Hastelloy C-276 alloy is a nickel-molybdenum-chromium formed alloy that is commonly considered a versatile corrosion-resistance alloy. The C-276 alloy is an enhanced wrought version of alloy C as it usually doesn’t need to be solution heat-treated after welding and has much improved fabricability. This alloy is resistant to the formation of grain-boundary precipitates in the weld heat-affected region, thus make it appropriate for most chemical process applications in the as-welded condition. However, in environments where the attack of the C-276 alloy weld joint is encountered, C-22 weld filler materials should be used. C-276 alloy possesses immense resistance to localized corrosion and to both oxidizing and reducing environments. Owing to its versatility, C-276 alloy can be used in conditions where “upsets” are likely to happen or in multipurpose plants.
Hastelloy C-276 alloy has excellent resistance to a wide variety of chemical process environments, including strong oxidizers such as ferric and cupric chlorides, hot contaminated media (organic and inorganic), chlorine, formic and acetic acids, acetic anhydride, and seawater and brine solutions. It is used in flue gas desulfurization systems because of its excellent resistance to sulfur compounds and chloride ions encountered in most scrubbers. The C-276 alloy has excellent resistance to pitting and to stress-corrosion cracking. It is also one of the few materials that withstands the corrosive effects of wet chlorine gas, hypochlorite, and chlorine dioxide.