ASTM A250 alloy steel tubes
ASTM A 250 Standard Specification for Electric-Resistance-Welded Ferritic Alloy-Steel Boiler and Superheater Tubes
ASTM A250 alloy boiler tubes are electric resistance welded (ERW) ferritic alloy steel tubes produced according to the ASTM A250 standard. Designed specifically for high-temperature and pressure-bearing applications such as boilers and superheaters, they meet the high-temperature and pressure resistance requirements of power plants, chemical plants, and other fields through precise composition control and stringent process requirements.
Size: OD 1/2in-5in(12.7-127mm),Wall thickness: 0.035in-0.320in(0.9-8.1mm)
Grade:T1, T1a, T1b ,T2, T11, T12 ,T22
Chemical Composition:
Mechanical Properties:
Manufacturing Process:
Electric-resistance welding
Heat treatment:
1. After welding, or when cold finished, after the final cold-drawing pass, all tubes shall be heat-treated. Furnished in the full annealed, isothermal annealed, normalized, or normalized and tempered condition at the option of the manufacturer, if furnished in the normalized and tempered condition.
2. When grades T1.T1a, T1 b, and T2 are cold finished, the tubes may, at the option of the manufacturer, be heat treated after the final cold-drawing pass at a temperature of 1200°F or higher.
Mechanical Testing:
1. Flattening Test: Verifies the ASTM A250 Alloy Boiler Tube's plasticity and weld integrity. Acceptance is determined by the absence of cracks or delamination after flattening.
2. Flanging Test: Verifies the pipe's cold-forming capability. Acceptance is determined by the absence of cracking after flanging.
3. Reverse Flattening Test: Further tests the weld strength. Acceptance is determined by the absence of weld damage after reverse compression.
4. Hardness Test: Determines the pipe's hardness to ensure that the heat treatment effect matches the mechanical properties.
5. Hydrostatic Test or Nondestructive Electrical Testing:
6. Hydrostatic Test: Verifies the pipe's sealing performance through a hydrostatic test at a specified pressure. Acceptance is determined by the absence of leakage.
7. Nondestructive Electrical Testing: A highly efficient alternative to the hydrostatic test to detect internal pipe or weld defects.
Applicable Scenarios and Procurement Recommendations
1. Core Applications
Power plant boiler water walls, superheater, and reheater piping;
Chemical high-temperature heating furnaces and waste heat boiler pressure piping;
Industrial steam boiler medium-temperature pressure piping (temperature ≤ 650°C, pressure ≤ 10 MPa).
2. Procurement Selection
For medium- and low-temperature applications (≤ 500°C): Grades T1, T1a, and T1b are preferred for lower cost;
For medium- and high-temperature applications (500-600°C): Grades T2, T11, and T12 are recommended for their balance of temperature resistance and cost-effectiveness;
For high-temperature and high-pressure applications (> 600°C): Grade T22 is mandatory, as its high chromium and molybdenum content ensures creep and oxidation resistance.
As a professional manufacturer of ASTM A250 alloy boiler tube, we offer a full range of grades: T1/T1a/T1b/T2/T11/T12/T22. Custom sizes are also available. Please contact us for inquiries and purchases.
