JSME Construction Standard for Superconducting Magnet of Fusion Facility “MATERIAL”

Abstract

A construction standard for a large superconducting magnet for a fusion device has been established by Japan Society of Mechanical Engineers in Japan. This paper describes the outline of the part of “Material” and interprets some special features provided in the standard. The standard was composed based on Japan Industrial Standard. The materials used for the superconducting magnet structure was limited and divided into two groups. The first group is for the materials of which cryogenic strength are not limited and will be used under the design with the strength at room temperature. The other group composes of the materials of which cryogenic strength are provided. The former group includes forged austenitic stainless steel, Inconel 718, Ni and Ni alloy, Cu and Cu alloy and welding wires for these materials. The latter group holds cryogenic structural materials, such as JJ1 and 316LN steels. The design strength of these materials is given in a quadratic function from room temperature to cryogenic temperature when the material is used in an as-solution heat treated condition. The standard also equips the process to register the new materials. One shall be able to prepare the data set necessary to make registration, and submit to the JSME Code Committee to register the materials with the standard.