Kanthal® APM is an advanced powder-metallurgical, dispersion-strengthened, ferritic iron-chromium-aluminium alloy (FeCrAl alloy) for use at temperatures up to 1425°C (2600°F). The alloy is characterized by exceptionally good form stability and oxidation resistance.
Kanthal® APM has low tendency to ageing and low resistance change. It has excellent surface oxide properties, which gives good protection in corrosive atmospheres as well as in atmospheres with high carbon potential, and no scaling.
The unique combination of excellent oxidation properties and form stability contributes to long element service life. The alloy's superior form stability reduces the amount of element support.
Typical applications for Kanthal® APM are electrical heating elements in industrial furnaces.
Chemical composition
|
C % |
Si % |
Mn % |
Cr % |
Al % |
Fe % |
| Nominal composition |
|
|
|
|
5.8 |
Bal. |
| Min |
- |
- |
- |
20.5 |
- |
|
| Max |
0.08 |
0.7 |
0.4 |
23.5 |
- |
|
Mechanical properties
| Thickness |
Yield strength |
Tensile strength |
Elongation |
Hardness |
|
Rp0.2 |
Rm |
A |
Hv |
| mm |
MPa |
MPa |
% |
|
| 1.0 |
470 |
680 |
20 |
230 |
Mechanical properties at elevated temperature
| Temperature °C |
900 |
1000 |
1100 |
1200 |
1300 |
| MPa |
40 |
23 |
16 |
12 |
9 |
Ultimate tensile strength - deformation rate 6.2 x 10-2 min-1
Creep strength - 1% elongation in 1000 h
| Temperature °C |
800 |
900 |
| MPa |
8.2 |
3.5 |
Creep strength - 0.1% elongation in 1000 h
| Temperature °C |
1100 |
1200 |
1300 |
1400 |
| MPa |
2.3 |
1.2 |
0.7 |
0.4 |
Creep rupture strength
| Time |
800°C
|
1472°F |
1000°C
|
1832°F |
1200°C
|
2192°F |
1400°C
|
2552°F |
| h |
MPa |
psi |
MPa |
psi |
MPa |
psi |
MPa |
psi |
| 100 |
15.0 |
2176 |
5.6 |
812 |
3.3 |
478 |
1.3 |
189 |
| 1000 |
11.3 |
1640 |
3.4 |
478 |
1.6 |
232 |
0.5 |
72 |
| 10000 |
8.2 |
1190 |
2.2 |
320 |
0.7 |
100 |
0.2 |
30 |
The data in the tables apply to material with fine grain structure in the temperature range from 800°C to 900°C and to material with coarse grain structure in the temperature range from 1100°C to 1400°C.
Physical properties
| Density g/cm3 |
7.10 |
| Electrical resistivity at 20°C Ω mm2/m |
1.45 |
| Poisson's ratio |
0.30 |
Young's modulus
| Temperature °C |
20 |
100 |
200 |
400 |
600 |
800 |
1000 |
| GPa |
220 |
210 |
205 |
190 |
170 |
150 |
130 |
Temperature factor of resistivity
| Temp. °C |
100 |
200 |
300 |
400 |
500 |
600 |
700 |
800 |
900 |
1000 |
1100 |
1200 |
1300 |
1400 |
| Ct |
1.00 |
1.00 |
1.00 |
1.00 |
1.01 |
1.02 |
1.02 |
1.03 |
1.03 |
1.04 |
1.04 |
1.04 |
1.04 |
1.05 |
Coefficient of thermal expansion
| Temperature °C |
Thermal Expansion x 10-6/ K |
| 20 - 250 |
11 |
| 20 - 500 |
12 |
| 20 - 750 |
14 |
| 20 - 1000 |
15 |
| 20 - 1200 |
16 |
| 20 - 1400 |
16 |
Thermal Conductivity
| Temperature °C |
50 |
600 |
800 |
1000 |
1200 |
1400 |
| W m-1 K-1 |
11 |
20 |
22 |
26 |
27 |
35 |
Specific heat capacity
| Temperature °C |
20 |
200 |
400 |
600 |
800 |
1000 |
1200 |
1400 |
| kJ kg-1 K-1 |
0.46 |
0.56 |
0.63 |
0.75 |
0.71 |
0.72 |
0.74 |
0.80 |
| Melting point °C |
1500 |
| Max continuous operating temperature in air °C |
1425 |
| Magnetic properties |
The material is magnetic up to approximately 600°C (Curie point). |
| Emissivity - fully oxidized material |
0.70 |
