Hastelloy C-22, UNS N06022, is a nickel chromium molybdenum tungsten alloy engineered for severe corrosion service. Its balance of chromium for oxidizing conditions and molybdenum with tungsten for reducing conditions makes it one of the few materials that resists both, and it shows outstanding resistance to pitting, crevice attack and chloride stress corrosion cracking.
It also resists weld heat affected zone attack, which allows fabrication without post weld solution annealing in most service.
Stocked as sheet, plate, bar, tube and forgings in the solution annealed condition.
Sizes and stock
- Round bar: up to 9" DIA
- Sheet / plate: up to 0.5" THK
- Tube per ASTM B622: various sizes
Processing capabilities
- Billet conversion and open die, closed die and ring forging
- Solution treat, age and anneal to the applicable spec
- Saw cutting, trepanning, gun drilling and CNC machining
- Ultrasonic, penetrant dye, micrography and physical testing
Specifications
Material is released to the applicable specification with mill test reports and, on request, independent lab verification.
Why engineers specify Hastelloy C-22
- Resists both oxidizing and reducing corrosive media
- Outstanding pitting and crevice corrosion resistance
- Resists weld heat affected zone attack
- Suited to mixed acid and unpredictable process chemistries
Nominal chemistry
Percent by weight, nominal composition per the governing specification. The mill test report for your heat is the controlling document.
Typical mechanical properties
| Condition | Tensile strength | Yield strength | Elongation | Hardness |
|---|---|---|---|---|
| Solution annealed | 100 ksi min | 45 ksi min | 45% min | - |
Typical published values for reference only, not for design. Properties vary with section size, product form and processing. Order to the specification and condition your drawing requires.
Typical applications
- Chemical process reactors and piping
- Flue gas desulfurization equipment
- Pharmaceutical and pulp bleaching hardware
- Waste treatment and scrubber components
Fabrication notes
Machining
Nickel and cobalt superalloys work harden aggressively. Use rigid setups, sharp tooling, slow speeds, positive feed that stays under the hardened skin, and flood coolant. Age hardened material machines far more slowly than solution treated material, so rough before aging wherever the print allows.
Welding
Most solid solution grades weld readily with matching filler. Age hardenable grades such as 718 and Waspaloy are welded in the solution treated condition and aged afterward to control strain age cracking.
Forming
Hot working ranges are narrow and forces are high. Cold form in the annealed condition with intermediate anneals, and stress relieve before final heat treatment.
Hastelloy C-22 compared with similar grades
C-276
Higher molybdenum for reducing acids, lower chromium for oxidizing service.
Alloy 625
Very good general corrosion resistance at lower cost, less capable in severe mixed acids.
Designations and cross reference
- Material family
- Nickel & Cobalt Alloys
- UNS number
- N06022
- Werkstoff (W.Nr)
- 2.4602
Working from an obsolete, foreign or superseded designation? Send it over and we will cross reference it to a current grade and specification.
Quality, testing and traceability
Supplied with mill test reports and heat traceability, with ultrasonic inspection, penetrant dye, micrography, grain size, stress rupture and mechanical testing available on request.
We are AS9100D and ISO 9001:2015 registered. If our stock does not already carry the inspection your specification requires, we can quote the material with that work performed. More on our quality system
Available forms
Custom sizes converted from billet, plus saw cut, waterjet and near-net blanks. See custom conversions
Hastelloy C-22 frequently asked questions
What is Hastelloy C-22?
Hastelloy C-22, UNS N06022, is a nickel chromium molybdenum tungsten alloy engineered for severe corrosion service. Its balance of chromium for oxidizing conditions and molybdenum with tungsten for reducing conditions makes it one of the few materials that resists both, and it shows outstanding resistance to pitting, crevice attack and chloride stress corrosion cracking.
What forms is Hastelloy C-22 available in?
We supply Hastelloy C-22 in bar, sheet, plate, tube. Custom sizes are converted from billet, and we can provide saw cut, waterjet or near net blanks so material arrives closer to your finished part.
What is the UNS or equivalent designation for Hastelloy C-22?
Hastelloy C-22 is designated UNS N06022, Werkstoff 2.4602. If your drawing calls out an obsolete or foreign designation we can cross reference it and confirm the equivalent before you order.
What specifications can Hastelloy C-22 be supplied to?
Commonly ordered specifications include ASTM B574, ASTM B575, ASTM B622, UNS N06022. Material is released to the specification and condition on your purchase order, with mill test reports supplied as standard.
What conditions can Hastelloy C-22 be ordered in?
We can supply Solution annealed. If our stock is not already in the condition you need, we can quote it with the heat treatment performed before shipment.
Can you cut Hastelloy C-22 to size?
Yes. Saw cutting, waterjet, laser and shearing are available, along with trepanning, gun drilling, lathe turning and CNC machining, so you can order blanks or rough machined pieces rather than full lengths.
Do you provide test reports and additional testing on Hastelloy C-22?
Every order ships with mill test reports and heat traceability. If your print calls for ultrasonic inspection, penetrant dye, magnetic particle, chemical assay, micrography, hardness or mechanical testing and our stock does not already carry it, we can quote the material with that work performed.
Can Hastelloy C-22 be supplied to DFARS domestic melt requirements?
Tell us at quote stage if the order is DFARS or domestic melt restricted and we will confirm availability against that requirement before you commit.
What do you need to quote Hastelloy C-22?
Grade, form, dimensions, quantity, specification and condition, plus any testing or certification requirements and the date you need it. Send a drawing if you have one. Quotes are typically ready within 24 hours.
How does Hastelloy C-22 compare with C-276?
Higher molybdenum for reducing acids, lower chromium for oxidizing service.