C22 alloy is a versatile nickel-chromium-molybdenum-tungsten alloy with better overall corrosion resistance than other Ni-Cr-Mo alloys available today, including C-276 and C-4 alloys and alloy 625. C22 alloy has outstanding resistance to pitting, crevice corrosion, and stress corrosion cracking. By virtue of its higher chromium content, C22 alloy is more resistant than C-4 and C-276 alloys to oxidizing acids and to acid streams containing oxidizing residuals such as dissolved oxygen, ferric ions, and wet chlorine. Because of such versatility it can be used in multipurpose processes and where “upset” conditions are likely to occur.
C22 alloy has exceptional resistance to a wide variety of chemical process environments, including strong oxidizers such as ferric and cupric chlorides, chlorine, hot contaminated solutions (organic and inorganic), formic and acetic acids, acetic anhydride, and seawater and brine solutions. C22 alloy resists the formation of grain-boundary precipitates in the weld heat-affected zone, thus making it suitable for most chemical process applications in the as-welded condition.
