ASTM A335 P91 — Chemical Composition & Mechanical Properties
ASTM A335 P91 is an ASTM specification for seamless pipe (UNS K91560). This sheet summarises its chemical composition limits and minimum mechanical properties. Typical use: 9Cr-1Mo-V main-steam / hot-reheat piping.
Chemical composition of ASTM A335 P91 (weight %)
Other elements and limits: V 0.18–0.25; Nb 0.06–0.10; N 0.030–0.070; Al 0.02 max; Ti 0.01 max; Zr 0.01 max
Mechanical properties
| Tensile strength, min | 585 MPa |
|---|---|
| Yield strength, min | 415 MPa |
| Elongation, min | 20 % |
| Hardness | 190–250 HBW |
Heat treatment
Normalized 1040–1080 °C and tempered 730–800 °C
Typical service
9Cr-1Mo-V main-steam / hot-reheat piping
Reference information compiled from the published standard for convenience. It does not replace the current edition of the governing standard, which takes precedence. Verify critical dimensions and properties before design, purchase or fabrication. Teshi Engineers & Sales Promoters (P) Ltd accepts no liability for errors or omissions.
FAQ
ASTM A335 P91: common questions
What is the minimum yield strength of ASTM A335 P91?
415 MPa, with a minimum tensile strength of 585 MPa.
What is the carbon content of ASTM A335 P91?
0.08–0.12 %.
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