Mechanical behaviour of high nitrogen stainless steel reinforced conductor for use in pulsed high field magnets at cryogenic temperature

The use of copper-high nitrogen stainless steel macrocomposites for applications such as pulsed high magnetic field coils is demonstrated in this contribution. The macrocomposite reveal an enhancement of up to 40% in strength when cooling from 300 K down to liquid nitrogen temperature. An ultimate tensile strength of 1.53 +/- 0.017 GPa is reached with a 3 mm x 2 mm wire with 52 vol.-% Cu and a logarithmic drawing strain of eta = 2.8 at liquid nitrogen temperature. Compared to the low nitrogen stainless steel macrocomposites in use up to now, which have an UTS of 1.02 +/- 0.017 GPa and reveal an enhancement of 28% in strength when cooling down, these values related to high nitrogen stainless steel macrocomposites bear great improvements. (C) 2003 Elsevier Science Ltd. All rights reserved.