It's a stainless steel alloy...made in an AOD and continuos caster into a slab, then to a hot rolling facility to get in into a coil, then to a finishing plant where I worked for descaling, annealing, cold rolling (me), final annealing, slitting, shipping. $100K for some of those coils. When you wreck it on a rolling mill...it 'crawls' all through the roll stack and takes 12 hrs. to extract the wrecked scrap...because it's very malleable, more so than most normal stainless grades like 201-301 etc.
edit: people buy it for the very light weight. many regular stainless grades have similar strength at 2x-3x the weight