Seamless Stainless Steel TP309 Tube
Distinguished by its high Chromium (22-24%) and Nickel (12-15%) content, our TP310MoLN tubing offers superior creep strength and thermal stability at continuous service temperatures up to 1038°C (1900°F). These tubes are indispensable for mission-critical components in industrial furnaces, boiler baffles, and thermo-wells. Through advanced cold-drawing and precise solution annealing, GZH ensures a stable austenitic microstructure that maintains maximum durability under aggressive thermal cycling and mildly carburizing atmospheres.
"While TP310S offers higher heat resistance, TP309 provides a more cost-effective solution for environments up to 1900°F, especially in sulfur-bearing atmospheres where its corrosion resistance is superior."
What Is a Seamless Stainless Steel TP309 Tube?
TP309 Seamless Stainless-Steel Tube is a high-temperature, corrosion-resistant tube crafted from a single, solid billet of a high-chromium and high-nickel austenitic stainless steel. Unlike welded tubes, it has no weld joint, ensuring superior structural integrity and reliability, especially under high-stress and high-temperature conditions. The"309"designation refers to a specific grade known for its excellent oxidation resistance and strength at elevated temperatures. Its balanced composition provides it with a notable ability to resist oxidation up to 1800°F (982°C) and to withstand high-temperature carburization. This makes it a top choice for demanding applications in industrial furnaces, power generation, and heat treatment.
Key Features and Advantages
Seamless TP309 Stainless Steel Tube offer a unique combination of benefits that make them invaluable in demanding high-temperature industries:
Outstanding High-Temperature Oxidation Resistance: The high chromium and nickel content provides superior resistance to oxidation and scaling in high-temperature air, performing better than 304 and 316 stainless steels in these conditions.
Excellent Creep-Rupture Strength: It maintains high tensile and creep-rupture strength at elevated temperatures, ensuring long-term structural stability under high-temperature loads.
Resistance to Carburization: The alloy is highly resistant to carburization, which is crucial for applications in high-temperature furnaces and reducing atmospheres.
High Pressure and Temperature Tolerance: The seamless construction and robust material allow the tube to safely handle high internal pressures and extreme temperatures.
Good Weldability: The alloy can be readily welded using standard methods, and its balanced composition helps prevent hot cracking.
Product Specifications and Data
To provide a comprehensive overview of this high-performance material, here are the detailed technical specifications and performance data for Stainless Steel 309.
Table 1: Chemical Composition of Stainless Steel 309
The composition of Stainless Steel 309 is carefully balanced to achieve its superior high-temperature oxidation resistance and strength.
| Cr | Ni | Mn | Si | P | S | Fe | C |
| 22.00 - 24.00 | 12.00 - 15.00 | ≤ 2.00 | ≤ 1.50 | ≤ 0.045 | ≤ 0.030 | Bal | ≤ 0.20 |
Table 2: Typical Mechanical Properties of Stainless Steel 309
Stainless Steel 309 is specifically designed to maintain its strength and shape in high-stress, high-temperature environments.
| Property | Value (Annealed) |
| Tensile Strength | ≥ 515 MPa |
| Yield Strength | ≥ 205 MPa |
| Elongation | ≥ 30% |
| Hardness | ≤ 217 HBW |
Table 3: Typical Physical Properties of Stainless Steel 309
These physical properties highlight the material's ability to perform reliably under a wide range of conditions.
| Property | Value |
| Density | 7.9 g/cm³ |
| Melting Point | 1400 - 1450 °C approx. |
| Thermal Expansion | 16.5 µm/m·°C (20-100°C) |
| Thermal Conductivity | 14.2 W/m·K (20°C) |
| Modulus of Elasticity | 200 GPa |
| Electrical Resistivity | 0.78 x 10⁻⁶ Ω·m (20°C) |
Table 4: The Standard of Stainless Steel Seamless Tube Size Tolerance Size Chart :
| Standard | OD(D) | Tolerance（MM) | Thickness(S) | Tolerance(MM) | Length | Tolerance | |
| MM | Common | High | MM | MM | |||
| EN 10216-5 HFD | 30≤D≤219.1（D2) | ±1.0% or ±0.5mm, whicever is the greater(取较大者) | T1, T≤4 | ±15% or ±0.6mm, whicever is the greater(取较大者) | L≤6M | +5/0 | |
| T2 | ±12.5% or ±0.4mm, whicever is the greater(取较大者) | ||||||
| 219.1≤D≤610 (D1) | ±1.5% or ±0.75mm, whicever is the greater (取较大者) | T≤0.05D | +22.5%/-15% | 6 | +10/0 | ||
| T1, 0.05D | ±15% or ±0.6mm, whicever is the greater(取较大者) | ||||||
| T2, T>0.09D | ±12.5% or ±0.4mm, whicever is the greater(取较大者) | L>12 | +by agreement/0 | ||||
| EN 10216-5 CFD | D3(D≤219.1) | ±0.75% or ±0.3mm, whicever is the greater(取较大者) | T3 | ±10% or ±0.2mm, whicever is the greater(取较大者) | |||
| D4(D≤219.1) | ±0.5% or ±0.mm, whicever is the greater(取较大者) | T4 | ±7.5% or ±0.15mm, whicever is the greater(取较大者) | ||||
| ASTM A213 HFD | D≤100 | +0.4/-0.8 | D<100,S≤2.4 | +40%/0 | HFD, all size | +5.0/0 | |
| +0.4/-1.2 | D<100,2.4 | +35%/0 | |||||
| +0.4/-1.6 | D<100,3.8 | +33%/0 | |||||
| D<100,S>4.6 | +28%/0 | ||||||
| 100 | +0.4/-1.2 | D>100, 2.4 | +35%/0 | ||||
| 200 | +0.4/-1.6 | D>100,3.8 | +33%/0 | ||||
| D>100,S>4.6 | +28%/0 | ||||||
| ASTM A213 CFD | D<25 | ±0.10 | D≤38.1 | +20%/0 | CFD, D<50.8 | +3.0/0 | |
| 25≤D≤40 | ±0.15 | ||||||
| 40 | ±0.20 | ||||||
| 50≤D<65 | ±0.25 | ||||||
| 65≤D<75 | ±0.30 | D>38.1 | +22%/0 | CFD, D≥50.8 | +5.0/0 | ||
| 75≤D≤100 | ±0.38 | ||||||
| 100 | +0.38/-0.64 | ||||||
| 200 | +0.38/-1.14 | ||||||
| ASTM A269 | D≤13 | ±0.13 | D≤13 | ±15% | D<38 | +3.2/0 | |
| 13 | ±0.13 | 13 | ±10% | ||||
| 38≤D<89 | ±0.25 | D>38 | +4.8/0 | ||||
| 89≤D<140 | ±0.38 | ||||||
| 140≤D<203 | ±0.76 | ||||||
| 203≤D<305 | ±1.01 | ||||||
| 305≤D<356 | ±1.26 | ||||||
| ASTM A270 | D<25 | ±0.13 | For weld pipe all size | ±12.5% | +3.0/0 | ||
| 25-50 | ±0.20 | ||||||
| 50-75 | ±0.25 | ||||||
| 75-100 | ±0.38 | For CD SMLS pipe D≤38.1 | +20%/0 | ||||
| 100-140 | ±0.38 | +5.0/0 | |||||
| 140-200 | ±0.75 | For CD SMLS pipe D>38.1 | +22%/0 | ||||
| 200-300 | ±1.25 | ||||||
Common Applications of TP309 Seamless Tube
The combination of high-temperature strength and exceptional oxidation resistance of seamless Stainless Steel 309 tubes makes them a preferred choice for:
Heat Treating Industry: Used in radiant tubes, muffles, retorts, and other furnace parts.
Power Generation: In boiler components, reheater tubes, and steam generator tubing.
Chemical and Petrochemical Processing: For furnace tubes, burner components, and other high-temperature applications.
Cement Industry: For kiln components and other high-temperature process equipment.
Manufacturing Process of TP309 Stainless Steel Seamless Tube
The manufacturing of a Seamless Stainless Steel TP309 Tube is a precise, multi-step process:
- Heating: A solid billet of Stainless Steel 309 is heated to a high temperature.
- Piercing: A piercing mill pushes a mandrel through the center of the heated billet to form a hollow shell.
- Drawing and Sizing: The hollow shell is then rolled and drawn to reduce its diameter and wall thickness to the desired dimensions.
- Heat Treatment: The tube is solution annealed to achieve its specified metallurgical properties and to ensure optimal performance.
- Finishing: The tube is cut to length, straightened, and subjected to rigorous testing to ensure it meets the highest standards for performance and reliability. This meticulous process ensures that every seamless Stainless Steel 309 tube is built to withstand the most extreme operating conditions.
