Hastelloy C22 Pipes and Tubes
Hastelloy C22 pipes and tubes are popular and most versatile nickel chromium and Monel based
alloy with extra-ordinary corrosion resistance properties when compared to other nickel and Monel
based alloys.
Chemical Composition
| GRADE | Ni | Cr | p | Si | S | Mn | C | V | Co | W | Fe | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ALLOY C-22 | Min | BALANCE | 20 | – | – | – | – | – | – | – | 2.5 | 2 |
| MAX | 22.5 | 0.02 | 0.08 | 0.02 | 0.5 | 0.015 | 0.35 | 0.25 | 3.5 | 6 |
Production Process
Alloy C-22 or UNS N06022 are manufactured like ERW (Electric Resistance Welded), Seamless and
EFW (Electric Fusion Welding) pipes and tubes with different forms like round, square, rectangle,
etc. having specific ends as in the plain end, bevel end, and threaded end with normal thickness of
different schedules ranging from SCH 5 to SCH XXS.
Mechanical Properties
| Grade | Tensile Strength | Yield Strength | Elongation |
|---|---|---|---|
| [MPA] | [MPA] | (% in 50mm) min | |
| Alloy C-22 | 690 | 310 | 45 |
Popular processes used to manufacture C22 pipes and tubes are cold pilgering process, extrusion
process, tube mill process, and piercing process which need to be followed by heat treatment and
mechanical testing.
Physical Properties
| Grade | Density (g/cm3) | Elastic Modulus (GPa) | Co-eff of Thermal Expansion (μm/m/°C) | Thermal Conductivity (W/m.K) | Electrical Resistivity (nΩ.m) | Elastic Modulus (GPa) | Specific Heat (J/Kg.K) | Melting Range |
|---|---|---|---|---|---|---|---|---|
| 24-100°C | 0-100°C | at 100°C | ||||||
| Alloy C-22 | 8.69 | 220 | 12.4 | 11.1 | 1.23 | 206 | 423 | 1399 |
Fabrication and Heat Treatment
The grade has enhanced resistance to corrosion, pitting, crevice corrosion, and excellent stress crack
corrosion resistance and many other resistive properties found.
HASTELLOY C22 pipes and tubes can be hot forged, hot rolled, hot upset, hot extruded, and hot
formed and then need to be heat treated. The hot working temperature range is quite limited. For
example, the recommended hot forging temperature starts at 1232°C (2250°F) and the
recommended end temperature is 954°C (1750°F).
Specifications
| GRADE | UNS | EURONORM | DIN | |
|---|---|---|---|---|
| NO | NAME | |||
| ALLOY C-22 | N06022 | 2.4602 | NiCr21Mo14W | 17744 |
Although ductile needs to be formed by cold working, intermediate annealing may be required due
to work hardening. Ideal temperature range for annealing is between 2020°F-2150°F followed by a
rapid quench.
Properties
C22 pipe fittings are a great option to super austenitic stainless steels (AL-6XN,904L, and 254 SMO)
and duplex stainless steels (2205 and 2507) which do not withstand extremely aggressive media.
This is because the alloy is a mix of nickel-chromium-molybdenum-tungsten elements along with
better overall resistance to uniform and localized corrosion than any other type of Ni-Cr-Mo alloy,
like Hastelloy C-276, C-4, and alloy 625 to name a few.
The grade also has good resistance to reducing and oxidizing environments. Due to all of these
qualities, the hastelloy c22 pipes have been popularly used in chemical processing units and other
industries where there is high amount of corrosion and other impurity.
Applications
- Acetic Acid/Acetic Anhydride
- Acid Etching
- Cellophane Manufacturing
- Chlorination Systems
- Complex Acid Mixtures
- Electro-Galvanizing Rolls
- Expansion Bellows
- Flue Gas Scrubber Systems
- Geothermal Wells
- HF Furnace Scrubbers
- Incineration Scrubber Systems
- Nuclear Fuel Reprocess
Specification
Alloy C-22 Seamless Pipe : ASTM/ASME B 622 / SB 622
Alloy C-22 Seamless tube : ASTM/ASME B 444 / SB 444
Alloy C-22 ERW Pipe : ASTM/ASME B 619 / SB 619
Alloy C-22 ERW Tube : ASTM/ASME B 626 / SB 626
NOTE: Hastelloy C22 pipes and tubes are a registered trademark of Haynes International Inc.
