ASTM B163 UNS N08825 Seamless Tube Incoloy 825 Alloy Tubes

High-Performance Nickel Alloy Seamless Tubing

ASTM B163 UNS N08825 seamless tubes, commonly known as Incoloy 825 alloy tubes, are nickel-iron-chromium alloy tubes engineered for heat exchangers, condensers, and corrosion-resistant applications. Alloy 825 offers excellent resistance to sulfuric and phosphoric acids, chloride stress corrosion cracking, and localized corrosion, making it a preferred material for chemical processing, oil & gas, offshore, and pollution control systems.

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 method

  • Heat treatment condition

  • Dimensional tolerances

  • Testing and inspection

ASTM B163 ensures the quality and reliability of Incoloy 825 seamless tubing for thermal and corrosive environments.

Material Grade: UNS N08825 (Incoloy® 825)

UNS N08825, also known as Incoloy 825, is a stabilized nickel alloy containing chromium, molybdenum, copper, and titanium. This alloy provides excellent corrosion resistance in both oxidizing and reducing environments.

Key Properties of Incoloy 825 Seamless Tubes

  • Outstanding resistance to sulfuric and phosphoric acids

  • Excellent resistance to chloride-induced stress corrosion cracking

  • Good resistance to pitting and crevice corrosion

  • Stable mechanical properties over a wide temperature range

  • 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″ – 4-1/2″)

  • Wall Thickness: 0.5 mm – 9.65 mm

  • Length: Random length or fixed length

Chemical Composition – UNS N08825 (Typical, wt %)

Element Content
Nickel (Ni) 38.0 – 46.0
Chromium (Cr) 19.5 – 23.5
Iron (Fe) ≥ 22.0
Molybdenum (Mo) 2.5 – 3.5
Copper (Cu) 1.5 – 3.0
Titanium (Ti) 0.6 – 1.2
Carbon (C) ≤ 0.05
Manganese (Mn) ≤ 1.0
Silicon (Si) ≤ 0.50
Sulfur (S) ≤ 0.03

Mechanical Properties (Room Temperature)

Property Requirement
Tensile Strength ≥ 550 MPa
Yield Strength (0.2%) ≥ 240 MPa
Elongation ≥ 30%

Heat Treatment

ASTM B163 Incoloy 825 seamless tubes are supplied in the solution annealed condition, followed by rapid cooling to ensure maximum corrosion resistance and structural stability.

ASTM-B163-UNS-N08825-Seamless-Tubes

ASTM-B163-UNS-N08825-Seamless-Tubes

Testing & Inspection

ASTM B163 UNS N08825 tubes are tested according to strict quality requirements, including:

  • Chemical analysis

  • Tensile testing

  • Eddy current or hydrostatic testing

  • Dimensional inspection

  • Surface inspection

  • Certification: EN 10204 3.1 / 3.2 (upon request)

Applications of Incoloy 825 Alloy Tubes

  • Heat exchangers and condensers

  • Chemical and petrochemical processing plants

  • Oil & gas production and refining

  • Offshore and marine systems

  • Acid pickling and handling equipment

  • Pollution control and FGD systems

ASTM B163 vs ASTM B423 Incoloy 825 Tubes

Item ASTM B163 ASTM B423
Product Type Heat exchanger tube Pipe & tube
Seamless Yes Yes
Typical Use Thermal systems General corrosion service

ASTM B163 UNS N08825 Incoloy 825 seamless tubes provide exceptional corrosion resistance, thermal stability, and long-term reliability in heat exchanger and condenser applications. Fully compliant with ASTM B163, Incoloy 825 alloy tubing is a proven solution for chemical, offshore, and acid service environments.