Nickel (Ni)is the main chemical element of chromel. Its weight percent is not less than 87%. Besides Ni, the material contains 0.6-1.2% of cobalt (Co) and 9.0-10.0% of chromium (Cr). The admixture content that includes arsenic (As), carbon (C), iron (Fe), phosphorus (P), lead (Pb), sulphur (S) and some other substances is 1.4%. Chromel grade - NiCr 9,5.
Properties
Chromel belongs to thermocouple materials. They are very highly demanded in the process of producing instruments. This alloy has several qualities required for fulfilling applied tasks: high TEMF, good mechanical properties, corrosive stability in various active media.
Physical properties
Property
Value
Melting temperature, °С
1430
Density, kg/m3
8730
Specific resistance, Ohm·m·108
68±5
Average temperature coefficient of resistance (20-100 °С), °С-1·104
4,1
Average thermal expansion coefficient (20-100 °С), °С-1·106
13,1
Magnetic behavior
Парамагнитен
Curie point, °С
-120
Chromel has some physical properties that depend on material temperature.
Temperature-dependant properties
Property
T, °С
20
200
400
600
800
1000
1200
Specific resistance, Ohm·m·10-8
68
74
81
85
88
93
97
Ratio of resistance under t to resistance under 20 °С
1,00
1,09
1,19
1,25
1,30
1,37
1,43
Average thermal expansion coefficient (20-t °С), °С-1·10-6
-
13,3
13,7
14,7
15,7
16,7
17,7
Specific heat, kJ/(kg·К)
0,428
0,460
0,495
0,531
0,567
0,602
0,638
Heat conductivity, W/(m·К)
17,6
21,8
26,4
30,6
34,3
37,7
-
Alloy mechanical properties
Property
Value
Ultimate tensile strength, MPa
620-720
Yield point, MPa
210-240
Percentage of elongation, %
24-34
Reduction in area, %
67-77
Brinell hardness
140-150
Applications
Chromel is a nickel alloy for producing thermocouple wires and compensating leads. It is used in CA (chromel-alumel), and CK (chromel-copel) thermocouples as an anode material and extension set for it.
Calculate the weight of products made of thermocouple alloys
