Alloy steel pipe is a kind of seamless steel pipe, which is made by hot rolling (extrusion, expansion) or cold rolling (drawing). Its performance is much higher than the general seamless steel pipe, because this steel pipe inside containing Cr. Alloy steel pipe is mainly used in high-pressure and high-temperature pipelines and equipment such as power plants, nuclear power, high-pressure boilers, high-temperature superheaters and reheaters. The advantages of alloy steel pipes can be 99% recycled, which is environmental protection and energy saving。
ASTM A335 Alloy pipe & tube Chemical Composition:
| Grade | UNS | C≤ | Mn | P≤ | S≤ | Si≤ | Cr | Mo |
| P5 | K41545 | 0.15 | 0.30-0.60 | 0.025 | 0.025 | 0.5 | 4.00-6.00 | 0.44-0.65 |
| P9 | S50400 | 0.15 | 0.30-0.60 | 0.025 | 0.025 | 0.50-1.00 | 8-10.00 | 0.44-0.65 |
| P11 | K11597 | 0.05-0.15 | 0.30-0.61 | 0.025 | 0.025 | 0.50-1.00 | 1.00-1.50 | 0.44-0.65 |
| P12 | K11562 | 0.05-0.15 | 0.30-0.60 | 0.025 | 0.025 | 0.5 | 0.80-1.25 | 0.44-0.65 |
| P22 | K21590 | 0.05-0.15 | 0.30-0.60 | 0.025 | 0.025 | 0.5 | 1.90-2.60 | 0.87-1.13 |
| P91 | K91560 | 0.08-0.12 | 0.30-0.60 | 0.02 | 0.01 | 0.20-0.50 | 8.00-9.50 | 0.85-1.05 |
| P92 | K92460 | 0.07-0.13 | 0.30-0.60 | 0.02 | 0.01 | 0.5 | 8.50-9.50 | 0.30-0.60 |
| Mechanical properties | Tensile, min, ksi[MPa] | Yield,min, ksi[MPa] | Elongation, %(min) | Hardness, HB（max） |
| P5 | 60[415] | 30[205] | 30 | - |
| P9 | 60[415] | 30[205] | 30 | - |
| P11 | 60[415] | 30[205] | 30 | - |
| P12 | 60[415] | 32[220] | 30 | - |
| P22 | 60[415] | 30[205] | 30 | - |
| P91 | 85[585] | 60[415] | 20 | 250 |
| P92 | 90[620] | 64[440] | 20 | 250 |
 A335 P5 Pipe |  A335 P9 Pipe |  A335 P11 Pipe |
 A335 P12 Pipe |  A335 P22 Pipe |  A335 P91 Pipe |
Test:Tension Test, Flattening Test, Hardness Test, or Bend Test; Hydrostatic Test or nondestructive electric test.
Applications: P11 pipe, P12 Pipe, P22 pipe, and P91 pipe, P92 Pipe are used in the power industry and petro-chemical plants, P5 pipe and P9 pipe are commonly used in refineries.
