C-276 Hastelloy

Product Overview

C-276 Hastelloy is a nickel-molybdenum-chromium-iron-tungsten alloy, known for its corrosion resistance in modern metal materials. It primarily resists wet chlorine, various oxidative chlorides, chloride salt solutions, sulfuric acid, and oxidative salts, demonstrating excellent corrosion resistance in both low and medium temperature hydrochloric acid. Consequently, over the past three decades, it has found extensive application in harsh corrosion environments, such as in the chemical, petrochemical, flue gas desulfurization, pulp and paper industries, and more.

The corrosion data for Hastelloy C-276 alloy is indicative but not to be used as a standard, especially in unknown environments where materials must be tested before selection. Hastelloy C-276 lacks sufficient Chromium (Cr) to resist corrosion in strongly oxidizing environments like hot concentrated nitric acid. This alloy is primarily designed for chemical processing environments, particularly where mixed acids are present, such as outlet pipes in flue gas desulfurization systems.

Hastelloy boasts exceptional mechanical properties, characterized by high strength and toughness, which makes it somewhat challenging to machine. At a deformation rate of 15%, it is approximately twice as deformable as 18-8 stainless steel. Hastelloy also has a medium-temperature sensitization zone, with its sensitization tendency increasing with the deformation rate. At higher temperatures, it readily absorbs harmful elements, leading to a decline in its mechanical and corrosion-resistant properties.

Mechanical Properties

Typical C-276 alloy material is solution treated at 1150℃ and quenched in water.

Mechanical property test values

Temperature (°C), Yield Strength σ0.2 (Mpa), Tensile Strength σb (Mpa), Elongation δ5 (%)

Cold working of C-276 alloy increases its strength. During impact testing, a V-notch impact specimen made of 10mm thick sheet (which must be annealed) is used. If the specimen is welded, it will exhibit some ductility within the same temperature range, due to the weld seam.

Corrosion resistance

C276 alloy is suitable for various chemical process industries involving oxidizing and reducing mediums. Its high molybdenum and chromium content allows the alloy to withstand corrosion from chloride ions, with tungsten further enhancing its corrosion resistance. C276 is one of the few materials that can resist corrosion from damp chlorine gas, hypochlorites, and chlorine dioxide solutions. This alloy exhibits high corrosion resistance to concentrated chloride salt solutions, such as ferric chloride and copper chloride.

Application Fields

C276 alloy finds extensive use in the chemical and petrochemical industries, such as in components and catalytic systems contacting chlorinated organic substances. This material is particularly suitable for use in high-temperature environments, mixed with impurities, and inorganic and organic acids (like formic and acetic acids), as well as in seawater corrosion conditions.