ASTM A335 P91 steel pipe is the part of ASTM A335, The pipe shall be suitable for bending, flanging, and similar forming operations, and for fusion welding. The steel material shall conform to chemical composition, tensile property, and hardness requirements. Each length of pipe shall be subjected to the hydrostatic test. Also, each pipe shall be examined by a non-destructive examination method in accordance to the required practices.
Chemical Requirements of ASTM A335 P91 steel pipe
| UNS Designation | K91560 |
| Carbon | 0.08-0.12 |
| Manganese | 0.30-0.60 |
| P&S(max) | 0.020-0.010 |
| Silicon | 0.20-0.50 |
| Chromium | 8.00-9.50 |
| Molybdenum | 0.85-1.05 |
| Others | — |
A335 P91 steel pipe Material Manufacture
Pipe may be either hot finished or cold drawn with the finishing heat treatment noted below.
A335 P91 steel pipe Heat Treatment
A / N+T
N+T / Q+T
N+T
A335 P91 steel pipe Notes for Hardness Test
P91 shall not have a hardness not exceeding 250 HB/265 HV [25HRC].
