P91 Material High Pressure Boiler Tube , Alloy Steel Pipe ASTM A335 Standard
Grade 91 contains 9 % Chromium and 1 % Molybdenum compared to 2.5 % Chromium in the next best P22 grade. Chromium improves high temperature strength and increases oxidation resistance. Molybdenum increases the creep resistance. Also present are smaller quantities of Nickel and Manganese which increase the hardenability of the steel.
More important than the alloying elements is the formation of this alloy steel. The steel is formed by normalizing at 1050 °C, air cooling down to 200 °C. It is then tempered by heating to 760 °C. The temperatures and the cooling rates are very important. This produces the microstructure that results in the high creep strength properties.
ASTM A335 ——Standard Specification for Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service
For the high-pressure boiler and steam pipes, and the petrochemical industry pipes;
Power plant; Chemical Fertilizer; Petrochemicals; Offshore Oils; Gas Productions; Refineries and etc.
3. Dimensional Tolerance
High Pressure Boiler Tube
-10% ~ +12.5%
4. Chemical Composition:
Ti 0.01 max
6. Mechanical Properties
Steel pipes No.
7. Available Size Range:
*If the steel grades and size you are looking for are not listed above, please contact us for further information.
MTC sample could be provided upon request.
For additional requirements on chemical composition, mechanical properties, and supplementary requirements, please contact us for customization!