ThePipingMart Blog Welding Electrodes AWS Class ERCuNi Filler Metal – Composition, Properties, and Uses

AWS Class ERCuNi Filler Metal – Composition, Properties, and Uses

AWS Class ERCuNi

AWS Class ERCuNi is a type of copper-nickel alloy that provides a range of beneficial properties, such as high corrosion resistance, superior strength, and excellent heat resistance. It is commonly used in various applications across several industries, including marine engineering, oil and gas, and chemical processing. This blog post will delve deeper into the composition, physical and mechanical properties, uses, heat treatment, and corrosion resistance of AWS Class ERCuNi.

What is AWS Class ERCuNi Filler Metal ?

AWS Class ERCuNi filler wire is a Ni-based copper alloy developed for arc welding. It is used mainly to fabricate pressure vessels, piping systems and other components requiring high strength at elevated temperatures. This alloy offers excellent corrosion resistance, high ductility and superior weldability, and good creep and stress rupture properties at elevated temperatures.

ERCuNi Weld Wire Composition

AWS Class ERCuNi welded electrode is a copper-nickel-based alloy that contains approximately 30% nickel, 3.5% iron, and 66.5% copper. The small addition of iron enhances the mechanical and thermal properties of the alloy. Additionally, including nickel provides excellent corrosion resistance in freshwater and seawater environments. To improve its overall properties, the alloy also contains small amounts of other elements like manganese, silicon, and chromium.

Fe Pb Mn P Si Ti Ni +Co Cu +Ag
0.59 0.001 0.69 0.001 0.07 0.30 30.3 Balance

ERCuNi Filler Wire Physical Properties

The high copper content of AWS Class ERCuNi Coated Electrode gives it excellent thermal and electrical conductivity properties. This alloy is also highly malleable and easily shaped without cracking or breaking. The density of AWS Class ERCuNi welding alloy is around 8.94 g/cm cubed, which is a little higher than pure copper. In addition, it has a melting point of approximately 1214℃, making it highly resistant to heat deformation.

ERCuNi Coated Electrode Mechanical Properties

The mechanical properties of AWS Class ERCuNi welding alloy are excellent, making it ideal for use in various industrial applications. It exhibits superior strength, particularly in marine environments, where it is resistant to both corrosion and biofouling. AWS Class ERCuNi has three primary variations, each with specific mechanical properties: the ER CuNi, ER CuNiFe-1, and ER CuNiFeMn-1. Fabricators and engineers use AWS Class ERCuNi welding electrode to manufacture several products, including pipes, valves, and fittings.

Tensile Strength MPa(ksi) Yield Strength MPa(ksi) Elongation %
Typical results as welded 54,000 psi 21,500 psi 32%

ERCuNi Coated Electrode Trade Names

Class UNS Oxford Alloys Special Metals UTP ESAB
ERCuNi C71581 Alloy 67 MONEL FILLER METAL 67 UTP A 387 OK AUTROD 19.49

ERCuNi MIG & TIG Filler Metal Parameters

Process Diameter of Wire Voltage (V) Amperage (A) Gas
Tig .035 inches x 36 12-15 60 -90 100% Argon
.045 inches x 36 13-16 80-110 100% Argon
1/16 inches x 36 14-18 90-130 100% Argon
3/32 inches x 36 15-20 120-175 100% Argon
1/8 inches x 36 15-20 150-220 100% Argon

ERCuNi Filler Wire Uses

AWS Class ERCuNi welding alloy is mainly used in marine engineering, where its excellent corrosion resistance, strength, and durability make it a valuable material for marine vessels and offshore installations. It is also used in the chemical processing and oil and gas industries, providing high corrosion resistance in harsh environments. Additionally, it is applied in electrical connectors, heat exchangers, condenser tubes, and many other applications.

ERCuNi Coated Electrode Heat Treatment

AWS Class ERCuNi welded coated electrode is not recommended for use above 204℃ as it may lead to embrittlement and reduced mechanical strength. However, it can be annealed or stress-relieved at temperatures below 260℃. That said, specific heat treatment processes depend on the product application, the intended use of the material, and the properties required. Therefore, consulting with an experienced fabricator or supplier is always advisable to determine the most suitable heat treatment process for AWS Class ERCuNi.

ERCuNi Weld Wire Corrosion Resistance

AWS Class ERCuNi coated electrode provides excellent corrosion resistance for freshwater and seawater applications. This alloy exhibits high resistance to corrosion and biofouling in marine environments. It also resists several acids, including sulfuric acid, phosphoric acid, acetic acid, and hydrochloric acid. Therefore, AWS Class ERCuNi welded  coated electrode is ideal for products exposed to harsh and corrosive environments.


AWS Class ERCuNi Welding Electrode is a highly valuable copper-nickel-based alloy with excellent mechanical and physical properties. Its high resistance to corrosion, biofouling, and harsh environments makes it a popular choice in various industries, including marine engineering, oil and gas, and chemical processing. Its ability to withstand high temperatures and heat-resistant properties allows it to be used in several high-stress applications. Contact a reputable supplier or fabricator to learn more about the potential uses and benefits of AWS Class ERCuNi.

Related Post