COEFFICIENT OF LINEAR THERMAL EXPANSION OF IRON AND IRON ALLOYS


Linear thermal expansion coefficients of various iron alloys are given in the following chart.

Linear Thermal Expansion Coefficient Values of Iron and Iron Alloys
Material Temp.  Coefficient of Thermal Expansion (CTE)
10-6 (°C)-1 10-6 (°F)-1
Pure Iron 20°C / 68°F 11.7 6.5
Fe-C alloys
0.06% C 20-100°C / 68-212°F 11.7 6.5
0.22% C 11.7 6.5
0.40% C 11.3 6.3
0.56% C 11.0 6.1
1.08% C 10.8 6.0
1.45% C 10.1 5.6
Invar (36% Ni) 20°C / 68°F 2.0 1.1
13Mn - 1.2C 18.0 10.0
13Cr - 0.35C 20-100°C / 68-212°F 10.0 5.6
17.7Cr - 9.6Ni - 0.06C 16.5 9.2
18W - 4Cr - 1V 0-100°C / 32-212°F 11.2 6.2
Gray cast iron 10.5 5.8
Malleable iron (pearlitic) 20-400°C / 68-752°F 12 6.7

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