ASTM A213 Steel Pipe
ASTM A213 Steel Pipe
Introduction
ASTM A213 is a standard specification for seamless ferritic and austenitic alloy-steel boiler, superheater, and heat-exchanger tubes. These pipes are designed for high-temperature service and are widely used in power plants, petrochemical industries, and refineries. The specification covers various grades, each tailored for specific applications and performance requirements.
Key Grades and Chemical Composition
ASTM A213 includes several grades, primarily categorized into ferritic (T) and austenitic (TP) steel grades. Here are some commonly used grades:
- Ferritic Grades: T2, T5, T9, T11, T12, T22, T91
- Austenitic Grades: TP304, TP304H, TP316, TP316H, TP321, TP347
Outside diameter tolerance of ASTM A213 Steel Tube:
Hot rolled | Outside Diameter, mm | Tolerance, mm |
---|---|---|
OD≤101.6 | +0.4/-0.8 | |
101.6<OD≤190.5 | +0.4/-1.2 | |
190.5<OD≤228.6 | +0.4/-1.6 | |
Cold Drawn | Outside Diameter, mm | Tolerance, mm |
OD<25.4 | ±0.10 | |
25.4≤OD≤38.1 | ±0.15 | |
38.1<OD<50.8 | ±0.20 | |
50.8≤OD<63.5 | ±0.25 | |
63.5≤OD<76.2 | ±0.30 | |
76.2≤OD≤101.6 | ±0.38 | |
101.6<OD≤190.5 | +0.38/-0.64 | |
190.5<OD≤228.6 | +0.38/-1.14 |
Wall thickness & Tolerance of ASTM A213 Steel Tube :
Hot rolled | Outside Diameter, mm | Tolerance, % |
---|---|---|
OD≤101.6, WT≤2.4 | +40/-0 | |
OD≤101.6, 2.4<WT≤3.8 | +35/-0 | |
OD≤101.6, 3.8<WT≤4.6 | +33/-0 | |
OD≤101.6, WT>4.6 | +28/-0 | |
OD>101.6, 2.4<WT≤3.8 | +35/-0 | |
OD>101.6, 3.8<WT≤4.6 | +33/-0 | |
OD>101.6, WT>4.6 | +28/-0 | |
Cold Drawn | Outside Diameter, mm | Tolerance, % |
OD≤38.1 | +20/-0 | |
OD>38.1 | +22/-0 |
Chemical Composition
Below are the chemical compositions for select ASTM A213 grades.
Ferritic Grades
Grade T2
- Carbon (C): 0.10%
- Manganese (Mn): 0.30 – 0.61%
- Phosphorus (P): ≤ 0.025%
- Sulfur (S): ≤ 0.025%
- Silicon (Si): 0.10 – 0.50%
- Chromium (Cr): 0.50 – 0.81%
- Molybdenum (Mo): 0.44 – 0.65%
Grade T91
- Carbon (C): 0.08 – 0.12%
- Manganese (Mn): 0.30 – 0.60%
- Phosphorus (P): ≤ 0.020%
- Sulfur (S): ≤ 0.010%
- Silicon (Si): 0.20 – 0.50%
- Chromium (Cr): 8.00 – 9.50%
- Molybdenum (Mo): 0.85 – 1.05%
- Vanadium (V): 0.18 – 0.25%
- Nitrogen (N): 0.03 – 0.07%
- Niobium (Nb): 0.06 – 0.10%
Austenitic Grades
Grade TP304
- Carbon (C): ≤ 0.08%
- Manganese (Mn): ≤ 2.00%
- Phosphorus (P): ≤ 0.045%
- Sulfur (S): ≤ 0.030%
- Silicon (Si): ≤ 1.00%
- Chromium (Cr): 18.00 – 20.00%
- Nickel (Ni): 8.00 – 11.00%
Grade TP316
- Carbon (C): ≤ 0.08%
- Manganese (Mn): ≤ 2.00%
- Phosphorus (P): ≤ 0.045%
- Sulfur (S): ≤ 0.030%
- Silicon (Si): ≤ 1.00%
- Chromium (Cr): 16.00 – 18.00%
- Nickel (Ni): 10.00 – 14.00%
- Molybdenum (Mo): 2.00 – 3.00%
Mechanical Properties
The mechanical properties of ASTM A213 pipes depend on the grade and heat treatment applied. Here are typical properties for some common grades:
Ferritic Grades
Grade T2
- Tensile Strength: ≥ 415 MPa (60,000 psi)
- Yield Strength: ≥ 205 MPa (30,000 psi)
- Elongation: ≥ 30%
Grade T91
- Tensile Strength: ≥ 585 MPa (85,000 psi)
- Yield Strength: ≥ 415 MPa (60,000 psi)
- Elongation: ≥ 20%
Austenitic Grades
Grade TP304
- Tensile Strength: ≥ 515 MPa (75,000 psi)
- Yield Strength: ≥ 205 MPa (30,000 psi)
- Elongation: ≥ 35%
Grade TP316
- Tensile Strength: ≥ 515 MPa (75,000 psi)
- Yield Strength: ≥ 205 MPa (30,000 psi)
- Elongation: ≥ 35%
ASTM A213 Alloy Steel Chemical Composition(%, max)
Steel Grade | Chemical Composition% | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
C | Si | Mn | P, S Max | Cr | Mo | Ni Max | V | Al Max | W | B | Nb | N | |
T2 | 0.10~0.20 | 0.10~0.30 | 0.30~0.61 | 0.025 | 0.50~0.81 | 0.44~0.65 | – | – | – | – | – | – | – |
T11 | 0.05~0.15 | 0.50~1.00 | 0.30~0.60 | 0.025 | 1.00~1.50 | 0.44~0.65 | – | – | – | – | – | – | – |
T12 | 0.05~0.15 | Max 0.5 | 0.30~0.61 | 0.025 | 0.80~1.25 | 0.44~0.65 | – | – | – | – | – | – | – |
T22 | 0.05~0.15 | Max 0.5 | 0.30~0.60 | 0.025 | 1.90~2.60 | 0.87~1.13 | – | – | – | – | – | – | – |
T91 | 0.07~0.14 | 0.20~0.50 | 0.30~0.60 | 0.02 | 8.0~9.5 | 0.85~1.05 | 0.4 | 0.18~0.25 | 0.015 | – | – | 0.06~0.10 | 0.03~0.07 |
T92 | 0.07~0.13 | Max 0.5 | 0.30~0.60 | 0.02 | 8.5~9.5 | 0.30~0.60 | 0.4 | 0.15~0.25 | 0.015 | 1.50~2.00 | 0.001~0.006 | 0.04~0.09 | 0.03~0.07 |
ASTM A213 Alloy Steel Mechanical properties:
Steel Grade | Mechanical Properties | ||||
---|---|---|---|---|---|
T. S | Y. P | Elongation | Hardness | ||
T2 | ≥ 415MPa | ≥ 205MPa | ≥ 30% | 163HBW(85HRB) | |
T11 | ≥ 415MPa | ≥ 205MPa | ≥ 30% | 163HBW(85HRB) | |
T12 | ≥ 415MPa | ≥ 220MPa | ≥ 30% | 163HBW(85HRB) | |
T22 | ≥ 415MPa | ≥ 205MPa | ≥ 30% | 163HBW(85HRB) | |
T91 | ≥ 585MPa | ≥ 415MPa | ≥ 20% | 250HBW(25HRB) | |
T92 | ≥ 620MPa | ≥ 440MPa | ≥ 20% | 250HBW(25HRB) |
Manufacturing Process
Seamless Pipe Manufacturing
Seamless tubes under ASTM A213 are manufactured through a series of steps:
- Billet Heating: Steel billets are heated to become malleable.
- Piercing: The heated billet is pierced to form a hollow tube.
- Rolling: The hollow tube is rolled to achieve the desired dimensions.
- Sizing: The tube is further processed to meet precise dimensional tolerances.
- Cold-Drawing (Optional): The tube may undergo cold-drawing for better dimensional accuracy and surface finish.
Heat Treatment
Heat treatment is crucial to achieve the required mechanical properties:
- Annealing: Heating the tube to a high temperature followed by slow cooling to soften the material.
- Normalizing: Heating the tube to a specific temperature and then air cooling to refine the grain structure.
- Quenching and Tempering: Heating followed by rapid cooling (quenching) and reheating to a lower temperature (tempering) to enhance toughness.
Testing Requirements
ASTM A213 specifies several tests to ensure tube quality and performance:
- Tensile Test: Measures tensile strength, yield strength, and elongation.
- Hardness Test: Ensures the material meets specified hardness levels.
- Hydrostatic or Non-Destructive Electric Test: Ensures the tube can withstand internal pressure without leaking.
- Flattening Test: Assures the tube’s ability to resist flattening without cracking.
- Dimensional Inspection: Ensures the tubes meet specified dimensions and tolerances.
Applications
ASTM A213 tubes are used in high-temperature and high-pressure environments, including:
- Power Generation: Boiler tubes, superheater tubes, and reheater tubes in power plants.
- Petrochemical Industry: Heat exchanger tubes and furnace tubes.
- Refineries: Tubes in catalytic cracking and hydrocracking units.
- General Engineering: Tubes requiring high-temperature strength and corrosion resistance.
Advantages and Limitations
Advantages
- High-Temperature Performance: Suitable for applications involving high temperatures.
- Corrosion Resistance: Austenitic grades offer excellent resistance to corrosion.
- Strength: High mechanical strength suitable for demanding applications.
- Dimensional Accuracy: Manufacturing processes ensure precise dimensions.
Limitations
- Cost: Higher cost compared to welded tubes due to the seamless manufacturing process.
- Complex Manufacturing: Requires precise control over chemical composition and heat treatment.
- Availability: Specific grades and sizes may have longer lead times.
Conclusion
ASTM A213 seamless alloy-steel tubes are essential for applications requiring high strength, corrosion resistance, and high-temperature stability. Their superior mechanical properties, combined with rigorous manufacturing and testing processes, ensure they meet the demanding requirements of various industries. Understanding the detailed specifications, grades, and applications of ASTM A213 tubes helps engineers and designers select the right materials for their projects, ensuring safety and efficiency in challenging environments.