In high-temperature and high-pressure applications such as heat recovery boilers, conventional carbon steel tubes often experience creep deformation or even premature failure within a short period. The root cause lies in whether the material's high-temperature strength, microstructural stability, and manufacturing quality truly meet the demands of long-term service.
ASTM A213 T5 alloy steel seamless tube we supply is specifically designed for high-temperature heat recovery systems. T5 is a Cr-Mo alloy steel, heat-treated through normalizing and tempering, with a tempering temperature typically not lower than 675°C. We also provide heat treatment curve documentation to ensure uniform microstructure, preventing excessive hardness or insufficient strength. In addition, the inner surface of T5 alloy steel tubes must be clean and free from loose oxide scale and rust, avoiding blockage risks during the initial operation of boiler systems.
ASTM A213 T5 seamless tubes contain 4.0–6.0% Cr, 0.45–0.65% Mo, and ≤0.15% C, offering excellent high-temperature oxidation resistance and microstructural stability. In terms of hardness control, all products undergo strict testing, with typical hardness maintained in the range of approximately 85–95 HRB. This ensures sufficient strength while maintaining good workability and weldability, and minimizes the risk of cracking due to excessive hardness.
T5 alloy steel tubes exhibit outstanding creep resistance in the temperature range of 500–600°C, maintaining dimensional stability under long-term stress. This makes them an ideal choice for heat recovery boilers and high-temperature heat exchange equipment.
ASTM A213 T5 T5b Alloy Steel Tubes specification
| Size (Seamless) | 6.35mm o.d to 101.60mm o.d |
|---|---|
| Standards | ASTM A213, ASME SA213 |
| Equivalent Standards | EN 10216-2, ASTM A335, GOST 550-75, WN 1.7362, K41545 |
| Material | P5, K41545 |
| Equivalent Material | T5, 15Ch5M |
| Type | Seamless |
| Specialized in | Large Diameter Size |
| Outer Dimensions | 6-2500mm; WT:1-200mm |
| Wall Thickness | Schedule 3mm to 15mm. |
| Length | max 1~12m |
| Schedule | STD, SCH40, SCH80 |
| Form | Round, Square, Rectangular, Hydraulic Etc. |
| Length | Single Random, Double Random & Cut Length. |
| Tubing End | Plain End, Beveled End, Treaded. |
Chemical Composition of Grade T5 (UNS K41545)
| Element | Requirement (%) |
| Carbon (C) | 0.15 max |
| Manganese (Mn) | 0.30 - 0.60 |
| Phosphorus (P) | 0.025 max |
| Sulfur (S) | 0.025 max |
| Silicon (Si) | 0.50 max |
| Nickel (Ni) | ... |
| Chromium (Cr) | 4.00 - 6.00 |
| Molybdenum (Mo) | 0.45 - 0.65 |
| Vanadium (V) | ... |
| Boron (B) | ... |
Heat Treatment Requirements for Grade T5 (UNS K41545)
| Parameter | Specification |
| Grade | T5 |
| UNS Number | K41545 |
| Heat Treat Type | Full or Isothermal Anneal, or Normalize and Temper |
| Subcritical Annealing or Tempering Temperature | 1200 to 1350 °F [650 to 730 °C] |
| Subcritical Annealing or Tempering Temperature (Alternative) | 1250 °F [675 °C] |
| ASTM Grain Size No. | Not Specified |
Mechanical Properties of Grade T5 (UNS K41545)
| Property | Requirement |
| Grade | T5 |
| UNS Designation | K41545 |
| Tensile Strength, min | 60 ksi [415 MPa] |
| Yield Strength (0.2% Offset), min | 30 ksi [205 MPa] |
| Elongation in 2 in. or 50 mm, min | 30% |
| Hardness, max | 163 HBW / 170 HV / 85 HRB |
Tolerances of Outside Diameter
| Pecified Outside Diameter,in. [mm] | Permitted Variations, in. [mm] | |
| Over | Under | |
| Hot-Finished Seamless Tubes | ||
| 4 [100] or under | 1 ⁄ 64 [0.4] | 1 ⁄ 32 [0.8] |
| Over 4 to 7 1 ⁄ 2 [100 to 200], incl | 1 ⁄ 64 [0.4] | 3 ⁄ 64 [1.2] |
| Over 7 1 ⁄ 2 to 9 [200 to 225], incl | 1 ⁄ 64 [0.4] | 1 ⁄ 16 [1.6] |
| Cold-Finished Seamless Tubes | ||
| Under 1 [25] | 0.004 [0.1] | 0.004 [0.11] |
| 1 to 1 1 ⁄ 2 [25 to 40], incl | 0.006 [0.15] | 0.006 [0.15] |
| Over 1 1 ⁄ 2 to 2 [40 to 50], excl | 0.008 [0.2] | 0.008 [0.2] |
| 2 to 2 1 ⁄ 2 [50 to 65], excl | 0.010 [0.25] | 0.010 [0.25] |
| 2 1 ⁄ 2 to 3 [65 to 75], excl | 0.012 [0.3] | 0.012 [0.3] |
| 3 to 4 [75 to 100], incl | 0.015 [0.38] | 0.015 [0.38] |
| Over 4 to 7 1 ⁄ 2 [100 to 200], incl | 0.015 [0.38] | 0.025 [0.64] |
| Over 7 1 ⁄ 2 to 9 [200 to 225], incl | 0.015 [0.38] | 0.045 [1.14] |
Tolerances of Length
| Method of Manufacture |
Specified Outside Diameter, in.[mm] |
Cut Length, in. [mm] | |
| Over | Under | ||
| Seamless, hot-finished | All sizes | 3 ⁄ 16 [5] | 0 [0] |
| Seamless, cold-finished | Under 2 [50.8] | 1 ⁄ 8 [3] | 0 [0] |
| 2 [50.8] or over | 3 ⁄ 16 [5] | 0 [0] | |
| 2 [50.8] or over | 3 ⁄ 16 [5] | 0 [0] | |
Surface Condition
ASTM A213 T5 Seamless Ferritic alloy cold-finished steel tubes shall be free of scale and suitable for inspection. A slight amount of oxidation is not considered scale.
ASTM A213 T5 Seamless Ferritic alloy hot-finished steel tubes shall be free of loose scale and suitable for inspection.
Any special finish requirement be subject to agreement between the supplier and the purchaser.
How does T5 compare to T9 or T22 alloy pipe?
T5 alloy pipe is a 5% chromium-moly steel known for excellent oxidation resistance, making it ideal for petrochemical applications. Compared to T22 (2.25% Cr) and T9 (9% Cr), T5 offers better corrosion resistance than T22, but lower high-temperature creep strength than T22 or T9.
Can A213 T5 be welded easily?
Yes, but it requires care. Because it is an alloy steel, Pre-heating and Post-Weld Heat Treatment (PWHT) are generally required to prevent the Heat Affected Zone (HAZ) from becoming brittle and cracking.
Quality inspection
Flattening Test-One flattening test shall be made on specimens from each end of one finished tube, not the one used for the flaring test, from each lot
Flaring Test-One flaring test shall be made on specimens from each end of one finished tube, not the one used for the flattening test, from each lot
Hydrostatic or Nondestructive Electric Test-Each ASTM A213 T5, T5b tube shall be subjected to the nondestructive electric test or the hydrostatic test. The type of test to be used shall be at the option of the manufacturer unless otherwise specified in the purchase order.
T5 Tubes Packing and Marking
Packed in bundles or ply wooden box wrapped in plastic, and suitably protected for sea-worthily delivery or as requested.
Marking prescribed in Specification A 1016/A 1016M, the marking shall include whether the tube is hot-finished or cold-finished and including not limited: Standard, graded, size, heat no. lot no.
