Hastelloy b3 vs Hastelloy c276

Hastelloy B-3 is a nickel-molybdenum alloy with excellent resistance to hydrochloric acid and other reducing acids. It is mainly used in chemical processing equipment exposed to severe reducing environments.
Hastelloy C-276 is a nickel-chromium-molybdenum alloy with broader corrosion resistance. It performs well in both oxidizing and reducing media, as well as in chloride-containing environments.

Grade A

Hastelloy b3

UNS: N10675
Family: Hastelloy / Nickel-Molybdenum Alloy
Common Forms: Plate, sheet, strip, pipe, tube, bar, forging

A nickel-molybdenum alloy offering exceptional resistance to hydrochloric acid and other strongly reducing media, with improved thermal stability and fabrication characteristics compared with earlier B-series alloys.

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Grade B

Hastelloy c276

UNS: N10276
Family: Hastelloy / Nickel-Chromium-Molybdenum-Tungsten Alloy
Common Forms: Plate, sheet, strip, pipe, tube, bar, forging

A versatile nickel-chromium-molybdenum-tungsten alloy with outstanding resistance to pitting, crevice corrosion and stress-corrosion cracking in both oxidizing and reducing environments, widely used in chemical processing and pollution-control equipment.

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Main Comparison

Hastelloy b3 and Hastelloy c276 comparison by engineering and purchasing factors

Review the key differences before confirming chemical media, product form, standard, certificate and delivery schedule.

Comparison Item	Hastelloy B-3	Hastelloy C-276	Selection Note
Basic Information
UNS Number	N10675	N10276	Use the UNS number on drawings, MTCs and purchase specifications.
Alloy Type	Nickel-molybdenum alloy	Nickel-chromium-molybdenum-tungsten alloy	B-3 is optimized for reducing acids; C-276 provides broader resistance in mixed and oxidizing environments.
Typical Product Forms	Plate, sheet, strip, bar, pipe, tube, forgings and fittings	Plate, sheet, strip, bar, pipe, tube, forgings and fittings	Availability depends on product form, size, specification, quantity and delivery schedule.
Weldability	Excellent with qualified procedures	Excellent with qualified procedures	Both alloys are designed to resist weld-zone corrosion when properly welded and heat treated.
Chemical Composition
Nickel (Ni)	Balance	Balance	Nickel provides the corrosion-resistant matrix and good ductility of both alloys.
Chromium (Cr)	Approximately 1.5%	Approximately 16%	C-276 contains much more chromium, giving it better resistance in oxidizing media.
Molybdenum (Mo)	Approximately 28.5%	Approximately 16%	B-3 has substantially higher molybdenum, making it especially effective in hydrochloric and other reducing acids.
Tungsten (W)	Approximately 3%	Approximately 4%	Tungsten contributes to localized corrosion resistance in both alloys.
Iron (Fe)	1.5% max	4.0-7.0%	B-3 has lower iron content and a highly nickel-molybdenum chemistry.
Cobalt (Co)	3.0% max	2.5% max	Cobalt is controlled as a minor alloying element in both grades.
Carbon (C)	0.01% max	0.01% max	Very low carbon supports resistance to grain-boundary corrosion after welding.
Silicon (Si)	0.10% max	0.08% max	Low silicon limits undesirable intermetallic or silicide formation.
Mechanical Properties
Typical Condition	Solution annealed	Solution annealed	Actual mechanical values depend on product form, thickness, heat treatment and ordered standard.
Yield Strength, RT	Approx. 350 MPa	Approx. 355 MPa	Typical annealed values; confirm the minimum values specified for the ordered product.
Tensile Strength, RT	Approx. 760 MPa	Approx. 785 MPa	C-276 is slightly higher in common annealed plate data, but values are close.
Elongation, RT	Approx. 40%	Approx. 40%	Both alloys provide good ductility for forming and fabrication.
High-Temperature Strength	Good	Good	These grades are generally selected primarily for corrosion resistance rather than maximum hot strength.
Corrosion Performance
Hydrochloric Acid	Excellent resistance over a broad concentration and temperature range	Very good resistance in many conditions	B-3 is often preferred for severe hydrochloric acid service.
Sulfuric Acid	Excellent in reducing sulfuric acid environments	Very good in many mixed-acid conditions	Final selection depends on concentration, temperature, aeration and contaminants.
Oxidizing Media	Limited compared with chromium-containing alloys	Excellent resistance in many oxidizing and mixed chemical environments	C-276 is generally the safer choice when oxidizing species are present.
Chloride Pitting and Crevice Corrosion	Good in reducing chloride-acid environments	Excellent resistance in many chloride-bearing environments	C-276 is usually preferred for wet chlorine, hypochlorite and oxidizing chloride service.
Stress-Corrosion Cracking	Excellent resistance in many reducing acid environments	Excellent resistance in severe mixed chemical service	Use environment-specific corrosion data for final engineering selection.
Price Comparison
Relative Material Cost	High to higher	High	B-3 can cost more because of its high molybdenum content and more limited production volume.
Stock Availability	Available, but some sizes may require special production	Generally broader availability in common plate, pipe, tube, bar and fitting sizes	C-276 is often easier to source for urgent or small-batch procurement.
Fabrication Cost	High	High	Both alloys require nickel-alloy tooling, qualified welding and careful contamination control.
Quotation Factors	Form, size, quantity, standard, MTC, testing and current nickel/molybdenum market	Form, size, quantity, standard, MTC, testing and current nickel/molybdenum market	Final pricing should be based on the actual drawing, tolerances, certification and delivery requirements.
Performance & Application
Primary Advantage	Exceptional resistance to reducing acids, especially hydrochloric acid	Broad resistance to reducing, oxidizing and mixed chemical environments	Choose B-3 for reducing acid duty and C-276 for more variable or oxidizing chemistry.
Typical Applications	Hydrochloric acid equipment, acid pickling systems, chemical reactors and reducing-acid piping	Flue-gas desulfurization, pollution-control equipment, chemical processing, wet chlorine systems and acid piping	Select by actual medium, concentration, temperature, aeration and cleaning process.
Best Use Case	Severe reducing-acid service where oxidizing contaminants are limited	Severe mixed chemical service with chloride, oxidizing species or uncertain process chemistry	Use corrosion test data and project specifications for final material selection.

Values are typical references for article comparison. Final supply should follow the ordered standard, product form, heat treatment, mill test certificate and project requirements.

Choose Choose Hastelloy b3 when

Hydrochloric acid, sulfuric acid or another strongly reducing environment is the key issue.
The equipment must resist localized corrosion and stress-corrosion cracking in non-oxidizing acid service.
You need better thermal stability and fabrication characteristics than earlier Hastelloy B-series alloys.

Choose Hastelloy c276 when

Mixed oxidizing and reducing chemicals, wet chlorine or chloride-induced localized corrosion is the key issue.
The equipment may face changing process conditions, contaminated acids or aggressive pollution-control media.
You need broad corrosion resistance and reliable performance in welded chemical-processing equipment.

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