Description of Alloy C22 Tube/Pipe
ALLOY22 is a Ni-Cr-Mo alloy containing W and extremely low carbon and Si contents. The high chromium content provides good resistance to oxidizing media while the molybdenum and tungsten content give good resistance to reducing media. This nickel steel alloy also has excellent resistance to oxidizing aqueous media including wet chlorine and mixtures containing nitric acid or oxidizing acids with chlorine ions. Other corrosives Hastelloy C-22 has resistance to are oxidizing acid chlorides, wet chlorine, formic and acetic acids, ferric and cupric chlorides, seawater, brine and many mixed or contaminated chemical solutions, both organic and inorganic. This nickel alloy also offers optimum resistance to environments where reducing and oxidizing conditions are encountered in process streams. This is beneficial in multi-purpose plants where such “upset” conditions occur frequently.
This nickel alloy 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.
Alloy C-22 should not be used in service temperatures above 1250° F due to the formation of detrimental phases that form above this temperature.
Specifications of Alloy C22 Tube/Pipe
Chemical composition %
|
Ni
|
Cr
|
Mo
|
Mn
|
Si
|
C
|
S
|
P
|
Cu
|
V
|
W
|
Fe
|
Min
|
-
|
20.0
|
12.5
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
2.5
|
-
|
Max
|
Balance
|
22.5
|
14.5
|
0.5
|
0.08
|
0.015
|
0.02
|
0.02
|
2.5
|
0.35
|
3.5
|
6.0
|
ASTM Specifications
Pipe
|
Tube
|
Sheet/Plate
|
Bar
|
Forging
|
Fitting
|
B622/619
|
B626
|
B575
|
B574
|
B564
|
B366
|
Applications of Alloy C22 Tube/Pipe
- Stack Liners:
- The alloy's exceptional corrosion resistance, particularly in oxidizing and reducing environments, ensures durability and longevity in this application.
- Ducts:
- Its resistance to oxidation and corrosion in a wide range of aggressive media makes it suitable for ensuring the integrity of ducts over extended periods.
- Dampers:
- The alloy's resistance to corrosion and oxidation ensures the reliable performance of dampers in environments with potentially corrosive gases.
- Scrubbers:
- Its excellent corrosion resistance makes it ideal for withstanding the corrosive nature of pollutants and chemicals in scrubbing applications.
- Heat Exchangers:
- The alloy's resistance to both oxidizing and reducing environments, along with its thermal stability, ensures the longevity and efficiency of heat exchangers.
- Reaction Vessels:
- Its resistance to a wide range of corrosive substances, including acids and chlorides, makes it suitable for ensuring the structural integrity of reaction vessels.
- Evaporators:
- Its corrosion resistance is crucial in environments where concentrated solutions and potentially corrosive substances are involved, ensuring the reliability of evaporators over time.