ASME SA335 P91 and P92 seamless alloy steel pipes are ferritic alloy steel pipes manufactured according to ASME SA335 / ASTM A335 requirements for high-temperature service.
ASTM A335 covers seamless ferritic alloy-steel pipe for high-temperature service. P91 and P92 are Cr-Mo alloy steel grades designed for high-temperature pressure-service applications.
P91 contains approximately 8.00–9.50% chromium and 0.85–1.05% molybdenum, with controlled additions of vanadium, niobium and nitrogen.
P92 uses a different alloy design, with approximately 8.50–9.50% chromium, 1.50–2.00% tungsten and controlled boron, together with vanadium, niobium and nitrogen.
The different alloy compositions make P91 and P92 suitable for demanding high-temperature pressure systems where material selection is based on design temperature, pressure, allowable stress and applicable engineering codes.
The pipes are supplied in seamless construction and can be customized in outside diameter, wall thickness, length, end preparation, heat treatment and inspection according to project requirements.
| Item | Specification |
|---|---|
| Product | Seamless Alloy Steel Pipe |
| Standard | ASME SA335 / ASTM A335 |
| Grade | P91 / P92 |
| P91 UNS | K91560 |
| P92 UNS | K92460 |
| Material | Ferritic Cr-Mo Alloy Steel |
| Manufacturing | Seamless |
| Service | High-Temperature Service |
| Outside Diameter | Customized |
| Wall Thickness | Customized |
| Length | Fixed / Random / Customized |
| Heat Treatment | According to ASTM A335 |
| End Finish | Plain / Beveled / Customized |
| Testing | Hydrostatic / NDE / Mechanical Testing |
| Certification | EN 10204 3.1 / 3.2, if required |
| Element | P91 | P92 |
|---|---|---|
| C | 0.08–0.12% | 0.07–0.13% |
| Mn | 0.30–0.60% | 0.30–0.60% |
| P | ≤0.020% | ≤0.020% |
| S | ≤0.010% | ≤0.010% |
| Si | 0.20–0.50% | ≤0.50% |
| Cr | 8.00–9.50% | 8.50–9.50% |
| Mo | 0.85–1.05% | 0.30–0.60% |
| Ni | ≤0.40% | ≤0.40% |
| V | 0.18–0.25% | 0.15–0.25% |
| Nb | 0.06–0.10% | 0.04–0.09% |
| N | 0.030–0.070% | 0.030–0.070% |
| W | — | 1.50–2.00% |
| B | — | 0.001–0.006% |
| Al | ≤0.02% | ≤0.02% |
| Ti | ≤0.01% | ≤0.01% |
| Zr | ≤0.01% | ≤0.01% |
| Property | P91 | P92 |
|---|---|---|
| Tensile Strength | ≥585 MPa | ≥620 MPa |
| Yield Strength | ≥415 MPa | ≥440 MPa |
| Elongation | ≥20% | ≥20% |
| Hardness | According to ASTM A335 | According to ASTM A335 |
Mechanical properties should be verified according to the applicable ASTM A335 / ASME SA335 edition and purchase order requirements.
Steelmaking → Billet Preparation → Heating → Piercing → Hot Rolling → Heat Treatment → Straightening → Cutting → NDE → Dimensional Inspection → Mechanical Testing → Final Inspection → Marking → Packing
The manufacturing process focuses on seamless pipe production, controlled heat treatment, dimensional accuracy and inspection traceability.
Heat treatment is an important part of P91/P92 production and is performed according to the applicable specification and project requirements.
Each ASME SA335 P91/P92 pipe can be inspected according to ASTM A335 / ASME SA335 and the applicable purchase order.
ASME SA335 P91/P92 seamless alloy steel pipes are used in high-temperature pressure systems, including:
Typical applications include:
P91 and P92 are both ferritic alloy steel grades covered by ASTM A335 / ASME SA335, but they use different alloy systems.
P91 contains approximately 8.00–9.50% chromium and 0.85–1.05% molybdenum, together with controlled vanadium, niobium and nitrogen.
P92 contains approximately 8.50–9.50% chromium and 1.50–2.00% tungsten, with controlled additions of molybdenum, vanadium, niobium, nitrogen and boron.
Grade selection should be based on:
We can supply ASME SA335 P91/P92 seamless alloy steel pipes according to project requirements, including:
For power plant projects, pipe dimensions and inspection requirements can be coordinated according to project drawings, piping specifications and applicable design codes.
Available surface conditions can include:
End preparation can be supplied according to the customer's piping and welding requirements.
P91/P92 seamless alloy steel pipes are packed according to pipe dimensions, quantity and transportation requirements.
Typical export packaging includes:
