General
Heat resistance
Temperature limits and oxidation resistance for FeCrAl, FeCrNi and CrNi alloys
Scaling temperatures in different environments
The temperatures listed are the scaling temperatures (°C/°F) — the temperature at which the protective oxide starts to spall off. While materials can function at these temperatures, lower operating temperatures significantly extend service life. Kanthal APM and APMT alloys are manufactured by powder metallurgy for enhanced creep strength.
| Environment / Property | Less Good | Good | Very Good | Better | Best |
|---|---|---|---|---|---|
| Hot strength, T >600°C / 1112°F | Kanthal D, Tp 446 | Kanthal AF | Alloy 600, Tp 310 | Kanthal APM | Kanthal APMT, Alloy 800HT, 253MA, Alloy 601 |
| Oxidation in dry air | Tp 309 (1050°C), Alloy 800HT (1050°C) | Tp 446 (1100°C), Alloy 600 (1100°C) | 253MA (1150°C), Alloy 601 (1150°C), Tp 310 (1150°C) | Kanthal APM/APMT (1425°C) | Kanthal AF (1300°C), Kanthal D (1300°C) |
| Oxidation in moist air | Tp 309 (900°C), Alloy 800HT (900°C) | Tp 446 (950°C), Alloy 600 (950°C) | 253MA (1000°C), Alloy 601 (1000°C), Tp 310 (1000°C) | Kanthal APM/APMT (1200°C) | Kanthal AF (1200°C), Kanthal D (1200°C) |
| N2 — nitrogen from oxygen plant | Tp 446 (650°C), Tp 309 (650°C) | 253MA (750°C), Tp 310 (800°C) | Alloy 600 (1000°C), Alloy 601 (1000°C), Alloy 800HT (900°C), Kanthal APM (1050°C, not pre-oxidized) | Kanthal AF (1100°C, not pre-oxidized) | Kanthal D (1000°C, not pre-oxidized); Kanthal APM/APMT/AF/D (1200°C, pre-oxidized) |
| Ar — argon | Tp 446 (950°C), Alloy 800HT (950°C), Alloy 600 (950°C) | 253MA (1000°C), Alloy 601 (1000°C), Tp 310 (1000°C) | — | Kanthal APM/APMT (1425°C) | Kanthal AF (1300°C), Kanthal D (1300°C) |
| Exothermic gas: 10CO, 15H2, 5CO2, 70N2 | Tp 446 | 253MA (850°C), Tp 310 (850°C) | Alloy 800HT (950°C) | Alloy 601 (1000°C), Alloy 600 (1000°C) | Kanthal APM/APMT (1150°C), Kanthal AF (1150°C), Kanthal D (1100°C) |
| Endothermic gas: 20CO, 40H2, 40N2 | Tp 446 | 253MA (700°C), Tp 310 (750°C) | Alloy 601 (900°C), Alloy 600 (900°C), Alloy 800HT (800°C) | Kanthal D (1000°C) | Kanthal APM/APMT (1050°C), Kanthal AF (1050°C) |
| H2 — hydrogen, dewpoint <−50°C | Tp 446 (900°C) | 253MA (1000°C), Alloy 800HT (1000°C) | — | Kanthal APM/APMT (1425°C) | Kanthal AF (1400°C), Kanthal D (1300°C) |
| Vacuum, 10−3 torr | — | — | Kanthal APM/APMT (1150°C), Kanthal AF (1200°C), Kanthal D (1100°C) | — | — |
| Oxidizing SO2/SO3-containing gas | Alloy 800HT (600°C) | 253MA (900°C), Tp 446 (950°C), Tp 310 (950°C) | — | Kanthal APM/APMT (1200°C), Kanthal AF (1200°C) | Kanthal D (1150°C) |
| Reducing sulfur-containing gas | 253MA (650°C), Alloy 800HT (600°C), Tp 310 (650°C), Tp 446 (700°C) | — | Kanthal APM/APMT (1025°C), Kanthal AF (1025°C), Kanthal D (1000°C) | — | — |
| Molten metals (Cu, Zn, Mg) | 253MA, Tp 446 | — | Kanthal APM/APMT, AF | — | — |
| Molten aluminum | Metallic materials dissolve! | ||||
| Cracked ammonia | 253MA (750°C), SS2361 (800°C) | Alloy 800HT (900°C), Kanthal APM/APMT (900°C), Kanthal AF (900°C), Kanthal D (900°C) | Alloy 601 (1000°C), Alloy 600 (1000°C) | — | — |
KANTHAL is a trademark of Kanthal AB. 253MA is a trademark of Outokumpu Oy. Process parameters do influence material behaviour; the information above is provided as a guideline only and does not constitute guaranteed values.