Test Lab, NDT Weld Training Course Institute India Bangalore | Trinity NDT

Welding Technology Glossary of Terms used in Weld Processes

Arc Blow

The deflection of an electric arc form its normal path required is obtained from an electric arc. See twin carbon arc brazing.

Arc cutting

A group of cutting processes which melts the metals to be cut with the heat of an arc between an electrode and the base metal. See carbon arc cutting, metal arc cutting, gas metal arc cutting, gas tungsten arc cutting, plasma arc cutting, and air carbon arc cutting. Compare with oxygen arc cutting.

Arc gouging

An arc cutting process variation used to form a bevel or groove.

Arc oxygen cutting

See preferred term oxygen arc cutting

Automatic welding

Welding equipment which performs the welding operation without adjustment of the controls by a welding operator. The equipment may or may not perform the loading and unloading of the work. See machine welding.

Backfire

The momentary recession of the flame into the welding tip or cutting tip followed by immediate reappearance or complete extinction of the flame.

Back gouging

The removal of weld metal and base metal from the other side of a partially welded joint to ensure complete penetration upon subsequent welding from that side.

Backing

A material (base metal, weld metal, carbon, or granular material) placed at the root of a weld joint for the purpose of supporting molten weld metal.

Backing ring

Backing in the form of a ring, generally used in the welding of piping.

Base material

The material to be welded, brazed, soldered, or cut. See also base metal and substrate. Base metal. The metal to be welded, brazed, soldered, or cut. The use of this term implies that materials other than metals are also referred to, where this is appropriate. See also base material and substrate.

Braze welding

A welding process variation in which a filler metal, having a liquids above 840° F and below the solidus of the base metal, is used. Unlike brazing, in braze welding the filler metal is not distributed in the joint by capillary action.

Brazing

A group of welding processes which produces coalescence of materials by heating them to a suitable temperature and by using a filler metal having a liquids above 840° F and below the solidus of the base metal. The filler metal is distributed between the closely fitted faying surfaces of the joint by capillary action.

Burn-thru weld

A term erroneously used to denote excessive melt-thru or a hole. See melt-thru. Capillary action. The force by which liquid, in contact with a solid, is distributed between closely fitted faying surfaces of the joint to be brazed or soldered.

Welding Technology Glossary of Terms used in Weld Processes

Carbon electrode

A non-filler material electrode used in arc welding or cutting , consisting of a carbon or graphite rod, which may be coated with copper or other coatings.

Cladding

A relatively thick layer (>0.04 in.) of material applied by surfacing for the purpose of improved corrosion resistances or other properties (see coating, surfacing, and hard facing).

Coalescence

The growing together terms covered electrode and lightly coated electrode. See electrode. Coating. a relatively thin layer (<0.04 in.) of material applied by surfacing for the purpose of corrosion prevention, resistance to high temperature scaling, wear resistance, lubrication, or other purposes. See cladding, surfacing, and hardfacing.

Constricted arc

(plasma arc welding and cutting). A plasma arc column that is shaped by a constricting nozzle orifice.

Constricted nozzle

(plasma arc welding and cutting) A water-cooled copper nozzle surrounding the electrode and containing the constricting orifice.

Consumable insert

Pre-placed filler metal which is completely fused into the root of the joint and becomes part of the weld.

Covered electrode

A composite filler metal electrode consisting of a core of a bare electrode or metal cored electrode to which a convering sufficient to provide a slag layer on the weld metal has been applied. The covering may contain materials providing such functions as shielding from the atmosphere, de-oxidation, and arc stabilization and can serve as a source of metallic additions to the weld.

Crack

A fracture type discontinuity characterized by a sharp tip and high ratio of length and width to opening displacement .

Crater

In arc welding, a depression at the termination of a weld bead or in the molten weld pool.

Crater crack

A crack in the crater of a weld bead.

Cutting torch (oxyfuel gas)

A device used for directing the preheating flame produced by the controlled combustion of fuel to the arc, and to direct the flow of plasma and shielding gas.

Defect

A discontinuity or discontinuities which by nature or accumulated effect (for example, total crack length) render a part or product unable to meet minimum applicable acceptance standards or specifications. This term designates rejectability. See discontinuity and flow.

Defective weld

A weld containing one or more defects.

Deposited metal

Filler metal that has been added during a welding operation.

Deposition efficiency (arc welding)

The ratio of the weight of deposited metal to the net weight of filler metal consumed, exclusive of stubs.

Deposition rate

The weight of material deposited in a unit of time. It is usually expressed as pounds per hour (lb/h).

Depth of fusion

The distance that fusion extends into the base metal or previous pass from the surface melted during welding.

Dilution

The change in chemical composition of a welding filler metal caused by the admixture of the base metal or previously deposited weld metal in the deposited weld bead. It is normally measured by the precentage of base metal or previously deposited weld metal in the weld bead.

Direct current electrode negative (DCEN)

The arrangement of direct current arc welding leads in which the work is the positive pole and the electrode is the negative pole of the welding arc. See also straight polarity.

Direct current electrode positive (DCEP)

The arrangement of direct current arc welding leads in which the work is the negative pole and the electrode is the positive pole of the welding arc. See also reverse polarity.

Discontinuity

An interruption of the typical structure of a weldment, such as a lack of homogeneity in the mechanical, metallurgical, or physical characteristics of the materials or weldment. A discontinuity is not necessarily a defect. See defect and flow.

Double-welded joint

In arc and oxy fuel gas welding, any joint welded from both sides. Dovetailing. (thermal spraying). A method of surface roughening involving angular undercutting to interlock the spray deposit.

Drop-thru

An undesirable sagging or surface irregularity, usually encountered when brazing or welding near the solidus of the base metal, caused by overheating with rapid diffusion or alloying between the filler metal and the base metal.

Duty cycle

The percentage of time during an arbitrary test period, usually 10 min. during which a power supply can be operated at its rated output without overloading.

Welding Technology Glossary of Terms used in Weld Processes

Edge preparation

The surface prepared on the edge of a member of a welding.Edge weld. A weld in an edge joint.

Effective length of weld

The length of weld throughout which the correctly proportioned cross section exists. In a curved weld, it shall be measured along the axis of the weld.

Effective throat

The minimum distance from the root of the weld to its face less any reinforcement. See also joint penetration.

Electrode

A component of the welding circuit through which current is conducted to the arc, molten slag, or base metal. See arc welding electrode, bare electrode , carbon electrode, composite electrode, covered electorde, electrode slag, welding electrode emissive electrode , flux cored electrode, lightly coated electrode, metal cored electrode, metal electorde, resistance welding electrode, stranded electrode, and tungston electrode.

Electrode extension (GMAW, FCAW, SAW)

The length of unmelted electrode extending beyond the end of the contact tube during welding.

Electrode holder

A device used for mechanically holding the electrode while conducting current to it.

Face of weld

The exposed surface of a weld on the side from which welding was done.

Face reinforcement

Reinforcement of weld at the side of the joint from which welding was done. See also root reinforcement.

Face shield (eye protection)

A device positioned in front of the eyes and a portion of, or all of, the face, whose predominant function is protection of the eyes and face. See also hand shield and helmet. Feed rate. (thermal spraying). The rate at which meterial passes through the gun in a unit of time. A synonym for spray rate.

Filler metal

The metal to be added in making a welded, brazed, or soldered joint, See electrode, welding filler metal, diffusion aid, solder, and spray deposit.

Filler metal start delay time

The time time interval from beginning of downslope time to the stop of filler metal.

Filler metal stop delay time

The time interval from beginning of downslope time to the stop of filler metal.

Fillet weld

A weld of approximately triangular cross section jointing two surfaces approximately at right angles to each other in a lap joint, T-joint, or corner joint.

Fusion

The melting together of filler metal and base metal (substrate), or of base metal only, which results in coalescence. See depth of fusion.

Fusion welding

Any welding process or method which uses fusion to complete the weld.

Fusion zone

The area of base metal melted as determined on the cross section of a weld.

Gas shielded arc welding

A general term used to describe gas metal arc welding, gas tungsten arc welding, and flux cored arc welding when gas shielding is employed.

Gas welding

See preferred term oxyfuel gas welding (OFW).

Groove

An opening or channel in the surface of a part or between two components which provides space to contain a weld.

Groove angle

The total included angle of the groove between parts to be joined by a groove weld.

Groove face

That surface of a member included in the groove.

Groove radius

The radius used to form the shape of a J-or U-groove weld joint.

Groove weld

A weld made in the groove between two members to be joined. The standard types of groove welds are as follows:

  • double-bevel-groove weld double-flare-bevel-groove weld. double-flare-V-groove weld. double-J-groove weld.
  • double-U-groove weld. double-V-groove weld. single-bevel-groove weld.
  • single-flare-bevel-groove weld. single-flare-V-groove weld. single-J-groove weld.
  • single-U-groove weld. single-V-groove weld. single-groove weld.

Hardfacing

A particular form of surfacing in which a coating or cladding is applied to a substrate for the main purpose of reducing wear or loss of material by abrasion, impact, erosion, galling, and cavitation.

See coating, cladding, and surfacing

Inadequate joint penetration. Joint penetration which is less than that specified.

Inclined position. (with restriction ring)

The position of a pipe joint in which the axis of the pipe joint in which the axis of the pipe is approximately at an angle of 45° to the horizontal and a restriction ring is located near the joint. The pipe is not rotated during welding.

Intermittent weld

A weld in which the continuity is broken by recurring unwelded spaces. Interpass temperatures. In a multiple-pass weld, the temperature (minimum or maximum as specified) of the deposited weld before the next pass is started.

Joint

The junction of members or the edges of members which are to be joined or have been joined.

Joint clearance

The distance between the faying surfaces of a joint. In brazing, this distance is referred to as that which is present before brazing, at the brazing temperature, or after brazing is completed.

Joint design

The joint geometry together with the required dimensions of the welded joint.

Joint efficiency

The ratio of the strangth of a joint to the strangth of the base metal (expressed in percent).

Joint geometry

The shape and dimensions of a joint in cross section prior to welding.

Joint penetration

The minimum depth a groove or flange weld extends from its face into a joint, exclusive of reinforcement. Joint penetration may include root penetration. See also complete joint penetration. See also complete joint penetration, root penetration, and effective throat.

Kerf

The width of the cut produced during a cutting process.

Keyhole

A technique of welding in which a concentrated heat source penetrates completely through a workpiece forming a hole at the lead edge of the molten weld metal. As the heat source prograsses, the molten metal fills in behind the hole to form the weld bead.

Lack of fusion

See preferred term incomplete fusion.

Lack of joint penetration

See preferred term inadequate joint penetration.

Metal cored electrode

A composite filler metal electrode consisting of a metal tube or other hollow configuration containing alloying ingredients. Minor amounts of ingredients providing such function as arc stabilization and fluxing of oxides may be included. External shielding gas may or may not be used.

Metal electrode

A filler or non-filler metal electrode used in arc welding or cutting which consists of a metal wire or rod that has been manufactured by any method and that is either bare or covered with a suitable covering or coating.

Molten weld pool

The liquid state of a weld prior to solidification as weld metal.

Nozzle

A devices which directs shielding media.

Overlap

The protrusion of weld metal beyond the toe, face, or root of the weld, in resistance seam welding, the area in the preceeding weld remelted by the succeeding weld.

Overlaying

See preferred term surfacing.

Oxyacetylene cutting (OFC-A)

An oxyfuel gas cutting process used to sever metals by means of the chemical reaction of oxygen with the base metal at elevated temperatures. The necessary temperature is maintained by gas flames resulting from the combustion of accetylene with oxygen.

Oxyacetylene welding (OAW)

An oxyfuel gas welding process which produces gas welding of metals by heating them with a gas flame or flames obtained from the combustion of acetylene with oxygen. The process may be used with or without the application of pressure and with or without the use of filler metal.

Parent metal

See preferred term base metal.

Partial joint penetration

Joint penetration which is less than complete. See also complete joint penetration.

Pass

See preferred term weld pass.

Peening

The mechanical working of metals using impact blows.

Penetration

See preferred term joint penetration and root penetration.

Pilot arc (plasma arc welding)

A low current continuous arc between the elctrode and the constricting nozzle to ionize the gas and facilitate the start of the main welding arc.

Plasma

A gas that has been heated to an at least partially ionized condition, enabling it to conduct an electric current.

Plug weld

A circular weld made through a hole in one member of a lap or T-joint fusing that member to the other. The walls of the hole may or may not be parallel and the hole may be partially or completely filled with weld metal. (A fillet welded hole or a spot weld should not be construced as conforming to this definition.

Polarity

See direct current electrode negative, direct current electrode positive, straight polarity, and reverse polarity.

Porosity

Cavity type discontinuities formed by gas entrapment during solidification.

Position of welding

See flat position, horizontal position, horizontal fixed position, horizontal rolled position, inclined position, overhead position, and vertical position.

The application of heat to an assembly after a welding, brazing, soldering, thermal spraying, or cutting operation. See post weld heat treatment.

Post heating

Postweld heat treatment

Any heat treatment subsequent to welding.

Preheat

See preferred term preheat temperature.

Preheating

The application of heat to the base metal immediately before welding. brazing, soldering, thermal spraying, or cutting.

Preheat temperature

A specified temperature that the base metal must attain in the welding, brazing, soldering, thermal spraying or cutting area immediately before these operations are performed.

Procedures

The detailed elements (with prescribed values or ranges of values) of a process or method used to produce a specific result.

Procedure qualification

The demonstration that welds made by a specific procedures can meet prescribes standards.

Procedure qualification record (PQR)

A document providing the actual welding varibles used to produce an acceptable test weld and the results of tests conducted on the weld for the purpose of qualifying a welding procedure specification.

Qualification

See preferred term welder performance qualification and procedure qualification. Random intermittent welds. Intermittent welds on one or both sides of a joint in which the weld increments are deposited without regard to spacing.

Shrinkage void

A cavity type discontinuity normally formed by shrinkage during solidification.

Size of weld

groove weld. The joint penetration (depth of bevel plus the root penetration when specified). The size of a groove weld and its effective throat are one and the same.

Fillet weld.

For equal legs fillet welds, the leg lengths of the largest isosceles right triangle which can be inscribed within the fillet weld cross section. For unequal leg fillet welds, the leg lengths of the largest right triangle which can be inscribed within the fillet weld cross sectiion. Note: When one number greater than 105 degrees, the leg length (size) is of less significance than the effective throat which is the controlling factor for the strength of a weld.

Slag inclusion

Nonmetallic solid material entrapped in weld metal or between weld metal and base metal.

Slugging

The act of adding a separate piece or pieces of material in a joint before or during welding that result in a welded joint not complying design, drawing, or specification requirements.

Spacer strip

A metal strip or bar prepared for a groove weld and inserted in the root of a joint to serve as a backing and to maintain root opening during welding. It can also bridge an exceptionally wide gap due to poor fitup.

Spatter

The metal particles expelled during welding and which do not form a part of the weld. Start time. The time interval prior to weld time during which arc voltage and current reach a preset value greater or less than welding values.

Surfacing

The deposition of filler metal (material) on a base metal (substrate) to obtain desired properties or dimensions. See also buttering, cladding, coating, and hardfacing.

Tack weld

A weld made to hold parts of a weldment in proper alignment until the final welds are made. Thermal cutting. A group of cutting processes which melts the metal (material) to be cut. See arc cutting, oxygen cutting, electron beam cutting, and laser beam cutting.

Throat of a fillet weld

Theoretical throat. The distance from the beginning of the root of the joint perpendicular to the hypotenuse of the largest right triangle that can be inscribed within the fillet weld cross section. This dimension is based on the assumption that the root opening is equal to zero.

Actual throat

The minimum distance minus any reinforcement from the root of weld to its face. The shortest distance from the root of weld to its face.

Effective throat

T-joint.

A joint between two members located approximately at right angles to each other in the form of a T.

Toe of crack

A crack in the base metal occurring at the toe of a weld.

Toe of weld

The junction between the face of a weld and the base metal.

Travel angle

The angle that the electrode made with a references line perpendicular to the axis of the weld in the plane of the weld axis. See also drag angle and push angle. Note: This angle can be used to define the position of the welding guns, welding torches, high energy beams, welding rods, thermal cutting and thermal spraying torches, and thermal spraying guns.

Travel angle (pipe)

The angle that the electrode makes with a reference line extending from the centre of the pipe through the molten weld pool in the plane of the weld axis. Note: This angle can be used to define the position of welding guns, welding torches, high energy beams, welding rods, thermal cutting and thermal spraying torches, and thermal spraying guns.

Welding

A localised coalescence of metals or non-metals produced either by heating the materials to suitable temperatures, with or without the application of pressure or by the application of pressure alone and with or without the use of filler material.

Weldability

The capacity of a material to be welded under the fabrication conditions imposed into a specific, suitably designed structure and to perform satisfactorily in the intended service.

Weld crack

A crack in weld metal.

Welder

One who performs a manual or semiautomatic welding operation. (sometimes erroneously used to denote a welding machine.)

Welder certification

Certification in writing that a welder has produced welds meeting prescribed standards.

Welder performances qualification

The demonstration of a welder’s ability to produce welds meeting prescribed standards.

Welding

A materials joining process used in making welds.

Welding current

The current in the welding circuit during the making of a weld.

Welding machine

Equipment used to perform the welding operation. For example, spot welding machine, arc welding machine, seam welding machine, etc.

Welding operator

One who operates machine or automatic welding equipment.

Welding position

see flat position, horizontal position, horizontal fixed position, horizontal rolled position, inclined position, overhead position, and vertical position.

Welding procedure

The detailed methods and practices including all welding procedures specifications involved in the production of a weldment. See welding procedure specification.

Welding procedure specification (WPS)

A document providing in detail the required variables for a specific application to assure repeatability by properly trained welders and welding operators.

Welding process

A materials joining process which produces coalescence of materials by heating them to suitable temperatures with or without the application of pressure or by the application of pressure alone, and with or without the use of filler metal.

Welding rod

A form of filler metal used for welding or brazing which does not conduct the electrical current.

Welding technique

The details of a welding procedure which are controlled by the welder or welding operator.

Weldment

An assembly whose component parts are joined by welding.

Weld metal

That portion of a weld which has been melted during welding.

Weld pass

A single progression of a welding or surfacing operation along a joint, weld deposit, or substrate. The result of a pass is a weld bead, layer or spray deposit.

Work angle

The angle that the electrode makes with the referenced plane or surface of the base metal in a plane perpendicular to the axis of the weld. See also drag angle and push angle. Note: This angle can be used to defined the position of welding guns, welding rods, thermal cutting and thermal spraying torches, and thermal spraying guns.

Work angle (pipe)

The angle that the electrode makes with the referenced plane extending from the centre of the pipe through the molten weld pool. Note: This angle can be used to defined the position of welding guns, welding rods, thermal cutting and thermal spraying torches, and thermal spraying guns.