ER2594 – wire and rod for super duplex 2507
Super duplex 25Cr-9.5Ni-4Mo-N filler metal, for super duplex 2507 steels (UNS S32750/S32760) and for alloy S32550, with PREN above 40.
Product forms and equivalents
| Process | Classification |
|---|---|
| TIG rod (GTAW) | ER2594 |
| Solid MIG/MAG wire (GMAW) | ER2594 |
| Covered electrode (SMAW) | E2594-16 – AWS A5.4 |
| Flux-cored wire (FCAW) | E2594T0-1/-4 – AWS A5.22* |
| Submerged arc wire (SAW) | ER2594 + flux |
| Designation | Value |
|---|---|
| AWS | ER2594 |
| Specification | AWS A5.9/A5.9M / ASME SFA-5.9 |
| UNS | S32594* |
| Others | EN ISO 14343-A: W/G 25 9 4 N L; W.Nr. 1.4501* |
Chemical composition (%)
| Element | wt. % |
|---|---|
| C | ≤ 0.03 |
| Cr | 24.0 – 27.0 |
| Ni | 8.0 – 10.5 |
| Mo | 2.5 – 4.5 |
| N | 0.20 – 0.30 |
| W | ≤ 1.0 |
| Cu | ≤ 1.5 |
| Mn | ≤ 2.5 |
| Si | ≤ 1.0 |
| P | ≤ 0.03 |
| S | ≤ 0.02 |
Properties of the deposited metal
| Property | Value |
|---|---|
| Tensile strength of deposited metal | ≥ 760 MPa (AWS A5.4 minimum for E2594, reference) |
| Elongation | ≥ 15 % (AWS A5.4 minimum for E2594, reference) |
Materials welded with ER2594
- Super duplex 2507 / F53 / S32750
- Super duplex Zeron 100 / F55 / S32760
- Ferralium 255 / F61
- Duplex F51 / S31803
Dissimilar joints: Can be used on duplex 2205 when a bead with higher pitting resistance than the base metal is wanted.
Why the composition differs from the base metal
As with 2209, the nickel is raised (about 9–10 %, versus 6–8 % in 2507) so that the rapidly cooled bead forms enough austenite. The high nitrogen keeps the PREN of the deposit at the same level as the base metal.
Welding precautions
- Typical heat input of 0.5 to 1.5 kJ/mm and maximum interpass of 100 °C.
- TIG with argon and 1–2 % N2 helps keep the nitrogen in the bead; purge with argon or argon-nitrogen.
- Avoid repeated reheating of the same region (risk of sigma phase).
- Do not weld the root without wire.
Frequently asked questions
What is ER2594 used for?
Super duplex 25Cr-9.5Ni-4Mo-N filler metal, for super duplex 2507 steels (UNS S32750/S32760) and for alloy S32550, with PREN above 40.
Why is the composition of ER2594 different from the material it welds?
As with 2209, the nickel is raised (about 9–10 %, versus 6–8 % in 2507) so that the rapidly cooled bead forms enough austenite. The high nitrogen keeps the PREN of the deposit at the same level as the base metal.
Which covered electrode corresponds to ER2594?
E2594-16 – AWS A5.4.
What precautions apply when welding with ER2594?
Typical heat input of 0.5 to 1.5 kJ/mm and maximum interpass of 100 °C. TIG with argon and 1–2 % N2 helps keep the nitrogen in the bead; purge with argon or argon-nitrogen. Avoid repeated reheating of the same region (risk of sigma phase). Do not weld the root without wire.
