Stainless Steel ER2594 AW-SAW
Finish state
AW-SAW = as-welded submerged-arc deposit with basic flux
Pick for high heat-input submerged-arc welding of heavy-wall pipe and pressure vessels; run with basic flux and limit interpass temperature, accepting 640 MPa yield.
Values for the AW-SAW condition
Other ER2594 tempers and conditions
ER2594 is listed in 4 conditions; see the grade overview at ER2594.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed ~1080–1120 °C + water quench | Specify solution annealing at 1080–1120 °C with water quench when phase balance and corrosion resistance must be fully restored, as on overlays and repair-welded castings. | 600 | 820 | 32 | 24 HRC | 2.2 % IACS |
AW-SAWThis page As-welded submerged-arc deposit with basic flux | Pick for high heat-input submerged-arc welding of heavy-wall pipe and pressure vessels; run with basic flux and limit interpass temperature, accepting 640 MPa yield. | 640 | 850 | 25 | 25 HRC | 2.2 % IACS |
As-welded MIG/pulsed-MIG deposit | Use for high-productivity multi-layer welding of thick sections; the higher heat input of MIG/pulsed-MIG makes ferrite control and toughness requirements stricter. | 660 | 870 | 25 | 27 HRC | 2.2 % IACS |
AWDefault As-welded deposit | Default pick for butt joints and overlays on 2507/S32760 super duplex, deposited by GTAW under Ar+2%N₂ typical shielding and used as welded with no post-weld heat treatment. | 680 | 880 | 27 | 26 HRC | 2.2 % IACS |
What is ER2594 AW-SAW?
ER2594 AW-SAW is ER2594 supplied in the AW-SAW condition — pick for high heat-input submerged-arc welding of heavy-wall pipe and pressure vessels; run with basic flux and limit interpass temperature, accepting 640 MPa yield. ER2594 AW-SAW has a yield strength of 640 MPa (92.8 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 90% of stainless steel grades. Elongation at break is 25% and the elastic modulus is 200 GPa (29 Msi). ER2594 AW-SAW 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). AW is the default condition FabDigit quotes; AW-SAW is available on request or by drawing note.
Advantages
- Good corrosion resistance — 85/100, better than 92% of stainless steel grades
- High strength — 640 MPa (92.8 ksi), better than 90% of stainless steel grades
Limitations
- Limited service temperature — 250°C (482 °F), worse than 99% of stainless steel grades
- Difficult to machine — 24/100, worse than 93% of stainless steel grades
- Low fracture toughness — 80 MPa·√m (72.8 ksi·√in), worse than 79% of stainless steel grades
- High embodied carbon — 5.5 kg CO₂/kg, worse than 77% of stainless steel grades
ER2594 AW-SAW properties
Typical room-temperature values for ER2594 AW-SAW; 22 are specific to this condition. Other listed values are ER2594 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
ER2594 AW-SAW 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).
Mechanical17
ER2594 AW-SAW has a yield strength of 640 MPa (92.8 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 90% of stainless steel grades. Elongation at break is 25% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
ER2594 AW-SAW is rated for continuous service to 250°C (482 °F). It conducts heat at 16 W/m·K (9.24 BTU/hr·ft·°F), better than 58% of stainless steel grades. Thermal expansion is 13 µm/m·K (7.22 µin/in·°F).
Electrical3
ER2594 AW-SAW conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), better than 92% of stainless steel grades.
Sustainability4
Producing a kilogram of ER2594 AW-SAW takes about 55 MJ of energy and emits 5.5 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 55%.
Manufacturability7
ER2594 AW-SAW's machinability is poor (24/100, worse than 93% of stainless steel grades); weldability very good (75/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with ER2594 AW-SAW
Is ER2594 easy to machine?
Weld metal work-hardens strongly and has low thermal conductivity; use rigid clamping, sharp carbide tooling, low speed with heavy feed and generous coolant.
Can ER2594 be welded?
Suitable for GTAW, GMAW and SAW. Control heat input to about 0.5–1.5 kJ/mm and interpass temperature to ≤150 °C, and use Ar + 1–3% N₂ for shielding and backing to maintain nitrogen content and phase balance.
Can ER2594 be formed, bent or molded?
As a filler metal it is not normally formed. Deposits have limited cold formability, so bend to large radii and keep high-strain areas away from the weld.
What surface finishes work on ER2594?
Heat tint must be removed after welding by pickling and passivation, or by mechanical grinding plus passivation, to restore the passive film. Electropolishing is possible; anodizing is not.
ER2594 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 | ≤ 0.03 | 0.02 |
| Cr | 24 – 27 | 25.5 |
| NiHigher than 2507 base metal; ensures as-welded austenite ratio | 8 – 10.5 | 9.5 |
| Mo | 2.5 – 4.5 | 4 |
| N | 0.2 – 0.3 | 0.25 |
| Mn | ≤ 2.5 | 0.5 |
| Si | ≤ 1 | 0.4 |
| Cu | ≤ 1.5 | 0.3 |
| W | ≤ 1 | 0.2 |
| P | ≤ 0.03 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Fe | balance | — |
ER2594 AW-SAW — frequently asked
What is ER2594 AW-SAW used for?
ER2594 AW-SAW is typically used for super duplex subsea equipment, high-strength corrosion-resistant piping, subsea manifolds and connectors, offshore riser and firewater systems, chemical process vessels in chloride service and heat exchanger welds in seawater service. In short: highest-alloy duplex filler; 2507 super duplex match; best pitting resistance here.
What is the yield strength of ER2594 AW-SAW?
ER2594 AW-SAW has a typical yield strength of 640 MPa (92.8 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 90% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is ER2594 AW-SAW easy to machine?
Not especially — machinability is rated poor (24/100, worse than 93% of stainless steel grades). Weld metal work-hardens strongly and has low thermal conductivity; use rigid clamping, sharp carbide tooling, low speed with heavy feed and generous coolant.
Can ER2594 AW-SAW be welded?
Yes — weldability is rated very good (75/100). Suitable for GTAW, GMAW and SAW. Control heat input to about 0.5–1.5 kJ/mm and interpass temperature to ≤150 °C, and use Ar + 1–3% N₂ for shielding and backing to maintain nitrogen content and phase balance.
What surface finishes work on ER2594 AW-SAW?
Heat tint must be removed after welding by pickling and passivation, or by mechanical grinding plus passivation, to restore the passive film. Electropolishing is possible; anodizing is not.
Can ER2594 AW-SAW be formed, bent or molded?
As a filler metal it is not normally formed. Deposits have limited cold formability, so bend to large radii and keep high-strain areas away from the weld.
What is the maximum service temperature of ER2594 AW-SAW?
ER2594 AW-SAW 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.
What is the difference between ER2594-AW and ER2594-SA?
AW is the default condition — default pick for butt joints and overlays on 2507/S32760 super duplex, deposited by GTAW under Ar+2%N₂ typical shielding and used as welded with no post-weld heat treatment. SA: specify solution annealing at 1080–1120 °C with water quench when phase balance and corrosion resistance must be fully restored, as on overlays and repair-welded castings. Yield strength is 680 MPa in AW versus 600 MPa in SA.
Sources
- AWS A5.9/A5.9M — Bare Stainless Steel Welding Electrodes and Rods (ER2594, UNS S39594) — AWS (2017)
- ASTM A276/A790 & ASTM A923 (duplex acceptance) — ASTM (2020)
- Super duplex filler metal 2594 data sheets — ESAB / Böhler Welding / Sandvik (2023)
- ASM Handbook Vol.6A — Welding of Duplex Stainless Steels — ASM International (2011)
- SAF 2507 / Forta SDX 2507 base-metal physical property data — Alleima (Sandvik) / Outokumpu (2023)
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.