The term “corrosion resistant alloys” (CRA’s) covers a wide range of materials from ferritic
stainless steels to nickel base or titanium alloys. Nickel, chromium and molybdenum contents
increase steadily as we progress from ferritic, duplex, super-duplex, austenitic, 6% or 7%
molybdenum super-austenitic stainless steels to nickel-chromium-molybdenum-tungsten alloys.
As this progression is made the corrosion resistance, and cost, increase dramatically. A
definitive ranking of the general and localized corrosion resistance of these materials in a variety
of environments is provided, with special emphasis on effects of welding and choice of filler
metals.
KEY WORDS: Nickel Alloys, Duplex Stainless Steels, Welding / Welds, Corrosion, Acids, Pitting