Stainless Steel 1.4507
EN 1.4507 · UNS S32550 · ASTM A240 S32550 · also Ferralium 255
EN 1.4507 (S32550, X2CrNiMoCuN25-6-3, Ferralium 255) is a copper-bearing 25Cr-6Ni-3Mo super duplex stainless combining high strength with resistance to sulfuric and phosphoric acid service and a corrosion score of 88.
Reference datasheet — 1.4507 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
1.4507 tempers and conditions
1.4507 is supplied in 7 conditions, soft to hard. SA is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hot rolled plate, solution annealed and pickled | Choose for pressure vessel and tank plate 5–100 mm; thickest sections sit at the low end of the strength band. | 600 | 820 | 32 | 25 HRC | 2 % IACS |
forged bar/flange, solution annealed and quenched (ASTM A182 F61) | For valve bodies, flanges and pump components; heavy sections need verified quench rate to avoid sigma phase at mid-wall. | 600 | 810 | 28 | 26 HRC | 2 % IACS |
As-welded deposit | Reference condition for weld-joint design; over-alloyed Ni filler restores austenite, but HAZ toughness and pitting resistance fall below parent metal. | 600 | 800 | 22 | 27 HRC | 2 % IACS |
SADefault Solution annealed + quenched | Standard stocked condition: ~1080–1120 °C solution anneal + rapid quench for balanced 50/50 phase ratio and full corrosion resistance. | 620 | 830 | 30 | 26 HRC | — |
Cold rolled sheet/coil, annealed and pickled | Thin gauge (<6 mm) sheet for linings, ducts and fabricated vessels; slightly higher strength and better surface than hot rolled plate. | 640 | 850 | 28 | 27 HRC | 2 % IACS |
Ferralium 255-3SC high-strength solution annealed bar | Proprietary tighter-chemistry version guaranteeing ≥620 MPa proof stress for subsea and pump-shaft duty at the same corrosion resistance. | 700 | 900 | 25 | 30 HRC | 2 % IACS |
Cold drawn | Pick for shafts and fasteners needing higher yield and tighter tolerance; ductility and impact toughness drop and residual stress rises. | 800 | 950 | 18 | 32 HRC | 2 % IACS |
Supply forms, finishes and certifications
Ways 1.4507 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
TUBE-SA | Seamless/welded tube and pipe, solution annealed | Supply form |
What is 1.4507?
EN 1.4507 (S32550, X2CrNiMoCuN25-6-3, Ferralium 255) is a copper-bearing 25Cr-6Ni-3Mo super duplex stainless combining high strength with resistance to sulfuric and phosphoric acid service and a corrosion score of 88. It is selected for 620 MPa yield, 830 MPa tensile, 30% elongation and 260 HB / 26 HRC in chemical process and marine equipment, and is stocked as solution-annealed plate, sheet, bar, forgings, tube, cold-drawn bar and 255-3SC material. Service is limited to about 300 °C, machining is slow and cold forming restricted; 1.4501 is the nearest tungsten-alloyed super duplex, 1.4462 the lower-cost option. 1.4507 has a density of 7.81 g/cm³ (0.282 lb/in³), heavier than 57% of stainless steel grades. It melts at 1,370°C (2,498 °F). 1.4507 has a yield strength of 620 MPa (89.9 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 88% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi).
What is 1.4507 used for?
- pumps and valves
- chemical process piping
- marine fasteners
- pulp and paper equipment
Advantages
- Good corrosion resistance — 88/100, better than 97% of stainless steel grades
- High strength — 620 MPa (89.9 ksi), better than 88% of stainless steel grades
Limitations
- Limited service temperature — 300°C (572 °F), worse than 90% of stainless steel grades
- Difficult to machine — 25/100, worse than 88% of stainless steel grades
- Low electrical conductivity — 2 % IACS, worse than 77% of stainless steel grades
1.4507 properties
Typical room-temperature values for 1.4507-SA; bars are the position among stainless steel grades.
Physical3
1.4507 has a density of 7.81 g/cm³ (0.282 lb/in³), heavier than 57% of stainless steel grades. It melts at 1,370°C (2,498 °F).
Mechanical15
1.4507 has a yield strength of 620 MPa (89.9 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 88% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
1.4507 is rated for continuous service to 300°C (572 °F). It conducts heat at 13.5 W/m·K (7.8 BTU/hr·ft·°F), worse than 83% of stainless steel grades. Thermal expansion is 12.5 µm/m·K (6.94 µin/in·°F).
Electrical3
1.4507 conducts electricity at 2 % IACS, worse than 77% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is excellent (88/100), better than 97% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4507 takes about 55 MJ of energy and emits 5 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 60%.
Manufacturability6
1.4507's machinability is poor (25/100, worse than 88% of stainless steel grades); weldability good (65/100); formability fair (45/100).
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. 1.4507 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 1.4507
Is 1.4507 easy to machine?
Machine like a super duplex: rigid setups, positive-rake coated carbide, ~30–60 m/min cutting speed, heavy constant feed and copious coolant to avoid work hardening and built-up edge.
Can 1.4507 be welded?
GTAW/GMAW/SMAW with over-alloyed 25.10.4.L (ER2553) filler, interpass ≤150 °C, heat input roughly 0.5–2.0 kJ/mm, no preheat and normally no PWHT; keep ferrite 30–65% and back-purge with Ar (+N2).
Can 1.4507 be formed, bent or molded?
Hot form 1000–1150 °C followed by full solution anneal and quench; cold forming needs ~2× the load of 304 with large springback allowance and is limited to moderate strains.
1.4507 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 |
|---|---|---|
| CEN 10088-2 max | ≤ 0.03 | 0.02 |
| Si | ≤ 0.7 | 0.4 |
| Mn | ≤ 2 | 0.8 |
| P | ≤ 0.04 | — |
| S | ≤ 0.02 | — |
| CrASTM S32550 allows 24.0–27.0 | 24 – 26 | 25 |
| NiASTM S32550: 4.5–6.5 | 5.5 – 7.5 | 6.5 |
| Mo | 2.7 – 4 | 3.3 |
| Cucopper addition for reducing-acid resistance | 1 – 2.5 | 1.8 |
| N | 0.15 – 0.3 | 0.22 |
| Fe | balance | — |
What surface finishes work on 1.4507?
Pickle and passivate (HNO3/HF) after hot work or welding to remove heat tint; electropolish or mechanical polish for hygienic/chemical service — do not anodize.
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 1.4507 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- S32550
- ASTM
- A240 S32550
- EN / DIN / Werkstoff-Nr.
- X2CrNiMoCuN25-6-3
- Trade names
- Ferralium 255
- Other
- 255
How much does 1.4507 cost?
1.4507 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.
1.4507 — frequently asked
What is 1.4507 used for?
1.4507 is typically used for pumps and valves, chemical process piping, marine fasteners and pulp and paper equipment. In short: copper-bearing super duplex; acid-service duplex grade; 620 MPa yield strength.
What is the yield strength of 1.4507?
1.4507 has a typical yield strength of 620 MPa (89.9 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 88% of stainless steel grades. Strength varies by condition: see the 7 listed tempers.
Is 1.4507 easy to machine?
Not especially — machinability is rated poor (25/100, worse than 88% of stainless steel grades). Machine like a super duplex: rigid setups, positive-rake coated carbide, ~30–60 m/min cutting speed, heavy constant feed and copious coolant to avoid work hardening and built-up edge.
Can 1.4507 be welded?
Yes — weldability is rated good (65/100). GTAW/GMAW/SMAW with over-alloyed 25.10.4.L (ER2553) filler, interpass ≤150 °C, heat input roughly 0.5–2.0 kJ/mm, no preheat and normally no PWHT; keep ferrite 30–65% and back-purge with Ar (+N2).
What surface finishes work on 1.4507?
Pickle and passivate (HNO3/HF) after hot work or welding to remove heat tint; electropolish or mechanical polish for hygienic/chemical service — do not anodize.
Can 1.4507 be formed, bent or molded?
Hot form 1000–1150 °C followed by full solution anneal and quench; cold forming needs ~2× the load of 304 with large springback allowance and is limited to moderate strains.
What is the maximum service temperature of 1.4507?
1.4507 is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4507-SA and 1.4507-CD?
SA is the default condition — standard stocked condition: ~1080–1120 °C solution anneal + rapid quench for balanced 50/50 phase ratio and full corrosion resistance. CD: pick for shafts and fasteners needing higher yield and tighter tolerance; ductility and impact toughness drop and residual stress rises. Yield strength is 620 MPa in SA versus 800 MPa in CD.
How much does 1.4507 cost?
1.4507 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
- EN 10088-2/-3 Stainless steels — sheet, plate and bars — CEN (2014)
- ASTM A240/A240M (UNS S32550) — ASTM International (2023)
- ASTM A479/A182/A790 duplex product specifications — ASTM International (2022)
- Ferralium 255 / 255-3SC alloy datasheet — Langley Alloys (2022)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels — ASM International (1990)
- Practical Guidelines for the Fabrication of Duplex Stainless Steels — IMOA (2014)
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.