What is the corrosion resistance weakness of Hastelloy C276, and what kind of substances can significantly corrode C276 alloy?
C-276
Hastelloy C-276
Hastelloy C-276 alloy is a tungsten-containing nickel-chromium-molybdenum alloy with extremely low silicon-carbon content and is considered the best corrosion-resistant alloy. Mainly resistant to wet chlorine, various oxidizing chlorides, chloride salt solutions, sulfuric acid and oxidizing salts, and has good corrosion resistance in low and medium temperature hydrochloric acid. Therefore, in the past thirty years, it has been widely used in harsh corrosive environments, such as chemical industry, petrochemical industry, flue gas desulfurization, pulp and paper making, environmental protection and other industrial fields.
Chinese name Hastelloy C-276 Tensile strength σb≥730Mpa Elongation δ≥40% Hardness HRB≤100
Corrosion resistance
This alloy has the following properties:
① In both oxidizing and reducing atmospheres, it has excellent corrosion resistance to most corrosive media.
②Excellent resistance to pitting corrosion, crevice corrosion and stress corrosion. The higher Mo and Cr content make the alloy resistant to chloride ion corrosion, and the W element further improves the corrosion resistance. At the same time, Hastelloy C-276 alloy is one of the only materials resistant to corrosion by moist chlorine, hypochlorite and chlorine dioxide solutions, and is resistant to high-concentration chloride solutions such as ferric chloride and copper chloride. Remarkable corrosion resistance. It is suitable for sulfuric acid solutions of various concentrations and is one of the few materials that can be used in hot concentrated sulfuric acid solutions.
Mechanical behavior
Tensile strength: σb≥730Mpa, elongation: δ≥40%, hardness: HRB≤100.
Hot forming of Hastelloy C-276 alloy is immediately annealed at 1150°C and quenched with water. Cold deformation of Hastelloy C-276 alloy will increase its strength.
Hastelloy C-276 alloy has similar formability to ordinary austenitic stainless steel. However, because it is stronger than ordinary austenitic stainless steel, there will be greater stress during cold forming. In addition, this material works harden much faster than ordinary stainless steel, so mid-process annealing is required during extensive cold forming processes.
Physical properties
The physical properties of Hastelloy C-276 alloy are as follows:
Material composition: 57Ni-16Cr-16Mo-5Fe-4W-2.5Co*-1Mn*-0.35V*-0.08Si*-0.01C* * is a large margin
Implementation standards: UNS N10276, ASTM B575, ASME SB575, DIN/EN 2.4819
Density: 8.90g/cm3
