to Metals
to Nickel alloys
Dr. Dmitri Kopeliovich
Heat-treatable nickel-chromium-iron alloys are nickel base alloys, containing 15-22% of chromium (Cr) and up to 33% of iron (Fe) as the major alloying elements.
Heat-treatable Nickel-Chromium-Iron Alloys contain such additional alloying elements like aluminum (Al), silicon (Si), beryllium (Be) and titanium (Ti); therefore these alloys may be strengthened by precipitation hardening.
Annealing of non-heat-treatable Nickel-Chromium-Iron Alloys is conducted at 1850-2075°F (1010-1135°C).
Solution treatment temperature is 1940-2100°F (1060-1150°C).
Aging (precipitation treatment) of the alloys is conducted at 1150-1550°F (620-845°C) for 2-24 hours.
The heat-treatable Nickel-Chromium-Iron Alloys are identified according to their trade names Nimonic 80A, Nimonic 115, Inconel X-750, Udimet, Waspaloy,Rene 41, Astroloy.
Heat-treatable Nickel-Chromium-Iron Alloys have high mechanical strength and high resistance to Creep at temperatures up to 1500°F (815°C ) combined with good Corrosion and oxidation resistance.
The alloys are used for manufacturing gas turbines components (blades, rings, combustors, flame holders, discs), parts of nuclear steam generators, die casting cores, hot working tools, exhaust valves in internal combustion engines.
| Designation | Cr,% | Fe,% | Mo,% | Al,% | Ti,% | Co,% | Others,% | Ni,% |
|---|---|---|---|---|---|---|---|---|
| Nimonic 80A | 18-21 | 3 max. | - | 1.0-1.8 | 1.8-2.7 | - | - | 69 min. |
| Nimonic 115 | 14-16 | 1 max. | 3-5 | 4.5-5.5 | 3.5-4.5 | 13-15.5 | B=0.01-0.025 C=0.12-0.2 | 54 min. |
| Inconel X-750 | 14-17 | 5-9 | 8-10 | 0.4-1.0 | 2.25-2.75 | - | Nb=0.7-1.2 | 70 min. |
| Waspaloy | 18-21 | 2 max. | 3.5-5 | 1.0-1.5 | 2.6-3.25 | 12-15 | C=0.02-0.1 Zr=0.02-0.12 B=0.003-0.008 | balance |
| Rene 41 | 18-20 | 5 max. | 9-10.5 | 1.4-1.6 | 3.0-3.3 | 10-12 | C=0.06-0.12 B=0.003-0.01 | balance |