Introduction to Hastelloy used in distillation columns

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Key features: Excellent corrosion resistance. HASTELLOY® C-276 is generally regarded as the universal corrosion-resistant nickel-chromium-molybdenum forged alloy. C-276 alloy is an improved forged C alloy; its advantage lies in the fact that no further solution heat treatment is required after welding, and its machinability has also been greatly improved. The C-276 alloy can prevent the formation of grain boundary precipitates in the weld heat-affected zone; therefore, products made from this alloy are suitable for most applications in chemical engineering processes. When the welded joints of C-276 alloy are corroded by the environment, C-22® alloy should be considered as the filler metal for welding. The C-276 alloy exhibits excellent resistance to both localized corrosion and redox media. Due to the versatility of the C-276 alloy, it can be widely used in factories serving various production purposes, even when the workshop reaction conditions may not be ideal. The C-276 alloy also exhibits excellent corrosion resistance in various chemical environments, including ferric trichloride and copper dichloride, hot polluted solutions (organic or inorganic), strong oxidizing agents such as formic acid, acetic acid, and acetic anhydride, as well as seawater and saline solution environments. Due to its excellent resistance to sulfides and chloride ions that may be encountered in most scrubbers, C-276 alloy can also be used in flue gas desulfurization systems. C-276 alloy exhibits excellent resistance to pitting corrosion and stress corrosion cracking. At the same time, it is also one of the few materials that can withstand corrosion caused by wet chlorine gas, hypochlorites, and chlorine dioxide. C-276 alloy can be manufactured using various processing methods, including forging, hot heading, and extrusion. Although this alloy has a tendency to work harden, it can withstand deep drawing, drawing, pressing, and punching well. The C-276 alloy can be welded using all common welding methods, but we do not recommend using oxy-acetylene welding and submerged arc welding for components intended for use in corrosive environments. Special attention should be paid to taking certain preventive measures during welding to avoid excessive heat input. For more detailed processing information, please refer to brochure H2010–“Processing of HAYNES® Corrosion-Resistant Alloys”