FeCrAl (0Cr23Al5)
Key Features:
- Superior oxidation resistance compared to NiCr alloys at temperatures above 1000°C
- Longer service life in air atmospheres than standard 20Cr-5Al alloys
- Cost-effective alternative to expensive brands like Kanthal D, Kanthal AF
- Stable resistance characteristics over extended service periods
About FeCrAl (0Cr23Al5)
The FeCrAl (0Cr23Al5) is a high-performance iron-chromium-aluminum alloy widely used in electric heating applications due to its excellent oxidation resistance and cost-effectiveness. As a mid-range composition in the FeCrAl alloy family, it balances performance and affordability for industrial heating applications.
FeCrAl (0Cr23Al5) Key Characteristics:
- Composition (wt%):
– Cr: 23% (provides oxidation and corrosion resistance)
– Al: 5% (forms protective Al₂O₃ scale)
– Fe: Balance (~72%)
– Trace elements: C ≤ 0.08%, Si ≤ 1%, Mn ≤ 0.7%
- Operating Temperatures:
– Continuous use: Up to 1300°C (2372°F)
– Intermittent use: Up to 1350°C (2462°F)
– Rapid cooling below 800°C should be avoided to prevent cracking
- Physical Properties:
– Density: 7.25 g/cm³
– Resistivity: 1.40 μΩ·m at 20°C
– Thermal expansion: 15.0 × 10⁻⁶/K (20-1000°C)
– Thermal conductivity: 15 W/(m·K) at 800°C
Performance Advantages:
– Superior oxidation resistance compared to NiCr alloys at temperatures above 1000°C
– Longer service life in air atmospheres than standard 20Cr-5Al alloys
– Cost-effective alternative to expensive brands like Kanthal D, Kanthal AF.
– Stable resistance characteristics over extended service periods
Comparative Analysis with other FeCrAl Alloys:
Alloy Grade | Cr % | Al % | Nb % | Max Temp (°C) | Key Advantage | Price |
0Cr23Al5 | 23% | 5% | — | 1300°C | Standard industrial grade | $8/kg-$20/kg |
0Cr25Al5 | 25% | 5% | – | 1300°C | Higher Cr for corrosion resistance | $8/kg-$20/kg |
0Cr21Al6Nb | 21% | 6% | 0.5-1% | 1350°C | Best oxidation + creep resistance | $18/kg-$28/kg |
HJ209(Kanthal A-1 Substitute) | 22% | 5.8% | – | 1400°C | Premium industrial grade | $20/kg-$30/kg |
HJ407(Kanthal APM Substitute) | 21% | 5% | 0.02% Ce | 1425°C | Rare-earth enhanced | $28/kg-$50/kg |
FeCrAl (0Cr23Al5) Industrial Applications:
- Electric Resistance Heating:
– Industrial furnace elements (sintering, annealing)
– Heat treatment equipment components
– Kiln heating systems for ceramics/glass
- Specialty Applications:
– High-temperature thermocouple sheaths
– Radiation shields in heat treatment furnaces
– Heating elements for laboratory equipment
Manufacturing Considerations:
– Cold working: Requires intermediate annealing at 750-850°C for severe deformation
– Hot working: Optimal between 900-1150°C
– Welding: Recommended methods:
– TIG welding with Ar shielding
– Laser welding for precision joints
– Post-weld annealing at 800°C recommended
Maintenance Guidelines:
- Initial Conditioning:
– Pre-oxidize at 1000°C for 1-2 hours to establish protective scale
- Operational Best Practices:
– Avoid temperature fluctuations >200°C/min
– Maintain oxidizing atmosphere (O₂ > 1%)
- Failure Analysis:
– Common failure modes:
Sulfur attack in reducing atmospheres
Thermal fatigue from rapid cycling
Mechanical failure from improper support
Technical Recommendation:
0Cr23Al5 represents an optimal balance for industrial heating applications requiring:
– Long-term operation at 1100-1300°C
– Cost-conscious material selection
– Reliable performance in oxidizing atmospheres
For applications exceeding 1300°C or requiring exceptional cyclic performance, consider Nb-modified or rare-earth doped alternatives.