ASTM A268 TP409 Stainless Steel Welded Tubes For Industrial Heating Applications

ASTM A268 TP409 Stainless Steel Welded Tubes For Industrial Heating Applications

ASTM A268 TP409 is a ferritic stainless steel tube made to the ASTM A268 standard, which specifies the requirements for seamless and welded ferritic stainless steel tubes used for applications like automotive exhaust systems, boilers, and heat exchangers. TP409 is a low-carbon, chromium-based stainless steel, which offers excellent corrosion resistance and high-temperature strength, making it suitable for use in environments that require both high thermal stability and resistance to corrosion.

TP409 maintains good strength and corrosion resistance at high temperatures, making it ideal for use in heat exchangers, boilers, and automotive exhaust systems, where parts are regularly exposed to thermal cycling.

Chemical Composition (%) max:

-Chromium (Cr): 10.5% - 11.75%

- Nickel (Ni): 0.75% max

- Manganese (Mn): 1.0% max

- Silicon (Si): 1.0% max

- Carbon (C): 0.08% max

- Phosphorus (P): 0.04% max

- Sulfur (S): 0.03% max

- Iron (Fe): Balance

Mechanical Properties:

- Tensile Strength: ~ 450 MPa (65,000 psi) (typical)

- Yield Strength: ~ 205 MPa (30,000 psi) (typical)

- Elongation: ~ 25% (in 50 mm gauge length)

- Hardness: ~ HRB 85 (typical)

Physical Properties:

- Density: ~ 7.70 g/cm³

- Melting Point: ~ 1400°C (2552°F)

- Thermal Conductivity: ~ 25.5 W/m·K (at 100°C)

- Specific Heat: ~ 460 J/kg·K

- Modulus of Elasticity: ~ 200 GPa

- Thermal Expansion: ~ 11.0 × 10^-6 /°C (at 20°C to 100°C)

Applications:

1.Automotive Exhaust Systems

TP409 is widely used in automotive exhaust systems, including exhaust pipes, mufflers, catalytic converter tubes, and heat shields. The material’s resistance to oxidation at elevated temperatures makes it ideal for environments where exhaust gases can reach high temperatures and contain corrosive elements.

2.Heat Exchangers

Heat exchangers used in industries like chemical processing, petrochemical, and power generation benefit from TP409’s ability to resist thermal cycling and high temperatures. TP409 is used in tube bundles where its thermal conductivity ensures effective heat transfer.

3.Boilers and Furnace Components

TP409 stainless steel tubes are used in boiler tubes and furnace components, particularly in low-pressure steam boilers, where resistance to thermal stress and oxidation resistance are required.

4.Industrial Heating Applications

TP409 is utilized in industrial heating systems such as electric furnaces or furnace tubes that operate at elevated temperatures. The material’s ability to withstand continuous high temperatures without deteriorating makes it useful for thermal processing.

5.Food Processing

TP409 stainless steel tubes are employed in food processing systems, particularly where heat transfer is critical. TP409’s non-reactivity with food and corrosion resistance make it a suitable choice for food industry applications like pasteurizers and sterilizers.

6.Power Generation

In power generation plants, TP409 is used in heat recovery systems and boilers, where high-temperature resistance and strength are vital for maintaining efficient heat exchange and thermal energy conversion.

7.Petrochemical and Chemical Industries

TP409 is also used in the petrochemical and chemical industries, where it is employed in reactors, tubes, and other components exposed to moderate corrosive conditions and high temperatures.