Alloy 20 resistant to chloride-ion stress-corrosion cracking. Copper and molybdenum give resistance to reducing environments. The molybdenum content also provides good resistance to pitting and crevice corrosion. The chromium gives resistance to oxidizing environments such as nitric acid. The addition of niobium reduces the effect of carbide precipitation during welding, thus increasing the alloy's resistance to intergranular corrosion.