Advantages of Fe-Cr-Al electric heating alloy wire
1. High operating temperature in atmospheric environment
Among Fe-Cr-Al electrothermal alloys, Cr27Al7Mo2 can reach a maximum working temperature of 1400℃, while Cr20Ni80 nickel-chromium alloy only tops 1200℃.
2. Long service life
Under the same high temperature conditions in air, the service life of Fe-Cr-Al heating elements is 2 to 4 times that of nickel-chromium ones.
3. High surface load
Thanks to its higher allowable temperature and longer lifespan, it supports higher surface load. It heats up faster and saves alloy raw materials.
4. Excellent oxidation resistance
A dense, well-adhered alumina (\ce{Al2O3}) oxide film forms on its surface, which is not easy to peel off and cause contamination. With high resistivity and melting point, the film delivers superior anti-oxidation performance. It also has better carburization resistance than the chromium oxide (\ce{Cr2O3}) film on nickel-chromium alloys.
5. Low specific gravity
Fe-Cr-Al alloy has lower density than nickel-chromium alloy, which reduces material consumption for making identical heating components.
6. High electrical resistivity
Its higher resistivity allows adopting larger-size alloy materials in design, effectively extending service life, especially for fine wires. With the same wire specification, higher resistivity cuts material usage and saves installation space in furnaces. Besides, its resistivity is less affected by cold working and heat treatment compared with nickel-chromium alloy.
7. Good sulfur resistance
It features strong corrosion resistance in sulfur-containing atmospheres and against sulfur contaminants, whereas nickel-chromium alloys suffer severe corrosion in such environments.
8. Cost-effective
Free from scarce nickel element, Fe-Cr-Al alloy is much cheaper than nickel-chromium alloy.
Disadvantages of Fe-Cr-Al electric heating alloy wire
It has low high-temperature strength and increases in plasticity as temperature rises. Above 1000℃, it tends to elongate and deform gradually under its own weight. After long-term high-temperature service and furnace cooling, grain growth makes it brittle, so it cannot be bent at room temperature. These drawbacks need to be avoided and overcome in design and practical application.
Grade ：1Cr13AL4 0Cr21AL6 0Cr25AL5 0Cr21AL6Nb 0Cr27AL7Mo2