ASTM B366 Hastelloy C276 Butt Welded Elbow Introduction Hastelloy C276 is a nickel-molybdenum-chromium superalloy with excellent corrosion resistance in a wide range of harsh environments. This alloy is particularly known for its resistance to pitting, crevice corrosion, and stress corrosion cracking. ASTM B366 specifies the requirements for wrought nickel and nickel alloy fittings, including butt