Alloy 230, 2.4733, UNS N06230, Haynes® 230 alloy - nickel alloy

Alloy 230, 2.4733, UNS N06230, Haynes® 230 alloy - nickel alloy according to ASTM B166, DIN 17752 etc.

Alloy 230, 2.4733, N06230, Haynes® 230 – description

Alloy 230 (N06230) is a Ni-Cr-W alloy with lanthanum, a rare earth element. It has an excellent balance of high-temperature strength, thermal stability, oxidation and nitridation resistance, thermal cycling resistance and fabricability.

Applications

Gas turbines, petrochemical and thermal processing, nitric acid production.

Haynes® 230 - physical and mechanical properties

Room temperature physical properties:

• Density: 8.97 g/cm³
• Melting temperature: 1301-1371 °C

High-temperature Coefficient of thermal expansion, from 20°C to:

• 100°C: 11.8 μm/m⋅K
• 200°C: 12.4 μm/m⋅K
• 300°C: 12.8 μm/m⋅K
• 400°C: 13.2 μm/m⋅K
• 500°C: 13.6 μm/m⋅K
• 600°C: 14.1 μm/m⋅K
• 700°C: 14.7 μm/m⋅K
• 800°C: 15.2 μm/m⋅K
• 900°C: 15.7 μm/m⋅K
• 1000°C: 16.1 μm/m⋅K

Electrical resistivity:

• 20°C: 1.25 μΩ·m
• 100°C: 1.258 μΩ·m
• 200°C: 1.265 μΩ·m
• 300°C: 1.273 μΩ·m
• 400°C: 1.284 μΩ·m
• 500°C: 1.302 μΩ·m
• 600°C: 1.312 μΩ·m
• 700°C: 1.307 μΩ·m
• 800°C: 1.291 μΩ·m
• 900°C: 1.271 μΩ·m
• 1000°C: 1.25 μΩ·m

Thermal diffusivity:

• 20°C: 2.4 10^–6⋅m²/s
• 100°C: 2.7 10^–6⋅m²/s
• 200°C: 3.0 10^–6⋅m²/s
• 300°C: 3.3 10^–6⋅m²/s
• 400°C: 3.6 10^–6⋅m²/s
• 500°C: 3.9 10^–6⋅m²/s
• 600°C: 4.2 10^–6⋅m²/s
• 700°C: 4.3 10^–6⋅m²/s
• 800°C: 4.3 10^–6⋅m²/s
• 900°C: 4.4 10^–6⋅m²/s
• 1000°C: 4.8 10^–6⋅m²/s

Thermal conductivity:

• 20°C: 8.9 W/m · K
• 100°C: 10.4 W/m · K
• 200°C: 12.4 W/m · K
• 300°C: 14.4 W/m · K
• 400°C: 16.4 W/m · K
• 500°C: 18.4 W/m · K
• 600°C: 20.4 W/m · K
• 700°C: 22.4 W/m · K
• 800°C: 24.4 W/m · K
• 900°C: 26.4 W/m · K
• 1000°C: 28.4 W/m · K

Specific heat capacity:

• 20°C: 397 J/kg⋅K
• 100°C: 419 J/kg⋅K
• 200°C: 435 J/kg⋅K
• 300°C: 448 J/kg⋅K
• 400°C: 465 J/kg⋅K
• 500°C: 473 J/kg⋅K
• 600°C: 486 J/kg⋅K
• 700°C: 574 J/kg⋅K
• 800°C: 595 J/kg⋅K
• 900°C: 609 J/kg⋅K
• 1000°C: 617 J/kg⋅K

Tensile modulus:

• 20°C: 209 GPa
• 100°C: 207 GPa
• 200°C: 200 GPa
• 300°C: 193 GPa
• 400°C: 186 GPa
• 500°C: 181 GPa
• 600°C: 175 GPa
• 700°C: 168 GPa
• 800°C: 159 GPa
• 900°C: 150 GPa
• 1000°C: 141 GPa

Young's Modulus:

• 20°C: 79 GPa
• 100°C: 79 GPa
• 200°C: 76 GPa
• 300°C: 73 GPa
• 400°C: 70 GPa
• 500°C: 67 GPa
• 600°C: 64 GPa
• 700°C: 61 GPa
• 800°C: 57 GPa
• 900°C: 52 GPa
• 1000°C: 48 GPa

Poisson's ratio:

• 20°C: 0.31 GPa
• 100°C: 0.31 GPa
• 200°C: 0.32 GPa
• 300°C: 0.32 GPa
• 400°C: 0.33 GPa
• 500°C: 0.33 GPa
• 600°C: 0.34 GPa
• 700°C: 0.34 GPa
• 800°C: 0.34 GPa
• 900°C: 0.35 GPa

Tensile properties of alloy 2.4733 plates after tempering designated as F76 according to DIN 17750:2021:

• Yield strength: >310 MPa
• Tensile strength: >750 MPa
• Elongation: >35 %

Tensile properties of Haynes® 230 sheets according to the producer:

• 20°C:
  • Yield strength: 417 MPa
  • Tensile strength: 837 MPa
  • Elongation: 47.3 %
• 540°C:
  • Yield strength: 294 MPa
  • Tensile strength: 690 MPa
  • Elongation: 51.7 %
• 650°C:
  • Yield strength: 291 MPa
  • Tensile strength: 666 MPa
  • Elongation: 56.9 %
• 760°C:
  • Yield strength: 311 MPa
  • Tensile strength: 538 MPa
  • Elongation: 59.5 %
• 870°C: 318 MPa
  • Yield strength: 236 MPa
  • Tensile strength: 308 MPa
  • Elongation: 74.2 %
• 980°C:
  • Yield strength: 123 MPa
  • Tensile strength: 169 MPa
  • Elongation: 54.1 %
• 1090°C:
  • Yield strength: 69 MPa
  • Tensile strength: 90 MPa
  • Elongation: 37 %

Tensile properties of Haynes® 230 plates according to the producer:

• 20°C:
  • Yield strength: 383 MPa
  • Tensile strength: 852 MPa
  • Elongation: 46.0 %
• 540°C:
  • Yield strength: 263 MPa
  • Tensile strength: 706 MPa
  • Elongation: 53.2 %
• 650°C:
  • Yield strength: 267 MPa
  • Tensile strength: 677 MPa
  • Elongation: 53.0 %
• 760°C:
  • Yield strength: 260 MPa
  • Tensile strength: 533 MPa
  • Elongation: 68.0 %
• 870°C: 318 MPa
  • Yield strength: 234 MPa
  • Tensile strength: 311 MPa
  • Elongation: 94.0 %
• 980°C:
  • Yield strength: 166 MPa
  • Tensile strength: 168 MPa
  • Elongation: 91.2 %
• 1090°C:
  • Yield strength: 63 MPa
  • Tensile strength: 91 MPa
  • Elongation: 92.1 %

Creep resistance of solutioned Haynes® 230 sheet - approximate initiall stress to produce 0,5% creep in given time and at given temperature:

• 650°C, 100h: 214 MPa
• 705°C, 10h: 200 MPa
• 705°C, 100h: 145 MPa
• 705°C, 1000h: 100 MPa
• 760°C, 10h: 132 MPa
• 760°C, 100h: 94 MPa
• 760°C, 1000h: 66 MPa
• 760°C, 10 000h: 50 MPa
• 815°C, 10h: 98 MPa
• 815°C, 100h: 71 MPa
• 815°C, 1000h: 52 MPa
• 815°C, 10 000h: 37 MPa
• 870°C, 10h: 78 MPa
• 870°C, 100h: 56 MPa
• 870°C, 1000h: 39 MPa
• 870°C, 10 000h: 28 MPa
• 925°C, 10h: 53 MPa
• 925°C, 100h: 38 MPa
• 925°C, 1000h: 26 MPa
• 925°C, 10 000h: 17 MPa
• 980°C, 10h: 48 MPa
• 980°C, 100h: 25 MPa
• 980°C, 1000h: 12 MPa
• 980°C, 10 000h: 5,9 MPa
• 1040°C, 100h: 12 MPa
• 1040°C, 1000h: 5,5 MPa

Rupture strength of solutioned Haynes® 230 sheet - approximate initiall stress to produce a rupture in given time and at given temperature:

• 650°C, 100h: 352 MPa
• 650°C, 1000h: 248 MPa
• 650°C, 10 000h: 193 MPa
• 705°C, 10h: 324 MPa
• 705°C, 100h: 234 MPa
• 705°C, 1000h: 179 MPa
• 705°C, 10 000h: 134 MPa
• 760°C, 10h: 221 MPa
• 760°C, 100h: 169 MPa
• 760°C, 1000h: 125 MPa
• 760°C, 10 000h: 91 MPa
• 815°C, 10h: 161 MPa
• 815°C, 100h: 121 MPa
• 815°C, 1000h: 86 MPa
• 815°C, 10 000h: 58 MPa
• 870°C, 10h: 117 MPa
• 870°C, 100h: 86 MPa
• 870°C, 1000h: 57 MPa
• 870°C, 10 000h: 39 MPa
• 925°C, 10h: 83 MPa
• 925°C, 100h: 55 MPa
• 925°C, 1000h: 35 MPa
• 925°C, 10 000h: 22 MPa
• 980°C, 10h: 69 MPa
• 980°C, 100h: 37 MPa
• 980°C, 1000h: 18 MPa
• 980°C, 10 000h: 8,3 MPa
• 1040°C, 100h: 21 MPa
• 1040°C, 1000h: 10 MPa

Temperature stability - alloy 230 exhibits excellent retained ductility after long-term thermal exposure at intermediate temperatures. It does not exhibit sigma phase, mu phase, or other deleterious phase formation even after 16,000 hours of exposure at temperatures from 649 to 870°C. Principal phases precipitated from solid solution are all carbides. Thermal stability is confirmed by high impact value after being exposed to high temperature for prolonged periods of time:

• No exposure: 54 J
• 650°C, 8 000h: 31,4 J
• 650°C, 20 000h: 28,9 J
• 650°C, 50 000h: 25,8 J
• 760°C, 8 000h: 18,7 J
• 760°C, 20 000h: 18,8 J
• 760°C, 50 000h: 20,7 J
• 870°C, 8 000h: 21,6 J
• 870°C, 20 000h: 19,5 J
• 870°C, 50 000h: 14,8 J

Corrosion behaviour

Alloy 230 has the best oxidation resistance of all chromium scale forming alloys. Very good nitridation resistance.

Oxidation - very good resistance, as evident from following data.

1008h long static oxidation test results:

• 980°C:
  • Metal loss: 0.0075 mm
  • Average metal affected: 0.018 mm
• 1095°C:
  • Metal loss: 0.013 mm
  • Average metal affected: 0.033 mm
• 1150°C:
  • Metal loss: 0.058 mm
  • Average metal affected: 0.086 mm
• 1205°C:
  • Metal loss: 0.11 mm
  • Average metal affected: 0.20 mm

The alloy exhibits very high resistance to cyclic oxidation, with heating and cooling cycles more representative of actual conditions in processing plants. Based on tests, it is extrapolated that in flowing air at 1095°C in 25-hour cycles, the corrosion rate is 0.71mm/year. For 168-hour cycles, the rate is 0.28mm/year. In these tests, only Alloy 214 with a high aluminum content showed better performance.

Dynamic oxidation resistance in high-velocity combustion gas stream test results (samples were cycled to less than 260°C once every 30 min):

• 500h, 1090°C:
  • Metal loss: 0.056 mm
  • Maximum metal affected: 0.15 mm
• 1000h, 980°C
  • Metal loss: 0.02 mm
  • Maximum metal affected: 0.089 mm

Results of field test in a natural gas-fired tube at 1010°C for 3000h:

• Metal loss: 0.028 mm
• Maximum metal affected: 0.1 mm
• Oxidation rate: 0.3 mm

High-temperature carburization - good resistance. 24 test in Ar-5H₂-5CO-5CH₄ at 1090°C resulted in carbon absorption of 10,3 mg/cm².

High-temperature nitridation - very good resistance, as validated by the test results provided in the following comparison. In each case, Alloy 230 was subjected to ammonia exposure for 168 hours.

• 650°C
  • Nitrogen absorption: 0.7 mg/cm²
  • Depth of nitride penetration: 0.03 mm
• 980°C
  • Nitrogen absorption: 1.4 mg/cm²
  • Depth of nitride penetration: 0.12 mm
• 1090°C
  • Nitrogen absorption: 1.5 mg/cm²
  • Depth of nitride penetration: 0.39 mm

Weldability

Alloy 230 has good weldability. Preheating nor postweld heat treatment are not required. Interpass temperature should be maintained below 100°C.

Selection of welding consumables for Alloy 230

• Coated electrodes: ENiCrWMo-1
• Filler metals: ERNiCrWMo-1 (Haynes® 230-W™)

Heat treatment, working and machining

Recommended working and heat treatment parameters:

• Solution-treatment: 1177-1246 °C; water quench
• Intermediate annealing: <1165°C

Alloy 230 can be both cold- and hot-worked. During working, intermediate annealing at a temperature lower than 1165°C can be performed. Post-working, the part should be subjected to solution annealing at a temperature of 1177-1246°C, typically 1230°C and water quenched.

We deliver this steel alloy as:

• Rod, bar, wire, forging according to AMS 5891, ASTM B 572 / ASME SB-572, ASTM B 472, ASTM B 564 / ASME SB-564
• Plates, strips and sheets according to AMS 5878, ASTM B 435 / ASME SB-435, DIN 17750
• Welded pipes according to ASTM B 619 / ASME SB-619, ASTM B 626 / ASME SB-626
• Seamless pipes according to ASTM B 622 / ASME SB-62

Replacements, equivalents and other designations:

Haynes® 230, Alloy 230, H06230, NS3313, 2.4733, NiCr22W14Mo, BNi6231, ENi6231, Ni6231, SNi6231, VDM® Alloy N06230, B50TF246, MTEK CP-20MW, AMS 5839, AMS 5878, AMS 5891, ASTM B 366 (CRH230) / ASME SB-366 (CRH230), ASTM B 366 (WPH230) / ASME SB-366 (WPH230), ASTM B 435 (N06230) / ASME SB-435 (N06230), ASTM B 472 (N06230) / ASME SB-472 (N06230), ASTM B 474 (N06230) / ASME SB-474 (N06230), ASTM B 564 (N06230) / ASME SB-564 (N06230), ASTM B 572 (N06230) / ASME SB-572 (N06230), ASTM B 619 (N06230) / ASME SB-619 (N06230), ASTM B 622 (N06230) / ASME SB-622 (N06230), ASTM B 626 (N06230) / ASME SB-626 (N06230), Inconel® N06230