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
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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:

  1. 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%

  1. 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

  1. 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:

  1. Electric Resistance Heating:

   – Industrial furnace elements (sintering, annealing)

   – Heat treatment equipment components

   – Kiln heating systems for ceramics/glass

  1. 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:

  1. Initial Conditioning:

   – Pre-oxidize at 1000°C for 1-2 hours to establish protective scale

  1. Operational Best Practices:

   – Avoid temperature fluctuations >200°C/min

   – Maintain oxidizing atmosphere (O₂ > 1%)

  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.