Lord Fin Tube-ASTM A213 TP309 Seamless Tube
ASTM A213 TP309 seamless tubes represent a premium category of austenitic stainless steel tubing specifically engineered for extreme service conditions. These high-performance tubes are manufactured to meet the rigorous standards of ASTM International for seamless ferritic and austenitic alloy-steel boiler, superheater, and heat-exchanger tubes.
ASTM A213 TP309 Material Composition & Metallurgical Characteristics
The TP309 grade belongs to the 300 series of stainless steels, with a balanced chemical composition that delivers superior high-temperature performance:
Chemical Composition (Weight %):
-Carbon (C): 0.08 max (low carbon content minimizes carbide precipitation)
-Manganese (Mn): 2.00 max (enhances hot workability)
-Phosphorus (P): 0.045 max -Sulfur (S): 0.030 max
-Silicon (Si): 0.75 max (improves oxidation resistance)
-Chromium (Cr): 22.0-24.0 (provides exceptional oxidation resistance)
-Nickel (Ni): 12.0-15.0 (stabilizes austenitic structure)
This specific alloy formulation creates a stable austenitic microstructure that remains resistant to sensitization and intergranular corrosion even after prolonged exposure to temperatures between 870°C and 925°C (1600°F-1700°F).
ASTM A213 TP309 Mechanical Properties & Performance Characteristics
|
Property |
Metric Values |
Imperial Values |
|
Tensile Strength |
≥515 MPa |
≥75,000 psi |
|
Yield Strength |
≥205 MPa |
≥30,000 psi |
|
Elongation |
≥40% |
≥40% |
|
Hardness (Max) |
Brinell 217 |
Rockwell B 95 |
The TP309 alloy demonstrates remarkable creep resistance at elevated temperatures, with a stress rupture limit of approximately 14 MPa (2000 psi) at 815°C (1500°F). Its thermal expansion coefficient of 16.0 μm/m·°C (20-100°C) and thermal conductivity of 14.2 W/m·K (100°C) make it particularly suitable for thermal cycling applications.
ASTM A213 TP309 Manufacturing Process & Quality Control
ASTM A213 TP309 tubes are produced through advanced seamless tube manufacturing processes:
1.Hot Extrusion: Billets are heated to 1200°C and extruded through a piercing mill
2.Cold Drawing: For precise dimensional control and improved surface finish
3.Solution Annealing: Performed at 1040-1120°C followed by rapid quenching to dissolve carbides
4.Non-Destructive Testing: Mandatory hydrostatic testing, eddy current examination, or ultrasonic testing
The seamless construction eliminates weld weaknesses, providing uniform mechanical properties throughout the tube length. Available in sizes ranging from 6.35mm to 127mm OD, with wall thicknesses from 0.8mm to 12.7mm.
ASTM A213 TP309 High-Temperature Applications
TP309 tubes excel in demanding environments:
-Power Generation: Superheater and reheater tubes in coal-fired boilers operating at 650°C+
-Petrochemical: Pyrolysis furnace tubes in ethylene crackers (service temperature up to 1100°C)
-Refining: Transfer lines in catalytic reforming units
-Heat Processing: Radiant tubes in annealing furnaces and heat treatment equipment
