Chemical composition and properties of FeCrAl alloys:
The chemical composition in w-% of different FeCrAl alloys are shown in the table below;
The scaling temperature is that temperature where the protecting oxide starts to crack and fall of with a high rate.
Download our brochure for more information
Trade Mark
% Cr
% Al
Other additions
Scaling temp in air, at constant temperature, degrees C (F)
Kanthal APM
22
5.8
1425(2600F)
Kanthal APMT
21
5.0
Mo 3.0
1425(2600F)
Kanthal A-1
22
5.8
1400(2550F)
Kanthal AF
22
5.3
Y
1300(2370F)
Kanthal D
22
4.8
1300(1300F)
Alkrothal
15
4.3
1100(2010F)
The high aluminum content, in combination with the high chromium content causes the scaling temperature to increase up to 1425 C (2600F ); Under the headline heat resistance, these FeCrAl alloys are compared with commonly used Fe and Ni base alloys. As can be seen from that table, the FeCrAl alloys have superior properties as compared to the other alloys in most environments.
It should be noted that, during alternating temperature conditions, the yttrium addition to the AF alloy which also is known as the Fecralloys alloys, improves the adherence of the protecting oxide, making the service life of components in the AF alloy longer than that of the A-1 grade.
Kanthal APM and APMT ferritic super alloys!
Kanthal APM and APMT are manufactured by powder metallurgy, which increases the high temperature strength quite substantially. Kanthal APM can therefore be used also in applications where a high temperature strength (creep strength) is of importance. Thus, Kanthal APM is a ferritic super alloy. Kanthal APMT is a further development of Kanthal APM, having an even higher creep strength.
Product forms and availability
The FeCrAl alloys are available as wire, strip, welded and seamless tubes; All these product forms are available from stock for fast deliveries.
Properties of FeCrAl alloys
FeCrAl alloys i.e. Ferretic
stainless steel with aluminium
Kanthal
AF, Fecralloy
Kanthal
A-1
Kanthal
APM
Kanthal
APMT
Kanthal
D
Scaling temperature temperature in air °C (°F)
1300 (2372)
1400 (2552)
1425 (2597)
1425 (2597)
1300 (2372)
Max continuous operating temperature in air °C (°F)
1300 (2372)
1400 (2552)
1250 (2282)
1250 (2282)
1300 (2372)
Nominal chemical composition, %
Cr
22
22
22
21
22
Al
5.3
5.8
5.8
5.0
4.8
Y
Addition
-
-
-
-
Fe
Balance
Balance
Balance
Balance
Balance
Mo
-
-
-
3.0
-
Density, g/cm3 (lb/in3)
7.15 (0.259)
7.10 (0.256)
7.10 (0.256)
7.25 (0.262)
7.25 (0.262)
Electrical resistivity at 20°C Ω mm2/m
1.39
1.45
1.45
1.40
1.35
Temperature factor of the resistivity, Ct
600°C (1112°F)
1.04
1.02
1.02
1.02
1.04
800°C (1472°F)
1.05
1.03
1.03
1.02
1.06
1000°C (1832°F)
1.06
1.04
1.04
1.03
1.07
1200°C (2192°F)
1.06
1.04
1.04
1.03
1.08
Coefficiency of thermal expansion, x 10-6/K
20-250°C (68-482°F)
11
11
11
12.4
11
20-500°C (68-932°F)
12
12
12
13.1
12
20-750°C (68-1382°F)
14
14
14
13.6
14
20-1000°C (68-1832°F)
15
15
15
14.7
15
20-1200°C (68-2192°F)
-
-
16
15.4
-
20-1400°C (68-2552°F)
-
-
16
-
-
Thermal conductivity, W m-1K-1
20°C (68°F)
11
-
-
-
-
50°C (122°F)
-
11
11
11
11
600°C (1112°F)
20
20
20
21
20
800°C (1472°F)
22
22
22
23
22
1000°C (1832°F)
26
26
26
27
26
1200°C (2192°F)
27
27
27
29
27
1400°C (2552°F)
-
35
35
-
-
Specific heat capacity,
kJ kg-1K-1
20°C (68°F)
0.46
0.46
0.46
0.48
0.46
200°C (392°F)
0.56
0.56
0.56
0.56
0.56
400°C (752°F)
0.63
0.63
0.63
0.64
0.63
600°C (1112°F)
0.75
0.75
0.75
0.71
0.75
800°C (1472°F)
0.71
0.71
0.71
0.67
0.71
1000°C (1832°F)
0.72
0.72
0.72
0.69
0.72
1200°C (2192°F)
0.74
0.74
0.74
0.70
0.74
1400°C (2552°F)
-
0.80
0.80
-
-
Melting point, °C (°F)
1500 (2732)
1500 (2732)
1500 (2732)
1500 (2732)
1500 (2732)
Mechanical properties
Tensil strength, MPa
650
670
670
742
630
Yield point, MPa
470
460
450
540
470
Hardness, Hv
230
225
225
250
220
Elongation, %
20
22
27
26
21
Creep strength - 1% elongation in 1000h, MPa
800°C (1472°F)
-
1.2
-
21.9
1.2
900°C (1652°F)
-
-
5.9
15.6
-
1000°C (1832°F)
-
0.5
2.0
10.9
0.5
1100°C (2012°F)
0.7
-
0.7
5.0
-
1200°C (2192°F)
0.3
-
0.3
2.1
-
Magnetic properties
(Currie point)
The material is magnetic up to approximately 600°C (1112°F)
The material is magnetic up to approximately 600°C (1112°F)
The material is magnetic up to approximately 600°C (1112°F)
The material is magnetic up to approximately 600°C (1112°F)
The material is magnetic up to approximately 600°C (1112°F)
Emissivity - fully oxidized material
0.70
0.70
0.70
0.70
0.70