Hastelloy Alloys

The Corrosion-Resistant Hastelloy alloys are widely used by the chemical processing industries. The need for reliable performance leads to their acceptance and growth in the areas of energy, health and environmental, oil and gas, pharmaceutical and flue gas desulfurization industries. The attributes of Hastelloy alloys include high resistance to uniform attack, outstanding localized corrosion resistance, excellent stress corrosion cracking resistance, and ease of welding and fabrication.

Hastelloy Alloy possesses outstanding resistance to non-oxidizing acids, such as hydrochloric acid and sulfuric acid. The advantages of Hastelloy B-3 alloy over previous B-family alloys are enhanced thermal stability and improved fabrication characteristics.

Hastelloy B-2

Hastelloy B-2 has outstanding resistance to hydrochloric acid at all concentrations and temperatures. It also has significant resistance to reducing environments like sulfuric, phosphoric, acetic acids and other nonoxidizing media. Hastelloy B-2 has excellent resistance to pitting corrosion, stress corrosion cracking, and knife line and weld heat-affected zone attack. Hastelloy B-2 has poor resistance to oxidizing environments, therefore, it should not be used where ferric or cupric salts are present as these salts may cause rapid corrosion failure.

Hastelloy C-22

Hastelloy C-22 is a versatile Ni-Cr-Mo-W alloy with better comprehensive corrosion resistance performance than other Ni-Cr-Mo alloys, including Hastelloy C-276, Hastelloy C-4 and Inconel 625. Hastelloy C-22 has outstanding resistance to pitting, crevice corrosion and stress corrosion cracking. It has excellent resistance to oxidizing aqueous media including wet chlorine and mixtures containing nitric acid or oxidizing acids with chloride ions. It also offers optimum resistance to environments where reducing and oxidizing conditions are encountered in process streams. So it can be used where “upset” conditions are likely to occur or in multi-purpose plants. Hastelloy C-22 has exceptional resistance to a wide variety of chemical process environments, including strong oxidizers such as ferric and cupric chlorides, chlorine, hot contaminated solutions (organic and inorganic), formic and acetic acids, acetic anhydride, and seawater and brine solutions. It resists the formation of grain boundary precipitates in the weld heat-affected zone, thus making it suitable for most chemical process applications in the as-welded condition.

Hastelloy C-276

Hastelloy C-276 has excellent resistance to localized corrosion, stress corrosion cracking, and to both oxidizing and reducing media, thus making it suitable for a wide variety of chemical process environments, including ferric and cupric chlorides, hot contaminated media (organic and inorganic), formic and acetic acids, seawater and brine solutions. It is one of the few materials that withstands the corrosive effects of wet chlorine gas, hypochlorite and chlorine dioxide.

Hastelloy X

Hastelloy X is a nickel-chromium-iron-molybdenum superalloy with outstanding high temperature strength, oxidation resistance, and fabricability. This nickel steel alloy has also been found to be exceptionally resistant to stress-corrosion cracking in petrochemical applications. Matrix stiffening provided by the molybdenum content results in high strength in a solid-solution alloy having good fabrication characteristics. Although this nickel alloy is primarily noted for heat and oxidation resistance it also has good resistance to chloride stress-corrosion cracking, carburization, and excellent resistance to reducing or carburizing atmospheres. Two common conditions that often lead to early failure in high temperature alloys, carburization and nitriding, Hastelloy X resists.