Stainless Steel E2594
UNS W39594 · ASTM A5.4
E2594 is a 25Cr-9Ni-4Mo super duplex covered electrode to AWS A5.4 (UNS W39594), formulated to match 2507-type (S32750) base metal and available in -15, -16 and -17 coatings.
Reference datasheet — E2594 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.
E2594 tempers and conditions
E2594 is supplied in one standard condition, SA.
Supply forms, finishes and certifications
Ways E2594 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
AW-15 | E2594-15 | Surface finish |
AW-16Default | E2594-16 | Surface finish |
AW-17 | E2594-17 | Surface finish |
What is E2594?
E2594 is a 25Cr-9Ni-4Mo super duplex covered electrode to AWS A5.4 (UNS W39594), formulated to match 2507-type (S32750) base metal and available in -15, -16 and -17 coatings. It is chosen where very high strength must be combined with superior pitting and crevice corrosion resistance, with as-welded properties near 680 MPa yield, 870 MPa tensile, 26% elongation and 27 HRC. Deposits require controlled heat input to keep ferrite in range and avoid sigma phase, and service is limited to about 250 °C. E2593 is the lower-alloy alternative when full 2507-level pitting resistance is not needed. E2594 has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,350°C (2,462 °F). E2594 has a yield strength of 680 MPa (98.6 ksi) and a tensile strength of 870 MPa (126 ksi) — stronger than 91% of stainless steel grades. Elongation at break is 26% and the elastic modulus is 200 GPa (29 Msi).
What is E2594 used for?
- subsea and offshore equipment
- desalination
- high chloride process piping
- heat exchangers
Advantages
- Good corrosion resistance — 86/100, better than 94% of stainless steel grades
- High strength — 680 MPa (98.6 ksi), better than 91% of stainless steel grades
- Readily welded — 80/100, better than 80% of stainless steel grades
Limitations
- Limited service temperature — 250°C (482 °F), worse than 99% of stainless steel grades
- Difficult to machine — 25/100, worse than 88% of stainless steel grades
- Hard to polish — 60/100, worse than 80% of stainless steel grades
- Limited formability — 25/100, worse than 78% of stainless steel grades
- Low fracture toughness — 90 MPa·√m (81.9 ksi·√in), worse than 75% of stainless steel grades
E2594 properties
Typical room-temperature values; bars are the position among stainless steel grades.
Physical3
E2594 has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,350°C (2,462 °F).
Mechanical15
E2594 has a yield strength of 680 MPa (98.6 ksi) and a tensile strength of 870 MPa (126 ksi) — stronger than 91% of stainless steel grades. Elongation at break is 26% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
E2594 is rated for continuous service to 250°C (482 °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
E2594 conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is excellent (86/100), better than 94% of stainless steel grades.
Sustainability4
Producing a kilogram of E2594 takes about 62 MJ of energy and emits 5.2 kg of CO₂ — more than 75% of stainless steel grades. Typical recycled content is 45%.
Manufacturability6
E2594's machinability is poor (25/100, worse than 88% of stainless steel grades); weldability very good (80/100); formability poor (25/100).
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. E2594 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with E2594
Is E2594 easy to machine?
Deposited super duplex work-hardens fast — use rigid setups, sharp carbide, heavy positive feed and flood coolant; grind rather than mill where possible.
Can E2594 be welded?
Redry electrodes (≈250–300 °C/2 h), DCEP (or AC for -16/-17), stringer beads, heat input 0.5–2.0 kJ/mm and interpass ≤150 °C to keep ferrite 30–60 FN and avoid σ-phase.
Can E2594 be formed, bent or molded?
Not a wrought product; consumable is used as-deposited, no post-weld cold forming of the weld metal is recommended.
E2594 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 |
|---|---|---|
| CAWS A5.4 max | ≤ 0.04 | 0.03 |
| Cr | 24 – 27 | 25.3 |
| Ni | 8 – 10.5 | 9.4 |
| Mo | 2.5 – 4.5 | 3.8 |
| Nkey austenite stabiliser / PREN contributor | 0.1 – 0.25 | 0.2 |
| Mn | 0.5 – 2 | 1 |
| Si | ≤ 1 | 0.5 |
| Cu | ≤ 1.5 | 0.3 |
| Woptional; higher in S32760-matching variants | ≤ 1 | 0.3 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Fe | balance |
What surface finishes work on E2594?
Remove slag and heat tint fully — pickle (HNO₃/HF paste) or blast plus passivate per ASTM A380 to restore the full pitting resistance of the weld and HAZ.
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 E2594 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- W39594
- ASTM
- A5.4
- Also called
- S32750/2507 filler
How much does E2594 cost?
E2594 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
E2594 — frequently asked
What is E2594 used for?
E2594 is typically used for subsea and offshore equipment, desalination, high chloride process piping and heat exchangers. In short: matched to 2507 base metal; highest strength duplex electrode; superior crevice corrosion resistance.
What is the yield strength of E2594?
E2594 has a typical yield strength of 680 MPa (98.6 ksi) and a tensile strength of 870 MPa (126 ksi) — stronger than 91% of stainless steel grades.
Is E2594 easy to machine?
Not especially — machinability is rated poor (25/100, worse than 88% of stainless steel grades). Deposited super duplex work-hardens fast — use rigid setups, sharp carbide, heavy positive feed and flood coolant; grind rather than mill where possible.
Can E2594 be welded?
Yes — weldability is rated very good (80/100). Redry electrodes (≈250–300 °C/2 h), DCEP (or AC for -16/-17), stringer beads, heat input 0.5–2.0 kJ/mm and interpass ≤150 °C to keep ferrite 30–60 FN and avoid σ-phase.
What surface finishes work on E2594?
Remove slag and heat tint fully — pickle (HNO₃/HF paste) or blast plus passivate per ASTM A380 to restore the full pitting resistance of the weld and HAZ.
Can E2594 be formed, bent or molded?
Not a wrought product; consumable is used as-deposited, no post-weld cold forming of the weld metal is recommended.
What is the maximum service temperature of E2594?
E2594 is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does E2594 cost?
E2594 is a high-cost stainless steel ($$$$), 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
- AWS A5.4/A5.4M — Specification for Stainless Steel Electrodes for Shielded Metal Arc Welding — American Welding Society (2012)
- ASTM A240 / UNS S32750 (2507) base-metal properties — ASTM International (2022)
- Super duplex SMAW electrode all-weld-metal data (2594-type) — ESAB / Böhler Welding / Metrode (2023)
- ASM Handbook Vol. 6 — Welding, Brazing and Soldering (duplex stainless welding) — ASM International (1993)
- Duplex stainless steel physical property data (2507) — Outokumpu (2020)
- NACE MR0175 / ISO 15156-3 hardness limits for duplex weld metal — NACE/ISO (2020)
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.