Heat Treatment Requirements of A335 Alloy Steel Seamless Pipes
| P5, P9, P11 and P22 | |||
| Grade | Heat Treatment Type | Normalizing Temperature Range F [C] | Subcritical Annealing or Tempering Temperature Range F [C] |
| P5 (b,c) | Full or isothermal Anneal | ||
| Normalize and Temper | ***** | 1250 [675] | |
| Subcritical Anneal (P5c only) | ***** | 1325 - 1375 [715 - 745] | |
| P9 | Full or isothermal Anneal | ||
| Normalize and Temper | ***** | 1250 [675] | |
| P11 | Full or isothermal Anneal | ||
| Normalize and Temper | ***** | 1200 [650] | |
| P22 | Full or isothermal Anneal | ||
| Normalize and Temper | ***** | 1250 [675] | |
| P91 | Normalize and Temper | 1900-1975 [1040 - 1080] | 1350-1470 [730 - 800] |
| Quench and Temper | 1900-1975 [1040 - 1080] | 1350-1470 [730 - 800] |
Chemical Requirements of A335 Alloy Steel Seamless Pipes
| Grade | P-5 | P-9 | P-11 | P-22 | P-91 | P-91 shall also include the following: | |
| Element | UNS Designation | K41545 | S50400 | K11597 | K21590 | K91560 | |
| Carbon | 0.15 max | 0.15 max | 0.05 - 0.15 | 0.05 - 0.15 | 0.08 - 0.12 | V at 0.18 - 0.25 | |
| Manganese | 0.30 - 0.60 | 0.30 - 0.60 | 0.30 - 0.60 | 0.30 - 0.60 | 0.30 - 0.60 | N at 0.030 - 0.070 | |
| Phosphorous, max | 0.025 | 0.025 | 0.025 | 0.025 | 0.020 | Ni at 0.40 max | |
| Sulfur, max | 0.025 | 0.025 | 0.025 | 0.025 | 0.010 | Al at 0.02 max | |
| Silicon | 0.50 max | 0.25 - 1.00 | 0.50 - 1.00 | 0.50 max | 0.20 -0.50 | Cb at 0.06 - 0.10 | |
| Chromium | 4.00 - 6.00 | 8.00 - 10.00 | 1.00 - 1.50 | 1.90 - 2.60 | 8.00 - 9.50 | Ti at 0.01 max | |
| Molybdenum | 0.45 -0.65 | 0.90 - 1.10 | 0.44 - 0.65 | 0.87 - 1.13 | 0.85 - 1.05 | Zr at 0.01 max | |
Tensile Requirements of A335 Alloy Steel Seamless Pipes
| Seamless | ||||||
| P-5 | P-9 | P-11 | P-22 | P-91 | P91 shall not have a hardness not exceeding 250 HB/265 HV [25HRC]. | |
| Tensile Strength, min., psi | ||||||
| ksi | 60 | 60 | 60 | 60 | 85 | |
| MPa | 415 | 415 | 415 | 415 | 585 | |
| Yield Strength, min., psi | ||||||
| ksi | 30 | 30 | 30 | 30 | 60 | |
| MPa | 205 | 205 | 205 | 205 | 415 | |
