What is the material composition of P11 pipe
Jan 06, 2026
A335 P11 seamless steel pipe is an alloy steel pipe mainly used in high-temperature service environments, such as petrochemical, power, and aerospace fields. Its chemical composition includes: carbon (C) (≤0.20%), silicon (Si) (≤0.50%), manganese (Mn) (≤0.75%), phosphorus (P) (≤0.035%), sulfur (S) (≤0.035%), chromium (Cr) (8.0-11.0%), molybdenum (Mo) (≤0.40%), and vanadium (V) (≤0.30%). This steel pipe has a tensile strength ≥485MPa, a yield strength ≥295MPa, an elongation ≥25%, and an impact energy ≥27J.
A335P11 alloy pipe is a commonly used seamless steel pipe. Its alloy composition mainly includes the following:
Carbon (C): The content is generally between 0.05% and 0.15%, which has a certain influence on the strength and hardness of the pipe.
Silicon (Si): Approximately 0.10% to 0.50%, which helps to improve the strength and toughness of the pipe.
Manganese (Mn): The content is usually between 0.30% and 0.60%, which can enhance the overall performance of the pipe.
Chromium (Cr): A key alloying element in this pipe, with a content of about 1.00% to 1.50%, which can improve the oxidation resistance and corrosion resistance of the pipe.
Molybdenum (Mo): Generally 0.45% to 0.65%, which can further improve the high-temperature resistance and creep resistance of the pipe.
What are the main performance characteristics of A335P11 seamless steel pipe?
1. High-temperature resistance: Thanks to the addition of chromium and molybdenum, this steel pipe can operate for extended periods at relatively high temperatures (typically up to approximately 593°C). A stable chromium oxide protective film forms on its surface, slowing down further oxidation.
2. Good mechanical properties: It possesses sufficient strength, toughness, and creep resistance at both room and high temperatures, capable of withstanding internal medium pressure and external loads.
3. Certain corrosion resistance: The chromium content gives it some resistance to oxidizing environments, but its resistance to highly corrosive media is limited, and it is generally not used in applications where corrosion is a primary concern.
4. Machinability and weldability: A335P11 steel pipe can be cold-bent and cut. Welding requires the use of matching welding materials and preheating and post-heating processes to prevent cold cracking.
A335 P11 Alloy steel pipe factory
