HAYNES® 242® alloy for High-temperature Fluorine-Bearing Environments Tech Brief

Home / HAYNES® 242® alloy for High-temperature Fluorine-Bearing Environments Tech Brief

 

For Excellent Resistance to High-Temperature Fluorine-Bearing Environments and Outstanding High-Temperature Strength

New from Haynes International, HAYNES® 242® alloy is a unique, age-hardenable Ni-Mo-Cr alloy that combines excellent resistance to high-temperature fluorine-bearing environments with outstanding strength. It is ideally suited for use in processes involving exposure to gaseous fluorine & HF, or molten fluoride salts, particularly where high strength up to 1300°F (705°C) is required. Areas of potential application include fluoro-polymer and fluoro-elastomer production, nuclear fuel processing, mineral and metals production, and hydrofluoric acid production/processing, among others. 242® alloy is available in a full range of forms in the as-solution-annealed condition, and is normally age-hardened before being placed in service. It may also be cold-worked and age-hardened to achieve exceptionally high strength levels while maintaining good ductility.

Nominal Composition

Nickel Balance
Molybdenum 25
Chromium 8
Iron 2 max.
Cobalt 2.5 max.
Manganese 0.8 max.
Silicon 0.8 max.
Aluminum 0.5 max.
Carbon 0.03 max.
Boron 0.006 max.
Copper 0.5 max.

Typical Tensile Properties, Plate

Test Temperature 0.2%Yield Strength Ultimate Tensile Strength Elongation
°F °C ksi MPa ksi MPa %
RT RT 113 780 184 1270 38
800 425 80 555 156 1075 44
1000 540 70 480 145 1000 47
1200 650 76 525 137 945 38
1400 760 42 290 106 730 66
1600 870 40 275 69 475 56
1800 980 28 190 41 285 65

Typical Rupture Strength, Plate

Test Temperature Typical Rupture Properties: Stress Required to Produce Rupture in Hours Shown
100 h 1,000 h 10,000 h
°F °C ksi MPa ksi MPa ksi MPa
1000 540 160 1105 140 965 120 825
1100 595 130 895 110 760 93 640
1200 650 105 725 90 620 75 515
1300 705 86 595 69 475 35 240
1400 760 59 425 29 200 17 115

Typical Room Temperature Physical Properties

Physical Property British Units Metric Units
Density
0.327 lb/in3
9.06 g/cm3
Electrical Resistivity 48.0 µohm-in 122.0 µohm-cm
Modulus of Elasticity
33.2 x 106 psi
 229 GPA
Thermal Conductivity
75.7 Btu-in/ft2-h-°F
 11.3 W/m-°C
Specific Heat 0.092 Btu/lb-°F 386 J/Kg-°C

Environmental Resistance

Oxidation Resistance – Excellent to 1400°F (760°C)

Gaseous Fluorine & HF – Excellent to 1650°F (900°C)

Molten Chloride/Fluoride Salts – Excellent to 1650°F (900°C)

Chloride Stress Cracking Resistance – Excellent

Chlorination – Excellent in Reducing Environments

Hydrogen Embrittlement Resistance – Fair to Good