NeoNickel

Alloy 625

We're Alloy 625 suppliers - A nickel-chromium-molybdenum-niobium grade, commonly referred to as Inconel® 625, offers outstanding corrosion resistance and superb weldability.

Characteristics of Alloy 625

Alloy 625, also known as Inconel® 625 (a registered trademark of Special Metals Corporation), is a nickel-chromium-molybdenum-niobium alloy designed for use in extreme environments that demand exceptional corrosion resistance, high strength, and superior weldability.

Thanks to its high nickel content, Alloy 625 is virtually immune to chloride-induced stress corrosion cracking, making it ideal for use in marine, offshore, chemical, and high-temperature applications. The addition of niobium enhances strength through solid-solution hardening, eliminating the need for post-weld heat treatment.

NeoNickel supplies certified grades including 625 LCF® and ATI 625 HP®, offering enhanced fatigue resistance and deep drawing capabilities.

  • Resistant to pitting, crevice corrosion, and intergranular attack
  • Excellent mechanical performance at temperatures up to 980°C (1800°F)
  • Outstanding weldability, even after extended service exposure
  • Available in sheet, plate, pipe, bar, wire, and custom forms
  • Suitable for both high-strength and corrosion-critical environments
  • UNS Number: N06625
  • Werkstoff Number: 2.4856
  • ASTM: B443, B444, B446, B704, B705
  • AMS: 5599, 5666, 5581, 5869

Product availability

Coil
Coiled Weld Wire
Flanges
Pipe (Seamless)
Pipe Fittings
Plate
Round Bar
Round Tube
Sheet
Welding Wire

Chemical analysis

%CrNiMoCoNb+TaAlTiCFeMnSiPS
Min20-8-3.15--------
Max23Balance1014.150.40.40.15.00.50.50.0150.015

Key Properties

  • Density: 8.442 g/cm³
  • Melting Point: 1287-1348°C
  • Thermal Expansion (µm/m·°C): 13.1–15.8 (204°C–871°C)
  • Thermal Conductivity: 8.5 to 19.6 kcal/(hr·m·°C)
  • Modulus of Elasticity: 2.07 x 10⁵ MPa

Designed for high performance across variable and elevated temperatures.

Mechanical & Physical Properties

Mechanical & Physical Properties21°C204 °C316 °C427 °C538 °C649 °C760 °C871 °C
Ultimate Tensile Strength /Mpa992.9923.9910.1910.1896.3820.5537.8275.8
0.2% Yield Strength /MPa579.2455.1434.4420.6420.6413.7406.8268.9
Elongation %444542.545483459117
Coefficient of Thermal Expansion µm/m⁰C-13.113.313.71414.815.315.8
Thermal Conductivity /kcal/(hr.m.°C)8.510.712.213.51516.417.919.6
Modulus of Elasticity/ MPa2.071.931.931.861.791.651.59-

Applications of Alloy 625

Alloy 625 is trusted across industries for its exceptional resistance to corrosion, heat, and mechanical stress, making it ideal for critical components in challenging environments.

Chemical Processing Industry

  • Reactors & Vessels – Withstands aggressive acids and chlorides
  • Piping & Heat Exchangers – Delivers long-term corrosion resistance
  • Furnace Parts – Performs under intense thermal cycling

Aerospace & Defense

  • Exhaust Ducts & Engine Components – Withstands high-temp oxidation
  • Turbine Shrouds & Bellows – High strength and fatigue resistance
  • Thrust Reversers – Excellent formability and weldability

Marine & Offshore

  • Subsea Piping & Risers – Corrosion-resistant in high-pressure seawater
  • Splash Zone Components – Withstands chloride-induced stress cracking
  • Weld Overlays – Protects against seawater degradation

Power & Energy

  • Heat Recovery Systems – Handles cyclic loading in high-heat systems
  • Valves & Spacers – Maintains stability under stress and pressure
  • Emission Control – Durable in corrosive gas environments

Environmental & Industrial

  • Scrubbers & Waste Units – Resists chemical attack in treatment systems
  • Fluid Handling Components – Ideal for aggressive media containment

Benefits of Alloy 625

Alloy 625 offers a robust combination of long-term corrosion resistance, mechanical durability, and fabrication versatility, making it an ideal material solution for demanding environments across marine, energy, aerospace, and chemical sectors.

  • Extends Component Lifespan: Exceptional resistance to seawater, chlorides, acids, and oxidizing environments reduces degradation and extends equipment service intervals
  • Reliable Performance in Harsh Conditions: Maintains strength and integrity under mechanical stress, thermal cycling, and corrosive exposure, improving uptime and operational safety.
  • Reduces Maintenance Downtime: Long-term material stability and resistance to pitting and crevice corrosion minimize the need for frequent replacements or repairs
  • Supports Multi-Industry Applications: Widely used in offshore platforms, chemical processing plants, aerospace systems, and high-temperature exhaust environments — Alloy 625 adapts to critical project needs.
  • Fabrication-Friendly: Outstanding weldability and availability in multiple certified grades (including LCF® and DDQ) simplify forming, joining, and fabrication processes.

Alloy 625 is a trusted choice for industries requiring proven long-term durability, corrosion resistance, and design flexibility. For application support or a tailored quote, contact our team of materials specialists today.

Proud members of the British Valve & Actuator AssociationProud members of the British Valve & Actuator Association