Controlled Expansion Alloys
NAS 36LG
At 36 percent, the primary component of NAS 36LG is nickel, giving this alloy an extremely low coefficient of thermal expansion—about one-tenth that of 18-8 stainless steel. NAS 36LG maintains thermal stress due to temperature variation at an extremely low level. When used with low-temperature materials, complex surface forms such as waves, bellows and loop patterns are not required, making NAS 36LG an easy metal to work with.
This alloy has a high ductility at extremely low temperatures and is particularly good for welding. Given these properties, NAS 36LG is used in liquefied natural gas ships, membrane material for land container tanks, and a variety of container and piping materials for handling extremely low-temperature fluids. Nippon Yakin supplies this product in coil and sheet forms.
Coil
Sheet
Chemical Composition
| C | Si | Mn | P | S | Ni | Fe | |
|---|---|---|---|---|---|---|---|
| Min | ― | ― | 0.2 | ― | ― | 35 | Balance |
| Max | 0.04 | 0.25 | 0.4 | 0.008 | 0.0015 | 36.5 |
Length change of NAS 36LG at low temperature
Physical Properties
| Specific heat (J/kg･K) | -196–20℃ | 92 |
| Specific resistivity (μΩ･cm) | at 20℃ | 78 |
| Thermal conductivity (W/m･K) | at 20℃ | 10.5 |
| at 50℃ | 5.4 | |
| Coefficient of thermal expansion (×10-6/℃) | -180–0℃ | 1.5±0.5 |
| Young's modulus (MPa) | 145,000 | |
| Curie point (℃) | 240–260 | |
Mechanical Properties
| 0.2% proof stress (N/mm2) |
Tensile strength (N/mm2) |
Elongation (%) |
|---|---|---|
| ≥ 275 | ≥ 460 | ≥ 30 |
Coefficient of thermal expansion
With a coefficient of thermal expansion about one-tenth of 18-8 stainless steel at room temperature, NAS 36LG undergoes little thermal deformation even when subjected to temperature changes.
Low-temperature ductility
Because of its austenitic structure, the impact value does not vary, ensuring adequate ductility at room temperature and even extremely low temperatures.