Stainless Steel 1.4547
EN 1.4547 · UNS S31254 · also 254SMO
1.4547 (S31254, 254SMO, X1CrNiMoCuN20-18-7) is a super-austenitic 6Mo stainless alloyed with copper and nitrogen for high chloride pitting and crevice corrosion resistance in seawater and other halide-bearing media.
Reference datasheet — 1.4547 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 SA condition
1.4547 tempers and conditions
1.4547 is supplied in 5 conditions, soft to hard. SA 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 |
|---|---|---|---|---|---|---|
SADefault Solution annealed | Standard supply condition for plate, pipe, fittings and forgings — maximum corrosion resistance and ductility. | 340 | 690 | 50 | 16 HRC | 2 % IACS |
Forged + solution annealed | Forged flanges, valve bodies and fittings solution annealed after hot working to restore corrosion resistance. | 340 | 690 | 40 | 17 HRC | 2 % IACS |
As-welded deposit | Property basis for as-welded joints made with Ni-base filler (e.g. ERNiCrMo-3) without post-weld solution treatment. | 350 | 660 | 35 | 200 HB | 2 % IACS |
Cold drawn | Cold drawn bar and tube for shafts, fasteners and pump/valve parts needing higher strength and tighter tolerances. | 550 | 800 | 30 | 25 HRC | 2 % IACS |
CW 1/4 Hard | Lightly temper-rolled strip when springback/stiffness or higher yield is needed and forming demands are modest. | 620 | 860 | 22 | 30 HRC | 2 % IACS |
Supply forms, finishes and certifications
Ways 1.4547 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
1D | Hot rolled, solution annealed and pickled plate | Surface finish |
2B | Cold rolled, annealed, pickled and skin-passed sheet | Surface finish |
BA | Bright annealed tube/strip | Surface finish |
What is 1.4547?
1.4547 (S31254, 254SMO, X1CrNiMoCuN20-18-7) is a super-austenitic 6Mo stainless alloyed with copper and nitrogen for high chloride pitting and crevice corrosion resistance in seawater and other halide-bearing media. In the solution-annealed condition it provides 340 MPa yield, 690 MPa tensile, 50 % elongation and about 210 HB, and is available as plate and sheet (1D, 2B, BA), cold-drawn and cold-worked bar, forgings and as-welded tube. The limits are alloy cost, low machinability (roughly one third of the productivity of 1212 steel) and a 400 °C service ceiling. Where chloride loading is lower, 316L or 2205 duplex is the cheaper choice. 1.4547 has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,325°C (2,417 °F). 1.4547 has a yield strength of 340 MPa (49.3 ksi) and a tensile strength of 690 MPa (100 ksi) — weaker than 55% of stainless steel grades. Elongation at break is 50% and the elastic modulus is 195 GPa (28.3 Msi).
What is 1.4547 used for?
- seawater handling
- desalination plants
- offshore piping
- flue-gas desulfurization
Advantages
- Good corrosion resistance — 86/100, better than 94% of stainless steel grades
- Ductile — tolerates forming and impact — 50%, better than 90% of stainless steel grades
- Tough — resists crack growth — 200 MPa·√m (182 ksi·√in), better than 86% of stainless steel grades
Limitations
- Difficult to machine — 25/100, worse than 88% of stainless steel grades
- Limited service temperature — 400°C (752 °F), worse than 78% of stainless steel grades
- Low electrical conductivity — 2 % IACS, worse than 77% of stainless steel grades
- High embodied carbon — 5.5 kg CO₂/kg, worse than 77% of stainless steel grades
1.4547 properties
Typical room-temperature values for 1.4547-SA; bars are the position among stainless steel grades.
Physical3
1.4547 has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,325°C (2,417 °F).
Mechanical17
1.4547 has a yield strength of 340 MPa (49.3 ksi) and a tensile strength of 690 MPa (100 ksi) — weaker than 55% of stainless steel grades. Elongation at break is 50% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal6
1.4547 is rated for continuous service to 400°C (752 °F). It conducts heat at 14 W/m·K (8.09 BTU/hr·ft·°F), worse than 80% of stainless steel grades. Thermal expansion is 16.5 µm/m·K (9.17 µin/in·°F).
Electrical3
1.4547 conducts electricity at 2 % IACS, worse than 77% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is excellent (86/100), better than 94% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4547 takes about 80 MJ of energy and emits 5.5 kg of CO₂ — more than 89% of stainless steel grades. Typical recycled content is 50%.
Manufacturability6
1.4547's machinability is poor (25/100, worse than 88% of stainless steel grades); weldability very good (75/100); formability good (62/100).
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. 1.4547 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 1.4547
Is 1.4547 easy to machine?
Tough, gummy and highly work-hardening — use rigid setups, positive-rake carbide, high feed with low-to-moderate speed, flood coolant and avoid dwelling; expect roughly a third of the productivity of 1212 steel.
Can 1.4547 be welded?
Readily welded by GTAW/GMAW/SMAW/PAW with over-alloyed Ni-base filler (ERNiCrMo-3 / ERNiCrMo-13) to keep weld-metal PREN up; no preheat, low interpass temperature, low heat input, and back-purge for root passes.
Can 1.4547 be formed, bent or molded?
Cold formable but needs about twice the press force of 316L and generous springback allowance; hot work 1150–1200 °C followed by solution anneal and quench, never air-cool from the 550–850 °C range.
1.4547 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 |
|---|---|---|
| Clow carbon for weldability | ≤ 0.02 | 0.01 |
| Si | ≤ 0.8 | 0.4 |
| Mn | ≤ 1 | 0.6 |
| P | ≤ 0.03 | |
| S | ≤ 0.01 | |
| Cr | 19.5 – 20.5 | 20 |
| Ni | 17.5 – 18.5 | 18 |
| Mo6Mo grade, drives PREN ≈ 43–45 | 6 – 6.5 | 6.1 |
| Cuimproves resistance in reducing acids | 0.5 – 1 | 0.7 |
| Nsolid-solution strengthening + pitting resistance | 0.18 – 0.22 | 0.2 |
| Fe | balance |
What surface finishes work on 1.4547?
Pickle and passivate after welding (or grind/blast then pickle) to restore the passive film; polishes to a bright durable finish, no anodizing — electropolishing is common for hygienic and seawater service.
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 1.4547 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does 1.4547 cost?
1.4547 is a high-cost stainless steel ($$$$), pricier than about 78% 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.
1.4547 — frequently asked
What is 1.4547 used for?
1.4547 is typically used for seawater handling, desalination plants, offshore piping and flue-gas desulfurization. In short: 6Mo super-austenitic grade; top chloride pitting resistance; needs Ni-base weld filler.
What is the yield strength of 1.4547?
1.4547 has a typical yield strength of 340 MPa (49.3 ksi) and a tensile strength of 690 MPa (100 ksi) — weaker than 55% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is 1.4547 easy to machine?
Not especially — machinability is rated poor (25/100, worse than 88% of stainless steel grades). Tough, gummy and highly work-hardening — use rigid setups, positive-rake carbide, high feed with low-to-moderate speed, flood coolant and avoid dwelling; expect roughly a third of the productivity of 1212 steel.
Can 1.4547 be welded?
Yes — weldability is rated very good (75/100). Readily welded by GTAW/GMAW/SMAW/PAW with over-alloyed Ni-base filler (ERNiCrMo-3 / ERNiCrMo-13) to keep weld-metal PREN up; no preheat, low interpass temperature, low heat input, and back-purge for root passes.
What surface finishes work on 1.4547?
Pickle and passivate after welding (or grind/blast then pickle) to restore the passive film; polishes to a bright durable finish, no anodizing — electropolishing is common for hygienic and seawater service.
Can 1.4547 be formed, bent or molded?
Cold formable but needs about twice the press force of 316L and generous springback allowance; hot work 1150–1200 °C followed by solution anneal and quench, never air-cool from the 550–850 °C range.
What is the maximum service temperature of 1.4547?
1.4547 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4547-SA and 1.4547-CD?
SA is the default condition — standard supply condition for plate, pipe, fittings and forgings — maximum corrosion resistance and ductility. CD: cold drawn bar and tube for shafts, fasteners and pump/valve parts needing higher strength and tighter tolerances. Yield strength is 340 MPa in SA versus 550 MPa in CD.
How much does 1.4547 cost?
1.4547 is a high-cost stainless steel ($$$$), pricier than about 78% 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
- ASTM A240/A240M (S31254 plate, sheet, strip) — ASTM International (2024)
- ASTM A182/A182M grade F44 (forgings) — ASTM International (2022)
- EN 10088-2 / 10088-3 (X1CrNiMoCuN20-18-7, 1.4547) — CEN (2014)
- 254 SMO / Outokumpu Ultra 254 SMO data sheet — Outokumpu (2023)
- Sandvik SX / 254 SMO tube and bar data sheet — Alleima (Sandvik Materials Technology) (2022)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
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.