Alloy 600 Steel Tube & Pipe • UNS N06600 • WNR 2.4816

Alloy 600, also known as Inconel 600, is a nickel-chromium-iron alloy noted for its excellent resistance to oxidation and corrosion at high temperatures. Its unique composition makes it suitable for a variety of demanding applications.

As a member of the Inconel family, Alloy 600 is celebrated for its superior performance in demanding environments. Its composition predominantly features nickel (approximately 72%) and chromium (around 15%), with smaller amounts of iron, manganese, and copper.

Engineered to maintain its mechanical integrity and resist corrosion at elevated temperatures, Alloy 600 can endure a wide temperature range, from cryogenic levels up to about 1093°C (2000°F).

Alloy 600 offers excellent resistance to a variety of corrosive environments, including nitric and sulfuric acids, alkaline solutions, and various gases.

Chemical Composition

The typical chemical composition of Alloy 600 includes:

Nickel (Ni): 72.0 min
Chromium (Cr): 14.0 – 17.0
Iron (Fe): 6.0 – 10.0
Manganese (Mn): 1.0 max
Silicon (Si): 0.5 max
Copper (Cu): 0.5 max
Carbon (C): 0.15 max
Sulfur (S): 0.015 max

Mechanical Properties

Tensile Strength: 655 MPa (95 ksi) min
Yield Strength (0.2% Offset): 240 MPa (35 ksi) min
Elongation: 30% min
Hardness: 85 HRB max

Physical Properties

Density: 8.47 g/cm³
Melting Point: 1354 – 1413 °C (2470 – 2575 °F)
Specific Heat: 444 J/kg-°C (0.106 Btu/lb-°F)
Thermal Conductivity: 14.8 W/m-°C (102 Btu-in/ft²-h-°F)

Applications

Alloy 600 is employed in various industries due to its excellent performance in high-temperature and corrosive environments. Common applications include:

Aerospace: Engine and airframe components exposed to high temperatures.
Chemical Processing: Heat exchangers, evaporators, and flaking trays.
Nuclear Engineering: Reactor components and heat exchangers.
Heat Treating: Furnace components, such as muffles, retorts, and radiant tubes.
Power Generation: Steam generators and other high-temperature components.

Corrosion Resistance

Alloy 600 is highly resistant to a variety of corrosive environments, including:

Oxidation and Carburization: Excellent resistance to oxidation and carburization at elevated temperatures.
Acids and Alkalis: Good resistance to a wide range of acids and alkalis, particularly in oxidizing and reducing environments.
Chlorides: Resistant to chloride-ion stress-corrosion cracking.

Fabrication and Welding

Alloy 600 is relatively easy to fabricate using standard techniques:

Forming: Can be hot or cold formed using conventional methods.
Machining: Machining should be performed with appropriate tooling and cutting fluids to manage work hardening.
Welding: Can be welded using standard welding techniques such as TIG, MIG, and resistance welding. Filler metals of matching composition are recommended.

Standards and Specifications

ASTM: B163, B167 (tubes); B168 (plates, sheets, and strips); B166 (bars and rods)
ASME: SB163, SB167 (tubes); SB168 (plates, sheets, and strips); SB166 (bars and rods)
DIN: 17742 (plates, sheets, and strips), 17750 (tubes), 17752 (bars and rods)
ISO: 6208

Summary

Alloy 600, with its superior resistance to oxidation, corrosion, and high temperatures, is a versatile material ideal for demanding applications in aerospace, chemical processing, nuclear engineering, heat treating, and power generation industries. Its excellent mechanical properties and ease of fabrication further enhance its suitability for critical high-temperature and corrosive environments.