Hastelloy C22 vs C276: Which Nickel Alloy Resists Chlorides Better?

Introduction

When comparing Hastelloy C22 vs C276, buyers should choose Hastelloy C22 when oxidizing chlorides, ferric chloride, cupric chloride, wet chlorine, mixed oxidizing acids and pharmaceutical or fine chemical environments are the main concern. Choose Hastelloy C276 when severe reducing acids, mixed chemical media, flue gas desulfurization systems, chemical waste treatment, pitting corrosion and crevice corrosion resistance are required. Both alloys resist chlorides far better than common stainless steels, but C22 is often stronger in oxidizing chloride service, while C276 is often selected for broader severe chemical processing environments.

Hastelloy C22 and Hastelloy C276 are nickel-chromium-molybdenum alloys used in chemical processing, pollution control, marine chemical equipment, pharmaceutical production, pulp and paper, oil and gas, and high-value corrosion-resistant components. They are commonly supplied as bar, plate, pipe, tube, flange, fitting, wire and forged products.

For procurement, buyers should compare chemical media, chloride concentration, temperature, oxidizing or reducing condition, pressure, fabrication method, standards, EN 10204 3.1 MTC, PMI testing, UT testing, heat number control, third-party inspection, surface finish, delivery capability and total life-cycle cost before selecting Hastelloy C22 or Hastelloy C276.

What Are Hastelloy C22 and Hastelloy C276?

Hastelloy C22, also known as Alloy C22 or UNS N06022, is a nickel-chromium-molybdenum-tungsten alloy designed for outstanding resistance to oxidizing and reducing chemical environments. Its higher chromium content compared with C276 gives it excellent resistance in oxidizing chloride media, wet chlorine and mixed acid environments.

Hastelloy C276, also known as Alloy C276 or UNS N10276, is a nickel-molybdenum-chromium-tungsten alloy widely used in severe chemical processing. It is highly resistant to pitting, crevice corrosion, stress corrosion cracking and many aggressive reducing environments. It is one of the most commonly specified nickel alloys for chemical plant components.

Fast Buyer Recommendation

Application Condition	Recommended Alloy	Reason
Oxidizing chlorides, ferric chloride, cupric chloride	Hastelloy C22	Higher chromium supports excellent oxidizing chloride resistance
Severe mixed chemical processing and waste treatment	Hastelloy C276	Broad corrosion resistance in many aggressive reducing and mixed media
Pharmaceutical and fine chemical production	Hastelloy C22	Strong resistance to oxidizing cleaning and process media
Flue gas desulfurization and pollution control	Hastelloy C276	Excellent performance in acidic chloride and wet gas environments
Cost-sensitive project with less severe corrosion	Evaluate 904L, Alloy 20, Inconel 625 or duplex first	C22 and C276 are premium alloys and may exceed project requirements

Chemical Composition Comparison

The corrosion behavior of Hastelloy C22 and C276 is mainly controlled by nickel, chromium, molybdenum and tungsten. C22 has higher chromium, which improves performance in oxidizing chemicals. C276 has higher molybdenum in many specifications, which supports strong resistance to pitting and reducing acids.

Element	Hastelloy C22 / UNS N06022	Hastelloy C276 / UNS N10276	Selection Note
Nickel (Ni)	Balance	Balance	Base element for broad corrosion resistance and metallurgical stability
Chromium (Cr)	20.0 – 22.5	14.5 – 16.5	Higher Cr gives C22 stronger oxidizing media resistance
Molybdenum (Mo)	12.5 – 14.5	15.0 – 17.0	Higher Mo supports C276 performance in many reducing and localized corrosion conditions
Tungsten (W)	2.5 – 3.5	3.0 – 4.5	Improves resistance in severe mixed chemical environments
Iron (Fe)	2.0 – 6.0	4.0 – 7.0	Must match the applicable ASTM, ASME or project specification
Carbon (C)	Max 0.015	Max 0.010	Low carbon helps reduce carbide precipitation during welding and fabrication

Mechanical Properties

Hastelloy C22 and C276 both offer strong mechanical performance for corrosion-resistant nickel alloys. In many procurement decisions, corrosion environment matters more than strength because the two alloys are often used for chemical equipment where material failure is driven by corrosion rather than mechanical overload.

Property	Hastelloy C22	Hastelloy C276	Buyer Note
Tensile Strength	High for nickel alloy products	High for nickel alloy products	Check actual values on MTC by product form and standard
Yield Strength	Suitable for pressure and machined components	Suitable for pressure and machined components	Confirm design load, temperature and product size
Elongation	Good ductility in solution annealed condition	Good ductility in solution annealed condition	Important for fabrication and forming
Weldability	Good with correct procedures	Good with correct procedures	Use qualified welding procedure and compatible filler material
Machinability	Difficult compared with stainless steel	Difficult compared with stainless steel	Confirm machining allowance, hardness and surface condition before ordering bars

Applicable Standards and Equivalent Grades

Hastelloy C22 and C276 are supplied under different standards depending on product form. Buyers should define whether the inquiry is for bar, plate, sheet, pipe, tube, flange, fitting, wire or forging. Correct standards help avoid certificate disputes and ensure the material can be accepted by the project owner or inspection company.

Item	Hastelloy C22	Hastelloy C276	Common Product Scope
UNS	N06022	N10276	Material identity and MTC verification
EN / W.Nr.	2.4602	2.4819	European drawings and engineering material comparison
Bar Standard	ASTM B574 / ASME SB574	ASTM B574 / ASME SB574	Round bar, rod, forged bar and machined parts
Plate / Sheet Standard	ASTM B575 / ASME SB575	ASTM B575 / ASME SB575	Plate, sheet, strip and cut-to-size products
Pipe / Tube Standard	ASTM B622 / B626 / B619 depending on product form	ASTM B622 / B626 / B619 depending on product form	Seamless pipe, welded pipe, seamless tube and welded tube
Forging Standard	ASTM B564 / ASME SB564	ASTM B564 / ASME SB564	Flanges, forged fittings, rings, discs and custom forgings

Quality Testing and Material Traceability

For high-value nickel alloys such as Hastelloy C22 and C276, traceability is critical. The heat number on the material, label, packing list and EN 10204 3.1 MTC should match. Buyers should also request PMI testing to verify Ni, Cr, Mo and W content, especially when different nickel alloys are purchased together.

Certificate and Inspection Checklist

Inspection / Document Item	What to Check	Why It Matters
EN 10204 3.1 MTC	Grade, UNS number, standard, heat number, chemical composition, mechanical properties, size and condition	Confirms batch-specific quality and supports project documentation
Heat Number Control	Heat number on material marking, label, packing list and MTC must match	Prevents mixed material supply and supports traceability
PMI Testing	Verify Ni, Cr, Mo, W and alloy identity	Helps distinguish C22 from C276 and avoid wrong-grade delivery
UT Testing	Check internal soundness for bars, plates, forgings and critical products	Important for machined parts, pressure components and high-reliability applications
Dimensional Inspection	Diameter, thickness, width, length, straightness, flatness and tolerance	Ensures machining, welding, assembly and installation requirements are met
Third-party Inspection	SGS, BV, TUV, Intertek or customer-appointed inspection before shipment	Provides additional confidence for export orders and critical chemical projects

Comparison With Similar Nickel Alloys

Hastelloy C22 and C276 are often compared with Inconel 625, Alloy 20, 904L stainless steel, duplex stainless steel and titanium. The correct selection depends on corrosion media, chloride concentration, oxidizing or reducing condition, temperature and cost target.

Material	Corrosion Resistance	Strength	Cost Level	Best-use Recommendation
Hastelloy C22	Excellent in oxidizing chlorides and mixed acids	High	High	Pharmaceutical, fine chemical, oxidizing chloride and wet chlorine service
Hastelloy C276	Excellent in many severe chemical and reducing environments	High	High	Chemical processing, FGD, waste treatment and severe mixed media
Inconel 625	Excellent in seawater and many chloride environments	High	High	Offshore, seawater systems, weld overlay and chloride service
Alloy 20	Good in selected sulfuric acid environments	Medium to high	Medium to high	Sulfuric acid service where C22 or C276 may exceed requirements
904L Stainless Steel	Good to excellent in many acid and chloride environments	Medium	Lower than C22 and C276 in many cases	Moderately aggressive chemical service with cost consideration

Industrial Applications of Hastelloy C22 and C276

Both alloys are used in high-value industrial systems where corrosion failure can cause downtime, leakage, contamination or safety risk. C22 is often selected for oxidizing chloride and pharmaceutical environments, while C276 is widely used in severe chemical processing and pollution control systems.

Industry / Application	Recommended Alloy	Common Products	Selection Reason
Pharmaceutical and Fine Chemical	Hastelloy C22	Reactor parts, valves, fittings, tubes, plates and machined components	Excellent resistance to oxidizing process media and cleaning environments
Chemical Processing	C22 or C276 depending on media	Bars, plates, pipes, flanges, fittings, valve parts and pump components	Select based on oxidizing/reducing condition, chloride level and temperature
Pollution Control / FGD	Hastelloy C276	Scrubber components, nozzles, plates, bolts and wet gas parts	Broad resistance in acidic chloride and wet flue gas environments
Pulp and Paper	C22 or C276	Bleaching equipment parts, rolls, shafts, tubes and fasteners	Strong resistance to chlorine-containing bleaching chemicals
Oil and Gas	C276 or project-specific alloy	Bolts, connectors, valve parts, downhole components and piping parts	Selected for sour, chloride or aggressive service where applicable

Why Choose Hastelloy C22 or C276?

The best choice depends on the real corrosion environment. C22 is often selected for oxidizing chloride environments and high-purity chemical production. C276 is often selected for severe mixed chemical service, acidic chloride environments and long-established chemical plant applications.

Corrosion, Strength and Cost Comparison

Selection Factor	Hastelloy C22	Hastelloy C276	Buyer Decision
Oxidizing Chlorides	Excellent	Very good to excellent depending on media	Choose C22 when oxidizing chloride resistance is the first priority
Reducing Acids and Mixed Chemicals	Excellent in many mixed environments	Excellent and widely used	Choose C276 for severe broad chemical processing service
Strength	High for nickel alloy products	High for nickel alloy products	Strength is usually not the main deciding factor between these two alloys
Cost	Premium alloy cost	Premium alloy cost	Compare life-cycle cost, downtime risk and actual media before choosing lower alloy alternatives
Availability	Available in bars, plates, pipes, fittings and flanges	Very widely specified in chemical processing	Confirm stock, MOQ, lead time and certificate requirements before ordering

Common Buyer Mistakes

A common mistake is selecting C276 only because it is more familiar, even when C22 may be better for oxidizing chloride service. Another mistake is selecting C22 or C276 for mild service where 904L, Alloy 20, Inconel 625 or duplex stainless steel may already be sufficient. Buyers should also avoid accepting material without clear UNS number, MTC, PMI testing, heat number traceability and correct ASTM or ASME standard.

Surface Finish, Processing and Export Packaging

Hastelloy C22 and C276 can be supplied as bars with black, peeled, turned, ground or polished surface; plates with hot rolled, solution annealed and pickled surface; pipes and tubes with pickled, bright or polished surface; and flanges or fittings with machined sealing faces. Surface condition should be matched to machining, welding or final assembly requirements.

Because these are high-value nickel alloys, export packaging should protect against scratches, moisture, deformation and contamination. Common packaging includes wooden cases, wooden pallets, plastic wrapping, end caps for pipes and tubes, steel strip bundling, heat number labels and waterproof protection for sea freight.

Related Nickel Alloy Products

SASA ALLOY supplies Hastelloy C22, Hastelloy C276 and related nickel alloy products for chemical processing, pollution control, oil and gas, marine, pharmaceutical and power generation projects. Buyers can select product forms according to equipment drawings, corrosion media and inspection requirements.

Product	Common Grades	Typical Use
Hastelloy Alloy Bar	C22, C276, B2, B3, C2000, G30, X	Valve stems, pump shafts, fasteners, machined parts and corrosion-resistant components
Hastelloy Alloy Plate	C22, C276, C2000, B2, G30	Reactors, vessels, tube sheets, corrosion-resistant linings and chemical equipment
Hastelloy Alloy Pipe and Tube	C22, C276, B2, C2000	Chemical transfer lines, heat exchangers, scrubbers and corrosion-resistant piping systems
Nickel Alloy Flanges	Hastelloy C22, C276, Inconel 625, Monel 400, Incoloy 825	Piping connections, pressure systems, chemical plants, oil and gas and marine projects
Nickel Alloy Fittings	Hastelloy C22, C276, Inconel 625, Incoloy 825, Monel 400	Elbows, tees, reducers, stub ends and customized corrosion-resistant piping fittings

FAQ About Hastelloy C22 vs C276

1. Which is better, Hastelloy C22 or C276?

Neither alloy is universally better. C22 is often better for oxidizing chloride and wet chlorine environments, while C276 is often better for broad severe chemical processing and reducing acid service. The correct choice depends on exact chemical media, concentration and temperature.

2. Which alloy resists chlorides better?

Both C22 and C276 provide excellent chloride resistance. C22 is often selected for oxidizing chlorides, while C276 is widely used for severe chloride-containing chemical processing, acidic chloride environments and pollution control systems.

3. Is C22 more expensive than C276?

Both are premium nickel alloys, and the price depends on raw material market, product form, size, quantity, testing requirements and delivery time. C22 may cost more in some cases due to availability or project-specific requirements, but actual quotation should be checked by size and form.

4. Can C22 and C276 be welded?

Yes. Both C22 and C276 can be welded using qualified procedures and suitable filler metals. Heat input, cleanliness, surface preparation and post-weld inspection should be controlled carefully for chemical processing applications.

5. What certificates should buyers request?

Buyers should request EN 10204 3.1 MTC showing grade, UNS number, standard, heat number, chemical composition, mechanical properties, size and delivery condition. PMI testing, UT testing and third-party inspection are recommended for high-value or critical projects.

6. How can buyers avoid wrong material selection?

Buyers should provide the exact chemical media, temperature, concentration, pressure, product form, standard and inspection requirement. Material should be verified by MTC, PMI testing, heat number control and third-party inspection when required.

7. What information is needed for a fast quotation?

A complete inquiry should include alloy grade, UNS number, product form, ASTM or ASME standard, size, quantity, surface finish, tolerance, testing requirement, MTC requirement, destination port and packing requirement. For example: ASTM B574 UNS N10276 Hastelloy C276 round bar, diameter 40 mm, length 3000 mm, EN 10204 3.1 MTC and PMI testing required.

Conclusion

Hastelloy C22 and Hastelloy C276 are both excellent nickel alloys for chloride and severe chemical environments, but they should be selected based on actual service conditions. C22 is often preferred for oxidizing chloride and wet chlorine environments, while C276 is widely used in severe mixed chemical processing, reducing acids, pollution control and chemical waste treatment.

For successful procurement, buyers should confirm UNS number, ASTM or ASME standard, product form, dimensions, surface finish, EN 10204 3.1 MTC, heat number control, PMI testing, UT testing, dimensional inspection, third-party inspection and export packaging. A professional nickel alloy supplier should help buyers compare C22 vs C276 based on corrosion resistance, strength, cost and delivery requirements.