Surface Treatments
Certifications
- ISO 9001:2015
- NORSOK M-650
- NACE MR0175
- ISO 15156-3
- PED 2014/68/EC
- EN 10204 type 3.2
- AD 2000 W2/W7/W10
Ferralium 255 Welding Filler and Consumables
Matching 25.10.4.L super duplex consumables for GTAW, GMAW, SMAW, FCAW, and SAW joining of UNS S32550
Super duplex weld metal solidifies almost entirely as ferrite, then transforms partially to austenite during solid-state cooling. The fast cooling rate of a typical fusion weld leaves too much ferrite (and too little austenite) if the consumable matches the parent composition exactly. The standard fix is an over-alloyed filler: super duplex consumables carry roughly 2 to 3 percentage points more nickel than the parent metal to push the as-deposited microstructure back into the 35 to 65% ferrite acceptance band of NORSOK M-630. The 25.10.4.L family (25Cr, 10Ni, 4Mo, low C) covers Ferralium 255 and 2507 parent metal in matching service. AWS A5.4 (SMAW), A5.9 (bare wire for GTAW / GMAW / SAW), and A5.22 (flux-cored) classify the consumables.
Consumable Designations
| Process | AWS classification | Trade name examples | Use |
|---|---|---|---|
| GTAW (TIG) bare wire | AWS A5.9 ER2594 | Sandvik 25.10.4.L, Avesta 2507/P100, Metrode 25Cr-10Ni-4Mo | Root pass and thin-section all-position, gas Ar + 2% N2 |
| GMAW (MIG) solid wire | AWS A5.9 ER2594 | Same as GTAW wire | Fill and cap, spray transfer, gas Ar + 30% He + 2% N2 |
| SMAW (stick) electrode | AWS A5.4 E2594-15 or -16 | Sandvik 25.10.4.L, Avesta 2507/P100 | Field repair, position welding, basic-coated -15 for impact-critical |
| FCAW (flux-cored) wire | AWS A5.22 E2594-T1 | Sandvik 25.10.4.L FCW, Lincoln Cor-A-Rosta P10 | Production fill and cap, position-capable |
| SAW (submerged-arc) wire + flux | AWS A5.9 ER2594 + matched flux | Sandvik 25.10.4.L + 15W neutral basic flux | Heavy-section thick-wall fill, flat position only |
Weld Metal Acceptance
Per NORSOK M-630 the welded joint must satisfy: (a) chemistry per AWS classification with PREN ≥ 40, (b) ferrite content 35 to 65% per ASTM E562 on the weld metal cross-section, (c) hardness ≤ 32 HRC for NACE MR0175 sour service, (d) Charpy V-notch ≥ 45 J at -46 °C in the weld metal centreline (transverse) and ≥ 35 J in the HAZ, (e) corrosion test per ASTM G48 method A at 35 °C for 24 hours with mass loss ≤ 4 mg/cm² and no localised pitting. The weld procedure qualification (PQR) per ASME IX with NORSOK M-630 supplementary documents these on the qualifying coupon, and the production WPS controls heat input, interpass temperature, and shielding gas to stay within the qualified envelope.
Process Rules
- Heat input 0.5 to 2.5 kJ/mm; outside this band ferrite balance fails
- Interpass temperature ≤ 150 °C; high interpass slows cooling and risks sigma
- No preheat above ambient (unlike carbon steel); preheat slows cooling and risks sigma
- No PWHT or stress-relief; any soak in 600 to 1000 °C precipitates sigma
- Backing gas (Ar with 2 to 5% N2) on root pass to maintain N content and pitting resistance
- Stringer beads preferred over weave; weave widens the HAZ and raises sigma risk
Related Pages
- Ferralium 255 welding procedure
- Ferralium 255 ferrite content (weld metal target band)
- Ferralium 255 sigma phase
- Ferralium 255 heat treatment (PWHT not permitted)
- NORSOK M-650 QTR (welding section)
Need Ferralium 255 welding filler / consumables? Email info@torqbolt.com or WhatsApp +91-22-66157017 with form, dimensions, quantity, ASTM/EN spec, MTC level (3.1 / 3.2). NACE MR0175 sour-service stamp on every heat. NORSOK M-650 QTR on request. Per-heat EN 10204 type 3.2 MTC included with every consignment.
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