Inconel 600 is a nickel-chromium alloy (approximately 72 percent nickel, 14 to 17 percent chromium, 6 to 10 percent iron) known for its excellent oxidation and corrosion resistance at high temperatures. It also maintains good mechanical properties from cryogenic temperatures up to about 1,090°C (2,000°F). The alloy is not precipitation hardenable; it is strengthened and hardened only by cold work.

The nominal chemical composition is: nickel (plus cobalt) 72.0 percent minimum, chromium 14.0 to 17.0 percent, iron 6.0 to 10.0 percent, manganese up to 1.0 percent, silicon up to 0.5 percent, carbon up to 0.15 percent, and copper up to 0.5 percent. The high nickel content gives excellent resistance to chloride stress corrosion cracking and to many corrosive chemicals.

Key mechanical properties (typical, annealed condition):

● Tensile strength: 550 to 690 MPa

● Yield strength (0.2% offset): 170 to 345 MPa

● Elongation: 35 to 55 percent

● Hardness: 65 to 85 HRB

● Density: 8.42 g/cm³

Corrosion resistance: Inconel 600 offers outstanding resistance to oxidation at high temperatures (up to 1,150°C intermittent service), good resistance to carburization and nitriding, and excellent performance in chlorine and chlorine-contaminated environments. It resists stress corrosion cracking in chloride and caustic solutions, and has good resistance to many organic and inorganic acids under moderate conditions. However, it is not recommended for strongly oxidizing acids such as concentrated nitric acid or strongly reducing acids such as hydrochloric acid.

Standards: ASTM B168 (plate, sheet, strip), B166 (rod, bar, wire), B167 (pipe, tube), B163 (seamless tube for heat exchangers). Also ASME SB specifications, AMS 5540 (sheet), AMS 5665 (bar and forgings).

Typical applications of Inconel 600 include:

- Heat treatment equipment: furnace components, retorts, muffles, radiant tubes, and conveyor belts.

- Chemical processing: reactor vessels, heat exchangers, evaporator tubes, and pressure vessels handling corrosive chemicals.

- Aerospace: jet engine components (combustion chambers, turbine seals) and airframe parts requiring oxidation resistance.

- Nuclear industry: reactor core components and steam generator tubing (though Inconel 690 is now preferred for some nuclear applications).

- Electronics: cathode ray tube filament supports and other high-temperature electronic components.

Comparison with other nickel alloys: Inconel 600 has lower strength than precipitation-hardened alloys like Inconel 718 or X-750, but better formability and weldability. Compared to Inconel 625, 600 has lower strength and poorer resistance to pitting in chloride environments, but is more resistant to caustic stress corrosion cracking. For higher temperature oxidation resistance (above 1,100°C), Inconel 601 is often preferred.

Selection guidance: Choose Inconel 600 for high-temperature oxidation and carburization resistance, for chloride stress corrosion cracking resistance, and for moderate chemical corrosion service. For stronger high-temperature performance, consider Inconel 601 or 625. For lower cost with good high-temperature strength, stainless steel 310 may suffice in less demanding environments. For extreme reducing acid service, nickel alloys such as Alloy B (Hastelloy B) are more suitable.