Inconel® is a material that is specifically optimized for some of the toughest use conditions to be found in manufacturing while Duplex stainless steels is the most recent family of stainless steels. They are called duplex (or austenitic-ferritic) grades because their metallurgical structure consists of two phases, austenite (face-centered cubic lattice) and ferrite (body centered cubic lattice) in roughly equal proportions.
Duplex Stainless Steel
Duplex and Super Duplex Steel Equivalent Grades
| STANDARD | WERKSTOFF NR. | UNS |
|---|---|---|
| Duplex 1803 | 1.4462 | S318032 |
| Duplex 2205 | 1.4462 | S32205 |
| Super Duplex S2507 | 1.4410 | S32750 / S32760 / S32950 |
Duplex and Super Duplex Composition
| Trade Name | UNS | Super Duplex Industry Specifications | Chemical Composition | Min.Tensile (KSI) | Min.Yield (KSI) | Elongation % |
|---|---|---|---|---|---|---|
| SAF 2507® | UNS S32750 | ASTM A182 F53, A240, A276, A479, A789, A790, A815, A928, A988 SAE J405 | C 0.030 max Cr 24.0-26.0 Cu 0.5 max Mn 1.20 max Mo 3.0-5.0 N 0.24-0.32 Ni 6.0-8.0 P 0.035 max S 0.020 max Si 0.8 max | 116 | 80 | 15 |
| UNS S32760 | ASTM A182 F55, A240, A276, A314, A473, A479, A789, A790, A815, A928, A988 SAE J405 | C 0.03 max Cr 24.0-26.0 Cu 0.5-1.0 Mn 1.0 max Mo 3.0-4.0 N 0.2-0.3 Ni 6.0-8.0 P 0.03 max S 0.01 max Si 1.0 max W 0.5-1.0 | 109 | 80 | 25 | |
| SAF 2205® 22Cr | UNS S31803 | ASME SA-182 (F51), SA-240, SA-798, SA-790, SA-815 ASTM A182 (F51),A240, A276, A479, A789, A790, A815, A928, A988 SAE J405 | C 0.30 max Cr 21.0-23.0 Mn 2.00 max Mo 2.50-3.50 N 0.08-0.20 Ni 4.50-6.50 P 0.030 max S 0.020 max Si 1.00 max | 90 | 65 | 25 |
| SAF 2205® 22Cr | UNS S32205 | ASME SA-182 (F60), SA-240, SA-798, SA-790, SA-815 ASTM A182 (F60), A240, A276, A479, A480, A798, A790, A815, A928, A988 SAE J405 | C 0.30 max Cr 22.0-23.0 Mn 2.00 max Mo 3.00-3.50 N 0.14-0.20 Ni 4.50-6.50 P 0.030 max S 0.020 max Si 1.00 max | 95 | 65 | 25 |
SAF 2205® & SAF 2507® are registered trademark for Sandvik
Inconel Alloy
| Inconel Composition | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Inconel | Element (% by mass) | ||||||||||||||
| Ni | Cr | Fe | Mo | Nb | Co | Mn | Cu | Al | Ti | Si | C | S | P | B | |
| 600 | 72.0 | 14.0–17.0 | 6.0–10.0 | 1.0 | 0.5 | 0.5 | 0.15 | 0.015 | |||||||
| 617 | 44.2–56.0 | 20.0–24.0 | 3.0 | 8.0–10.0 | 10.0–15.0 | 0.5 | 0.5 | 0.8–1.5 | 0.6 | 0.5 | 0.15 | 0.015 | 0.015 | 0.006 | |
| 625 | 58.0 | 20.0–23.0 | 5.0 | 8.0–10.0 | 3.15–4.15 | 1.0 | 0.5 | 0.4 | 0.4 | 0.5 | 0.1 | 0.015 | 0.015 | ||
| 690 | 59.5 | 30 | 9.2 | 0.35 | 0.01 | 0.02 | 0.35 | 0.019 | 0.003 | ||||||
| 718 | 50.0–55.0 | 17.0–21.0 | balance | 2.8–3.3 | 4.75–5.5 | 1.0 | 0.35 | 0.2–0.8 | 0.65–1.15 | 0.3 | 0.35 | 0.08 | 0.015 | 0.015 | 0.006 |
| X-750 | 70.0 | 14.0–17.0 | 5.0–9.0 | 0.7–1.2 | 1.0 | 1.0 | 0.5 | 0.4–1.0 | 2.25–2.75 | 0.5 | 0.08 | 0.01 | |||
Inconel alloys
Alloys of inconel include:
- Inconel 600: Solid solution strengthened
- Inconel 601
- Inconel 625: Acid resistant, good weldability. The LCF version is typically used in bellows.
- Inconel 690: Low cobalt content for nuclear applications, and low resistivity
- Inconel 713C: Precipitation hardenable nickel-chromium base cast alloy
- Inconel 718: Gamma double prime strengthened with good weldability
- Inconel 751: Increased aluminium content for improved rupture strength in the 1600 °F range
- Inconel 792: Increased aluminium content for improved high temperature corrosion properties, used especially in gas turbines
- Inconel 939: Gamma prime strengthened to increase weldability
Inconel Equivalent Grades
| STANDARD | WERKSTOFF NR. | UNS | GOST | AFNOR | JIS | BS | EN | OR |
|---|---|---|---|---|---|---|---|---|
| Inconel 600 | 2.4816 | N06600 | МНЖМц 28-2,5-1,5 | NC15FE11M | NCF 600 | NA 13 | NiCr15Fe | ЭИ868 |
| Inconel 601 | 2.4851 | N06601 | XH60BT | NC23FeA | NCF 601 | NA 49 | NiCr23Fe | ЭИ868 |
| Inconel 617 | 2.4663 | N06617 | ||||||
| Inconel 625 | 2.4856 | N06625 | ХН75МБТЮ | NC22DNB4M | NCF 625 | NA 21 | NiCr22Mo9Nb | ЭИ602 |
| Inconel 690 | 2.4642 | N06690 | ||||||
| Inconel 718 | 2.4668 | N07718 | ||||||
| Inconel 725 | – | N07725 | ||||||
| Inconel X-750 | 2.4669 | N07750 |
Inconel Melting Point, Density and Tensile Strength
| Density | Melting Point | Tensile Strength | Yield Strength (0.2%Offset) | Elongation | |
|---|---|---|---|---|---|
| 600 | 8.47 g/cm3 | 1413 °C (2580 °F) | Psi – 95,000 , MPa – 655 | Psi – 45,000 , MPa – 310 | 40 % |
| 601 | 8.1 g/cm3 | 1411 °C (2571 °F) | Psi – 80,000 , MPa – 550 | Psi – 30,000 , MPa – 205 | 30 % |
| 617 | 8.3g/cm³ | 1363°C | ≥ 485 MPa | ≥ 275 MPa | 25 % |
| 625 | 8.4 g/cm3 | 1350 °C (2460 °F) | Psi – 135,000 , MPa – 930 | Psi – 75,000 , MPa – 517 | 42.5 % |
| 690 | 8.3g/cm³ | 1363°C | ≥ 485 MPa | ≥ 275 MPa | 25 % |
| 718 | 8.2 g/cm3 | 1350 °C (2460 °F) | Psi – 135,000 , MPa – 930 | Psi – 70,000 , MPa – 482 | 45 % |
| 725 | 8.31 g/cm3 | 1271°C-1343 °C | 1137 MPa | 827 MPa | 20 % |
| X-750 | 8.28 g/cm3 | 1430°C | 1267 MPa | 868 MPa | 25 % |