Product Specification for ASTM A213 T11/P11 Alloy Seamless Steel Tubes
1. Overview
ASTM A213 T11/P11 designates seamless ferritic alloy steel tubes intended for high-temperature service in boilers, superheaters, and heat exchangers. These tubes are manufactured to withstand extreme thermal and mechanical stress in power generation, petrochemical, and refinery applications. The material combines excellent creep resistance, oxidation resistance, and weldability.
2. Chemical Composition
The chemical composition of ASTM A213 T11/P11 (Grade T11) meets stringent requirements for high-temperature performance:
| Element |
Composition Range (%) |
| Carbon (C) |
0.05–0.15 |
| Manganese (Mn) |
0.30–0.60 |
| Phosphorus (P) |
≤0.025 |
| Sulfur (S) |
≤0.025 |
| Chromium (Cr) |
1.00–1.50 |
| Molybdenum (Mo) |
0.44–0.65 |
| Silicon (Si) |
0.50–1.00 |
| Iron (Fe) |
Balance |
Note:
- Chromium enhances oxidation and corrosion resistance at elevated temperatures.
- Molybdenum improves creep strength and thermal stability.
- Low carbon content ensures good weldability and ductility.
3. Mechanical Properties
The tubes are heat-treated (normalized and tempered) to achieve the following mechanical properties:
| Property |
Requirement |
| Tensile Strength |
≥415 MPa (60,200 psi) |
| Yield Strength |
≥205 MPa (29,700 psi) |
| Elongation (in 50 mm) |
≥30% |
| Hardness |
≤77 HRB (Rockwell B) |
Key Notes:
- Mechanical properties are tested at room temperature.
- High-temperature creep resistance is a critical feature for applications above 540°C (1,004°F).
4. Technical Requirements
4.1 Bright Annealing
- Process: Tubes undergo bright annealing in a controlled atmosphere (e.g., hydrogen or nitrogen) to prevent surface oxidation.
- Purpose: Achieve a smooth, oxide-free surface finish.
- Enhance corrosion resistance and dimensional stability.
- Remove internal stresses from cold working.
- Temperature Range: 700–850°C (1,292–1,562°F), depending on tube dimensions.
4.2 Manufacturing Process
- Seamless Production: Tubes are manufactured via hot extrusion or rotary piercing, followed by cold drawing for precision dimensions.
- Surface Finish: Bright annealed surface with minimal roughness (Ra ≤ 0.8 µm).
- Dimensional Tolerances:
- Outer Diameter: ±0.10 mm
- Wall Thickness: ±10% of nominal thickness.
5. Applications
ASTM A213 T11/P11 tubes are ideal for:
- Boilers and Superheaters: High-pressure steam generation in power plants.
- Heat Exchangers: For corrosive and high-temperature fluids in refineries.
- Petrochemical Processing: Resistant to sulfur-containing environments.
- Nuclear Power Systems: Auxiliary cooling circuits and steam lines.
6. Compliance and Testing
- Standards: Compliant with ASTM A213/A213M and ASME SA-213/SA-213M.
- Testing: Hydrostatic or nondestructive electric testing (NDT) for integrity.
- Hardness, tensile, and chemical analysis per batch.
- Ultrasonic testing (UT) for defect detection.
7. Packaging and Storage
- Packaging: Tubes are coated with anti-corrosive oil and wrapped in plastic film. Bundled with steel straps for secure transport.
- Storage: Store in dry, temperature-controlled environments to prevent moisture absorption.
Note: Custom lengths, special coatings, or additional certifications (e.g., EN 10216, PED) are available upon request.
References
ASTM A213/A213M Standard Specification.
ASME Boiler and Pressure Vessel Code, Section II.
Manufacturer Quality Assurance Documentation
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ASTM A213 T11/P11 Cold Drawing/ Cold Rolled Alloy Boiler Seamless Steel Tubes Images
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