What Does the AWS Classification ERNiCu-7 Mean?
The AWS designation ERNiCu-7 breaks down as follows. Each segment identifies a specific characteristic of the filler metal per AWS A5.14.
| Designation Segment |
Meaning |
| ER |
Electrode/Rod: bare solid wire or rod for GTAW, GMAW, SAW, PAW |
| Ni |
Primary element is Nickel (62-69%) |
| Cu |
Secondary element is Copper (remainder, approx. 28-34%) |
| 7 |
Seventh composition variant in the NiCu family within AWS A5.14 |
ERNiCu-7 (UNS N04060) is not the same composition as Monel 400 base metal (UNS N04400). The filler metal has more titanium (1.5-3.0% vs trace in base metal) and manganese (up to 4.0%) to reduce porosity. AWS A5.11-compliant SMAW electrode is ENiCu-7.
Weld Deposit Chemical Composition of ERNiCu-7
Chemical composition requirements for the ERNiCu-7 weld deposit, per AWS A5.14, are listed below.
The chemical composition of ERNiCrMo-13 Welding Wire, as per AWS A 5.14, along with its proportion, is listed below in the table:
| Element |
Nickel (Ni) |
Copper (Cu) |
Titanium (Ti) |
Manganese (Mn) |
Iron (Fe) |
Silicon (Si) |
Aluminium (Al) |
Carbon (C) |
Phosphorus (P) |
Sulphur (S) |
Other Elements, Total |
| Composition (wt%) |
62.0–69.0 |
Remainder |
1.5–3.0 |
4.0 max |
2.5 max |
1.25 max |
1.25 max |
0.15 max |
0.020 max |
0.015 max |
0.50 max |
These numbers represent weld deposit analysis. Base metal dilution, pass count, and process factors affect chemistry. Titanium at 1.5-3.0% creates stable TiO₂ and TiS compounds, forming sound, porosity-free deposits in slag.
All-Weld-Metal Mechanical Properties of ERNiCu-7
Mechanical properties of the ERNiCu-7 weld deposit include AWS A5.14 minimum requirements and typical as-welded.
| Property |
Tensile Strength (AWS min) |
Tensile Strength (Typical) |
Yield Strength, 0.2% Offset (Typical) |
Elongation (AWS min) |
Elongation (Typical) |
| Value |
480 MPa (70 ksi) |
517 MPa (75 ksi) |
358 MPa (52 ksi) |
30% |
34% |
The weld deposit is solid-solution reinforced, not age-hardenable. Gamma-prime precipitation hardening hardens Monel K-500 base metal to 1000+ MPa, whereas the ERNiCu-7 weld zone stays at 517 MPa.
Base Metal Compatibility and P-Number Matrix for ERNiCu-7
ERNiCu-7 Monel 400 TIG filler rod and MIG wire are qualified for joining the following base metals. ASME Section IX classifies ERNiCu-7 as F-42 per QW-432 (A-Number: not applicable, as it is a non-ferrous filler).
Similar metal joints:
| Base Metal | P-Number | ASTM Specs |
|---|
| Monel 400 (N04400) | P-42 | B127, B163, B164, B165 |
| Monel R-405 (N04405) | P-42 | B164 |
| Monel K-500 (N05500) | P-42 | B865 |
Dissimilar metal joints:
| Combination |
Classification / Note |
| Nickel 200/201 (N02200/N02201) |
P-41 to P-42 |
| CuNi 70/30 (C71500) |
P-34 to P-42 |
| CuNi 90/10 (C70600) |
P-34 to P-42 |
| Carbon Steel (P-1) to Monel 400 (P-42) |
ERNi-1 buffer layer required |
When overlaying ERNiCu-7 on carbon steel, apply a buffer layer of ERNi-1 (pure nickel, F-41) as the first pass. Direct deposition of NiCu weld metal on steel causes iron dilution that degrades corrosion resistance and can trigger hot cracking at the fusion line.
Recommended Welding Parameters for ERNiCu 7 Tig Rod
The table below shows important welding parameters for ERNiCu-7, such as the maximum interpass temperature and the steps for cleaning the surface.
GTAW (TIG) parameters:
| Joint Thickness |
Tungsten Dia. |
Filler Dia. |
Amps (A) |
Volts (V) |
Gas |
| 0.75-1.6 mm |
1.6 mm |
1.6 mm |
35-60 |
9-12 |
100% Ar |
| 1.6-3.2 mm |
1.6-2.4 mm |
1.6-2.4 mm |
50-95 |
9-12 |
100% Ar |
| 3.2-6.4 mm |
2.4-3.2 mm |
2.4-3.2 mm |
75-150 |
10-13 |
100% Ar |
| 6.4 mm+ |
2.4-3.2 mm |
2.4-3.2 mm |
95-200 |
10-13 |
100% Ar |
GMAW (MIG) short-circuiting parameters:
| Wire Dia. |
Amps (A) |
Volts (V) |
Wire Speed (ipm) |
Gas |
| 0.9 mm |
70-90 |
18-20 |
150-200 |
75Ar/25He |
| 1.2 mm |
75-160 |
19-22 |
175-225 |
75Ar/25He |
Use 1.2 mm wire at 190–250 A and 30–32 V with 100% Argon shielding for GMAW spray transfer. To get the best results with SAW, use 2.4 mm wire at 275–350 A or 3.2 mm wire at 350-450 A with a suitable flux.
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Industrial Applications of ERNICU 7 Filler Wire
The following are the industrial applications of ERNiCu-7 filler wire:
Storage and Handling of ERNiCu-7 Welding Filler Wire
ERNiCu-7 is a bare solid wire, so the storage concern is surface contamination rather than moisture absorption. Spools and rods should be stored in their original packaging at 15-30 °C with humidity below 60% RH. Avoid carbon steel tools and grinding dust. Even trace iron on the wire surface reduces the NiCu weld deposit’s corrosion resistance. Clean TIG rods with acetone first. After each shift, seal partially used MIG spools.
Available Forms, Diameters and Packaging of ERNiCu-7 Wire
ERNiCu-7 MIG & TIG filler metal and wire from Nicorex Alloys is stocked in the following forms.
| Form |
Diameter |
Packaging |
| TIG Rod (GTAW) |
1.6, 2.0, 2.4, 3.2, 4.0 mm |
5 kg tubes, 20 kg cartons |
| MIG Spool (GMAW) |
0.8, 0.9, 1.0, 1.2, 1.6 mm |
15 kg spool (D300) |
| SAW Wire |
2.4, 3.2 mm |
25 kg coils |
| Strip (Cladding) |
Available on request |
Per order |
All shipments carry Mill Test Certificate 3.1 per EN 10204 with full heat and lot traceability.
How to Order ERNiCu-7 MIG & TIG Filler Metal from Nicorex Alloys
To get a quotation for ERNiCu-7 Monel 400 welding wire, share these 8 details:
As a distributor, Nicorex Alloys supplies matching consumables across processes: ERNiCu-7 TIG rod, MIG wire, and ENiCu-7 SMAW electrode for the same Monel 400 project.
Frequently Asked Questions