Hastelloy X is a Nickel-Chromium-Iron-Molybdenum alloy with an exceptional combination of oxidation resistance, ease of fabrication and high temperature strength. It has also been found to be exceptionally resistant to stress corrosion cracking in petrochemical applications.
Hastelloy X is also known as Inconel HX, Nicrofer 4722 Co, and Pyromet 680.
| Element | Min % | Max % |
| Cr | 20.50 | 23.00 |
| Mo | 8.00 | 10.00 |
| Fe | 17.00 | 20.00 |
| W | 0.20 | 1.00 |
| C | 0.05 | 0.15 |
| Si | – | 1.00 |
| Co | 0.50 | 2.50 |
| Mn | – | 1.00 |
| P | – | 0.04 |
| S | – | 0.03 |
| B | – | 0.01 |
| Ni | bal | |
Density
8.22 g/cm³ | 0.297 lb/in³
Melting Point
1355°C | 2470°F
Coefficient of Expansion
13.9 μm/m °C (20 – 100°C) | 7.7 x 10-6 in/in °F (70 – 212°F)
Modulus of Rigidity
77.6 kN/mm² | 11255 ksi
Modulus of Elasticity
205 kN/mm² | 29733 ksi
Heat Treatment of Finished Parts
| Condition as supplied by Alloy Wire | Type | Temperature | Time (Hr) | Cooling | |
| °C | °F | ||||
| Annealed or Spring Temper | Stress Relieve | 400 – 450 | 750 – 840 | 2 | Air |
Properties
| Condition | Approx. tensile strength | Approx. operating temperature | ||
| N/mm² | ksi | °C | °F | |
| Annealed | 850 – 1050 | 123 – 152 | -200 to +400 | -330 to +750 |
| Spring Temper | 1350 – 1550 | 196 – 225 | -200 to +400 | -330 to +750 |