For decades scientists have been struggling to find materials that simultaneously endure extreme cold and extreme force. At the heart of a nuclear fusion reactor is an ultra-powerful superconducting magnet operating at temperatures near absolute zero and under immense magnetic stress, requiring such materials. Chinese production of China High-Strength Low-Temperature Steel No. 1 (CHSN01) serves that purpose.
The team of Li Laifeng at the Chinese Academy of Sciences’ Technical Institute of Physics and Chemistry began working on this in 2011. In 2017, Li went to the U.S. to attend the International Cryogenic Materials Conference, where he introduced the nitrogen-enhanced N50 stainless steel they were working on, which improved yield strength but failed to enhance cryogenic toughness.
Foreign experts told him that the route he was pursuing was “absolutely impossible” for producing better cryogenic steel. But he persisted. In 2017, subsequent trials incorporating vanadium helped achieve a better strength-toughness balance, but still not at the necessary level.
