Nickel - Chromium Alloy Bellows Materials - Bellows Systems

Alloy 600 (UNS: N06600)

Bellows Materials Alloy 600
Trade Name Inconel 600
Description A nickel-chromium alloy designed for use from cryogenic to very high temperatures in the range of 2000 °F (1093 °C).
Application Notes Inconel 625 has tremendous resistance to a wide range of unusually severe corrosive environments including high-temperature effects such as oxidation and carburization. Its outstanding strength and toughness in temperature ranges from cryogenic temperatures to high temperature up to 2000° F (1093° C) are derived primarily from the solid solution effects of the refractory metals Columbium and molybdenum in a nickel-chromium matrix. Nickel chromium alloy 625 has excellent resistance to pitting and crevice corrosion, high corrosion-fatigue strength, high tensile strength as well as resistance to stress corrosion cracking to chloride ions — making it an excellent choice for sea-water applications. Inconel is used in aerospace applications as well as marine applications.
Industry Uses / Products Furnace components, chemical processing, food processing nuclear engineering, flexible metal hose tubing, bellows manufacturing
UNS N06600
Specifications ASTM B168, ASME SB-168, AMS 5540

Material Properties

Density, ρ, lbs/in^3 0.304
Yield Strength, Sy, Psi 35,000
Tensile Strength, Su, Psi 80,000
Elongation % 30
Youngs Modulus, E psi 30000000
Coeff. Thermal Expansion, in/in/˚F 0.0000092

Post Weld Heat Treatement (PWHT)

Hardening Cannot be hardened by heat treating

Chemical Compostion, %

Iron, Fe 6.00 – 10.00
Nickel, Ni 72.0 min.
Chromium, Cr 14.0 – 17.0

Alloy 625 (UNS: N06625)

Bellows Materials Alloy 625
Trade Name Inconel 625
Description A non-magnetic, corrosion and oxidation resistant, nickel-chromium alloy. The high strength of Inconel 625 is the result of the stiffening combination of molybdenum and niobium on the nickel chromium base of the alloy.
Application Notes Inconel 625 has tremendous resistance to a wide range of unusually severe corrosive environments including high-temperature effects such as oxidation and carburization. Its outstanding strength and toughness in temperature ranges from cryogenic temperatures to high temperature up to 2000° F (1093° C) are derived primarily from the solid solution effects of the refractory metals Columbium and molybdenum in a nickel-chromium matrix. Nickel chromium alloy 625 has excellent resistance to pitting and crevice corrosion, high corrosion-fatigue strength, high tensile strength as well as resistance to stress corrosion cracking to chloride ions — making it an excellent choice for sea-water applications. Inconel is used in aerospace applications as well as marine applications.
Industry Uses / Products Flexible metal hose, Tubing bellows Heat exchangers, Seals, Bellows, Marine Components
UNS N06625
Specifications ASTM B443 Gr 2, ASME SB-443, AMS 5599

Material Properties

Density, ρ, lbs/in^3 0.305
Youngs Modulus, E psi 28000000
Coeff. Thermal Expansion, in/in/˚F 0.0000069

Alloy 625 LCF (UNS: N06626)

Bellows Materials Alloy 625 LCF
Trade Name Inconel 625 LCF
Description A fatigue-resistant, bellows-quality version of INCONEL alloy 625. Process designed and controlled to provide a sheet product with optimum resistance to low-cycle and thermal fatigue at up to 1200°F (650°C).
Application Notes The alloy offers a high level of performance in aircraft exhaust and automotive flexible coupling bellows, expansion joints in process or transport piping, and other applications involving resistance to low-cycle or thermal fatigue.
UNS N06626

Material Properties

Density, ρ, lbs/in^3 0.305
Poisson’s Ratio, ν 0.31
Youngs Modulus, E psi 28000000
Coeff. Thermal Expansion, in/in/˚F 0.0000092

Alloy 718 (UNS: N07718)

Bellows Materials Alloy 718
Trade Name Inconel 718
Description A high strength nickel base superalloy used for cryogenic temperatures up to long term service at 1200°F.
Application Notes The alloy is readily fabricated and may be welded in either the annealed or precipitation (age) hardened condition. Anneal 1700 -1850°F, air cool or faster. Age 1325°F 8 hours, furnace cool to hold at 1150°F, for a total aging time of 18 hours, air cool. Alloy 718 will show a contraction of 0.0008 inch/inch after precipitation hardening.
UNS N07718
Specifications ASTM, ASME SB AMS 5596

Material Properties

Density, ρ, lbs/in^3 0.297
Poisson’s Ratio, ν 0.31
Youngs Modulus, E psi 28000000
Coeff. Thermal Expansion, in/in/˚F 0.0000076