Alloy 80A, 2.4952, UNS N07080, Nimonic® 80A - nickel alloy

Alloy 80A, 2.4952, UNS N07080, Nimonic® 80A - nickel alloy according to ASTM B637 and other standards

Alloy 80A, 2.4952, UNS N07080, Nimonic® 80A – description

Alloy 80A (UNS N07080) is a Ni-Cr alloy with alloying of titanium and aluminium, age-hardened, heat-resistant, creep-resistant and resistant to sulphur in combustion gas. It is used up to 815°C.

Applications

Used in automotive for exhaust valves, in aerospace for fasteners and gas turbine blades, rings and discs and in nuclear power plants for boiler tube supports.

Physical and Tensile Properties

Room temperature physical properties:

• Density: 8.19 g/cm³
• Melting Temperature: 1320-1365 °C
• Magnetic Permeability: 1.0006

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

• 100°C: 12.7 μm/m⋅K
• 200°C: 13.3 μm/m⋅K
• 300°C: 13.7 μm/m⋅K
• 400°C: 14.1 μm/m⋅K
• 500°C: 14.4 μm/m⋅K
• 600°C: 15.0 μm/m⋅K
• 700°C: 15.5 μm/m⋅K
• 800°C: 16.2 μm/m⋅K
• 900°C: 17.1 μm/m⋅K
• 1000°C: 18.1 μm/m⋅K

Thermal Conductivity:

• 20°C: 11.2 W/m · K
• 100°C: 11.6 W/m · K
• 200°C: 14.4 W/m · K
• 300°C: 16.1 W/m · K
• 400°C: 17.8 W/m · K
• 500°C: 19.4 W/m · K
• 600°C: 20.8 W/m · K
• 700°C: 22.3 W/m · K
• 800°C: 24.5 W/m · K
• 900°C: 26.5 W/m · K
• 1000°C: 28.4 W/m · K

Specific Heat Capacity:

• 20°C: 448 J/kg⋅K
• 100°C: 469 J/kg⋅K
• 200°C: 494 J/kg⋅K
• 300°C: 519 J/kg⋅K
• 400°C: 548 J/kg⋅K
• 500°C: 573 J/kg⋅K
• 600°C: 599 J/kg⋅K
• 700°C: 628 J/kg⋅K
• 800°C: 653 J/kg⋅K
• 900°C: 678 J/kg⋅K
• 1000°C: 703 J/kg⋅K

Electrical Resistivity:

• 20°C: 12.4 μΩ·m
• 100°C: 12.49 μΩ·m
• 200°C: 12.68 μΩ·m
• 300°C: 12.8 μΩ·m
• 400°C: 13.19 μΩ·m
• 500°C: 13.3 μΩ·m
• 600°C: 13.19 μΩ·m
• 700°C: 13.19 μΩ·m
• 800°C: 13.1 μΩ·m
• 900°C: 12.79 μΩ·m
• 1000°C: 12.61 μΩ·m

Young's Modulus:

• 20°C: 216 GPa
• 100°C: 212 GPa
• 200°C: 208 GPa
• 300°C: 202 GPa
• 400°C: 196 GPa
• 500°C: 189 GPa
• 600°C: 179 GPa
• 700°C: 161 GPa
• 800°C: 130 GPa
• 900°C: 120 GPa
• 1000°C: 110 GPa

Shear Modulus:

• 20°C: 85 GPa
• 100°C: 84 GPa
• 200°C: 82 GPa
• 300°C: 79 GPa
• 400°C: 77 GPa
• 500°C: 74 GPa
• 600°C: 70 GPa
• 700°C: 67 GPa
• 800°C: 64 GPa
• 900°C: 58 GPa
• 1000°C: 53 GPa

High-Temperature Mechanical Properties of Pyromet Alloy 80A in solutioned (1080°C, 8h, AC) and aged (700°C; 16h, AC) condition, according to the producer:

• 20°C:
  • Yield strength: 1000 MPa
  • Tensile strength: 621 MPa
  • Elongation: 39 %
• 540°C:
  • Yield strength: 876 MPa
  • Tensile strength: 531 MPa
  • Elongation: 37 %
• 600°C:
  • Yield strength: 834 MPa
  • Elongation: 27 %
  • Reduction of area: 28 %
• 650°C:
  • Yield strength: 793 MPa
  • Tensile strength: 552 MPa
  • Elongation: 21 %
• 700°C:
  • Yield strength: 724 MPa
  • Elongation: 15 %
  • Reduction of area: 19 %
• 760°C:
  • Yield strength: 600 MPa
  • Tensile strength: 503 MPa
  • Elongation: 17 %
• 800°C:
  • Yield strength: 496 MPa
  • Elongation: 21 %
  • Reduction of area: 19 %
• 870°C:
  • Yield strength: 310 MPa
  • Tensile strength: 262 MPa
  • Elongation: 30 %
• 900°C:
  • Yield strength: 234 MPa
  • Elongation: 26 MPa
  • Reduction of area: 35 %

Stress-Rupture Properties of alloy 80A according to DIN EN 10302 - stress causing rupture in:

• 500°C, 10⁴h: 745 MPa
• 500°C, 10⁵h: 587 MPa
• 550°C, 10⁴h: 582 MPa
• 550°C, 10⁵h: 416 MPa
• 600°C, 10⁴h: 433 MPa
• 600°C, 10⁵h: 272 MPa
• 650°C, 10⁴h: 300 MPa
• 650°C, 10⁵h: 157 MPa
• 700°C, 10⁴h: 186 MPa
• 700°C, 10⁵h: 75 MPa
• 750°C, 10⁴h: 114 MPa
• 750°C, 10⁵h: 37 MPa
• 800°C, 10⁴h: 70 MPa
• 800°C, 10⁵h: 20 MPa

Creep-Rupture Properties of alloy 80A according to DIN EN 10302 - stress to produce 1% plastic creep in:

• 500°C, 10⁴h: 624 MPa
• 500°C, 10⁵h: 530 MPa
• 550°C, 10⁴h: 523 MPa
• 550°C, 10⁵h: 390 MPa
• 600°C, 10⁴h: 398 MPa
• 600°C, 10⁵h: 257 MPa
• 650°C, 10⁴h: 275 MPa
• 650°C, 10⁵h: 149 MPa
• 700°C, 10⁴h: 183 MPa
• 700°C, 10⁵h: 72 MPa
• 750°C, 10⁴h: 106 MPa
• 750°C, 10⁵h: 33 MPa
• 800°C, 10⁴h: 58 MPa
• 800°C, 10⁵h: 16 MPa

Corrosion Resistance

Alloy 80A forms a protective Cr₂O₃ layer, which gives it high resistance to oxidation and scaling up to 1000°C. It resists sulphur compounds for exhaust valves in engines operated with heavy oil. It has good resistance to nitric, phosphoric, sulfuric and acetic acid, moderate resistance to sea water and excellent resistance to salt spray (NaCl) as well as humidity.

High-temperature Oxidation - very good resistance up to 1000°C, although it deals with short-time exposition to higher temperatures. Descaled weight loss after continuous heating in air:

• 750°C, 30h: 1,8 mg/cm²
• 750°C, 100h: 1,9 mg/cm²
• 750°C, 300h: 2,5 mg/cm²
• 750°C, 1000h: 5,3 mg/cm²
• 900°C, 30h: 3,9 mg/cm²
• 900°C, 100h: 3,8 mg/cm²
• 900°C, 300h: 4,2 mg/cm²
• 900°C, 1000h: 6,6 mg/cm²
• 1000°C, 30h: 7,1 mg/cm²
• 1000°C, 100h: 7,4 mg/cm²
• 1000°C, 300h: 10,5 mg/cm²
• 1000°C, 1000h: 16 mg/cm²
• 1100°C, 30h: 8 mg/cm²
• 1100°C, 100h: 12,9 mg/cm²
• 1100°C, 300h: 18,8 mg/cm²
• 1100°C, 1000h: 21,2 mg/cm²
• 1200°C, 30h: 9,1 mg/cm²
• 1200°C, 100h: 1,5 mg/cm²
• 1200°C, 300h: 20 mg/cm²
• 1200°C, 1000h: 64,5 mg/cm²

Weldability

Fair weldability. Post-weld heat treatment is necessary to achieve the best properties.

Heat Treatment, Working and Machining

Recommended work and heat treatment parameters that aim to achieve high stress-rupture strength, taken from Special Metals datasheet, unless otherwise stated:

Hot working should take place in the range 1200-1050°C.

Heat treatment for extruded bars:

• Solution-treatment: 1080°C 8h; AC
• Age-hardening: 700°C 16h; AC

Heat treatment for extruded bars, subsequently cold stretched:

• Solution-treatment: 1080°C 8h; AC
• Stabilizing anneal: 850°C 24h; AC
• Age-hardening: 700°C 16h; AC

Heat treatment for cold rolled sheet:

• Solution-treatment: 1150°C 2-3 min; fluidized bed quench
• Solution-treatment: 1040°C 20 min; AC
• Age-hardening: 750°C 4h; AC

Heat treatment for welded sheet:

• Solution-treatment: 1150°C 2-3 min; AC
• Weld
• Post-weld heat treatment: 925°C 1h AC
• Age-hardening: 750°C 4h; AC

Cold working is difficult because alloy 80A work hardens rapidly; frequent interstage anneals (1040°C for 20 min; RAC/WQ) are required. Cold work in the solutioned condition.

VDM® describes an alternative plastic and heat treatment which aims to optimize the tensile properties at the cost of stress-rupture strength:

• Solution-treatment: 1050-1080°C; 8h; AC (for max creep-resistance)
• Solution-treatment: 1010-1050°C; 8h; AC (for max tensile ductility)
• Stabilizing anneal: 840-860°C; 24h; AC
• Age-hardening: 690-710°C; 16h; AC

The machinability of alloy 80A is similar to that of an annealed high-speed steel. Parts that have only undergone stabilisation annealing, without aging, are LESS machinable than parts that have been fully aged.

We deliver this steel alloy as:

• Rod, bar, wire, forging according to DIN 17742, DIN 17240, DIN EN 10090, BS 3076 & HR 1; ASTM B 637 / ASME SB-637; AECMA PrEn 2188, AECMA PrEn 2189, AECMA PrEn 2190, AECMA PrEn 2396, AECMA PrEn 2197, AIR 9165-37
• Plates, strips and sheets according to BS HR 201, AECMA PrEn 2191, DIN 17742, DIN EN 10302, ISO 6208
• Pipes according to BS HR 401
• Parts according to BS HR 601, AFNOR NC 20TA

Replacements, equivalents and other designations:

Alloy 80a, 2.4952, UNS N07080, Nimonic® 80A, GH4080A, NiCr20TiAl, 2.4631, NA 20 BS 3072, NA 20 BS 3073, Haynes 80A, NCF80A, ChN77TJuR, El437B, HEV 5, Pyromet® 80A, J467 (Nimoni80A), Nickelvac® 80A, Udimet® Ni-80A, ASTM B 637 (N07080) / ASME SB-637 (N07080), CarTech® 80A Alloy, VDM® alloy 80 A, Nicrofer 7520 Ti, NC 20 TA