Alloy 242, UNS N10242, Haynes® 242 alloy - nickel alloy

Alloy 242, UNS N10242, Haynes® 242 alloy - nickel alloy according to ASTM B366-17

Alloy 242, UNS N10242, Haynes® 242 alloy – description

Alloy 242, Haynes® 242® alloy is an age-hardenable nickel-molybdenum-chromium alloy with high creep-resistance up to 700°C and high oxidation-resistance up to 800°C. Moreover, it has good thermal stability and low cycle fatigue properties and the high molybdenym content gives it very high resistance to high-temperature fluoride environments. For similar applications that require higher creep-resistance, consider alloy 244.

Applications

Used in aero and industrial gas turbines for rings, casings, fasteners, nozzles, pumps, as well as in chemical processing in high-temperature hydrofluoric acid (HF) containing processes.

Physical and Tensile Properties

Room temperature physical properties:

• Density: 9.05 g/cm³
• Melting temperature: 1290-1375 °C

High-Temperature Coefficient of Thermal Expansion, from 20°C to:

• 100°C: 10.8 μm/m⋅K
• 200°C: 11.3 μm/m⋅K
• 300°C: 11.6 μm/m⋅K
• 400°C: 11.9 μm/m⋅K
• 500°C: 12.2 μm/m⋅K
• 600°C: 15.8 μm/m⋅K
• 700°C: 13.0 μm/m⋅K
• 800°C: 14.0 μm/m⋅K
• 900°C: 14.5 μm/m⋅K
• 1000°C: 15.0 μm/m⋅K

Thermal Conductivity:

• 20°C: 11.3 W/m · K
• 100°C: 12.6 W/m · K
• 200°C: 14.2 W/m · K
• 300°C: 15.9 W/m · K
• 400°C: 17.5 W/m · K
• 500°C: 19.2 W/m · K
• 600°C: 20.9 W/m · K
• 700°C: 22.5 W/m · K
• 800°C: 24.2 W/m · K
• 900°C: 25.8 W/m · K
• 1000°C: 27.5 W/m · K

Electrical Resistivity:

• 20°C: 1.22 μΩ·m
• 100°C: 1.23 μΩ·m
• 200°C: 1.25 μΩ·m
• 300°C: 1.26 μΩ·m
• 400°C: 1.28 μΩ·m
• 500°C: 1.29 μΩ·m
• 600°C: 1.3 μΩ·m
• 700°C: 1.32 μΩ·m
• 800°C: 1.32 μΩ·m
• 900°C: 1.29 μΩ·m
• 1000°C: 27.5 μΩ·m

Specific Heat Capacity:

• 20°C: 386 J/kg⋅K
• 100°C: 405 J/kg⋅K
• 200°C: 419 J/kg⋅K
• 300°C: 431 J/kg⋅K
• 400°C: 439 J/kg⋅K
• 500°C: 451 J/kg⋅K
• 600°C: 470 J/kg⋅K
• 700°C: 595 J/kg⋅K
• 800°C: 605 J/kg⋅K
• 900°C: 610 J/kg⋅K
• 1000°C: 627 J/kg⋅K

Young's Modulus:

• 20°C: 229 GPa
• 100°C: 225 GPa
• 200°C: 219 GPa
• 300°C: 213 GPa
• 400°C: 206 GPa
• 500°C: 199 GPa
• 600°C: 193 GPa
• 700°C: 185 GPa
• 800°C: 172 GPa
• 900°C: 163 GPa
• 1000°C: 152 GPa

High-Temperature Mechanical Properties of Haynes® 242 alloy rings and bars:

• 20°C:
  • Yield strength: 845 MPa
  • Tensile strength: 1290 MPa
  • Elongation: 33.7 %
  • Reduction of area: 45.7 %
• 650°C:
  • Yield strength: 570 MPa
  • Tensile strength: 1000 MPa
  • Elongation: 33.2 %
  • Reduction of area: 41.1 %

Stress-Rupture Strength of Haynes® 242® alloy:

• 540°C, 100h: 965 MPa
• 540°C, 1000h: 825 MPa
• 595°C, 100h: 760 MPa
• 595°C, 1000h: 640 MPa
• 650°C, 100h: 620 MPa
• 650°C, 1000h: 515 MPa
• 705°C, 100h: 475 MPa
• 705°C, 1000h: 240 MPa
• 760°C, 100h: 200 MPa
• 760°C, 1000h: 115 MPa
• 815°C, 100h: 110 MPa
• 815°C, 1000h: 76 MPa
• 870°C, 100h: 74 MPa

Creep Strength - stress to produce 0,5% creep in Haynes® 242® age-hardened plate:

• 595°C, 10000h: 517 MPa
• 650°C, 100h: 565 MPa
• 650°C, 1000h: 427 MPa
• 650°C, 10000h: 262 MPa
• 705°C, 100h: 331 MPa
• 705°C, 1000h: 228 MPa
• 705°C, 10000h: 90 MPa
• 760°C, 100h: 165 MPa
• 760°C, 1000h: 83 MPa

Failure Fatigue of hot-rolled rings as supplied for gas turbine operation. Cycles to failure at 650°C under a given load with 20 cycles per minute:

• 760 MPa: 845 cycles
• 690 MPa: 12,220 cycles
• 655 MPa: 32,587 cycles
• 620 MPa: 76,763 cycles
• 585 MPa: 297,848 cycles
• 550 MPa: 304,116 cycles

High-Temperature Hardness:

• 425°C: 26 HRC
• 540°C: 24 HRC
• 650°C: 95 HRBW
• 760°C: 75 HRBW

Corrosion Resistance

High-Temperature Oxidation - good resistance up to 815°C, as confirmed by tests - after 1008 hours in flowing air at 815°C, the average depth of metal affected was just 13µm.

High-Temperature Fluoride Environments - very good resistance to both fluoride gas and salt, as confirmed by the tests - after 136 hours in a 70% HF solution, the alloy lost just 0.3mm thickness.

Corrosion rates to specific corrosive media:

• Hydrogen fluoride (HF) 5%°C, at 79°C°C: 0.36 mm/year
• Hydrogen fluoride (HF) 48%°C, at 79°C°C: 0.81 mm/year
• Hydrogen fluoride (HF) 70%°C, at 52°C°C: 0.89 mm/year
• Hydrochloric acid (HCl) 10%, boiling: 0.56 mm/year
• Hydrochloric acid (HCl) 20%, boiling: 1.04 mm/year
• Phosphoric acid (H₃PO₄) 55%, boiling: 0.08 mm/year
• Phosphoric acid (H₃PO₄) 85%, boiling: 0.1 mm/year
• Acetic acid (CH₃COOH) 99%, boiling: <0.03 mm/year

Weldability

Good weldability. Post-weld solution annealing is recommended, followed by aging.

Coated electrode - SFA 5.14 / A 5.14; ERNiCrMo-12

Heat Treatment, Working and Machining

Recommended work and heat treatment parameters:

Recommended heat treatment after hot work:

• Hot working: 1230-980 °C; air cool / water quench
• Solution-treatment: 1120-1040 °C; air cool / water quench
• Age hardening: 650°C, 24h ; air cool

Recommended heat treatment after cold work:

• Solution-treatment: 1120-1040 °C; air cool / water quench
• Cold work up to 40%
• Age hardening: 650°C, 24h ; air cool

We deliver this steel alloy as:

• Plates, strips and sheets according to ASTM B 434 / ASME SB-434
• Rod, bar, wire, forging according to ASTM B 573 / ASME SB-573
• Seamless pipes according to ASTM B 622 / ASME SB-622
• Welded pipes according to ASTM B 619 / ASME SB-619, ASTM B 626 / ASME SB-626
• Fittings according to ASTM B 366 / ASME SB-366
• Forgings according to ASTM B 564 / ASME SB-564

Replacements, equivalents and other designations:

Alloy 242, Haynes® 242, N10242, Haynes 242, ASTM B 366-19 (CRH242) / ASME SB-366-19 (CRH242), ASTM B 366-19 (WPH242) / ASME SB-366-19 (WPH242), ASTM B 434-22 (N10242) / ASME SB-434-22 (N10242), ASTM B 472-18 (N10242) / ASME SB-472-18 (N10242), ASTM B 564-19 (N10242) / ASME SB-564-19 (N10242), ASTM B 573-06 (N10242) / ASME SB-573-06 (N10242), ASTM B 619-19 (N10242) / ASME SB-619-19 (N10242), ASTM B 622-17b (N10242) / ASME SB-622-17b (N10242), ASTM B 626-19 (N10242) / ASME SB-626-19 (N10242)