AWS A5.7 Copper & Copper Alloy Bare Welding Rods & Electrodes

ERCu

ERCu filler metals are made of deoxidized copper, but also may contain one or more of the following elements: phosphorus, silicon, tin, manganese, and silver. Phosphorus and silicon are added primarily as deoxidizers. The other elements add either to the ease of welding or to the properties of the final weldment. ERCu filler metals generally are used for the welding of deoxidized and electrolytic tough pitch copper. Reactions with hydrogen in oxygen-free copper, and the segregation of copper dioxide in tough pitch copper may detract from joint efficiency. ERCu welding electrode and rods may be used to weld these base metals when the highest quality is not required.

Preheating is desirable on most work; on thick base metal it is essential. Preheat temperatures of 400°F to 1000°F (205 to 540°C) are suitable.

For thick base metals, gas metal arc welding is preferred. Conventional joint designs consistent with good welding practice are generally satisfactory. An external source of preheating generally is not needed when welding base metal thicker than 1/4 in. (6.4 mm) if high-quality welds are to be obtained.

ERCuAl-A1

ERCuAl-A1 filler metal is an iron-free aluminum bronze. It is recommended for use as a surfacing metal for wear-resistant surfaces having relatively light loads, for resistance to corrosive media such as salt or brackish water, and for resistance to many commonly used acids in varying concentrations and temperatures. This alloy is not recommended for joining.

Because of the formation of aluminum oxide in the molten weld pool, aluminum bronze filler metals are not recommended for use with the oxyfuel gas welding process.

Copper-aluminum weld metals are characterized by relatively high tensile strength, yield strength, and hardness. Depending upon the thickness or composition of the base metal, preheat may or may not be necessary.

Welding in the flat position is preferred. Welding in other positions can be done successfully with pulsed arc welding equipment and welder technique.

ERCuAl-A2

ERCuAl-A2 filler metal is an iron-bearing aluminum bronze and is generally used for joining aluminum bronzes of similar composition: manganese, silicon bronzes, some copper-nickel alloys, ferrous metals and dissimilar metals. The most common dissimilar metal combinations are aluminum bronze to steel and copper to steel. This alloy also is used to provide wear- and corrosion-resistant surfaces.

Welding in the flat position is preferred. Welding in other positions can be done successfully with pulsed arc welding equipment and welder technique.

ERCuNi

In ERCuNi filler metals, the nickel addition strengthens the weld metal and improves the corrosion resistance, particularly against salt water. The weld metal has good hot and cold ductility. Copper-nickel filler metals are used for welding most copper-nickel alloys.

When tungsten gas or gas metal arc welding with ERCuNi filler metals, preheating is not required. Welding is done in all positions. The arc should be kept as short as possible to assure adequate shielding gas coverage and thus minimize porosity.

ERCuSi-A

ERCuSi-A filler metals are copper-base alloys containing approximately 3% silicon; they may also contain small percentages of manganese, tin, or zinc. The are used for gas tungsten and gas metal arc welding of copper-silicon and copper-zinc base metal, to themselves and also to steel.

When gas metal arc welding with ERCUSi-A filler metals, it generally is best to keep the weld pool small and the interpass temperature below 150°F (65°C) to minimize hot cracking. The use of narrow weld passes reduces contraction stresses and also permits faster cooling through the hot-short temperature range.

When gas tungsten arc welding with ERCuSi-A filler metals, best results are obtained by keeping the weld pool small. Preheating is not required. Welding can be done in all positions, but the flat position is preferred.