ASTM B163 UNS N06625 Seamless Tube Inconel 625 Alloy Tubes
Inconel® 625 Seamless Tubing for Heat Exchangers & Condensers
High-Strength & Corrosion-Resistant Nickel Alloy Tubes
ASTM B163 UNS N06625 seamless tubes, commonly known as Inconel 625 seamless tubes, are nickel-chromium-molybdenum alloy tubes engineered for heat exchanger, condenser, and high-corrosion service applications. With outstanding resistance to pitting, crevice corrosion, oxidation, and chloride stress corrosion cracking, Inconel 625 tubing is widely used in chemical processing, offshore, marine, power generation, and oil & gas industries.
What Is ASTM B163?
ASTM B163 is the standard specification for seamless nickel and nickel alloy condenser and heat exchanger tubes. It defines requirements for:
-
Chemical composition
-
Mechanical properties
-
Manufacturing process
-
Dimensional tolerances
-
Testing and inspection
ASTM B163 ensures reliable performance of Inconel 625 seamless tubes in demanding thermal and corrosive environments.
Material Grade: UNS N06625 (Inconel® 625)
UNS N06625 is a solid-solution-strengthened nickel alloy containing chromium, molybdenum, and niobium. It offers exceptional corrosion resistance and high mechanical strength without the need for precipitation hardening.
Key Properties of Inconel 625 Seamless Tubes
-
Excellent resistance to pitting and crevice corrosion
-
Outstanding resistance to chloride-induced stress corrosion cracking
-
High strength across a wide temperature range
-
Good fatigue and thermal fatigue resistance
-
Excellent weldability and fabrication characteristics
Product Form & Manufacturing
-
Product Form: Seamless tube
-
Manufacturing Process: Hot finished / cold drawn
-
Delivery Condition: Solution annealed
Size Range & Specifications
-
Outside Diameter: 6.35 mm – 114.3 mm (1/4″ – 4″)
-
Wall Thickness: 0.5 mm – 9.65 mm
-
Length: Random or fixed length
Chemical Composition – UNS N06625 (Typical, wt %)
| Element | Content |
|---|---|
| Nickel (Ni) | ≥ 58.0 |
| Chromium (Cr) | 20.0 – 23.0 |
| Molybdenum (Mo) | 8.0 – 10.0 |
| Niobium + Tantalum (Nb+Ta) | 3.15 – 4.15 |
| Iron (Fe) | ≤ 5.0 |
| Carbon (C) | ≤ 0.10 |
| Manganese (Mn) | ≤ 0.50 |
| Silicon (Si) | ≤ 0.50 |
Mechanical Properties (Room Temperature – Typical)
| Property | Requirement |
|---|---|
| Tensile Strength | ≥ 827 MPa |
| Yield Strength (0.2%) | ≥ 414 MPa |
| Elongation | ≥ 30% |
Heat Treatment
ASTM B163 Inconel 625 seamless tubes are supplied in solution annealed condition, followed by rapid cooling to achieve optimal corrosion resistance and mechanical stability.
Testing & Inspection
ASTM B163 UNS N06625 tubes undergo:
-
Chemical analysis
-
Tensile testing
-
Eddy current or hydrostatic testing
-
Dimensional inspection
-
Surface inspection
-
Certification: EN 10204 3.1 / 3.2 (upon request)
Applications of Inconel 625 Seamless Tubes
-
Heat exchangers and condensers
-
Offshore and subsea systems
-
Chemical processing equipment
-
Power generation and nuclear systems
-
Oil & gas production and refining
-
Marine and desalination plants
ASTM B163 Inconel 625 Alloy seamless Tubes
ASTM B163 UNS N06625 Seamless Tube Inconel 625 Alloy Tubes
ASTM B163 vs ASTM B167 Inconel 625 Tubes
| Item | ASTM B163 | ASTM B167 |
|---|---|---|
| Tube Type | Heat exchanger / condenser | General purpose |
| Seamless | Yes | Seamless / welded |
| Typical Use | Thermal systems | Process piping |
ASTM B163 UNS N06625 Inconel 625 seamless tubes provide exceptional corrosion resistance, high strength, and long-term reliability in heat exchanger and condenser applications. Fully compliant with ASTM B163, Inconel 625 seamless tubing is a proven solution for offshore, chemical, and high-performance thermal systems.
