|
| ब्रांड नाम: | YUHONG |
| एमओक्यू: | 200-500kgs |
| मूल्य: | विनिमय योग्य |
| भुगतान की शर्तें: | एल/सी, टी/टी, दृष्टि में |
| आपूर्ति की योग्यता: | ग्राहकों की आवश्यकताओं के अनुसार |
The ASTM A335 Gr.11 alloy steel high-frequency serrated finned tube is a high-performance heat exchange component designed for medium to high temperature and high pressure industrial applications. Known for its durability, corrosion resistance, and excellent heat transfer performance, it is widely used in boilers, power generation systems, petrochemical reactors, and other demanding environments where efficient heat exchange is critical. The tube is made from ASTM A335 P11 grade chromium-molybdenum alloy steel, containing about 1.25% chromium (Cr) and 0.5% molybdenum (Mo). Compared to carbon steel, this alloy combination provides better creep strength, oxidation resistance, and thermal fatigue resistance, making it suitable for high-temperature service up to about 593°C (1100°F). The serrated (H-type) fin design on the outer surface increases the heat exchange area, which significantly improves the overall heat transfer efficiency
|
Element |
C |
Mn |
P (max) |
S (max) |
Si |
Cr |
Mo |
|
Range |
0.05-0.15 |
0.30-0.60 |
0.025 |
0.025 |
0.50-1.00 |
1.00-1.50 |
0.44-0.65 |
Mechanical Properties (Base Tube):
|
Tensile Strength |
Yield Strength (min) |
Elongation (min) |
|
≥ 415 MPa (60 ksi) |
≥ 205 MPa (30 ksi) |
≥ 30% |
Temperature Range: ASTM A335 Gr.11 performs optimally in the temperature range of 540-593°C (1000-1100°F), while ASTM A335 Gr.9 (P9) can operate at higher temperatures (up to 650°C / 1200°F), making P9 more suitable for ultra-high-temperature applications.
Application: Gr.11 is often used for refinery heaters, power plant economizers, and petrochemical reformers in moderate-temperature environments, while P9 is more suited for petrochemical cracking furnaces and high-temperature reactors.
Bond Integrity: High-frequency welded fins offer a stronger bond (≥ 20% higher than mechanically embedded fins) and significantly lower thermal resistance, improving heat transfer and ensuring the fins remain securely attached in dynamic conditions.
Performance: The serrated fins help in reducing thermal stress and improve turbulence, making them ideal for high-velocity, high-fouling environments. In contrast, mechanically embedded fins are better suited for less demanding applications.
· Power Plant Boilers: Especially in high-pressure economizers and air preheaters where feedwater or air preheating occurs in fouling conditions.
· Petrochemical Heaters: Used in hydroprocessing reactors, ethylene crackers, and reformer heaters, where high heat exchange rates are required.
· Gas Processing & Sulfur Recovery Units: Employed in waste heat boilers handling process gases with contaminants.
· Refinery Applications: Effective in atmospheric and vacuum heaters in refineries where crude oil is processed under moderate sulfur corrosion conditions.
· Metallurgical Flue Gas Recovery: Suitable for steel mill flue gas systems in dusty conditions.
A1: High-frequency welding provides a continuous metallurgical bond that minimizes thermal contact resistance, improving heat transfer efficiency. It also prevents fin detachment during thermal cycling and vibration, ensuring the long-term performance of the tubes.
A2: The ASTM A335 Gr.11 base tube can withstand continuous operation at temperatures up to 593°C (1100°F). The actual maximum temperature may depend on the fin material and specific service conditions.
A3: While ASTM A335 Gr.11 has good resistance to oxidation and thermal fatigue, its sulfidation resistance is moderate. For more aggressive corrosive environments, higher-alloy materials such as ASTM A335 P9 or stainless steels may be more appropriate.
A4: The serrated design improves heat transfer by creating turbulence and reducing the risk of fouling. It also helps to reduce thermal stress and improve the tube's performance in high-gas velocity environments, making it a more efficient option for high-duty cycles.
