invar 36 is a Nickel-Iron, low expansion alloy containing 36% Nickel,has a low coefficient of expansion

Note:
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°C. Nilo 36 also retains good strength and toughness at cryogenic temperatures. Applications include standards of length, thermostat rods, laser components and tanks and piping for the storage and transportation of liquefied gasses.

Relative Grade:

Grade & Chemical Composition (see Table 1)
Table 1 Grade & Chemical Composition

Grade

Chemical Composition (%)

C

Si

P

S

Cu

Se

Mn

Ni

Co

Fe

≤

4J32

0.05

0.20

0.020

0.020

0.400.80

0.200.60

31.533.0

3.204.20

Balance

4J36

0.05

0.30

0.020

0.020

0.200.60

35.037.0

Balance

4J38

0.05

0.20

0.020

0.020

-

0.100.25

0.80

35.037.0

-

Balance

4J40

0.05

0.15

0.020

0.020

-

-

≤0.25

32.433.4

7.008.00

Balance

Notes:
1Under condition that the average coefficient of the linear expansion meets the requirements of the standard, the content of nickel and cobalt are allowed to deviate from the stated range.
2The shape and dimensions of the alloys are in compliance with GB/T14985.

Physical Property (see Table 2 Table 3)
Table 2 Coefficient of Linear Expansion

Grade

Heat Treatment of the Samples

Mean Coefficient of Linear Expansion

20l00

20300°C

4J32

To heat the semi-finished products samples to 840±10°C, hold for 1hour, and quench in the water. Machine the samples to finished samples. And heat at 315±10 for 1h, furnace or air cool.

≤1.0

4J36

≤1.5

4J38

4J40

≤2.0

Table 3 Typical Expansion Coefficient

Grade

Mean Coefficient of Linear Expansion

20~50

20100

20200

20300

20400

20500

4J32

0.7

0.8

1.4

4.3

7.2

9.3

4J36

0.6

0.8

2.0

5.1

8.0

10.0

4J40

1.4

1.3

1.2

1.7

4.5

Note: The data in the tables are just for reference.