Our welded serrated finned tubes utilize premium ASTM A312 TP304H austenitic stainless steel base pipes, engineered specifically for high-stress, high-temperature thermal power generation environments. The high-carbon "H" grade provides superior creep rupture strength at temperatures exceeding 525°C (975°F), making it the definitive choice for utility boiler superheaters, reheaters, and waste heat recovery systems (HRSG).

By utilizing a serrated fin profile, this design introduces controlled turbulence into the gas stream. This configuration disrupts the thermal boundary layer far more effectively than solid fins, increasing the heat transfer coefficient by up to 15-20% while optimizing space and weight.

The controlled carbon content (0.04–0.10%) is critical. It guarantees high-temperature strength and long-term structural stability against phase transformation.

• Carbon (C): 0.04% – 0.10%
• Chromium (Cr): 18.00% – 20.00%
• Nickel (Ni): 8.00% – 11.00%
• Manganese (Mn): 2.00% max
• Silicon (Si): 0.75% max
• Phosphorus (P): 0.045% max
• Sulfur (S): 0.030% max

• Tensile Strength: ≥ 515 MPa (75 ksi)
• Yield Strength (0.2% Offset): ≥ 205 MPa (30 ksi)
• Elongation (in 2 inches): ≥ 35%
• Hardness: ≤ 192 HBW / 200 HV

Every tube undergoes rigorous quality assurance to meet the zero-tolerance safety mandates of modern thermal power plants.

• High-Frequency Resistance Welding (HFRW): Ensures a continuous, 100% metallurgical bond between the base tube and the serrated fin to eliminate thermal resistance at the interface.
• Non-Destructive Testing (NDT): 100% Eddy Current and Ultrasonic testing are performed on the base tubes prior to finning.
• Hydrostatic Testing: Performed in accordance with ASTM A999 to guarantee pressure containment integrity.
• Weld Pull Test: Destructive mechanical testing of fin-to-tube bond to ensure structural rigidity against thermal cycling and soot-blower impact.
• Grain Size Verification: ASTM E112 tracking to verify grain size is No. 7 or coarser, ensuring optimal long-term high-temperature creep performance.

• Maximum Heat Flux: Serrated geometry creates localized vortex shedding, multiplying gas-side heat transfer efficiency.
• Fouling Resistance: The segmented fin structure reduces ash accumulation zones compared to solid fins, making cleaning via soot-blowers highly efficient.
• Oxidation Resistance: High chromium-nickel chemistry forms a stable protective oxide scale that resists flue gas corrosion at elevated temperatures.