There are four types of Metal Heating Elements called "PYROMAX":
three types of Fe-Cr-Al alloys series and one type of Ni-Cr alloy series.They can be used in high temperature ranges.
Of these, PX-C is our own proprietary material, and has high anti-oxidization properties thanks to its high aluminum content. The PX-PM-D material also has excellent resistance to high-temperature deformation and oxidation for sintering processes, and has received high acclaim both domestically and internationally.
PX-C
PYROMAX-C is a high-grade electric heating material with a high concentration of Al and Cr. PYROMAX-C has an electric resistance of 1.60μΩ-m and a maximum service temperature of 1,400℃. This material is very economical since it has a longer service life than other materials even in a carburizing atmosphere such as RX and DX and in a various of atmospheres such as N₂. With its high resistance, PYROMAX-C is also used as a resistant material.
PX-DS
PYROMAX-DS is an alloy with an electric resistance of 1.45 μΩ-m. It is made with high-grade heating materials that feature the same maximum service temperature of 1,400℃ as PX-C. The alloy features superior oxidation resistance under a normal atmosphere and it is suitable for high-temperature industrial furnaces and electric heating equipment as well as domestic electric heating appliances with fine wires. The alloy may also be used as heat-resistant structural materials or resistant materials for the electronics industry.
PX-PM-D
PYROMAX-PM-D is a metallic heating material that features a maximum service temperature of 1,420℃. The heating material is manufactured by making full use of powder metallurgical and various processing technologies. The material features high deformation resistance in high temperatures and oxidation resistance, which had been impossible in traditional molten metal heating materials.
Features
・Superior deformation resistance in high-temperature settings
Almost free from sagging and deformation in high temperatures (1,100℃ up to 1,420℃).
・Superior oxidation resistance
Strong alumina film is formed on the heating elements’ surface, resulting in long sustained service life.
・Superior workability
Has superior mechanical properties, ensuring easy formation and machining.
・Easy heating element design and work
When determining the shape of molten alloy heating elements, material deformation is usually taken into account.
However, PYROMAX-PM-D is almost free from deformation even after long use.
This feature along with superior welding performance makes PYROMAX-PM-D easy to design and process.
Applications
PYROMAX-PM-D may be used for high-temperature furnaces, diffusion furnaces, and ceramic sintering furnaces with heating element temperatures up to 1,420℃. The material may also be used as a structural material in high temperatures. The brackets for supporting PYROMAX-PM-D heating wires are also available upon request. Please consider using them.
Reference） Deformation resistance graph at high temperature
PX-N1
PYROMAX-N1 is a heating material that falls under the category of JIS NCH-1 and features high strength in high temperatures, and easy cold processing and welding. Furthermore, this material will not become brittle even after use in high temperatures. This material is applicable in many industrial furnaces and may be used as an electric-resistant material.
| Fe-Cr-Ar Heating Elements | Ni-Cr Heating Elements |
|||
| PX-C | PX-DS | PX-PM-D | PX-N1 | |
| Standard chemical components （％） |
Al 7.5 Cr 26 Fe remainder |
Al 6.0 Cr 23 Fe remainder |
Al 6.0 Cr 23 Fe remainder Other elements in small q'ty |
Cr 19 ～ 21 Fe 1 or less Ni 77 or more |
|---|---|---|---|---|
| Specific gravity | 7.00 | 7.10 | 7.10 | 8.40 |
| Thermal expansion factor 20℃～1000℃ （℃ -1） |
17×10-6 | 15.1×10-6 | 14.8×10-6 | 17.6×10-6 |
| Melting point（℃） | 1,490 | 1,500 | 1,500 | 1,400 |
| Electric resistivity 20℃ （μΩ･m） |
1.60±5% | 1.45±5% | 1.45±5% | 1.08±5% |
| Max. service temp. （Heating element） （℃） |
1,400 | 1,400 | 1,420 | 1,100 |
| Increase by oxidation 1,200℃ （mg/cm2・h） |
0.005 | 0.005 | 0.005 | 0.25 or less |
| Tensile strength Mpa （kgf/mm2） |
700 ～ 1,000 （70 ～ 100） |
650 ～ 900 （65 ～ 90） |
650 ～ 900 （65 ～ 90） |
700 ～ 900 （70 ～ 90） |
| Elongation（%） | 10～25 | 15～25 | 15～ 25 | 20 or more |
| Vickers hardness （HV） |
250 ～270 | 220 ～240 | 220 ～240 | 150 ～190 |
| Service life index （Cycle） |
Ⓤ 300 or more | Ⓤ 300 or more | Ⓤ 300 or more | Ⓘ 300 or more |
Note）
●Service life span Ⓤ JIS C2524 U Standard 1,300℃
Ⓘ JIS C2524 I Standard 1,200℃ (comparative value)
●Mechanical properties shown above are values for round wire with standard dimensions of 1～5mmΦ.