Mechanical Properties of ITER CICC Jacket in China

The ITER magnet system is made up of four main subsystems: 18 toroidal field (TF) coils, a six-module central solenoid coil, 6 poloidal field (PF) coils, and 18 correction coils (CCs). The Feeder system with its main busbar and correction coil busbar represents one of the main magnet components as well. All coils and busbars with different dimensions used cable-in-conduit conductors (CICCs). China needs to provide six different types of conductors. The ITER CICCs consist of a cable made of Nb3Sn or Nb-Ti strands inserted in a stainless steel tube (called jacket or conduit). Depending on the coil type, the jacket material is either made of a low carbon AISI 316LN (for TF coil) or AISI 316L grade stainless steels (for PF and CC coils, etc). Mechanical properties of base material need to be tested at room and/or cryogenic temperature under predefined mechanical deformation and heat treatment conditions. This paper concerns mechanical tests on the jacket materials, including static tensile tests, fatigue crack growth rate, and fracture toughness tests.