What material is equivalent to A335 P91 pipe
Jan 08, 2026
P91 steel, equivalent to the national standard 10Cr9Mo1VNbN, possesses numerous superior properties. Firstly, it exhibits high resistance to oxidation and high-temperature steam corrosion, enabling stable operation for extended periods in harsh high-temperature environments. Secondly, its excellent impact toughness makes it resistant to damage from sudden external impacts. Furthermore, its high and stable creep ductility and thermal strength ensure reliable operation under high-temperature conditions. When operating at temperatures below 620℃, its allowable stress is higher than that of austenitic stainless steel, demonstrating a significant advantage. Above 550℃, the recommended design allowable stress is approximately twice that of T9 and 2.25Cr-1Mo steel, making P91 more competitive in high-temperature applications.
The corresponding grades of A335P91 in different standard systems are as follows:
Chinese Standard:
GB 5310: 10Cr9Mo1VNb (or 10Cr9Mo1VNbN), with chemical composition and properties highly consistent with P91.
Other Standards: Some literature mentions 9Cr1MoG, but attention should be paid to its compositional differences (e.g., vanadium and niobium content may differ).
International Standards:
ASME SA-335: P91 (core standard).
A213/SA213: T91
EN Standard: X10CrMoVNb9-1 (European equivalent grade).
JIS Standard: STBA28 (Japanese equivalent grade).
Chemical Composition
The chemical composition of A335P91 seamless steel pipe is strictly controlled according to ASTM standards, and mainly includes:
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): 0.85~1.0% 5% Vanadium (V): 0.18~0.25% Nitrogen (N): 0.030~0.070% Nickel (Ni): ≤0.40% Aluminum (Al): ≤0.040% Niobium (Nb): 0.06~0.10%
Mechanical Properties
The mechanical properties of A335 P91 seamless steel pipe are also excellent, mainly including:
Tensile strength: ≥585MPa
Yield strength: ≥415MPa
Elongation: ≥20%
A335 P91 Chrome Moly Pipe in stock
