Welding Terms and Definitions

Weldability

Ability of material to be welded. Weldability depends on metallurgical and chemical properties and joint designs.

Direct Current Reverse Polarity

Also known as direct Current electrode positive. On this polarity, the work is negative and the electrode is positive.The current flow is from the work to the electrode (negative to positive)

Direct Current Straight Polarity

Also known as direct current electrode negative. On this polarity, the electrode is negative and the work is positive. The current flow is from the electrode to the work (negative to positive)

Root Opening

Also known as the gap. It is the open or gapped area between the two plates in a groove weld.

Root Face

Also known as the land. It is the parallel surface at the root of a groove joint.

Land

Also known as the root face, it is the flat parallel surface on a groove joint.

Bevel Angle

Angle at which the metal is prepared in a groove joint of welding.

Travel Angle

Angle of lean either into, or away from, the direction of travel. The terms "pushing" and "pulling" denote of direction of travel angle is being used.

TIG (Tungsten Inert Gas)

Another (unofficial) name given to the gas tungsten arc welding (GTAW) process.

Gas Tungsten Arc Welding

Arc welding process that creates an arc between a tungsten electrode and the work or the part to be welded.

Gas Metal Arc Welding

Arc welding process that feeds consumable wire electrode filler continuously into the molten puddle.

Heated- Affected Zone

Area that was superheated by the weld metal arc but did not actually melt.

Cascading Beads

Beads that slope down toward the crater continuous staring and stopping in the same place on multiple-pass welds that may result in cascading beads.

Brazing

Capillary action process rather than fusion welding.

Short-Circuit Transfer

Col. Low-voltage, low amperage mode of GMAW transfer. The cycle actually causes a short circuit against the work, melts off, and short circuits again.

Air Carbon Arc Cutting

Cutting process using a carbon graphite elctrode and compressed air to cut,bevel, and remove defective welds.

Craters

Depressions found at the end of the weld bead and are the result of high heat and the force of the arc.

Contact Tip

Device that transmits the current from the cable of the filter wire electrode in GNAW.

Torch

Device used to carry, mix, contain fuel and oxidizer gases in oxy/fuel welding and cutting.

Porosity

Discontinuity produced by air or some gas being trapped into the weld as it is solidifying.

Toe

Edge at the top of a weld, where the filler metal meets the base teal there are two toes on the fillet and groove welds.

Lack of Fusion

Flaw that is usually found in the side of the joint where the metal has not fully fused into the sides of the joint.

Defects

Flaws that because of their type, size, or location are considered defective

Inert Gas

Gas that is chemically inactive. Argon and helium are typical inert gases used in welding a shield gases.

Bevel Grooving

Groove with only one side prepared.

Stress Relief Heat Treatment

Heat treating method that heats the metal below the critical temperature, holds or soaks at the temperature, then is allowed to cool.

Filler Metals

Includes all the additional metal added to the weld deposit.

Electrode Holders

Insulated "grippers"that both hold the electrode in place and conduct the current into the electrode in shielded metal arc welding.

Axis of a weld

Line through the length of a weld, perpendicular to the cross section at its center of gravity.

Weldor

Machine designed for producing welds.

Kerf

Metal remove from cutting process.

Peening

Method of reducing residual stress in the weld area.

Ultrasonic Welding

Method of testing metal and welds using high-frequency sound waves, produced and received by a crystal, then plotted on CRT (cathode-Ray tube or tube or paper printout.

Complete Penetration

One hundred percent fusion at the root weld. This means no infused metal or factory edge visible at the root side of groove-type welds.

Welder

Person capable of producing welds

Capillary Action

Principal on which brazing and soldering rely for bonding.

Arc Blow

Problem encountered mainly when applying shielded metal arc welding on direct current.

Back Gauging

Process of removing the root pass from the backside of a groove weld, usually with air carbon arc.

Neutral Flame

Recognized by a soft inner cone with no feather showing around the inner cone.

Fissures

Small cracks

Spatter

Small metal particle that drop off and deposit on either side of the weld bead. It is usually the result of too long an economic too much current or voltage , or the wrong electrode angle.

Tack Welds

Small welds destined to hold parts together temporarily until the welder can deposit the permanent weld.

Electrode

The electrode in any electric arc welding processing is the current-carrying conductor, which carries the current to the arc.

Keyhole

The keyhole is the hole produced by fused metal at the root of an open butt groove weld.

Leg (Fillet Weld Legs)

The leg length is also the weld size on fillet welds. The legs are the two perpendicular lines of fusion from the root to the toes.

Mixing Chamber

The mixing chamber, or mixer, is where the oxygen and fuel gas are mixed in the oxy/fuel torch.

Shielded Metal Arc Welding

The process uses a flux covered consumable electrode to heat and melt the base metal.

Weldment

The whole product fabricated by welding

Backfire

This results from combustion of the fuel mixture in the oxy/fuel torch tip.

Staggered Intermittent Welds

Two strings of fillet welds that are opposite and offset for each other. A good rule to keep the stagger even is to take one-half the pitch for the starting point of the opposite side of the staggered weld.

Arc Strikes

Undesirable melted spots left from striking SMAW elec. trades on the base metal caused by the arc.

Tungstens

Used in GTAW, PAW, PAC ( gas tungsten arc welding, plasma arc welding, and plasma arc cutting) as the non-consumable electrode for carrying the high currents required by these processes.

Plasma Arc Welding

Uses a high-velocity plasma gas to melt and fuse metals to be welded.

Oxy/fuel Cutting

Using a fuel gas mixed with pure oxygen to produce an extremely hot flame.

Positions (Weld Positions)

Weld point positions for plate and pipe are identified with the following system. G-Grove F-Fillet 1.Flat 2.Horizontal 3.Vertical 4.Overhead

Slot Weld

Weld produced by cutting slot into the top plate of a lap joint and filling it with weld.

Gun (Welding Gun)

Welding gun used in GNAW, it contains the can tact tip, cup micro-switch for pulling in the conductor, and the shielding gas and electric cable junction block.

Duty Cycle

Welding power source capability to operate safely under load. It is based on the percentage of time it can operate under load in 10 minute period.

Flux Cored Arc Welding

Welding process similar to gas metal arcing welding but tubular, flux- cored is used instead of solid wire. The process used a constant volatile power source.

Plug Weld

Welds made on lap joints by drilling, punching, or cutting a hole into one of the plates and then filling the holes with weld.

Convex Welds

Welds that have a protruding surface or reinforcement at trace of the weld.

Concave Welds

Welds that have a sunken surface at the face of the weld.