Steel for central solenoid

[jonmaddock]

In GitLab by @mkovari on Dec 19, 2022, 09:55

This paper proposes a new steel for the jacket of a cable-in-conduit conductor for the CS:

Mechanical Properties Evaluation of ReBCO CICC Jacket Based on Super-Austenitic Stainless Steel for CFETR High-field Magnet

Nitronic 50 (N50) super-austenitic stainless steel material has great optimization potential for the development of jacket. ... The N50 circle-in-square jackets ... showed a yield strength greater than 1600 MPa and a fracture toughness K_IC better than 110 MPa·m^1/2 after cold work at 4.2 K.

...it is also necessary to evaluate the fatigue performance and welding performance in the future.

It might be sensible to use these parameters for DEMO and STP runs.

I am not sure if there is any way to infer fatigue properties from the data in the paper above, but see The research on high-strength CICC jackets with YS> 1500 MPa at 4.2 K for future fusion applications, which does give the fatigue crack growth rate.

@ajpearcey @kj5248