Excellence & expertise in manufacturing stainless steel wires & bars since 1990
Stainless Steel - Grade 409 / 1.4512
Description
Stainless Steel Grade 409/1.4512 is a ferritic stainless steel that is primarily used in automotive exhaust systems and other applications requiring good resistance to oxidation and corrosion at elevated temperatures. It offers a combination of durability and resistance to various environmental factors, making it a suitable choice for demanding applications. This grade is characterized by its high chromium content, which enhances its resistance to oxidation, while its low carbon content ensures excellent weldability.
Chemical Composition
- Chromium (Cr): 10.5 - 11.75%
- Nickel (Ni): ≤ 0.75%
- Silicon (Si):≤ 0.75%
- Manganese (Mn): 0.5 - 1.0%
- Carbon (C): ≤ 0.08%
- Phosphorus (P): ≤ 0.04%
- Sulfur (S): ≤ 0.03%
- Iron (Fe): Balance
Mechanical Properties
- Tensile Strength: 450 - 600 MPa (65 - 87 ksi)
- Yield Strength: 275 MPa (40 ksi)
- Elongation: 20% (min)
- Hardness: Typically around 200 HV (Vickers Hardness)
Thermal & Physical Properties
- Density: 7.75 g/cm³ (0.28 lb/in³)
- Melting Point: Approx. 1480°C (2700°F)
- Thermal Conductivity: 24.0 W/m•K (167 BTU•in/hr•ft²•°F)
- Specific Heat Capacity: 500 J/kg•K (0.12 BTU/lb•°F)
- Coefficient of Thermal Expansion: 11.0 × 10⁻⁶/K (6.1 × 10⁻⁶/°F)
Other Designations
- UNS:S40900
- JIS: SUS 409
- AISI: 409
Fabrication and Heat Treatment
- Welding: Grade 409 can be welded using conventional welding methods such as MIG, TIG, and resistance welding. Preheating is generally not required, but post-weld heat treatment may be performed to relieve stresses and reduce hardness.
- Machining: This grade can be machined using standard tools. Due to its toughness, cutting speeds may need to be adjusted accordingly.
- Heat Treatment: Generally, Grade 409 is not heat-treated in most applications. It is used in the as-rolled or annealed condition. If heat treatment is required, it typically involves heating to 800 - 850°C (1470 - 1560°F) followed by cooling in air.
Applications
- Automotive Exhaust Systems: Commonly used in mufflers, catalytic converters, and exhaust manifolds due to its resistance to high temperatures and oxidation.
- Industrial Equipments: Used in various components exposed to high temperatures and corrosive environments.
- Architectural Applications: Occasionally used in decorative and structural elements where a combination of strength and resistance to weathering is required.
Supplied Forms
- Bars:
- Coils
Features
- Oxidation Resistance: Offers good resistance to oxidation and scaling at elevated temperatures.
- Corrosion Resistance: Provides moderate resistance to corrosion in mildly corrosive environments.
- High Strength: Ensures durability and performance under stress and high-temperature conditions.
- Cost-Effectiveness: More affordable compared to higher nickel-containing stainless steels, making it a cost-effective choice for many applications.
- Weldability: Good weldability, suitable for various fabrication processes.