C276

The weld deposit perfectly matches the C276 base alloy, composed of Ni-15%Cr-16%Mo-4%W-5%Fe. The carbon (C) and silicon (Si) content is carefully controlled to minimize the formation of carbide precipitates and intermetallic phases. Cast alloy variants generally present higher levels of carbon and silicon, but repair welds are typically heat-treated for solutionizing to ensure optimal corrosion resistance. The C276 alloy offers excellent corrosion resistance in a wide range of acids and salts, under both oxidizing and reducing conditions. These include hydrochloric acid, hydrofluoric acid, hypochlorites, chlorides, wet chlorine gas, sulfuric acid, phosphoric acid, and numerous organic acids. It demonstrates exceptional pitting and crevice corrosion resistance in saltwater and shows high resistance to chloride-induced stress corrosion cracking, superior to alloy 62. Its excellent mechanical properties at temperatures down to -196 °C make it ideal for welding cryogenic plants with a Ni content between 5-9%. Typical applications include use in
pumps, valves, piping, and vessels for aggressive environments in chemical processing plants, as well as in flue gas desulfurization equipment and the offshore oil and gas sector. No preheat is necessary; the interpass temperature should preferably be maintained below 100 °C, and the heat input must be limited to 1.5 kJ/mm.

Alloy C276 is a Ni-15%Cr-16%Mo-4%W-5%Fe nickel base alloy.

In the as-welded condition the weld metal consists of austenite with some carbides.

• EN W.Nr.: 2.4819 (NiMo16Cr15W), 2.4883 (G-NiMo16Cr)
• ASTM: A494 CW-12MW, A743/A744 CW-12M
• UNS: N10276
• PROPRIETARY: Hastelloy® Alloy C-276 (Haynes International Inc), Inconel® Alloy C-276 (Special Metals), Nicrofer 5716hMoW (VDM)