Why is Inconel so expensive?
Inconel 725 is a nickel-based grade primarily alloyed with chromium, with significant additions of molybdenum, niobium and titanium. Nickel is considered an expensive metal and prices are subject to change. Other major alloying elements are also relatively expensive. As a result, the cost of Inconel 725 is higher.
Additionally, its extremely high strength is achieved through a metallurgical process called precipitation strengthening. During the additional heat treatment, very fine precipitates form in the metal and "fix" its microstructure when subjected to external loads, thereby increasing its strength and toughness. The cost of Inconel 725 is therefore also affected by the time and energy costs of further heat treatment processes and the challenge of meeting the necessary high intensity.
| Inconel | Ni | Cr | Fe | Mo | Nb | Co | Mn | Cu | Al | Ti | Si | C | S | P | B |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 600 | 72 | 14.0-17.0 | 6.0-10.0 | 1 | 0.5 | 0.5 | 0.15 | 0.015 | |||||||
| 617 | 44.2-56.0 | 20.0-24.0 | 3 | 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 | 20.0-23.0 | 5 | 8.0-10.0 | 3.15-4.15 | 1 | 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 | 0.35 | 0.2-0.8 | 0.65-1.15 | 0.3 | 0.35 | 0.08 | 0.015 | 0.015 | 0.006 |
| X-750 | 70 | 14.0-17.0 | 5.0-9.0 | 0.7-1.2 | 1 | 1 | 0.5 | 0.4-1.0 | 2.25-2.75 | 0.5 | 0.08 | 0.01 |
