Inconel Alloy 625 UNS N06625 for High-Temperature Environments Outstanding Properties and Versatility

Inconel 625 (UNS N06625) is a high-performance superalloy known for its exceptional resistance to high-temperature environments, oxidation, and corrosion. It is primarily made of nickel, chromium, and molybdenum, with small amounts of niobium, iron, and other trace elements. Inconel 625 (UNS N06625) is a nickel-based superalloy with outstanding resistance to high temperatures, oxidation, and corrosion, making it ideal for extreme environments. Its versatility in both high-temperature and chemically aggressive conditions makes it highly valued in industries such as aerospace, chemical processing, marine, nuclear, and oil and gas. It maintains its strength and integrity across a wide range of temperatures and corrosive environments, making it essential for critical applications in demanding industries.

Trade Code

Key Features:

• Composition (Approximate):

Nickel: 58-67%

Chromium: 20-23%

Molybdenum: 8-10%

Niobium: 3.15-4.15%

Iron: 5% max

Other elements: Small amounts of titanium, aluminum, and trace elements like manganese, silicon, and carbon.

• Mechanical Properties:

Tensile Strength: Typically 760 MPa (110,000 psi) at room temperature, but increases significantly at higher temperatures.

Yield Strength: Approximately 350 MPa (50,000 psi) at room temperature.

Elongation: About 35% minimum.

Hardness: Hardness varies with processing, typically around 90-160 HRB depending on the form and heat treatment.

• Corrosion and Oxidation Resistance:

Excellent resistance to a wide range of harsh environments, including:

Oxidation: Highly resistant to oxidation, even at elevated temperatures (up to 980°C or 1800°F).

Corrosion: Resistant to corrosion in seawater, sulfuric acid, hydrochloric acid, and other aggressive chemicals.

Pitting and Crevice Corrosion: Excellent resistance in marine and other chloride-rich environments.

Stress Corrosion Cracking: Highly resistant to stress corrosion cracking, even in high-stress applications.

• Thermal Properties:

Melting Point: Approximately 1350-1400°C (2462-2552°F).

Thermal Conductivity: Relatively low compared to many other metals, due to its composition.

Coefficient of Expansion: Moderate, which is beneficial for maintaining dimensional stability in varying temperatures.

• Weldability & Fabrication:

Inconel 625 is known for its excellent weldability. It can be welded using most common methods, including TIG, MIG, and gas tungsten arc welding (GTAW).

Excellent formability and can be fabricated into complex shapes like sheets, tubes, and wires without a significant loss of properties.

The alloy maintains its high strength and resistance to oxidation even after welding and heat treatment.

Applications:

• Aerospace: Used in jet engines, gas turbines, and exhaust systems due to its resistance to high-temperature oxidation and corrosion.
• Chemical Processing: Equipment exposed to highly corrosive environments, such as reactor cores, heat exchangers, and piping in the chemical industry.
• Marine: Components used in sea water applications, including heat exchangers, marine gas turbines, and seawater pumps.
• Nuclear: Components in nuclear reactors, such as control rods and core structural elements, because of its resistance to radiation and high temperature.
• Oil and Gas: Equipment exposed to extreme conditions in deep-sea drilling or high-pressure, high-temperature environments.
• Industrial: Heat exchangers, furnaces, and other high-temperature industrial equipment.