Applications:
Although Alloy 409 is designed principally for the automotive exhaust industry, it has been successfully used in other industrial applications as well. Some examples of applications that call for Alloy 409 include:
- Automotive exhaust systems
- Catalytic converters
- Mufflers
- Tailpipes
- Farm equipment
- Structural support and hangers
- Transformer cases
- Furnace components
- Heat exchanger tubing
Standards:
- ASTM/ASME: UNS S40900
- EURONORM: FeMi35Cr20Cu4Mo2
- DIN: 2.4660
Corrosion Resistance:
- Resists atmospheric and exhaust gas corrosion
- In most atmospheres a light surface rust will form which inhibits further corrosion but makes the surface less appealing
 Heat Resistance
- Generally classified as resistant to scaling in intermittent service up to 1499oF (815oC ) and up to 1247oF (675oC) in continuous service
Weldability
- Readily weldable
- Pre-heat of 302 to 500oF (150 to 260oC) is recommended
- Post-weld annealing at 1400 to 1499oF improved weld ductility
- Post-weld annealing is not required when welding thin sections
- Automotive exhaust tubing is typically welded without filler metal