Description
ASTM A335 P91 Alloy Steel Seamless Pipe
ASTM A335 P91 Pipe is a seamless ferritic alloy steel pipe designed for high-temperature service, particularly in boilers, power plants, refineries, and heat exchangers. It’s known for excellent strength, oxidation resistance, and creep resistance at elevated temperatures.
Containing 8.00–9.50% chromium and 0.85–1.05% molybdenum, this alloy provides excellent creep strength, oxidation resistance, and long-term stability under elevated temperatures. With a minimum yield strength of 205 MPa and a tensile strength of 415 MPa, ASTM A335 P91 offers mechanical properties superior to conventional carbon steels, and it is often compared to ASTM A335 P9 pipe due to its similar alloying base but enhanced performance.
A335 P91 Chemical Composition :
| Element | Composition (%) |
|---|---|
| Carbon (C) | 0.08 – 0.12 |
| Manganese (Mn) | 0.30 – 0.60 |
| Phosphorus (P) | ≤ 0.020 |
| Sulfur (S) | ≤ 0.010 |
| Silicon (Si) | 0.20 – 0.50 |
| Chromium (Cr) | 8.0 – 9.5 |
| Molybdenum (Mo) | 0.85 – 1.05 |
| Vanadium (V) | 0.18 – 0.25 |
| Niobium (Nb) | 0.06 – 0.10 |
| Nitrogen (N) | 0.03 – 0.07 |
A335 P91 Mechanical Properties :
| Property | Value |
|---|---|
| Tensile Strength | ≥ 585 MPa |
| Yield Strength | ≥ 415 MPa |
| Elongation | ≥ 20% |
| Hardness (HB) | ≤ 250 HB |
Equivalent Grades :
| Standard | Grade |
|---|---|
| ASME | SA335 P91 |
| EN | X10CrMoVNb9-1 |
| DIN | 1.4903 |
Applications of P91 Grade Seamless Pipes & Tubes :
• Superheater and reheater tubes
• Power generation & thermal plants
• Oil and gas refineries
• Petrochemical plants
• High-pressure steam lines
Available Forms of P91:
• Seamless Pipes
• Tubes
• Boiler Tubes
• Heat Exchanger Tubes
