24 July 2021 Hastelloy®
Hastelloy X Nickel Based Superalloy
Hastelloy X is a nickel-chromium-molybdenum alloy with cobalt and tungsten added. Hastelloy X alloy has excellent oxidation resistance at high temperatures up to 1200°C and can also be used in neutral and reducing atmospheres. At the same time, Hastelloy X alloy can resist carbonization and nitriding atmosphere. Hastelloy X has good oxidation and corrosion resistance, moderate durability and creep strength at 900°C, good cold and hot processing formability and welding performance. It is suitable for the manufacture of combustion chamber parts and other high-temperature parts of aero-engines. It can be used for a long time below 900°C, and the short-term working temperature can reach 1080°C.
Chemical Composition:
| Mo | Cr | Fe | W | Co | Mn | C | P | S | Si | Al | Ti | B | Cu |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 8.0-10.0 | 20.5-23.0 | 17.0-20.0 | .2-1.0 | .5-2.5 | 1.0 max | .05-.15 | .04 max | .03 max | 1.0 max | .50 max | .15 max | .01 max | .50 max |
Mechanical Properties:
Representative Tensile Properties, sheet
| Temp° F | Tensile (psi) | .2% Yield (psi) | Elongation in 2” % |
|---|---|---|---|
| 70 | 110,600 | 54,900 | 44 |
| 1000 | 89,000 | 35,600 | 49 |
| 1200 | 83,000 | 35,400 | 54 |
| 1400 | 67,000 | 34,400 | 53 |
| 1600 | 45,000 | 28,200 | 58 |
Hastelloy X process performance and requirements:
- The alloy has good cold and hot workability, and the forging heating temperature is 1170℃.
- The average grain size of the alloy is closely related to the degree of deformation of the forging and the final forging temperature.
- The alloy has satisfactory welding performance and can be welded by argon arc welding, seam welding, spot welding and other methods.
- The alloy can be directly added to the furnace that has been heated to the highest working temperature. After the necessary time for heat preservation, it will be released from the furnace and processed to the specified specifications. If the metal temperature drops below the minimum processing temperature, it needs to be heated again.
- The adhesion of the surface oxide of the alloy and the welding slag around the weld is stronger than that of stainless steel. It is recommended to use a fine-grained abrasive belt or a fine-grained grinding wheel for grinding.
Heat Treatment:
Wrought forms of HASTELLOY® X alloy are furnished in the solution heat-treated condition unless otherwise specified. X alloy is typically solution heat-treated at 2150°F (1177°C) and rapid cooled. Bright annealed products are cooled in hydrogen. Annealing at temperatures lower than the solution heat- treating may cause precipitation of secondary phases, which may affect the alloy’s strength and ductility.
Hastelloy X application:
- Industrial and aviation steam turbines (combustion chamber, rectifier, structural cover)
- Industrial furnace parts, support rollers, grids, ribbons and radiant tubes
- Spiral tube in petrochemical furnace
- High temperature gas cooled nuclear reactor