Can Alloy 400 be magnetic?
A. Although this is a fully austenitic material, alloy 400 can still become magnetic, especially after cold work. The reason relates to the Curie temperature associated with the nickel-copper chemistry relationship. Alloy K500 will remain totally non-magnetic at room temperature, since its Curie point for magnetic/non-magnetic response occurs at -100F(-73C) to -150F(-101C). Alloy 400, depending upon its copper-nickel chemistry relationship could range from 30 to 70 F, and therefore could show a weak magnetic response. This could be further emphasized by cold work. If the magnetic structure is immersed in boiling water, all magnetic sensitivity will disappear.
