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ERNiCr-4 Welding Wire Supplier — Inconel® Filler Metal 72 | AWS A5.14 | UNS N06072
Nicorex Alloys is an ISO 9001 / ISO 14001 certified Mumbai-based supplier and stockist of ERNiCr-4 welding wire. We provide these welding wires as classified under AWS A5.14 (ASME SFA-5.14) with UNS designation N06072.
Also called Inconel Filler Metal 72, this nickel‑chromium TIG rod has the highest chromium content in the AWS A5.14 standard (43–46%). This high chromium level forms a tough Cr₂O₃ scale on weld overlays that protects coal‑fired and waste‑to‑energy boiler tubes from sulfidation, V₂O₅/Na₂SO₄ fuel‑ash attack, carburisation, and metal dusting. The weld metal contains about 52–56% Ni and 43–46% Cr, with controlled additions of Al (0.50–1.50%), Ti (0.50–1.00%), and Nb (0.30–1.10%) to improve oxide scale adhesion and reduce hot cracking in service. ERNiCr-4 welding wire is primarily used for high-chromium overlay cladding on boiler tubes in coal-fired and waste-to-energy power boilers, and for high-temperature protective cladding in petrochemical reformers to resist sulfidation, fuel-ash corrosion, carburisation, and metal dusting. Inconel filler metal 72 (EN ISO 18274: S Ni 6072, NiCr44Ti) is made for GTAW overlay cladding on carbon steel and Cr-Mo boiler tubes. It is not meant for general-purpose dissimilar metal joining. This alloy has no molybdenum and is used only in high-temperature oxidation environments.
The overlay also becomes harder during service, reaching HRC 46–52 in low-NOx boiler conditions at 649–677°C (1200–1250°F). This extra hardness improves erosion resistance in soot blower lanes. Every shipment from Nicorex Alloys comes with an EN 10204/3.1B mill test certificate, providing full material traceability.
ERNiCr-4 Filler Wire Specifications
The table below lists the core specifications for ERNiCr-4 welding wire as supplied by Nicorex Alloys.
| UNS Designation | N06072 |
|---|---|
| Welding Processes | GTAW (primary), SAW, ESW, PAW |
| Polarity | DCEN |
| Positions | All positions |
| TIG Rod Diameters | 2.4 mm (3/32″), 3.2 mm (1/8″) |
| Rod Length | 915–1000 mm |
| Shielding Gas | 100% Argon |
| Certification | MTC 3.1 per EN 10204 |
Understanding the ERNiCr-4 AWS Classification
The AWS naming system encodes the filler’s base metal and variant number into a short alphanumeric string. The table below breaks down each element of the ERNiCr-4 designation.
| Code Element | Meaning |
|---|---|
| ER | Electrode/Rod — solid bare wire suitable for GTAW and GMAW |
| Ni | Nickel is the primary base element |
| Cr | Chromium is the principal alloying element |
| -4 | 4th variant in the NiCr family within AWS A5.14 |
ERNiCr-4 (Inconel FM 72) is a TIG rod for boiler overlays; ERNiCr-7 is its MIG wire version, both around 44% Cr. ERNiCr-3 (Inconel 82) and ERNiCr-6 (NC80/20) have about 20% Cr. ERNiCr-4 has over twice its chromium, making it the preferred ultra-high-chromium overlay filler.
Weld Deposit Chemical Composition of ERNiCr-4
The chemical composition of ERNiCr-4 welding wire, along with its proportions, is listed in the table below.
| Element | Nickel (Ni) | Chromium (Cr) | Iron (Fe) | Carbon (C) | Manganese (Mn) | Silicon (Si) | Aluminium (Al) | Titanium (Ti) | Niobium + Tantalum (Nb+Ta) | Phosphorus (P) | Sulphur (S) | Copper (Cu) | Cobalt (Co) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Composition (wt%) | Remainder (~52–56) | 43.0–46.0 | 0.50 max | 0.15 max | 1.0 max | 0.20 max | 0.50–1.50 | 0.50–1.00 | — | 0.02 max | 0.015 max | 0.50 max | — |
Al (0.50–1.50%) and Ti (0.50–1.00%) promote oxide scale adhesion and contribute high-temperature strength. Iron is held to 0.50% max to preserve the Ni-Cr balance. For comparison, ERNiCr-3 (Inconel 82) contains only 18–22% Cr; ERNiCr-4 delivers more than double that figure.
All-Weld-Metal Mechanical Properties of ERNiCr-4
Typical all-weld-metal mechanical properties for ERNiCr-4 welding wire in the as-welded condition are listed below in the table.
| Property | Tensile Strength | Yield Strength (0.2% Offset) | Elongation |
|---|---|---|---|
| Typical Value | 580–650 MPa (84–94 ksi) | 350–450 MPa (51–65 ksi) | 15–25% |
Base Metal Compatibility and P-Number Matrix for ERNiCr-4
The table given below lists the base metal and its compatibility with the wires, along with the P-number.
| Base Metal | UNS Number | ASME P-Number | Joint Type / Application |
|---|---|---|---|
| 50Cr-50Ni Alloy (Alloy 671) | N06671 | P-43 | Similar welding: matching composition joining |
| Inconel 600 | N06600 | P-43 | Joining and repairing of Ni-Cr components |
| Inconel 601 | N06601 | P-43 | Joining and repair: high-temperature oxidation service |
| Incoloy 800H / 800HT | N08810 / N08811 | P-45 | Dissimilar: NiCr overlay cladding onto Ni-Fe-Cr superheater tubing |
| Carbon Steel (SA-210, SA-106) | K02707 / K03006 | P-1 | Dissimilar: boiler waterwall tube overlay cladding (primary application) |
| Low-Alloy Steel T11 (1.25Cr-0.5Mo) | K11597 | P-4 Gr.1 | Dissimilar: boiler tube overlay substrate |
| Low-Alloy Steel T22 (2.25Cr-1Mo) | K21590 | P-5A Gr.1 | Dissimilar: superheater tube overlay substrate |
| Stainless Steel 304H / 347H | S30409 / S34709 | P-8 | Dissimilar: high-temperature boiler tube overlay |
Get ERNiCr-4 Welding Filler Wire at Competitive Prices
Industrial Applications of ERNiCr-4 Welding Filler Wires
ERNiCr-4 overlay cladding protects critical components in two major sectors: power generation boilers and petrochemical high-temperature processing.
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Coal-Fired & WTE Boiler Tube Overlay: This is the primary application for Inconel FM 72. Automatic GTAW overlay of waterwall panels, superheater/reheater tubes, and soot blower lane protection tubes in coal-fired and waste-to-energy boilers relies on this filler’s 44% Cr barrier.
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Petrochemical High-Temperature Cladding: In petrochemical reformer environments rich in CO and CH₄, ERNiCr-4 overlay prevents metal dusting and carburisation on reactor internals.
Available Forms & Packaging
Nicorex Alloys stocks ERNiCr-4 (FM 72) in various forms, diameters and packaging. We provide TIG rods upto 915-1000 mm length.
| Form | Diameter | Packaging |
|---|---|---|
| TIG rods (ERNiCr-4 / FM 72) | 2.4 mm (3/32″), 3.2 mm (1/8″) | 4.5–5 kg (10–11 lb) tubes |
| MIG wire on spools (ERNiCr-7 / FM 72M) | 0.8 mm (0.030″) – 1.6 mm (0.062″) | 13.6 kg (30 lb) spools |
| Wire on drums or reels for automatic GTAW overlay (FM 72) | 1.0 mm (0.040″) – 1.6 mm (0.062″) | Drums or reels |
How to Order ERNiCr-4 Welding Wire from Nicorex Alloys
To place an order or request a quotation for ERNiCr-4 welding wire, provide these 10 details:
- Wire Type: GTAW / GMAW Solid Overlay Wire (S Ni 6072 / ERNiCr-4)
- Size: 1.2mm (GMAW) / 1.6mm / 2.4mm / 3.2mm (GTAW)
- Current Type: DCEN (GTAW) / DCEP (GMAW)
- Welding Position: Flat & Horizontal preferred
- Material Grade: UNS N06072 / EN ISO 18274: S Ni 6072 (NiCr44Ti) / AWS ERNiCr-4
- Quantity: Spools/packs or total weight in kg
- Standard: EN ISO 18274, AWS A5.14 / ASME SFA 5.14, ASME Section IX
- Documentation: MTC EN 10204 3.1/3.2, PMI Report, Weld Deposit Composition Report, TPI Certificate
- Packaging: Vacuum-sealed foil bag with silica gel desiccant, ISPM 15-compliant export cartons
- Delivery Destination: Domestic
Clarify the welding process upfront so we ship the correct variant. Custom packaging and export-grade wooden cases are available on request.
Frequently Asked Questions — ERNiCr-4 Welding Wire
What is the difference between ERNiCr-4 (FM 72) and ERNiCr-7 (FM 72M)?
ERNiCr-4 is Inconel FM 72, the original classification designed for GTAW (TIG) and supplied as cut-length rods (UNS N06072). ERNiCr-7 is Inconel FM 72M, the modified classification designed for GMAW (MIG) and supplied on spools (UNS N06073). Both carry the same ~44% Cr base composition. The “M” in 72M stands for “Modified,” with trace element adjustments for improved wire feeding in GMAW equipment.
Why does ERNiCr-4 overlay outperform ERNiCrMo-3 (Alloy 625) in Boiler Tube Service?
ERNiCr-4 contains 43–46% Cr versus only ~21% Cr in ERNiCrMo-3. That significantly higher chromium produces a denser Cr₂O₃ scale that resists penetration by molten V₂O₅ and Na₂SO₄ fuel-ash deposits.
What is the Chromium content of ERNiCr-4 compared to other Nickel Alloy Fillers?
ERNiCr-4 has the highest chromium content of all AWS A5.14 fillers at 43–46%, which is much higher than ERNiCr-3 (18–22%), ERNiCrFe-7 (28–31.5%), and ERNiCrMo-3 (20–23%).
What base metals does ERNiCr-4 overlay protect?
Primarily carbon steel (SA106, SA210) and low-alloy Cr-Mo boiler tubes (SA213-T2, T11, T22, T91) in coal-fired and waste-to-energy boiler service. ERNiCr-4 is also used for welding Inconel 671 (UNS N06671, ~48% Cr) and Inconel 690 (UNS N06690) to themselves and to steels..
When should you not use ERNiCr-4 Filler Wire?
Avoid ERNiCr-4 in situations like aqueous corrosion service (zero Mo content means negligible pitting resistance in chloride or acid media); general-purpose dissimilar joining (use ERNiCr-3 or ERNiCrMo-3 instead); welding Inconel 600 base metal (that’s ERNiCr-3 territory); and GMAW applications (specify ERNiCr-7 / FM 72M for better wire feeding).