Alloy Geek 347 Stabilized Austenitic Stainless Steel Standard
Alloy 347, also known as UNS S34700, is a stabilized austenitic stainless steel alloy. It's specifically designed to offer improved high-temperature corrosion resistance compared to standard austenitic stainless steels. Alloy 347 contains niobium (columbium) which helps to stabilize the alloy against sensitization and intergranular corrosion, making it suitable for applications in high-temperature environments.
The composition of Alloy 347 typically includes:
- Chromium (Cr): Around 17.0-20.0%
- Nickel (Ni): Around 9.0-13.0%
- Niobium (Columbium, Cb): Around 10x(C%) - 1.0%
- Manganese (Mn): Around 2.0% max
- Silicon (Si): Around 0.75% max
- Carbon (C): Around 0.08% max
- Phosphorus (P): Around 0.045% max
- Sulfur (S): Around 0.030% max
- Iron (Fe): Remaining balance
Key features and characteristics of Alloy 347:
High-Temperature Corrosion Resistance: Alloy 347 offers improved resistance to sensitization and intergranular corrosion at elevated temperatures, making it suitable for applications involving exposure to high temperatures and corrosive environments.
Stabilization: The addition of niobium provides stabilization against sensitization and subsequent intergranular corrosion. This allows the alloy to maintain its corrosion resistance even after exposure to high temperatures.
Applications: Alloy 347 is commonly used in applications where exposure to high temperatures and corrosive environments is expected. It's used in industries such as chemical, petrochemical, and power generation. Common applications include exhaust systems, boiler tubes, and high-temperature equipment.
Weldability: The alloy has good weldability and can be used in welded components. Post-weld heat treatment might be necessary to restore corrosion resistance in the heat-affected zone.
Formability: Alloy 347 can be formed and fabricated using standard methods.
Magnetic Properties: Alloy 347 is generally non-magnetic in the annealed condition.
Forms: Alloy 347 is available in various forms, including sheets, plates, bars, and pipes.
Due to its resistance to sensitization and intergranular corrosion, Alloy 347 is often chosen for applications that involve exposure to high temperatures and corrosive environments. If you're considering using Alloy 347 for a specific project, consulting with materials experts or manufacturers is recommended to ensure it meets your desired performance requirements, especially in terms of high-temperature corrosion resistance, weldability, and compatibility with the specific conditions of your application.
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