Nickel alloys – comparative overview
Selection guide to the 13 nickel alloys in the Dustre portfolio
Nickel alloys are divided by function. Pure nickel and Ni-Cu (200, 400, K500) serve alkalis, HF and seawater. Ni-Cr-Fe and Fe-Ni-Cr (600, 601, 800HT) serve oxidation and creep at high temperature. Ni-Fe-Cr-Mo-Cu, Ni-Cr-Mo and Ni-Mo (825, 625, C4, C22, C276, B2) serve aqueous corrosion by acids and chlorides. The 718 superalloy is chosen for mechanical strength. The tables below summarize the base composition and the standard minimums of each alloy; the full values are in each material's data sheet.
Designations and equivalents
| System | Designation |
|---|---|
| UNS | N02200, N04400, N05500, N06600, N06601, N06625, N07718, N08811, N08825, N06455, N06022, N10276, N10665 |
| W.Nr./EN | 2.4066, 2.4360, 2.4375, 2.4816, 2.4851, 2.4856, 2.4668, 1.4959, 2.4858, 2.4610, 2.4602, 2.4819, 2.4617 |
| Trade names | Inconel, Incoloy and Monel (Special Metals); Hastelloy (Haynes); Nicrofer/Nimofer/Nicorros (VDM) |
| Others | Trade names are registered trademarks; buy by UNS and ASTM standard |
Standards by product form
| Form | Standard |
|---|---|
| Bar | ASTM B160 (200), B164 (400), B865 (K500), B166 (600/601), B446 (625), B637 (718), B408 (800HT), B425 (825), B574 (C4/C22/C276), B335 (B2) |
| Forging | ASTM B564 (200, 400, 600, 625, 800HT, 825, C22, C276, B2); 718: B637/AMS 5663/API 6A718; K500: B865 |
| Plate | ASTM B162, B127, B168, B443, B670, B409, B424, B575, B333 |
| Tube | ASTM B161, B165, B167, B444, B407, B423, B622, B163 (exchanger) |
Tolerances and HS codes
- Forged bars (round and square): machining allowance from 2 mm (Ø 6–16 mm) to 24 mm (Ø 400–500 mm) on the diameter. E.g. Ø 100–125 mm finished: +7 mm, tolerance +6 / −0 (length up to 3,500 mm).
- Forged discs: allowance of 4 to 9 mm on the diameter and 3 to 11 mm on the height, plus-only tolerance.
- Cutting and machining: band saw −0 / +5 to +15 mm on length; waterjet +10 % of thickness on the diameter (min. 2 mm); machined parts −0 / +2 to +5 mm on the diameter. See the full tables (INF 002 and INF 003, the same for every alloy).
| Form | NCM (Brazil, 8 digits) | HS (international, 6 digits) | HTS (USA, 10 digits)* | CN (European Union, 8 digits)* |
|---|---|---|---|---|
| Forged bar | 7505.12.10 | 7505.12 | 7505.12.3000 | 7505 12 00 |
| Hot-rolled bar | 7505.12.10 | 7505.12 | 7505.12.3000 | 7505 12 00 |
| Plate (> 10 mm, width ≥ 600 mm) | 7506.20.00 | 7506.20 | 7506.20.3000 | 7506 20 00 |
| Seamless pipe | 7507.12.00 | 7507.12 | 7507.12.0000 | 7507 12 00 |
| Welded pipe | 7507.12.00 | 7507.12 | 7507.12.0000 | 7507 12 00 |
| Flange and fitting | 7507.20.00 | 7507.20 | 7507.20.0000 | 7507 20 00 |
Class in Dustre's NCM table (INF 004): nickel alloy.
*: US and EU codes are for reference; confirm with your customs broker. NCM codes with * were checked by Dustre against the current NCM, outside the INF 004 table. HS = first 6 digits of the NCM.
Chemical composition (%)
Summarized base composition (main elements, % by mass; full ranges in each alloy's data sheet)
| Element | Range (%) |
|---|---|
| Nickel 200 | Ni ≥ 99.0 |
| Monel 400 | Ni ≥ 63 · Cu 28 – 34 |
| Monel K500 | Ni ≥ 63 · Cu 27 – 33 · Al 2.3 – 3.15 · Ti 0.35 – 0.85 |
| Inconel 600 | Ni ≥ 72 · Cr 14 – 17 · Fe 6 – 10 |
| Inconel 601 | Ni 58 – 63 · Cr 21 – 25 · Al 1.0 – 1.7 · Fe balance |
| Incoloy 800HT | Fe ≥ 39.5 · Ni 30 – 35 · Cr 19 – 23 · Al+Ti 0.85 – 1.20 |
| Incoloy 825 | Ni 38 – 46 · Fe ≥ 22 · Cr 19.5 – 23.5 · Mo 2.5 – 3.5 · Cu 1.5 – 3.0 |
| Inconel 625 | Ni ≥ 58 · Cr 20 – 23 · Mo 8 – 10 · Nb 3.15 – 4.15 |
| Inconel 718 | Ni 50 – 55 · Cr 17 – 21 · Fe balance · Nb 4.75 – 5.5 · Mo 2.8 – 3.3 |
| Hastelloy C-4 | Ni balance · Cr 14 – 18 · Mo 14 – 17 · Ti ≤ 0.7 |
| Hastelloy C-22 | Ni balance · Cr 20 – 22.5 · Mo 12.5 – 14.5 · W 2.5 – 3.5 |
| Hastelloy C-276 | Ni balance · Mo 15 – 17 · Cr 14.5 – 16.5 · W 3 – 4.5 · Fe 4 – 7 |
| Hastelloy B-2 | Ni balance · Mo 26 – 30 · Cr ≤ 1 |
Mechanical properties
Standard minimums (YS 0.2% / UTS / elongation). Annealed or solution-annealed condition, except 718 and K500 (aged)
| Property | Value |
|---|---|
| Nickel 200 (B564) | ≥ 105 / ≥ 380 MPa / ≥ 40% |
| Monel 400 (B564) | ≥ 172 / ≥ 483 MPa / ≥ 35% |
| Monel K500 aged (B865) | ≥ 690 / ≥ 965 MPa / ≥ 20% |
| Inconel 600 (B564) | ≥ 241 / ≥ 552 MPa / ≥ 30% |
| Inconel 601 (B166) | ≥ 205 / ≥ 550 MPa / ≥ 30% |
| Incoloy 800HT (B564) | ≥ 172 / ≥ 448 MPa / ≥ 30% |
| Incoloy 825 (B564) | ≥ 241 / ≥ 586 MPa / ≥ 30% |
| Inconel 625 Gr.1 ≤ 102 mm (B564) | ≥ 414 / ≥ 827 MPa / ≥ 30% |
| Inconel 718 aged (AMS 5663) | ≥ 1,034 / ≥ 1,276 MPa / ≥ 12% |
| Hastelloy C-4 (B574) | ≥ 276 / ≥ 690 MPa / ≥ 40% |
| Hastelloy C-22 (B564) | ≥ 310 / ≥ 690 MPa / ≥ 45% |
| Hastelloy C-276 (B564) | ≥ 283 / ≥ 690 MPa / ≥ 40% |
| Hastelloy B-2 (B564) | ≥ 350 / ≥ 760 MPa / ≥ 40% |
Typical physical properties
| Property | Value |
|---|---|
| Density | 7.94 (800HT) to 9.22 g/cm³ (B-2) |
| Melting range | ≈ 1,260 (718) to 1,446 °C (Ni 200) |
| Modulus of elasticity | ≈ 179 (Monel) to 217 GPa (B-2) |
| Thermal conductivity (20 °C) | ≈ 10 W/m·K (Ni-Cr-Mo) to 70 W/m·K (Ni 200) |
| Thermal expansion (20–100 °C) | ≈ 10.8 (C-4, B-2) to 14.4 µm/m·K (800HT) |
Heat treatment, welding and machining
| Item | Usual practice |
|---|---|
| Service temperature | High temperature: 601 (oxidation up to ~1,200 °C), 600 (~1,100 °C), 800HT (creep from 600 to 1,000 °C), 718 (mechanical strength up to ~650 °C). Aqueous corrosion: 825, 625, C4, C22, C276, B2, 400 and 200. Ni 200 is limited to ~315 °C and B2 must avoid 540 – 870 °C. |
| Heat treatment | Most are supplied annealed or solution annealed and do not harden by heat treatment. Only 718 and K500 are precipitation hardenable (aging after solution treatment). 800HT requires solution annealing ≥ 1,149 °C to obtain a coarse grain. |
| Welding | AWS A5.14/A5.11 consumables by alloy: Ni 200 ERNi-1; 400/K500 ERNiCu-7; 600/601/800HT ERNiCr-3; 625/825 ERNiCrMo-3; 718 ERNiFeCr-2; C-4 ERNiCrMo-7; C-22 ERNiCrMo-10; C-276 ERNiCrMo-4; B-2 ERNiMo-7. |
| Machining | All work harden quickly and conduct little heat: use carbide, low speed, constant feed and abundant coolant. Aged 718 and K500 are the most difficult. |
Typical applications
- Alkalis and caustic soda: Nickel 200
- Seawater and hydrofluoric acid: Monel 400 and K500
- Furnaces and heat treatment: 600, 601 and 800HT
- Sour oil and gas wells: 825, 625, C276 and 718
- Acids with chlorides, FGD, pulp and paper: C-276, C-22 and C-4
- Pure (reducing) hydrochloric acid: Hastelloy B-2
- Turbines and high-strength fasteners: 718
Alternatives: To choose the alloy: first identify the medium (alkaline, seawater, hot oxidizing, reducing acid, acid with chlorides), then the temperature and only then the required mechanical strength. In aqueous corrosion, super-austenitic stainless (904L, 6Mo) and duplex/super duplex are lower-cost alternatives when the required PREN is ≤ 45.
Frequently asked questions
What is the chemical composition of Nickel alloys?
Per Summarized base composition (main elements, % by mass; full ranges in each alloy's data sheet): Nickel 200 Ni ≥ 99.0; Monel 400 Ni ≥ 63 · Cu 28 – 34; Monel K500 Ni ≥ 63 · Cu 27 – 33 · Al 2.3 – 3.15 · Ti 0.35 – 0.85; Inconel 600 Ni ≥ 72 · Cr 14 – 17 · Fe 6 – 10; Inconel 601 Ni 58 – 63 · Cr 21 – 25 · Al 1.0 – 1.7 · Fe balance; Incoloy 800HT Fe ≥ 39.5 · Ni 30 – 35 · Cr 19 – 23 · Al+Ti 0.85 – 1.20.
Which standards cover Nickel alloys?
Bar: ASTM B160 (200), B164 (400), B865 (K500), B166 (600/601), B446 (625), B637 (718), B408 (800HT), B425 (825), B574 (C4/C22/C276), B335 (B2). Forging: ASTM B564 (200, 400, 600, 625, 800HT, 825, C22, C276, B2); 718: B637/AMS 5663/API 6A718; K500: B865. Plate: ASTM B162, B127, B168, B443, B670, B409, B424, B575, B333. Tube: ASTM B161, B165, B167, B444, B407, B423, B622, B163 (exchanger).
Up to what temperature can Nickel alloys be used?
High temperature: 601 (oxidation up to ~1,200 °C), 600 (~1,100 °C), 800HT (creep from 600 to 1,000 °C), 718 (mechanical strength up to ~650 °C). Aqueous corrosion: 825, 625, C4, C22, C276, B2, 400 and 200. Ni 200 is limited to ~315 °C and B2 must avoid 540 – 870 °C.
Which materials can replace Nickel alloys?
To choose the alloy: first identify the medium (alkaline, seawater, hot oxidizing, reducing acid, acid with chlorides), then the temperature and only then the required mechanical strength. In aqueous corrosion, super-austenitic stainless (904L, 6Mo) and duplex/super duplex are lower-cost alternatives when the required PREN is ≤ 45.
