2019 年 54 巻 6 号 p. 445-451
JJ1 steel was developed through joint research between the Japan Atomic Energy Research Institute (JAERI, now the National Institute for Quantum and Radiological Science and Technology, QST) and Japan Steel Works, Ltd. (JSW). This steel became the structural material for the superconducting magnet coils of fusion reactors in the early 1980s. JJ1 steel is a non-magnetic steel that demonstrates good mechanical and metallurgical properties at liquid He temperatures (4 K) as well as good weldability. JJ1 steel is being used as the structural material for the Toroidal field (TF) coil of the International Thermonuclear Experimental Reactor.