Stainless Steel E2594-SA (Solution annealed weld metal)
Heat-treated state
UNS W39594 · ASTM A5.4
Only for castings/overlays that are re-solution treated with the component; restores phase balance and toughness but lowers strength slightly.
Values for the SA condition
What is E2594-SA?
E2594-SA is E2594 heat treated to SA — only for castings/overlays that are re-solution treated with the component; restores phase balance and toughness but lowers strength slightly. E2594-SA has a yield strength of 600 MPa (87 ksi) and a tensile strength of 820 MPa (119 ksi) — stronger than 86% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi). E2594-SA 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).
Advantages
- Good corrosion resistance — 88/100, better than 97% of stainless steel grades
- High strength — 600 MPa (87 ksi), better than 86% 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-SA properties
Typical room-temperature values for E2594-SA; 7 are specific to this condition. Other listed values are E2594 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
E2594-SA 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-SA has a yield strength of 600 MPa (87 ksi) and a tensile strength of 820 MPa (119 ksi) — stronger than 86% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
E2594-SA 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-SA conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is excellent (88/100), better than 97% of stainless steel grades.
Sustainability4
Producing a kilogram of E2594-SA 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-SA's machinability is poor (25/100, worse than 88% of stainless steel grades); weldability very good (80/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with E2594-SA
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.
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.
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 |
E2594-SA — frequently asked
What is E2594-SA used for?
E2594-SA 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-SA?
E2594-SA has a typical yield strength of 600 MPa (87 ksi) and a tensile strength of 820 MPa (119 ksi) — stronger than 86% of stainless steel grades.
Is E2594-SA 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-SA 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-SA?
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-SA 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-SA?
E2594-SA 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.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.