NC2294 sheets produced from alloy C22 (Hastelloy C22)

Description of Alloy C22 Plates

ALLOY22 is a Ni-Cr-Mo alloy containing tungsten with extremely low carbon and silicon contents. The elevated chromium level provides resistance to oxidising media, while the contents of molybdenum and tungsten ensure resistance to reducing media. This nickel alloy exhibits resistance to oxidising aqueous environments, including wet chlorine and mixtures that contain nitric acid or oxidising acids with chloride ions. Additional corrosive substances against which Hastelloy C-22 is effective include oxidising acid chlorides, wet chlorine, formic and acetic acids, iron and copper chlorides, sea water, brine and many mixed or contaminated chemical solutions, both organic and inorganic. The alloy also maintains its resistance in environments where reducing and oxidising conditions occur in process streams, which is pertinent in multipurpose facilities where such conditions arise frequently.

This nickel alloy resists the formation of grain boundary precipitates in the heat affected zone of the weld; it is therefore suitable for most chemical process applications in the welded condition.

The C-22 alloy should not be used at operating temperatures above 1250° F, as harmful phases form above this temperature.

Specifications of Alloy C22 Plates

ASTM Specifications

Applications of Alloy C22 Plates

• Chimney Linings:
• The corrosion resistance of the alloy under oxidising and reducing conditions ensures durability in this application.
• Pipes:
• Given that the alloy withstands oxidation and corrosion in a broad range of aggressive media, it is suitable for maintaining the integrity of channels over extended periods.
• Dampers:
• The alloy’s corrosion and oxidation resistance ensures reliable performance in environments containing potentially corrosive gases.
• Washers:
• The alloy is capable of withstanding corrosive pollutants and chemicals encountered in washers.
• Heat Exchangers:
• The alloy’s resistance to oxidising and reducing conditions, together with its thermal stability, ensures the longevity and efficiency of heat exchangers.
• Reaction Vessels:
• Given its resistance to a variety of corrosive substances, including acids and chlorides, the alloy maintains the structural integrity of reaction vessels.
• Evaporators:
• The corrosion resistance is critical in environments where concentrated solutions and corrosive substances are present, thereby ensuring the reliable performance of evaporators.