| Application: | Heat Exchangers， Condensers， Evaporators， Boilers | Fin Height: | 0.5mm-20mm |
|---|---|---|---|
| Fin Pitch: | 2.5mm-20mm | Fin Thickness: | 0.08mm-1.5mm |
| Fin Type: | Louver， Wavy， Plain， Serrated， Extruded | Material: | Alloy Steel |
| Tube Diameter: | 6mm-219mm | Tube Length: | 50mm-6000mm |
| Tube Material: | Carbon Steel， Stainless Steel， Copper， Aluminum | Tube Wall Thickness: | 0.5mm-20mm |
ASTM A355 P9 11CR SERRATED FIN TUBE
ASTM A355 is a standard specification for seamless ferritic alloy-steel pipe for high-temperature service. P9 refers to the grade of steel used in the pipe， which is a low alloy steel with chromium and molybdenum content.11CR refers to the 11% chromium content in the steel， which provides enhanced corrosion resistance and high-temperature strength.
Serrated fin tube refers to a type of heat exchanger tube that has fins on the outer surface. These fins increase the surface area of the tube， allowing for more efficient heat transfer between the fluid inside the tube and the surrounding environment. The serrated design of the fins helps to improve heat transfer even further.
Heat Treatement Requirement
| P5， P9， P11， and P22 | ||||
| Grade | Heat Treatment Type | Normalizing Temperature Range F [C] | Subcritical Annealing | |
| or Tempering | ||||
| Temperature Range F | ||||
| [C] | ||||
| P5 (b，c) | Full or isothermal Anneal | |||
| Normalize and Temper | ***** | 1250 [675] | ||
| Subcritical Anneal (P5c only) | ***** | 1325 – 1375 [715 – 745] | ||
| P9 | Full or isothermal Anneal | |||
| Normalize and Temper | ***** | 1250 [675] | ||
| P11 | Full or isothermal Anneal | |||
| Normalize and Temper | ***** | 1200 [650] | ||
| P22 | Full or isothermal Anneal | |||
| Normalize and Temper | ***** | 1250 [675] | ||
| P91 | Normalize and Temper | 1900-1975 [1040 – 1080] | 1350-1470 [730 – 800] | |
| Quench and Temper | 1900-1975 [1040 – 1080] | 1350-1470 [730 – 800] | ||
Chemical Requirements
| Grade | P-5 | P-9 | P-11 | P-22 | ||
| Element | UNS Designation | K41545 | S50400 | K11597 | K21590 | |
| Carbon | 0.15 max | 0.15 max | 0.05 – 0.15 | 0.05 – 0.15 | ||
| Manganese | 0.30 – 0.60 | 0.30 – 0.60 | 0.30 – 0.60 | 0.30 – 0.60 | ||
| Phosphorous， max | 0.025 | 0.025 | 0.025 | 0.025 | ||
| Sulfur， max | 0.025 | 0.025 | 0.025 | 0.025 | ||
| Silicon | 0.50 max | 0.25 – 1.00 | 0.50 – 1.00 | 0.50 max | ||
| Chromium | 4.00 – 6.00 | 8.00 – 10.00 | 1.00 – 1.50 | 1.90 – 2.60 | ||
| Molybdenum | 0.45 -0.65 | 0.90 – 1.10 | 0.44 – 0.65 | 0.87 – 1.13 | ||
APPLICATION OF ASTM A355 P9 11CR SERRATED FIN TUBE
ASTM A355 is a standard specification for seamless ferritic alloy-steel pipe for high-temperature service. P9 refers to the grade of steel used in the pipe， which is a low alloy steel with chromium and molybdenum content.
11CR refers to the 11% chromium content in the steel， which provides enhanced corrosion resistance and high-temperature strength.
Serrated fin tube refers to a type of heat exchanger tube that has fins on the outer surface. These fins increase the surface area of the tube， allowing for more efficient heat transfer between the fluid inside the tube and the surrounding environment. The serrated design of the fins helps to improve heat transfer even further.
