Project Description

Low Expansion Alloy

Invar

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.

Equivalent Grades

GBГОСТASTMUNSDINW.Nr.NFBSJISSS
4J3636НInvar
Unipsan 36
K93600Vacodil 36
Ni36
1.3912Nilo 36Cactus LE

Chemical Composition, %

AlloyCMnSiPSNiCuCoFe
4J32≤0.050.2-0.6≤0.2≤0.02≤0.0231.5-33.00.4-0.83.2-4.2Rest
4J36≤0.050.2-0.6≤0.3≤0.02≤0.0235-37Rest
Nb-Invar≤0.05≤0.6≤0.3≤0.02≤0.0230-35Nb≤0.53-5Rest

Average Linear Expansion Coefficient

AlloyHeat treatment for sampleAverage linear expansion coefficient a/10-6.K-1
20~100℃-40~20℃-20~20℃
4J32Heating 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 ForgingsYB/T5241-2014, Q/SYY 7-1999, ГОСТ 10994-1974, ГОСТ 14080-78
Plate, Sheet and StripYB/T5241-2014, Q/SYY 7-1999, ГОСТ 10994-1974, ГОСТ 14080-78
Pipe and TubeYB/T5241-2014, Q/SYY 7-1999, ГОСТ 10994-1974, ГОСТ 14080-78
Welding Product
OthersYB/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.