Comprehensive Guide to Nickel-Based Alloys: Hastelloy C-276 (UNS N10276)
What is Hastelloy C-276?
UNS N10276 or DIN 2.4819, Hastelloy C-276 (also known as Alloy C-276), is a nickel-molybdenum-chromium-iron-tungsten alloy that is one of the most corrosion resistant alloys available. The high molybdenum content resists localized corrosion, such as pitting. The low carbon minimizes carbide precipitation during welding to maintain resistance to intergranular attack in the heat-affected zone of the weld joint.
Corrosion Resistance of Hastelloy C-276
Alloy C276 Nickel Alloy Plate is one of the premier corrosion resistant materials that performs well in both oxidizing and reducing environments. It resists chloride stress corrosion cracking, pitting, crevice and general corrosion. The alloy also resists carbide precipitation during welding, allowing it to be used in the as-welded condition.
In chemical processing applications, the alloy offers excellent resistance to sulfuric, hydrochloric, formic, acetic, and phosphoric acids. Alloy C276 Nickel Alloy Plate performs well in environments containing acid chlorides, solvents, and acetic anhydride, and the alloy is one of the few grades that can withstand wet chlorine, hypochlorite, and chlorine dioxide solutions.
Alloy C276 Nickel Alloy Plate is highly resistant to concentrated solutions of oxidizing salts, including ferric and cupric chlorides. It also performs well in seawater, especially in crevice conditions where other commonly used alloys such as stainless steel, Alloy 400, and Alloy 625 fail.
The operating conditions of flue gas desulfurization systems provide a challenging environment for corrosion resistant materials. Scrubber liquids and gas condensates often contain chlorides. Alloy C276 Nickel Alloy Plate Nickel alloy plates have been shown to withstand higher chloride levels than other grades in these systems before localized corrosion occurs.
Alloy C276 Nickel Alloy Plate is widely used in the recovery and processing of sour natural gas containing hydrogen sulfide, carbon dioxide, and chlorides. Carbon steel and alloy steels cannot withstand this corrosive environment. They are susceptible to failure due to sulfide stress cracking or stress corrosion cracking. The rich chemical composition of Alloy C276 Nickel Alloy Plate makes it resistant to acidic environments even at high temperatures in deep wells.
