Project Description
Low Expansion Alloy
Nb-Invar
Nb-Invar has a certain coefficient of linear thermal expansion in the range of 20-100 degrees Celsius. It mainly produces various instruments and instrument parts requiring stable size, or thermal bimetallic passive layer.
Chemical Composition, %
| Alloy | C | Mn | Si | P | S | Ni | Cu | Co | Fe |
| 4J32 | ≤0.05 | 0.2-0.6 | ≤0.2 | ≤0.02 | ≤0.02 | 31.5-33.0 | 0.4-0.8 | 3.2-4.2 | Rest |
| 4J36 | ≤0.05 | 0.2-0.6 | ≤0.3 | ≤0.02 | ≤0.02 | 35-37 | – | – | Rest |
| Nb-Invar | ≤0.05 | ≤0.6 | ≤0.3 | ≤0.02 | ≤0.02 | 30-35 | Nb≤0.5 | 3-5 | Rest |
Average Linear Expansion Coefficient
| Alloy | Heat treatment for sample | Average linear expansion coefficient a/10-6.K-1 | ||
| 20~100℃ | -40~20℃ | -20~20℃ | ||
| 4J32 | Heating to temperature between 840℃±10℃ in a protective or vacuum atmosphere. Holding for 1hour then water cooling. Machining the sample to the finial dimensions, reheating them to 315℃±10℃ holding for 1 hour, then furnace/air cooling | ≤1.0 | ||
| 4J36 | ≤1.5 | |||
| Nb-Invar | ≤0.5 | ≤0.6 | ≤0.5 | |
Available Products and Specifications
| Rod, Bar, Wire and Forgings | YB/T5241-2014, Q/SYY 7-1999, ГОСТ 10994-1974, ГОСТ 14080-78 |
| Plate, Sheet and Strip | YB/T5241-2014, Q/SYY 7-1999, ГОСТ 10994-1974, ГОСТ 14080-78 |
| Pipe and Tube | YB/T5241-2014, Q/SYY 7-1999, ГОСТ 10994-1974, ГОСТ 14080-78 |
| Welding Product | – |
| Others | YB/T5241-2014, Q/SYY 7-1999, ГОСТ 10994-1974, ГОСТ 14080-78 |
Features
Fairly low linear expansion coefficient at the temperature between -60℃ and 100℃.
Applications
They are usually applied for making dimension stable components in various instruments.
