Magneto-elastic Effect for 316LN-IG Stainless Steel at Low Temperature

AbstractTensile tests of 316LN-IG austenitic stainless steel samples cut out from tubes along their axis are carried out in liquid and gaseous helium below 7K. The tubes were intended for conductor conduits for the toroidal magnet system for ITER. Time dependences of temperature, strain and strain induced magnetization normal to the sample surface are examined with respect to stress. A complicated behavior of the local deformation near slip bands is detected that seems as unloading and shrinking regions adjacent to slip planes. The magneto-elastic effect indicating a negative longitudinal magneto-striction for the initial γ phase and the α phase induced by strain is found. The events without local heat release when jumping strain are explained as a result of the magneto-caloric effect in the regions unloaded in slipping

Design and Test Results of a 1 MVA Resistive Type Fault Current Limiter

AbstractThe 1 MVA resistive type single phase AC fault current limiter (FCL) was build and successfully tested by capacitors battery discharge. FCL rated voltage is 3.5kV, current 250 Arms. The 240 m of HTS tape (type SF12100 by SupePower) was used for FCL production. The FCL consists of 8 bifilar coils each wound onto glass-fiber 70mm diameter tube and connected in series. The HTS tapes were additionally stabilized with Cu laminated highly resistive foil. During the tests of separate FCL coils at 380V an excellent limiting performance was observed. Tested FCL coil was switched off after 75ms, the maximum temperature at the HTS tape was less then 230K, the recovery time was about 5 s