ASTM A335 P22 Alloy Steel Seamless Serrated Fin Tube For Power Plants
ASTM A335 P22 Serrated Fin Tube
I. Product Overview
ASTM A335 P22 serrated fin tubes are manufactured from P22 chromium-molybdenum alloy steel, a material specifically designed for high-temperature and high-pressure service. With a nominal composition of 2.25% chromium and 1% molybdenum, this grade provides excellent resistance to oxidation, creep, and sulfur attack at elevated temperatures. The tube utilizes a seamless base pipe combined with helically wound, serrated (notched) fins that are securely attached through high-frequency welding or an embedded process. The serrated fin design significantly increases turbulence and disrupts boundary layers, enhancing heat transfer efficiency compared to plain fins. This construction maintains robust pressure integrity while offering superior thermal performance in demanding environments. Suitable for high-temperature heat exchangers, boilers, heaters, and other critical pressure equipment, it can be supplied in custom dimensions and fin configurations to meet specific project requirements.
II. Chemical & Mechanical Properties
Base Tube Chemical Composition (%)
| Element | C | Si (max) | Mn | P (max) | S (max) | Cr | Mo |
| Range | 0.05–0.15 | 0.50 | 0.30–0.60 | 0.025 | 0.025 | 1.90–2.60 | 0.87–1.13 |
Mechanical Properties (Base Tube)
| Tensile Strength (min) | Yield Strength (min) | Elongation (min) |
| 415 MPa | 205 MPa | 30% |
III. Equivalent Material of P22
| ASTM | EN/DIN | UNS | JIS | GB | Common Name |
| A335 P22 | 10CrMo9-10 | K21590 | STPA24 | 12Cr2MoG | T22 / 2.25Cr-1Mo |
IV. Comparison: P22 vs P11 & P5 Alloy Steels
| Property | P22 (2.25Cr-1Mo) | P11 (1.25Cr-0.5Mo) | P5 (5Cr-0.5Mo) |
| Core Advantage | Best high-temp strength | Most cost-effective | Best corrosion resistance |
| Temp Limit | 565-600°C | 540-550°C | 600°C |
| Key Application | Power generation (high temp/pressure) | General industrial heat exchangers | Refineries (high sulfur) |
| Weldability | Good | Excellent | Good |
| Cost | Medium-High | Lowest | Medium-High |
V. Key Applications
● Power Generation Boilers: Superheater and reheater tubes, economizer sections, and high-pressure steam lines in coal-fired and thermal power plants.
● Petrochemical & Refinery Heaters: Process heater coils, convection and radiant sections in crude, vacuum, and reformer heaters.
● Heat Recovery Steam Generators (HRSG): Evaporator and superheater coils in gas turbine co mbined-cycle units.
● High-Temperature Heat Exchangers: Waste heat recovery units, air preheaters, and process gas coolers in chemical and metallurgical industries.
● Industrial Boilers & Steam Systems: High-pressure steam coils, boiler bank tubes, and steam distribution piping in pulp/paper, textile, and food processing plants.
Get in Touch
Have questions about our products or want to discuss a custom order? Our team is ready to help you.