Introduction
Seamless P11 Alloy Steel Pipe is a chromium-molybdenum alloy designed for high-temperature service. This P11 seamless pipe offers excellent strength and oxidation resistance, making it ideal for power generation, refinery, and high-pressure applications. Its reliable performance under extreme conditions ensures long-term durability.
ASTM A335 /A335M ASME SA335 pipes shall be made by the seamless process and shall be either hot-finished or cold drawn with the finishing treatment.
ASTM A335 /A335M covers nominal wall and minimum wall seamless ferritic alloy-steel pipe intended for high-temperature service.
Referenced Documents
ASTM A 999/A999M specification for general requirements for alloy and stainless-steel pipe
E92 Test method for Vickers hardness of metallic materials
E213 practice for ultrasonic testing of metal pipe and tubing
E309 practice for Eddy-Current examination of steel tubular products using magnetic saturation
E381 method of macro etch testing steel bars, billets, blooms, and forgings
| Grade | C | Mn | P
| S
| Si | Cr | Mo | V | Nb | N | Al | Others |
| P11 | 0.05-0.15 | 0.30-0.60 | ≤0.025 | ≤0.025 | 0.50-1.00 | 1.0-1.50 | 0.44-0.65 | /
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| P12 | 0.05-0.15 | 0.30-0.61 | ≤0.025 | ≤0.025 | ≤0.50 | 0.80-1.25 | 0.45-0.65 | /
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| P22 | 0.05-0.15 | 0.30-0.60 | ≤0.025 | ≤0.025 | ≤0.50 | 1.90-2.60 | 0.87-1.13 | /
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| P91 | 0.08-0.12 | 0.30-0.60 | ≤0.020 | ≤0.010 | 0.20-0.50 | 8.0-9.50 | 0.85-1.05 | 0.18-0.25 | 0.030-0.070 | ≤0.40 | ≤0.02 | Cb 0.06-0.10 Ti 0.01max Zr 0.01max |
Heat Treatment Requirements
Grade | P11 | P12 | P22 | P91 |
UNS Number | K11597 | K11562 | K21590 | K91560 |
Heat Treat Type | full or isothermal anneal normalize and temper | full or isothermal anneal normalize and temper subcritical anneal | full or isothermal anneal normalize and temper | normalize and temper quench and temper |
Austenitizing/ Solutioning Temperature, min or range °F [°C] | … | … | … | 1900-1975[1040-1080] 1900-1975[1040-1080] |
Subcritical Annealing or Tempering Temperature, Min or range °F [°C] | 1200 [650] | 1200 [650] 1200-1300 [650 to 705] | 1250 [675] | 1350-1470[730-800] 1350-1470[730-800] |
Tensile Requirements and Hardness:
Grade | Tensile | Yield | Elongation | Hardness |
Strength (Mpa) | Strength (Mpa) | (%) |
P11 P12 | ≥415 | ≥220 | ≥30 | ≤89HRB |
P22 | ≥415 | ≥200 | ≥30 | ≤89HRB |
P91 | ≥585 | ≥415 | ≥20 | 91HRB-25HRC |
