ThePipingMart Blog Welding Electrodes AWS Class ECuNi Coated Electrode – Composition, Properties, and Uses

AWS Class ECuNi Coated Electrode – Composition, Properties, and Uses

AWS Class ECuNi

AWS Class ECuNi is an alloy of copper, nickel, and iron. This special alloy is widely used in the manufacturing industry, particularly in the naval and marine industries. This alloy has exceptional mechanical and physical properties, including corrosion resistance and thermal conductivity. This blog delves deeper into AWS Class ECuNi, its composition, properties, uses, and heat treatment.

What is AWS Class ECuNi Coated Electrode?

AWS Class ECuNi welding electrodes are a type of low-alloy, copper-nickel (CuNi) submerged arc welding electrodes. They are used for welding high-strength base materials that need good corrosion resistance and excellent weldability properties. AWS Class ECuNi coated electrodes offer superior mechanical properties such as higher tensile strength, elongation percentage and impact toughness at cryogenic temperatures compared to other types of CuNi filler alloy choices. The potential applications of this electrode include shipbuilding, pipelines, off-shore structure and storage tanks in chemical plants, among others. In addition to its excellent toughness at low temperatures, AWS Class ECuNi is also characterized by great oxidation resistance throughout the entire fusion range due to its intrinsic stability in an oxidizing environment, making it suitable for fabrication jobs involving complex joint designs or severe operating conditions.

ECuNi Coated Electrode Composition

AWS Class ECuNi is a unique alloy comprising 40-60% copper, 30-40% nickel, and 1-3% iron. The iron content in AWS Class ECuNi helps to improve the alloy’s strength and durability, while copper and nickel are added to increase its corrosion resistance. AWS Class ECuNi may also contain small quantities of manganese, aluminium, and titanium.

Mn Fe Si Cu including Ag Ni including Cobalt P Pb Ti Other
1.00-2.50 0.40-0.75 0.50 Remainder 29.0-33.0 0.020 0.02 0.50 0.50

ECuNi Coated Electrode Physical Properties

AWS Class ECuNi is an alloy with remarkable physical properties such as high electrical and thermal conductivity. It is exceptionally ductile and has excellent hot and cold working properties. AWS Class ECuNi is also known for its high melting point, which makes it an excellent choice for high-temperature applications.

ECuNi Coated Electrode Mechanical Properties

AWS Class ECuNi welding rod is known for superior mechanical properties. It has high tensile strength, high yield strength, and excellent toughness. AWS Class ECuNi is also highly resistant to fatigue crack propagation, making it suitable for critical applications.

Tensile Strength, kpsi: 50
Yield Strength, kpsi: *NS
Elongation %: 20 min

ECuNi Coated Electrode Trade Names

Class UNS Oxford Alloys Special Metals UTP SANDVIK

ECuNi Coated Electrode Parameters

Diameter Process Volt Amps (flat) Amps (V/OH)
in (mm)
 3/32  (2.4) SMAW 24-28 70-85 65-75
 1/8  (3.2) SMAW  26-30 85-110  80-90
 5/32  (4.0) SMAW  28-32 110-140  100-120
 3/16  (4.8) SMAW  28-32 120-160  110-130

ECuNi Coated Electrode Uses

AWS Class ECuNi filler wire is a highly versatile alloy used in several industries, particularly the marine and naval industries. It is primarily used to construct boats, ship hulls, and propellers due to its excellent corrosion resistance and mechanical properties. AWS Class ECuNi welding rod is also used in aerospace applications, automotive components, and power generation equipment.

ECuNi Welding Rod Heat Treatment

AWS Class ECuNi can be heat treated to enhance its mechanical properties further. The process involves heating the alloy to high temperatures and then rapidly cooling it. Heat treatment can increase strength and toughness, making it more suitable for severe applications.

ECuNi Welding Rod Corrosion Resistant

AWS Class ECuNi is widely known for its exceptional corrosion resistance. The alloy can resist the corrosive effects of seawater, making it ideal for marine applications. It is also resistant to atmospheric corrosion, making it useful for outdoor applications.


AWS Class ECuNi is a specially designed alloy with exceptional physical and mechanical properties. It is highly versatile and is widely used in several critical applications. Its exceptional corrosion resistance, flexibility, and high-temperature resistance make it suitable for various applications. With its many advantages, AWS Class ECuNi is quickly becoming popular for modern manufacturing needs.

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