Stainless Steel 1.4901
EN 1.4901
A 9%Cr martensitic creep-resisting steel (commonly known as P92) used for high-temperature boiler and power-plant components; listed here for designation completeness though it is not a true two-phase duplex stainless.
Reference datasheet — 1.4901 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the N+T condition
1.4901 tempers and conditions
1.4901 is supplied in 5 conditions, soft to hard. N+T is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Interim softened condition for heavy machining or cold bending; must be re-normalized and tempered before creep service. | 370 | 570 | 26 | 9 HRC | 3.1 % IACS |
N+T + PWHT | Condition of a fabricated/welded assembly after mandatory subcritical PWHT; slightly softened base metal, code-required before service. | 480 | 660 | 23 | 17 HRC | 3 % IACS |
N+TDefault Normalized and tempered | Standard mill delivery condition for P92/T92 seamless pipe and tube; use for all code-design creep applications. | 520 | 700 | 22 | 20 HRC | — |
Quenched and tempered | For thick forgings, valve bodies and headers where liquid/accelerated quenching is needed to obtain fully martensitic through-thickness structure. | 550 | 730 | 20 | 22 HRC | 3 % IACS |
As-welded deposit | Transient condition only — hard, brittle untempered martensite; never acceptable for service, PWHT is mandatory. | 720 | 950 | 12 | 43 HRC | 2.8 % IACS |
What is 1.4901?
A 9%Cr martensitic creep-resisting steel (commonly known as P92) used for high-temperature boiler and power-plant components; listed here for designation completeness though it is not a true two-phase duplex stainless. 1.4901 has a density of 7.78 g/cm³ (0.281 lb/in³), lighter than 57% of stainless steel grades. It melts at 1,425°C (2,597 °F). 1.4901 has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 79% of stainless steel grades. Elongation at break is 22% and the elastic modulus is 218 GPa (31.6 Msi).
What is 1.4901 used for?
- power plant superheater tubing
- high-pressure steam piping
- boiler headers
Advantages
- Low embodied carbon — 2.6 kg CO₂/kg, better than 100% of stainless steel grades
- Conducts heat well — 27 W/m·K (15.6 BTU/hr·ft·°F), better than 97% of stainless steel grades
- High strength — 520 MPa (75.4 ksi), better than 79% of stainless steel grades
Limitations
- Needs corrosion protection — 30/100, worse than 99% of stainless steel grades
- Hard to polish — 55/100, worse than 89% of stainless steel grades
- Difficult to weld — 45/100, worse than 79% of stainless steel grades
- Limited ductility — 22%, worse than 75% of stainless steel grades
1.4901 properties
Typical room-temperature values for 1.4901-N+T; bars are the position among stainless steel grades.
Physical3
1.4901 has a density of 7.78 g/cm³ (0.281 lb/in³), lighter than 57% of stainless steel grades. It melts at 1,425°C (2,597 °F).
Mechanical17
1.4901 has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 79% of stainless steel grades. Elongation at break is 22% and the elastic modulus is 218 GPa (31.6 Msi).
Thermal6
1.4901 is rated for continuous service to 620°C (1,148 °F). It conducts heat at 27 W/m·K (15.6 BTU/hr·ft·°F), better than 97% of stainless steel grades. Thermal expansion is 10.8 µm/m·K (6 µin/in·°F).
Electrical2
1.4901 has an electrical resistivity of 5.7×10⁻⁷ Ω·m.
Chemical & Environmental3
Corrosion resistance is poor (30/100), worse than 99% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4901 takes about 33 MJ of energy and emits 2.6 kg of CO₂ — less than 100% of stainless steel grades. Typical recycled content is 45%.
Manufacturability7
1.4901's machinability is fair (40/100, better than 72% of stainless steel grades); weldability fair (45/100); formability fair (35/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. 1.4901 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 1.4901
Is 1.4901 easy to machine?
Machines like a 200–230 HB Q&T alloy steel — rigid setups, coated carbide, moderate speed with generous feed; avoid overheating the surface which can locally re-harden.
Can 1.4901 be welded?
GTAW root + SMAW/FCAW fill with matching 9Cr-2W filler, preheat 200–250 °C, interpass ≤300 °C, cool to <100 °C then mandatory PWHT 750–775 °C; strict control needed to limit Type IV HAZ cracking.
Can 1.4901 be formed, bent or molded?
Hot form/bend at 950–1150 °C followed by full re-normalizing and tempering; cold bends above a few percent strain also require re-N+T.
1.4901 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| C | 0.07 – 0.13 | 0.1 |
| Si | ≤ 0.5 | 0.3 |
| Mn | 0.3 – 0.6 | 0.45 |
| P | ≤ 0.02 | 0.01 |
| S | ≤ 0.01 | 0 |
| Cr | 8.5 – 9.5 | 9 |
| Mo | 0.3 – 0.6 | 0.45 |
| Wkey creep-strengthening addition vs P91 | 1.5 – 2 | 1.75 |
| V | 0.15 – 0.25 | 0.2 |
| Nb | 0.04 – 0.09 | 0.06 |
| N | 0.03 – 0.07 | 0.05 |
| Bstabilizes M23C6 during creep | 0 – 0.01 | 0 |
| Ni | ≤ 0.4 | 0.15 |
| Allow Al so that AlN does not consume nitrogen | ≤ 0.02 | 0.01 |
| Ti | ≤ 0.01 | |
| Zr | ≤ 0.01 | |
| Fe | balance |
What surface finishes work on 1.4901?
Not corrosion resistant — shot blast plus primer/paint or preservation oil for storage; internal steam-side relies on the chromia/magnetite oxide, external hot surfaces may be aluminized.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Organic Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel 1.4901 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- X10CrWMoVNb9-2
How much does 1.4901 cost?
1.4901 is a premium-cost stainless steel ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
1.4901 — frequently asked
What is 1.4901 used for?
1.4901 is typically used for power plant superheater tubing, high-pressure steam piping and boiler headers. In short: P92 creep-resisting 9Cr steel; service to 620 °C; mandatory post-weld heat treatment.
What is the yield strength of 1.4901?
1.4901 has a typical yield strength of 520 MPa (75.4 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 79% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is 1.4901 easy to machine?
Not especially — machinability is rated fair (40/100, better than 72% of stainless steel grades). Machines like a 200–230 HB Q&T alloy steel — rigid setups, coated carbide, moderate speed with generous feed; avoid overheating the surface which can locally re-harden.
Can 1.4901 be welded?
With care — weldability is rated fair (45/100). GTAW root + SMAW/FCAW fill with matching 9Cr-2W filler, preheat 200–250 °C, interpass ≤300 °C, cool to <100 °C then mandatory PWHT 750–775 °C; strict control needed to limit Type IV HAZ cracking.
What surface finishes work on 1.4901?
Not corrosion resistant — shot blast plus primer/paint or preservation oil for storage; internal steam-side relies on the chromia/magnetite oxide, external hot surfaces may be aluminized.
Can 1.4901 be formed, bent or molded?
Hot form/bend at 950–1150 °C followed by full re-normalizing and tempering; cold bends above a few percent strain also require re-N+T.
What is the maximum service temperature of 1.4901?
1.4901 is rated for continuous use to about 620°C (1,148 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4901 N+T and 1.4901-AW?
N+T is the default condition — standard mill delivery condition for P92/T92 seamless pipe and tube; use for all code-design creep applications. AW: transient condition only — hard, brittle untempered martensite; never acceptable for service, PWHT is mandatory. Yield strength is 520 MPa in N+T versus 720 MPa in AW.
How much does 1.4901 cost?
1.4901 is a premium-cost stainless steel ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- EN 10216-2 — Seamless steel tubes for pressure purposes, alloy steels with specified elevated-temperature properties (X10CrWMoVNb9-2, 1.4901) — CEN (2020)
- ASTM A335/A335M Grade P92 — Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service — ASTM International (2022)
- ASTM A213/A213M Grade T92 and A182 Grade F92 — ASTM International (2022)
- GB/T 5310 — (10Cr9MoW2VNbBN) — SAC (2017)
- ASME BPVC Section II Part D — allowable stresses and physical properties for 9Cr-2W steel — ASME (2023)
- NIMS Creep Data Sheet series on ASME Gr.92 (9Cr-0.5Mo-1.8W-V-Nb) steel — NIMS (2014)
- Seamless P92/T92 boiler tube datasheets — Vallourec / Sandvik / Baosteel (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.