ASTM B622 Hastelloy C276 Seamless Tube Specification Guide

Hastelloy C276, designated UNS N10276, is one of the most widely used nickel-based corrosion-resistant alloys. Its ability to withstand strong oxidizing acids and chlorides makes it ideal for chemical plants, power generation, and offshore applications.

 

Seamless tubes manufactured under ASTM B622 specifications are preferred when:

• High corrosion resistance is critical
• High-pressure service is required
• Uniform tube quality is necessary

TSM Technology offers high-quality C276 seamless tubes with full traceability, MTC certification, and custom dimensions for industrial projects.

ASTM B622 Standard Overview

ASTM B622 governs seamless nickel and nickel-cobalt alloy tubes intended for corrosive service.

Item	Requirement
Material Grade	UNS N10276 (C276)
Product Form	Seamless Tube
Heat Treatment	Solution Annealed
Testing	Hydrostatic or Non-Destructive Testing (NDT)
Certification	EN 10204 3.1 / Mill Test Certificate
Applications	Chemical processing, acid handling, heat exchangers

The standard ensures that each tube maintains uniform chemical composition, mechanical strength, and corrosion resistance.

Chemical Composition of Hastelloy C276

Element	Weight %
Nickel (Ni)	Balance
Chromium (Cr)	15–17
Molybdenum (Mo)	15–17
Iron (Fe)	4–7
Cobalt (Co)	3–7
Tungsten (W)	0.5–3
Carbon (C)	≤0.03
Manganese (Mn)	≤1.5
Silicon (Si)	≤0.08

Key Benefits of Each Element

Element	Function
Ni	General corrosion resistance
Cr	Oxidation resistance
Mo	Pitting and crevice corrosion resistance
Co	Strengthens alloy in oxidizing acids
W	Enhances resistance to oxidizing agents
C	Limits carbide precipitation
Mn & Si	Improve manufacturing properties

Mechanical Properties of C276 Seamless Tube

Property	Typical Value
Tensile Strength	≥485 MPa
Yield Strength	≥205 MPa
Elongation	≥30%
Hardness	≤95 HRB
Density	8.9 g/cm³

These mechanical properties ensure that C276 tubes can safely operate in high-pressure and high-temperature systems.

Tube Sizes and Specifications

ASTM B622 C276 seamless tubes are supplied in various dimensions to suit chemical processing equipment and heat exchangers.

Parameter	Range
Outside Diameter	6 mm – 114.3 mm
Wall Thickness	0.5 mm – 10 mm
Length	Up to 12 meters
Tube Type	Seamless
Surface Finish	Pickled, bright annealed, polished

Custom dimensions can be provided for project-specific requirements.

Corrosion Resistance Performance

C276 seamless tubes resist a wide variety of corrosive environments.

Chemical Environment	Performance
Sulfuric Acid	Excellent
Hydrochloric Acid	Excellent (reducing conditions)
Nitric Acid	Very Good
Phosphoric Acid	Excellent
Chloride-Containing Solutions	Excellent
Mixed Acid Systems	Excellent

C276's combination of high molybdenum and nickel content provides superior resistance to both oxidizing and reducing chemicals.

Industrial Applications of C276 Tubes

Chemical Processing Equipment

Process piping

Reactor tubes

Evaporators

Condensers

Acid Production Plants

Sulfuric acid systems

Hydrochloric acid pipelines

Phosphoric acid reactors

Heat Exchanger Systems

Shell-and-tube heat exchangers

Condenser tubing

Cooling coils

Waste Treatment Plants

Scrubbers

Neutralization tanks

Recovery systems

Quality Assurance and Testing Methods

C276 seamless tubes are tested to ensure safety and reliability in corrosive service.

Test Method	Purpose
PMI	Confirms alloy chemistry
Hydrostatic Test	Pressure integrity
Eddy Current Testing	Surface defect detection
Ultrasonic Testing	Internal defect detection
Flattening & Flaring	Ductility and forming capability
Hardness Test	Material strength verification
Dimensional Inspection	Confirm size and tolerances

All testing conforms to ASTM B622 and EN 10204 3.1 certification requirements.

Purchasing Guide for C276 Tubes

Supplier Evaluation Checklist

Requirement	Verification
ASTM B622 Compliance	✓
UNS N10276 Material	✓
EN 10204 3.1 Certificate	✓
PMI Testing Report	✓
Hydrostatic Test Report	✓
Dimensional Inspection Report	✓
Heat Number Traceability	✓
Custom Manufacturing Capability	✓

Choosing a certified supplier ensures reliability and long-term service performance.

FAQ

Q1: What is the UNS number for Hastelloy C276?
A1: UNS N10276.

Q2: Is C276 tube suitable for sulfuric acid?
A2: Yes, especially in reducing and mixed acid conditions.

Q3: Can ASTM B622 C276 tubes be welded?
A3: Yes, proper welding procedures maintain corrosion resistance.

Q4: What industries use C276 seamless tubes?
A4: Chemical processing, heat exchangers, acid production plants, waste treatment, and offshore systems.

Q5: How does C276 compare to Hastelloy G30?
A5: G30 is better for oxidizing acids, while C276 offers broader resistance in reducing and chloride-rich environments.

Q6: Are both seamless and welded tubes available?
A6: Yes. Seamless is preferred for high-pressure and high-purity applications.

Conclusion

ASTM B622 Hastelloy C276 seamless tubes provide exceptional corrosion resistance, mechanical strength, and versatility for chemical processing, heat exchangers, and acid handling equipment. Selecting certified tubes with proper testing ensures reliable, long-term service in highly corrosive environments.

Looking for Certified C276 Seamless Tubes?

TSM Technology offers ASTM B622 Hastelloy C276 seamless tubes with full traceability, EN 10204 3.1 certification, PMI testing, and custom manufacturing options.

Email: info@tsm-titanium.com