UNS N10675|2.4600|Hastelloy B3 Seamless Tube
Seamless Hastelloy B3 (UNS N10675) is a premium nickel-molybdenum alloy specifically engineered for extreme resistance to Hydrochloric Acid (HCl) across all concentrations and temperatures. As a leading manufacturer based in Wenzhou, China, XinZhe produces precision-engineered seamless tubing that strictly adheres to ASTM B622 and ASME SB622 international standards.
The B3 Advantage: Enhanced Thermal Stability
While both Alloy B2 and B3 offer exceptional corrosion resistance, Hastelloy B3 represents a significant metallurgical evolution. The primary advantage of B3 is its superior thermal stability, which drastically reduces the risk of intergranular carbide precipitation and embrittlement during welding and fabrication.
• Ductility Retention: Unlike B2, Alloy B3 maintains its excellent ductility even after prolonged exposure to intermediate temperatures during the manufacturing process.
• Fabrication Reliability: The enhanced chemistry minimizes the formation of deleterious second-order phases, ensuring the structural integrity of complex piping systems.
Key Technical Features & Material Properties
XinZhe’s B3 seamless tubes are optimized for the most aggressive chemical processing environments:
• Acid Resistance: Unrivaled protection against Hydrochloric, Sulfuric, Phosphoric, and Acetic acids.
• Corrosion Mitigation: Exceptional resistance to Stress-Corrosion Cracking (SCC), pitting, and knife-line attack in the heat-affected zone (HAZ).
• Precision Manufacturing: Utilizing advanced cold-drawing and vacuum annealing, we guarantee uniform wall thickness and a high-integrity surface finish (low RA value).
What Is a Seamless Hastelloy B3 Tube?
Hastelloy B3 (UNS N10675) is a nickel-molybdenum alloy developed as an improved successor to Hastelloy B2. Tight control of iron and chromium allows excellent resistance to hydrochloric and other reducing acids, while the upgraded chemistry greatly reduces the risk of the intermetallic-phase embrittlement that can restrict the fabrication of B2 — without sacrificing corrosion performance.
A Seamless Hastelloy B3 (UNS N10675) tube is a high-performance nickel–molybdenum (Ni–Mo) alloy tube designed for use in highly corrosive and high-temperature environments. Manufactured through hot extrusion and cold pilgering from a solid billet, seamless tubes eliminate weld seams, resulting in:
Hastelloy B3 is an advanced evolution of Hastelloy B2, offering improved thermal stability and significantly reduced susceptibility to intermetallic phase precipitation. This advancement minimizes risks such as embrittlement during fabrication and welding.
Key Features and Technical Advantages
Excellent Resistance to Reducing Acids
Hastelloy B3 withstands hydrochloric acid, sulphuric acid and other reducing media across a wide range of concentrations and temperatures.
Improved Thermal Stability over B2
Tight control of iron and chromium greatly reduces the risk of intermetallic-phase embrittlement, making B3 easier to fabricate and weld than B2.
Resistance to Chloride-Free Media
Because the alloy is essentially chromium-free, it is immune to the chloride-induced pitting that affects high-chromium alloys in reducing acids.
Good Mechanical Properties
B3 retains useful strength and ductility, with good resistance to stress-corrosion cracking in the environments it is designed for.
Seamless Tube Integrity
Hot extrusion and cold pilgering produce a homogeneous wall with no weld seam, maximising pressure containment.
Product Specifications and Data
To provide a comprehensive overview of this high-performance material, here are the detailed technical specifications and performance data for Hastelloy B3.
The composition of Hastelloy B3 is carefully balanced to achieve its superior corrosion resistance and high thermal stability.
| Grade | Ni | Cr | Mo | Fe | W | C | Si | Co | Mn | V | P | Ti | Cu | Al | Zr |
| N10675 | ≥65.00 | 1.00-3.00 | 27.00-32.00 | 1.00-3.00 | ≤3.00 | ≤0.01 | ≤0.10 | ≤3.00 | ≤3.00 | ≤0.20 | ≤0.03 | ≤0.20 | ≤0.20 | ≤0.50 | ≤0.10 |
Key Insight: The high nickel and molybdenum content is responsible for its exceptional resistance to reducing acids.
Hastelloy B3 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% | ≤ 110 HRB |
These physical properties highlight the material's ability to perform reliably under a wide range of conditions.
| Density | Melting Point | Thermal Expansion | Thermal Conductivity | Modulus of Elasticity | Electrical Resistivity |
|---|---|---|---|---|---|
| 9.24 g/cm³ | 1350 - 1390 °C approx. | 10.1 µm/m·°C (20-100°C) | 11.1 W/m·K (20°C) | 210 GPa | 1.35 x 10⁻⁶ Ω·m (20°C) |
Industrial Applications of Seamless Hastelloy B3 Tubes
Seamless Hastelloy B3 tubing is widely used in critical industrial environments where corrosion resistance and reliability are essential:
Chemical Processing Industry (CPI)
- Hydrochloric acid production systems
- Alkylation units
- Agrochemical manufacturing (herbicides, pesticides)
Petrochemical Industry
- Heat exchangers
- Reactors exposed to aggressive catalysts
- High-temperature processing systems
Pharmaceutical Industry
- High-purity processing equipment
- Systems exposed to organic acids and halides
Energy and Environmental Applications
- Hydrogen production systems
- Waste-to-energy plants
- Advanced corrosion-resistant piping systems
Seamless Hastelloy B3 (UNS N10675) tubes represent a next-generation corrosion-resistant alloy solution for industries requiring extreme durability, thermal stability, and chemical resistance. With superior performance over traditional B-series alloys, they are an optimal choice for high-risk, high-value industrial systems.
Dimensional Standards and Tolerances
Hastelloy B3 seamless tubes are supplied to the dimensional tolerances of ASTM B622 / B829 unless a tighter project specification applies.
Common Industrial Applications
Chemical Processing
- Reactors and heat exchangers
- Hydrochloric and sulphuric acid service
- Reducing-acid handling lines
Petrochemical Processing
- Acetic acid and PTA plants
- Vacuum distillation equipment
- Process piping
Pharmaceutical and Fine Chemicals
- Reactor vessels
- Purification equipment
- Corrosive media transfer
Pollution Control and Waste Treatment
- Scrubber internals
- Waste acid handling
- Recovery equipment
Quality Assurance and Manufacturing Process
Certification
All Hastelloy B3 tubes are supplied to ASTM B622 / ASME SB622 and ASTM B619 / ASME SB619 with EN 10204 3.1 mill test certificates. Third-party inspection (SGS, BV, TUV, Lloyd's), PMI reports and full heat-number traceability can be provided on request.
Non-Destructive Testing (NDT)
Hydrostatic or eddy-current testing is performed on 100% of tubes. Ultrasonic testing (UT) and dye-penetrant inspection (PT) are available for critical service, with records retained for each production lot.
Material Verification
Positive Material Identification (PMI) and spectrometric analysis confirm that the chemical composition matches the ordered grade. Intergranular corrosion (IGC) testing to ASTM A262 Practice E is available for austenitic and nickel-alloy tubes.
Mechanical Testing
Tensile, yield, elongation and hardness tests are carried out per heat. Flattening, flaring and reverse-bend tests verify ductility, while creep-rupture data can be supplied for high-temperature grades.
Dimensional Inspection
Outside diameter, wall thickness, ovality and straightness are measured against ASTM A1016 / A1016M or EN 10216-5 tolerances. Length, square-cut ends and end-finish conditions are verified before packing.
Hastelloy B3 vs Hastelloy B2 – Technical Comparison
Hastelloy B3 was developed specifically to remove the fabrication limitations of Hastelloy B2 while preserving its corrosion performance in reducing acids.
Chemistry and Phase Stability
- B3: tightly controlled iron and chromium, with additions that suppress intermetallic-phase formation
- B2: lower tolerance for iron and chromium, higher risk of Ni-Mo phase precipitation in the 600–1,000 °C range
Fabrication and Welding
The practical difference is most obvious after welding. B2 can form intermetallic phases in the heat-affected zone and in service at intermediate temperature, causing embrittlement and loss of corrosion resistance. B3 tolerates those conditions substantially better, which reduces the need for restrictive fabrication procedures.
Corrosion Performance
In hydrochloric and sulphuric acid service the two alloys perform comparably. B3 gives up nothing in reducing-acid resistance while gaining durability in fabrication and welding.
Selection Guide
- Choose Hastelloy B3 for welded equipment and for service that passes through the intermediate temperature range
- Choose Hastelloy B2 where an existing specification or drawing requires it and the fabrication route is controlled
- Neither grade is suitable for oxidising media or for service where chlorides and oxidisers are present together
Frequently Asked Questions
What is a Hastelloy B3 seamless tube?
Hastelloy B3 (UNS N10675) is a nickel-molybdenum alloy tube produced without a longitudinal weld, developed as an improved successor to Hastelloy B2. It resists hydrochloric and other reducing acids while greatly reducing the risk of intermetallic-phase embrittlement.
What is the difference between Hastelloy B2 and B3?
B2 has a lower tolerance for iron and chromium and can form intermetallic phases in the 600–1,000 °C range, which causes embrittlement and loss of corrosion resistance after welding or intermediate-temperature service. B3 controls those elements tightly to suppress the problem without sacrificing reducing-acid performance.
What is Hastelloy B3 tube used for?
B3 is used for reactors, heat exchangers and process piping in hydrochloric and sulphuric acid service, and in acetic acid and PTA plants where reducing conditions dominate and welded fabrication is required.
Can Hastelloy B3 be used in oxidising media?
No. Like B2, B3 is essentially chromium-free and must not be used where oxidising species are present, as they accelerate attack severely. For mixed oxidising and reducing service, a nickel-chromium-molybdenum alloy such as Hastelloy C276 or C22 is the correct choice.
Ready to Request a Quotation?
Send your Seamless Hastelloy B3 Tube enquiry with grade, application, size (OD and wall thickness or schedule), quantity, length, end finish and inspection requirements. Our technical team will confirm availability, testing scope and lead time.
