Key Characteristics of SA213 T11 Seamless Tube:

1. Material Composition:

The chromium and molybdenum in T11 give it excellent strength at high temperatures, resistance to oxidation, and enhanced creep resistance under prolonged heat exposure. The carbon content is kept low to improve toughness and reduce the risk of embrittlement.

• Chromium (Cr): 1.00–1.50%
• Molybdenum (Mo): 0.44–0.65%
• Carbon (C): 0.05–0.15%
• Manganese (Mn): 0.30–0.60%
• Silicon (Si): 0.10–0.50%
• Phosphorus (P): ≤ 0.025%
• Sulfur (S): ≤ 0.010%

2. Mechanical Properties:

These properties make SA213 T11 highly suitable for applications where the material will be subjected to high pressures and temperatures without compromising its structural integrity.

• Tensile Strength: 415–585 MPa (60–85 ksi)

• Yield Strength: 205 MPa (30 ksi)

• Elongation: 30% in 8 inches (200 mm)

• Hardness: Typically measured by Brinell or Rockwell hardness testing, it is generally kept low to maintain ductility.

3. Key Features:

• High-Temperature Strength: T11 tubes can withstand temperatures up to 500-600°C (932-1112°F), making them ideal for applications like boilers and superheaters.

• Corrosion Resistance: The chromium and molybdenum content provides moderate resistance to oxidation in steam and high-temperature environments. Though not as corrosion-resistant as stainless steels, it still performs well in many industrial applications.

• Seamless Construction: Being a seamless tube, the T11 tube is formed from a solid billet, ensuring better mechanical properties and reliability under high pressure than welded tubes.

4. Applications:

• Power Plants: Used for boiler tubes, superheater tubes, and heat exchangers to handle steam and other high-temperature fluids.

• Petrochemical Industry: In the processing of hydrocarbons and petrochemicals, especially in high-pressure reactors and heat exchangers.

• Chemical Industry: Commonly used in equipment designed to handle high-temperature fluids and gases.

• Pressure Vessels: Suitable for use in high-pressure steam systems, ensuring long-term reliability in critical applications.

5. Manufacturing Process:

• Seamless Tubing: The T11 tubes are manufactured using the seamless extrusion process, which involves forming the tube from a solid billet of steel by either piercing and elongating it or pushing it through a die. This process helps eliminate the possibility of defects in the weld seam, which are more common in welded tube products.

• Heat Treatment: The tubes typically undergo heat treatment processes, such as normalizing, annealing, or tempering, to achieve the desired mechanical properties.

​6. Standards and Testing:

• ASTM A213: The tubes are made according to the ASTM A213 standard, which outlines the requirements for seamless ferritic and austenitic alloy-steel tubes used in high-temperature applications.

• Hydrostatic Test: The tubes are typically tested under hydrostatic conditions to ensure their ability to handle high pressure.

• Tensile Testing: Mechanical properties like tensile strength, yield strength, and elongation are evaluated to verify that the tubes meet the standard's requirements.

• Impact Testing: For ensuring toughness at low temperatures (though this is less critical for T11 compared to some other materials).