309S/309 stainless steel round bar

Overview of Alloys 309 and 309S

Alloys 309 and 309S are austenitic chromium-nickel stainless steels specifically designed for high-temperature applications. Thanks to their elevated chromium and nickel content, these alloys exhibit excellent corrosion resistance, outstanding oxidation resistance, and superior heat resistance. They also provide good strength at both room and elevated temperatures. The primary distinction between 309 and 309S lies in their carbon content; Alloy 309S features a lower carbon composition, which helps minimize carbide precipitation and enhances weldability.

Applications of 309 and 309S Stainless Steel Round Bars

These alloys are particularly valued for their high-temperature oxidation resistance and strength. Common applications include:

• Heating elements
• Aircraft and jet engine parts
• Heat exchangers
• Carburizing annealing products
• Sulfite liquor handling equipment
• Kiln liners
• Boiler baffles
• Refinery and chemical processing equipment
• Auto exhaust parts

In terms of product offerings, both 309 stainless steel black round bar and 309S stainless steel black round bar are available, providing excellent options for various industrial needs.

Corrosion Resistance and High-Temperature Performance

Both alloys deliver remarkable corrosion resistance, outperforming Alloy 304 in marine environments. They are ideal for higher temperature applications, leveraging their oxidation resistance. Notably, they exhibit good scaling resistance under continuous and intermittent service, with a destructive scaling temperature of approximately 2000°F (1093°C).

High-Temperature Operating Conditions

• Oxidizing Conditions (max. sulfur content–2 g/m³):

  • Continuous service: 1922°F (1050°C)
  • Peak temperature: 2012°F (1100°C)

• Oxidizing Conditions (max. sulfur > 2 g/m³):

  • Maximum temperature: 1742°F (950°C)

• Low Oxygen Atmosphere (max. sulfur content–2 g/m³):

  • Maximum temperature: 1832°F (1000°C)

• Nitriding or Carburizing Atmospheres:

  • Maximum: 1562–1742°F (850–950°C)

While Alloy 309 may not perform as effectively as Alloy 600 or Alloy 800 in reducing, nitriding, or carburizing atmospheres, it still surpasses many other heat-resistant stainless steels in these conditions. For industries seeking durable and resilient materials, 309 stainless steel round bars and 309S stainless steel round bars provide excellent options.