Products Description
ASTM A335 P9 is part of the ASTM A335 standard for seamless ferritic alloy-steel pipes designed for high-temperature service. These pipes are suitable for bending, flanging, and other forming operations, as well as fusion welding, while maintaining excellent mechanical performance.
The steel material contains controlled levels of carbon, chromium, and molybdenum, providing a yield strength of over 200 MPa and a tensile strength ranging from approximately 415 to 550 MPa.
The elongation after fracture exceeds 20%, and Charpy impact tests at -29°C typically show energy absorption above 27 Joules. With a Brinell hardness in the range of 160 to 200, ASTM A335 P9 pipes exhibit reliable strength, toughness, and resistance to creep at high temperatures, making them ideal for boilers, heat exchangers, and pressure piping systems operating up to around 540°C.
Chemical composition
| Compositions | Data |
| UNS Designa-tion | K41545 |
| Carbon(max.) | 0.15 |
| Manganese | 0.30-0.60 |
| Phosphorus(max.) | 0.025 |
| Silicon(max.) | 0.50 |
| Chromium | 4.00-6.00 |
| Molybdenum | 0.45-0.65 |
| Other Elements | … |
Mechanical Properties of ASTM A335 P9 Pipe
| Properties | Data |
| Tensile strength, min, (MPa) | 415 Mpa |
| Yield strength, min, (MPa) | 205 Mpa |
| Elongation, min, (%), L/T | 30/20 |
Heat Treatment Requirements of ASTM A335 P9 Pipes
| 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] |
