Hastelloy C-22 Uns n06022 Alloy C22 is a nickel-chromium-molybdenum solid solution strengthened super-alloy with a nominal chemical composition of 56% nickel, 22% chromium, and 13% molybdenum, with additions of iron, tungsten, and cobalt. It is commonly referred to by the tradename Hastelloy C22 and the universal designation UNS N06022.