UNS N10665|2.4617|Hastelloy B2 Seamless Pipe
Our Hastelloy B2 seamless pipes are designed to resist the formation of grain-boundary carbide precipitates in the weld heat-affected zone, ensuring superior intergranular corrosion resistance in the as-welded condition. This alloy offers outstanding protection against pitting, stress-corrosion cracking (SCC), and sulfuric or phosphoric acids in reducing environments. Through advanced cold-drawing and vacuum annealing, XinZhe ensures every pipe maintains tight dimensional tolerances and a high-integrity surface finish for the most demanding chemical processing and petrochemical applications.
"For applications requiring enhanced thermal stability during fabrication, please also check our Hastelloy B3 solutions."
What Is Seamless Hastelloy B2 Pipe?
Hastelloy B2 (UNS N10665) is a high-performance nickel–molybdenum corrosion-resistant alloy specifically designed to withstand extremely reducing chemical environments. With its high molybdenum content and minimal chromium concentration, Hastelloy B2 offers exceptional resistance to hydrochloric acid and other non-oxidizing acids.
A Seamless Hastelloy B2 Pipe is manufactured from a solid billet using hot extrusion and precision cold drawing, eliminating welded seams that could become weak points in corrosive environments. This seamless construction ensures uniform metallurgical structure, consistent wall thickness and enhanced mechanical reliability for high-pressure and high-vacuum chemical processing systems.
Seamless Hastelloy B2 pipes are typically produced according to ASTM B622 (Seamless Nickel and Nickel-Cobalt Alloy Pipe and Tube) and ASTM B829 (General Requirements), and remain one of the most trusted materials for concentrated hydrochloric acid, sulfuric acid catalysts and other reducing chemical media.
Key Features and Technical Advantages
Exceptional Resistance to Hydrochloric Acid
outstanding corrosion resistance in boiling hydrochloric acid at nearly all concentrations, plus strong performance in phosphoric, sulfuric (reducing conditions) and organic acids.
Resistance to Chloride-Induced SCC
the high nickel base provides excellent resistance to chloride-induced stress corrosion cracking, which commonly affects stainless steels in chloride environments.
Low Carbon Content
minimizes carbide precipitation at grain boundaries, helping maintain corrosion resistance in heat-affected zones during welding.
Stable Mechanical Performance
reliable mechanical properties from cryogenic temperatures up to approximately 800°C in non-oxidizing environments.
Product Specifications and Data
Chemical Composition
The balanced composition of nickel and molybdenum provides superior corrosion resistance in reducing media.
| Grade | Ni | Cr | Mo | Fe | C | Si | Co | Mn | P | S |
|---|---|---|---|---|---|---|---|---|---|---|
| N10665 | Balance | ≤ 1.00 | 26.00–30.00 | ≤ 2.00 | ≤ 0.02 | ≤ 0.10 | ≤ 1.00 | ≤ 1.00 | ≤ 0.04 | ≤ 0.03 |
Typical Mechanical Properties
Hastelloy B2 is specifically designed to maintain its strength and shape in high-stress, corrosive environments.
| Tensile Strength | Yield Strength | Elongation | Hardness |
|---|---|---|---|
| ≥ 760 MPa | ≥ 350 MPa | ≥ 40% | ≤ 100 HRB |
Typical Physical Properties
These physical properties make the alloy suitable for heat exchangers, reactors and distillation equipment in corrosive environments.
| Density | Melting Point | Thermal Expansion | Thermal Conductivity | Modulus of Elasticity | Electrical Resistivity |
|---|---|---|---|---|---|
| 9.22 g/cm³ | 1330–1380 ℃ | 10.3 µm/m·℃ | 9.1 W/m·K | 205 GPa | 1.37 µΩ·m |
Industrial Applications of Seamless Hastelloy B2 Pipes
Due to its exceptional resistance to reducing acids, Hastelloy B2 pipes are widely used in industries requiring high corrosion resistance and process reliability.
Chemical Processing
- Plasticizers production
- Magnesium chloride systems
- Organic acids
- Agricultural chemicals
Petrochemical Processing
- Catalytic alkylation units
- Isomerization processes
- Acid-resistant process piping
Pharmaceutical Industry
- High-purity reactors
- Equipment handling aggressive reducing reagents
Vacuum and Distillation Systems
- Vacuum distillation columns
- Acid-resistant heat exchangers
- Reduced-pressure processing pipelines
Quality Assurance and Traceability
Material Verification
100% PMI (Positive Material Identification) to confirm chemical composition.
Non-Destructive Testing
Ultrasonic Testing (UT), hydrostatic pressure testing and Eddy Current Testing (ET).
Certification and Documentation
EN 10204 3.1 / 3.2 Material Test Certificates, third-party inspection reports (SGS, ABS, Lloyd’s Register) and intergranular corrosion (IGC) testing reports.
Important Technical Considerations for Hastelloy B2
Avoid Oxidizing Contaminants: Hastelloy B2 has limited resistance to oxidizing media. Oxidizing ions such as ferric ions (Fe³⁺), cupric ions (Cu²⁺) and nitrates can significantly accelerate corrosion. If oxidizing impurities are present, alloys such as Hastelloy C276 or Hastelloy B3 may be more suitable.
Intermediate Temperature Sensitivity: embrittlement can occur between 600°C and 800°C, where brittle intermetallic phases may form. Strict control of welding and heat-treatment temperatures is recommended.
Frequently Asked Questions About Hastelloy B2 Pipe
What is Hastelloy B2 pipe used for?
Hastelloy B2 seamless pipe is used for concentrated hydrochloric acid service, sulfuric acid catalysts, plasticizer and organic acid production, pharmaceutical reactors, and vacuum distillation equipment handling reducing media.
What standards apply to Hastelloy B2 seamless pipe?
Seamless pipe and tube are typically produced to ASTM B622, with general requirements per ASTM B829.
How does Hastelloy B2 differ from Hastelloy B3?
B3 is an improved B-series alloy with better thermal stability and lower embrittlement risk during welding and heat treatment, while B2 offers the same strong reducing-acid resistance at typically lower cost.
Can Hastelloy B2 handle oxidizing chemicals?
No. Ferric and cupric ions, nitrates and other oxidizing species accelerate corrosion. For mixed oxidizing/reducing media, Hastelloy C276 is the more suitable choice.
What temperature limits apply to Hastelloy B2?
Mechanical properties are stable from cryogenic temperatures up to about 800°C in non-oxidizing environments, but exposure in the 600–800°C range should be controlled to avoid embrittlement.
Ready to Request a Quotation?
Send your Hastelloy B2 pipe enquiry with grade, ASTM B622 and edition, OD × wall thickness, length, quantity, end finish, delivery destination and inspection documents — you will get a written quotation stating the specification and edition, delivery condition, documents included and lead time.
Contact Us
