Electrode Selection 270

AC

An abbreviation for alternating current. AC regularly reverses the direction of its flow.

alloy

A metal consisting of a mixture of two or more materials. One of these materials must be a metal.

American Welding Society

The non-profit organization that regulates the industrial standards for welding and promotes the welding industry in the United States.

argon

An inactive gas commonly used as shielding. Argon is much heavier than air, thus it effectively shields the weld area.

balled tip

A tungsten electrode in which the tip is formed into a hemispherical ball. This shape is required for AC and DCEP welding.

calcium

A nonmetallic material that is often present in the powdered coating of a SMAW electrode. Calcium floats to the top of the molten weld puddle and forms slag.

carbon

A common, nonmetallic element found in all types of steel. Carbon is the main hardening element in steel.

carbon dioxide

An active gas commonly used as shielding for GMAW. Carbon dioxide is inexpensive but yields a violent arc.

carbon steel

A steel that contains a certain amount of carbon. Low-carbon steels are some of the most commonly welded metals.

ceriated tungsten electrode

A type of tungsten electrode that contains small amounts of cerium. Ceriated tungsten electrodes have good arc starting characteristics, work well with low amperage settings, and can be used for both AC and DC applications.

chromium

A grayish metal that improves corrosion resistance. Chromium is sometimes added to SMAW, GMAW, and FCAW electrodes.

circuit

A controlled path for electricity. A circuit includes a source, path, load, and control.

conical tip

A tungsten electrode in which the tip is formed into a cone shape. This shape is used for DC welding.

contact tip

The device located inside the welding gun that conducts electricity to the electrode. The contact tip is usually made of copper.

corrosion resistance

A metal's ability to resist attack by other elements and chemicals.

cracking

A fracture that develops in the weld after solidification is complete. Welds with high hardness can cause cracking.

DCEN

An abbreviation for direct current electrode negative. DCEN is another way of expressing direct current with straight polarity.

deoxidizer

A material that removes oxygen from the molten weld puddle and arc. Oxygen can ruin a weld bead.

deposition rate

The rate at which an electrode melts into the molten weld puddle to form a weld.

direct current electrode negative

Direct current with straight polarity. Direct current electrode negative is often expressed as DCEN.

direct current electrode positive

Direct current with reverse polarity. Direct current electrode positive is often expressed as DCEP.

ductility

A metal's ability to be drawn, stretched, or formed without breaking.

electrode

A device in an electrical circuit that conducts electricity. In welding, the electrode also can act as the filler metal.

electrode diameter

A measurement of the thickness of the electrode.

fast-fill electrode

A SMAW electrode that fills up a joint quickly. Fast-fill electrodes are ideal for large workpieces.

fast-freeze electrode

A SMAW electrode that solidifies quickly. Fast-freeze electrodes are ideal for overhead welding.

filler metal

Metal deposited into the weld that often adds strength and mass to the welded joint. In some arc welding processes, the electrode acts as the filler metal.

fill-freeze electrode

A SMAW electrode that has both fast-fill and fast-freeze characteristics. Fill-freeze electrodes fill up a joint quickly as well as solidify quickly.

flux

A nonmetallic material used to protect the weld puddle and solid metal from atmospheric contamination. In FCAW, flux material is contained in the core of the electrode. In SMAW, flux coats the electrode.

flux-cored arc welding

An arc welding process that uses a continuously fed consumable electrode that contains flux in a hollowed-out center. It is also referred to as FCAW.

gas metal arc welding

An arc welding process in which a bare wire electrode and inert or active shielding gas is fed to the weld through a welding gun. It is also referred to as GMAW or MIG welding.

gas tungsten arc welding

A very precise arc welding process that uses a nonconsumable tungsten electrode. It is also referred to as GTAW or TIG welding.

GTAW

The American Welding Society abbreviation for gas tungsten arc welding.

helium

An inactive gas commonly used as shielding for GMAW. Helium is much lighter than air and can escape the weld area quickly.

joint

The meeting point of the two materials that are joined together. Welding creates a permanent joint.

lanthanated tungsten electrode

A type of tungsten electrode that contains small amounts of lanthanum. Lanthanated tungsten electrodes are nonradioactive and maintain a sharp tip very well.

lap joint

A type of joint between two overlapping metal parts in parallel planes.

low-hydrogen electrode

A SMAW electrode that is used to weld metals that can be susceptible to cracking.

manganese

A hard, brittle, gray-white metal that increases the hardenability of steel. Manganese also increases strength and hardness.

mechanical properties

The properties that describe a material's ability to compress, stretch, bend, scratch, dent, or break.

metal transfer method

The way in which filler metal is deposited into a weld.

molybdenum

A metallic, alloying element often added to GMAW electrodes to increase strength and hardness without decreasing ductility.

nickel

A hard, malleable, silvery white metal often added to GMAW electrodes to increase strength and hardness without decreasing ductility.

nitrogen

A colorless, odorless, tasteless gas that naturally exists in the atmosphere. Nitrogen can ruin a weld bead. Often, electrodes contain elements to de-nitrify the molten metal.

nonconsumable tungsten electrode

An electrode made of tungsten that is not melted by welding heat nor does it become part of the molten weld metal.

oxygen

A colorless, odorless, tasteless gas that naturally exists in the atmosphere. A small amount of oxygen is sometimes used for shielding. However, too much oxygen causes cracking and rusting in the metals.

physical properties

The properties that describe a material's ability to melt, emit heat, conduct electricity, and expand or shrink.

porosity

The appearance of tiny bubbles on a weld bead as a result of gas entrapment. Excessive porosity can weaken a weld.

power source

A device that generates electricity. Arc welding power sources can be plugged into a wall outlet, or they can generate electricity through the use of a mechanical device like a motor or generator.

pulse arc metal transfer

A type of metal transfer in which as little as one droplet of metal forms on the end of the electrode at a time. Pulse arc is the most precise transfer method.

pure tungsten electrode

A type of tungsten electrode made with 99.5 percent tungsten. Pure tungsten electrodes are primarily used with AC for welding aluminum and magnesium.

rod oven

A special heating device that stores SMAW electrodes at temperatures from 250 to 300 degrees.

root opening

The separation at the joint root between the base metals. The size of the root opening determines how much weld metal is needed to obtain fusion at the root.

rutile

A reddish brown mineral sometimes used as an electrode coating.

shielded metal arc welding

An arc welding process that uses a flux-coated consumable rod electrode. It is also referred to as SMAW or stick welding.

shielding gas

An inert or slightly active gas that protects the weld puddle and arc from reacting negatively with the atmosphere.

short circuit metal transfer

A type of metal transfer in which the electrode produces a short circuit and high current when it touches the workpiece. The high current level causes a violent transfer of metal, which creates the weld.

silicon

A nonmetallic material that is often present in some arc welding electrodes. Silicon acts as a deoxidizer.

slag

Cooled flux that forms on top of the bead. Slag protects cooling metal and is then chipped off.

spatter

Liquid metal droplets expelled from the welding process.

stick welding

Shielded metal arc welding. In industry, many welders refer to shielded metal arc welding as stick welding.

suffix

An addition at the end of a word or stem. Arc welding electrode labels often contain suffixes, which give further information about the electrode's characteristics.

tensile strength

The ability of a metal to resist forces that attempt to pull apart or stretch it.

thoriated tungsten electrode

A type of tungsten electrode that contains approximately 2 percent thorium. Thoriated tungsten electrodes have higher conductivity and generally last longer.

thorium

A heavy, radioactive element used in tungsten electrodes.

tungsten

A gray metal that is very strong at elevated temperatures. Tungsten is used to make nonconsumable electrodes.

weld bead

The end product of a joint that has been welded.

weldability

The ability of a material to be welded under imposed conditions into a specific, suitable structure and to perform satisfactorily for its intended use.

welding code

A standard used to govern welding processes and ensure safe welding practices and high-quality welded products.

wire electrode

An electrode that is in the form of a wire. Wire electrodes are more productive than stick electrodes because they do not require frequent changing.

zirconiated tungsten electrode

A type of tungsten electrode, which contains small amounts of zirconium oxide. Zirconiated tungsten electrodes combine the characteristics of pure tungsten and thoriated tungsten electrodes.

zirconium oxide

A white, crystalline powder used in zirconiated tungsten electrodes.