Stainless Steel S32404
UNS S32404
S32404 (Uranus 50) is a 22Cr-5.5Ni-2.5Mo-Cu-N duplex stainless steel developed by Creusot-Loire/Industeel, with copper added for resistance to sulfuric acid and general corrosion beyond standard 2205.
Reference datasheet — S32404 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
S32404 tempers and conditions
S32404 is supplied in 4 conditions, soft to hard. SA is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Forged + Solution Annealed | For flanges, valve bodies and heavy fittings; requires full solution anneal and quench after forging to restore phase balance. | 500 | 690 | 28 | 24 HRC | 2.2 % IACS |
SADefault Solution Annealed | Standard supply condition for plate, bar, tube and forgings — balanced 50/50 ferrite–austenite with best corrosion resistance and toughness. | 510 | 700 | 30 | 24 HRC | 2.2 % IACS |
As-welded deposit | Property set for fabricated joints left in the as-welded condition — strength near base metal but reduced toughness and pitting margin in the HAZ. | 520 | 700 | 22 | 25 HRC | 2.2 % IACS |
Cold drawn | Choose for small-diameter shafts, fasteners and machined pump/valve parts needing tighter tolerance and higher strength. | 650 | 830 | 20 | 29 HRC | 2.2 % IACS |
Supply forms, finishes and certifications
Ways S32404 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, Solution Annealed | Supply form |
CRA | Cold Rolled, Annealed Sheet / Strip | Surface finish |
HRAP | Hot Rolled, Solution Annealed and Pickled Plate | Surface finish |
What is S32404?
S32404 (Uranus 50) is a 22Cr-5.5Ni-2.5Mo-Cu-N duplex stainless steel developed by Creusot-Loire/Industeel, with copper added for resistance to sulfuric acid and general corrosion beyond standard 2205. Engineers specify it for its 510 MPa yield, 700 MPa tensile and 30 % elongation at about 240 HB (24 HRC), supplied as solution-annealed plate, hot- and cold-rolled sheet, cold-drawn bar, forgings and tube. Service is capped at 300 °C and the duplex structure demands controlled heat input and solution annealing after hot work; where copper is not needed for acid service, 2205 (S32205) is cheaper and easier to source. S32404 has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,400°C (2,552 °F). S32404 has a yield strength of 510 MPa (74 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 78% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi).
What is S32404 used for?
- chemical process vessels
- heat exchangers
- pulp and paper equipment
- flue gas desulfurization
- marine components
Advantages
- High strength — 510 MPa (74 ksi), better than 78% of stainless steel grades
Limitations
- Limited service temperature — 300°C (572 °F), worse than 90% of stainless steel grades
S32404 properties
Typical room-temperature values for S32404-SA; bars are the position among stainless steel grades.
Physical3
S32404 has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical17
S32404 has a yield strength of 510 MPa (74 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 78% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi).
Thermal5
S32404 is rated for continuous service to 300°C (572 °F). It conducts heat at 15 W/m·K (8.67 BTU/hr·ft·°F), worse than 59% of stainless steel grades. Thermal expansion is 13 µm/m·K (7.22 µin/in·°F).
Electrical3
S32404 conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (70/100), better than 68% of stainless steel grades.
Sustainability4
Producing a kilogram of S32404 takes about 62 MJ of energy and emits 5.2 kg of CO₂ — more than 75% of stainless steel grades. Typical recycled content is 70%.
Manufacturability6
S32404's machinability is poor (28/100, worse than 79% of stainless steel grades); weldability good (62/100); formability good (55/100).
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. S32404 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with S32404
Is S32404 easy to machine?
Machine like 2205 but tougher: rigid setups, positive-rake carbide, ~60–90 m/min with heavy constant feed and flood coolant; avoid dwelling to prevent work hardening.
Can S32404 be welded?
Weld with 22Cr duplex (2209/25.10.4) filler, GTAW/GMAW/SMAW, interpass ≤150 °C and heat input ~0.5–2.0 kJ/mm; no preheat, avoid PWHT below 1020 °C, use N₂-bearing backing gas on root passes.
Can S32404 be formed, bent or molded?
Cold form with ~50% more force and larger bend radii than 304; hot work 1000–1150 °C followed by full solution anneal and water quench — never finish-form or cool slowly through 600–950 °C.
S32404 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 | ≤ 0.04 | 0.02 |
| Si | ≤ 1 | 0.5 |
| Mn | ≤ 2 | 1.2 |
| P | ≤ 0.03 | |
| S | ≤ 0.01 | |
| Cr | 20.5 – 22.5 | 21.5 |
| Ni | 5.5 – 8.5 | 6.5 |
| Mo | 2 – 3 | 2.5 |
| Cuimproves acid resistance | 1 – 2 | 1.5 |
| N | ≤ 0.2 | 0.15 |
| Fe | balance |
What surface finishes work on S32404?
Pickle (HNO₃/HF) and passivate after welding or grinding to restore the passive film; can be electropolished or mechanically polished, but not anodised or conventionally plated.
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 S32404 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- Uranus 50
How much does S32404 cost?
S32404 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.
S32404 — frequently asked
What is S32404 used for?
S32404 is typically used for chemical process vessels, heat exchangers, pulp and paper equipment, flue gas desulfurization and marine components. In short: copper-bearing duplex; sulfuric acid service; twice the yield of 316L.
What is the yield strength of S32404?
S32404 has a typical yield strength of 510 MPa (74 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 78% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is S32404 easy to machine?
Not especially — machinability is rated poor (28/100, worse than 79% of stainless steel grades). Machine like 2205 but tougher: rigid setups, positive-rake carbide, ~60–90 m/min with heavy constant feed and flood coolant; avoid dwelling to prevent work hardening.
Can S32404 be welded?
Yes — weldability is rated good (62/100). Weld with 22Cr duplex (2209/25.10.4) filler, GTAW/GMAW/SMAW, interpass ≤150 °C and heat input ~0.5–2.0 kJ/mm; no preheat, avoid PWHT below 1020 °C, use N₂-bearing backing gas on root passes.
What surface finishes work on S32404?
Pickle (HNO₃/HF) and passivate after welding or grinding to restore the passive film; can be electropolished or mechanically polished, but not anodised or conventionally plated.
Can S32404 be formed, bent or molded?
Cold form with ~50% more force and larger bend radii than 304; hot work 1000–1150 °C followed by full solution anneal and water quench — never finish-form or cool slowly through 600–950 °C.
What is the maximum service temperature of S32404?
S32404 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 S32404-SA and S32404-CD?
SA is the default condition — standard supply condition for plate, bar, tube and forgings — balanced 50/50 ferrite–austenite with best corrosion resistance and toughness. CD: choose for small-diameter shafts, fasteners and machined pump/valve parts needing tighter tolerance and higher strength. Yield strength is 510 MPa in SA versus 650 MPa in CD.
How much does S32404 cost?
S32404 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 — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip (UNS S32404) — ASTM International (2023)
- ASTM A479/A479M and A182/A182M — bars and forgings for pressure service — ASTM International (2022)
- URANUS 50 (UNS S32404) duplex stainless steel data — Industeel / ArcelorMittal (formerly Creusot-Loire) (2019)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (duplex stainless section) — 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.