously securing the safety of nuclear fusion demonstration reactor construction and achieving material technology independence,” adding, “Great synergy is also expected in enhancing the competitiveness of the domestic steel industry.”

This project was carried out with the support of the Ministry of Science and ICT and the National Research Foundation of Korea's nuclear fusion research and development project, and has produced about 30 academic achievements to date, including about 20 SCI(E) papers.