Comprehensive Guide to Nickel-Based Alloys: Hastelloy C-276 (UNS N10276)
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. High molybdenum content resists localized corrosion such as pitting. Low carbon can minimize the precipitation of carbides during the welding process to maintain the resistance to intergranular corrosion in the heat-affected zone of the welded joint.
As can be seen from its chemical composition, it is a nickel-chromium-molybdenum alloy containing tungsten. As a matrix, nickel itself has excellent corrosion resistance, is not easy to rust in the atmosphere, and can resist corrosion by caustic soda. Nickel forms a NiO film on its surface in air or oxygen, which can prevent further oxidation. At the same time, Hastelloy C-276 contains a large amount of chromium, molybdenum, and tungsten, which also determines its excellent strength. Because Hastelloy C-276 has excellent corrosion resistance in environments such as strong acids, we usually choose it as the liquid contact material for testing in these media.
Corrosion Resistance of Hastelloy C-276
Alloy C276 Nickel Alloy Plate is one of the premier corrosion-resistant materials and performs well in both oxidizing and reducing environments. It resists chloride stress corrosion cracking, pitting, crevices and general corrosion. The alloy is also resistant to carbide precipitation during welding, allowing it to be used in the welded state.
In chemical processing applications, the alloy provides excellent resistance to sulfuric acid, hydrochloric acid, formic acid, acetic acid and phosphoric acid. 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 chloride and copper chloride. It also performs well in seawater, particularly 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 plate has been proven to withstand higher chloride levels than other grades before localized corrosion develops in these systems.
Alloy C276 nickel alloy plate is widely used in the recovery and processing of sour natural gas containing hydrogen sulfide, carbon dioxide and chloride. Carbon and alloy steel 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.
