Invar 36 (UNS: K93600)
| Bellows Materials | Invar 36 |
| Description | A nickel-iron, low-expansion alloy containing 36% nickel. It maintains nearly constant dimensions over the range of normal atmospheric temperatures, and has a low coefficient of expansion from cryogenic temperatures to about 500°F. |
| Application Notes | The alloy also retains good strength and toughness at cryogenic temperatures. INVAR 36 can be hot and cold formed and machined using processes similar to austenitic stainless steels. |
| Industry Uses /Products | Cryogenic bellows, Instrument bellows, Vacuum Bellows for semiconductor industry |
| UNS | K93600 |
Material Properties
| Density, ρ, lbs/in^3 | 0.293 |
| Yield Strength, Sy, Psi | 35000 |
| Tensile Strength, Su, Psi | 42 |
| Coeff. Thermal Expansion, in/in/˚F | 0.0000008 |
| Melting Point, ˚F | 2605 |
Post Weld Heat Treatement (PWHT)
| Stress Relive | 2 hrs at 600F air or oven cool |
| Annealing | 1 hr at 1550F after forming and /or welding |