21Cr-6Ni-9Mn (Nitronic 40) is a high-manganese nitrogen strengthened, austenitic stainless steel that combines high strength in the annealed condition, excellent resistance to oxidation at high temperatures, good resistance to lead oxide, and a high level of corrosion resistance at ambient temperatures. The alloy can be fabricated and formed much the same as 304 and 316, is readily weldable, and remains nonmagnetic after severe cold work.
