ASTM B444 UNS N06625 tube (commonly known as Alloy 625) is a high-performance nickel-chromium-molybdenum alloy tube designed for extreme corrosion and high-temperature environments. It offers outstanding strength, oxidation resistance, and corrosion resistance, making it suitable for the most demanding industrial applications.
UNS N06625 is strengthened by niobium (Nb) and molybdenum, providing excellent mechanical properties without the need for heat treatment. Its superior resistance to pitting, crevice corrosion, and stress corrosion cracking makes it a preferred material in aggressive chemical and marine environments.
Key Features:
1) Exceptional corrosion resistance to pitting, crevice corrosion, and stress corrosion cracking (SCC) in chloride and seawater environments
2) The addition of niobium stabilizes the alloy against sensitization and provides high yield and tensile strength without requiring heat treatment
3) Good weldability without post-weld heat treatment
4) Resists scaling and oxidation at elevated temperatures up to 1800°F (982°C)
ASTM B444 Gr. UNS N06625 Chemical Composition & Mechanical Property:
Chemical Composition, max, % |
Chemical Composition, % | UNS N06625 |
C, max | 0.10 |
Mn, max | 0.50 |
Si, max | 0.50 |
P, max | 0.015 |
S, max | 0.015 |
Cr | 20.0-23.0 |
Nb + Ta | 3.15-4.15 |
Co, max | 1.0 |
Mo | 8.0-10.0 |
Fe, max | 5.0 |
Al, max | 0.40 |
Ti, max | 0.40 |
Ni, min | 58.0 |
Tensile Requirements |
Grade | Delivery Condition | Yield Strength (min)
MPa (psi) | Tensile Strength (min)
MPa (psi) |
UNS N06625 | Annealed | 414 (60,100) | 827 (120,000) |
Solution annealed | 276 (40,000) | 690 (100,100) |
General information:
Standard: ASTM B444
Grade: UNS N06625
Size: OD: 6-219mm; WT:0.8-20mm; L: SRL / DRL / Cut to length
Ends:
1) Plain ends
2) Beveled ends
3) Special cutting / chamfering available upon request
Available Coating: annealed & pickled (AP); annealed (BA); oiled.
Package: Hexagonal bundled with steel strips, plastic caps on both ends, waterproof material wrapped, wooden cases or crates for small sizes or precision tubes.
Shipment: Land transportation by truck or train, sea transportation by container shipment or bulk vessel.
Hebei K-Steel Pipe Industry Our advantage:
Flexible Project Customization
We provide tailored manufacturing solutions to meet diverse project requirements, including customized outer diameter, wall thickness, and length specifications. In addition, we offer precision end preparation and a full range of anti-corrosion coating options to ensure optimal performance in various operating environments. This flexibility enables us to deliver line pipe solutions that align seamlessly with your technical and application needs.
Fast & Reliable Lead Time
With strong mill partnerships and readily available inventory resources, we are able to shorten production cycles and respond quickly to urgent project demands. Our integrated supply network ensures stable material availability, efficient scheduling, and on-time delivery — helping clients keep their projects on track without delay.
Advanced Technical & Quality Assurance
Equipped with our own metallurgical laboratories and supported by trusted third-party inspection agencies, we ensure every line pipe meets international standards and project specifications. Comprehensive testing and verification guarantee consistent mechanical properties, chemical composition, and coating integrity, providing clients with reliable, high-quality pipeline solutions.
Rapid Delivery & Complete Logistics
Leveraging fast supply capabilities and a well-established logistics network, we ensure timely delivery of line pipes to any project location. Our streamlined transportation and warehousing system minimize lead time, helping clients maintain smooth operations and meet critical project schedules.
