Welding Terms Part-10 (S)

Dear Readers,

This continues Part-9. Knowing the list of welding abbreviations is crucial. Recognizing these abbreviations is the initial step in blueprint reading. Therefore, understanding the terms used in welding is essential.

Scarf – The chamfered surface of a joint.

Scarfing – A process for removing defects and checks which develop in the rolling of steel billets by the use of a low velocity oxygen de-seaming torch.

Scarf Joint – A form of butt joint.

Scratch Start TIG – A common method of striking an arc in the TIG welding process which involves dragging the tungsten electrode across the surface of the metal.

Seal Weld – Any weld designed primarily to provide a specific degree of tightness against leakage.

Seam Weld – The seam is right where the two plates, strips, etc. touch. It is important that you get half of the Weld Pool on each side of the seam.

Semi-Automatic Welding – MIG is an example. The machine runs the wire (Filler Metal) and supplies the Shielding Gas automatically, but it takes a person to pull the trigger and manipulate the gun to make the weld.

Self-Shielded Flux Cored Arc Welding (FCAW-S) – A flux-cored arc welding process variation in which shielding gas is obtained exclusively from the flux within the electrode.

Series Welding – A resistance welding process in which two or more welds are made simultaneously by a single welding transformer with the total current passing through each weld.

Sheet Separation – In spot, seam, and projection welding, the gap surrounding the weld between faying surfaces, after the joint has been welded.

Shielded Metal Arc Welding (SMAW) – A process that welds by heat from an electric arc, between a flux-covered metal electrode and the work. Shielding comes from the decomposition of the electrode covering.

Shielding Gas – Protective gas used to prevent atmospheric contamination.

Shoulder – The portion of the prepared edge of a member to be joined by a groove weld which is not beveled or grooved.

Shrinkage Stress – Stress remaining in a structure or member as a result of thermal and/or mechanical treatment.

Shrinkage Void – A cavity-type discontinuity normally formed by shrinkage during solidification.

Single Impulse Welding – The making of spot, projection, and upset welds by a single impulse of current. When alternating current is used, an impulse may consist of a fraction of a cycle or a number of cycles.

Single-Welded Joint – In arc and gas welding, any joint welded from one side only.

Size of Weld – The size of weld refers to the dimensions of the weld, typically its diameter or width and depth, depending on the type of weld.

Skip Weld – A sequence used to control warping (distortion).

Skull – The un-melted residue from a liquated filler metal.

Slag – when the Flux on a welding Rod melts it produces the Shielding Gas to protect the weld, and then forms a hardened protective coating over the weld. It is called Slag.

Slag Inclusion – Slag inclusions are one of the main Weld Defects. If you don't properly clean the Slag from a Bead, you run the risk of it becoming part of the weld when you run the next bead.

Slot – Slot welds are just like Plug Welds except instead of being round, they are elongated. (Long and narrow/ Elongated Hole).

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

SMAW – Shielded Metal (stick) arc welding uses a consumable electrode that has a solid metal rod in the core. The rod and electrode melt down and become part of the weld. The electrode is flux coated to protect the weld from contamination.

Soldering – A joining process using a filler metal with a liquidus less than 840 °F and below the solidus of the base metal.

Solid State Welding – A group of welding processes which produces coalescence at temperatures essentially below the melting point of the base materials being joined, without the addition of a brazing filler metal. Pressure may or may not be used.

Solidus – The highest temperature at which a metal or alloy is completely solid.

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 fit up.

SPALL – Small chips or fragments which are sometimes given off by electrodes during the welding operation. This problem is especially common with heavy-coated electrodes.

Spatter – Metal particles expelled during welding that do not form a part of the weld.

Spatter loss – Metal lost due to spatter.

Spot Weld – (also known as resistance spot welding) is a resistance welding process. This welding process is used primarily for welding two or more metal sheets together by applying pressure and heat from an electric current to the weld area. Used on thin gauge metal like car bodies.

Spray Transfer – In arc welding, a type of metal transfer in which molten filler metal is propelled axially across the arc in small droplets.

Spray Welding – Another term for spray arc welding or GMAW.

Square-Groove Weld – A type of groove weld.

Staggered Intermittent Fillet Welding - Two lines of intermittent fillet welding on a joint in which the fillet weld increments are one line are staggered with respect to those in the other line.

Standard Temperature and Pressure (STP) – An internationally accepted reference base where standard temperature is 0 °C (32 °f) and standard pressure is one atmosphere, or 14.6960 psia.

Steel – Steel is iron ore mined from the ground, purified in blast furnaces, and then carbon added in its molten stage.

Stick Welding – Same as Shielded Metal Arc Welding (SMAW)

Sticking – It is the occurrence when the rod sticks to the steel instead of starting an arc. It's usually caused by the heat not being hot enough, or the wrong ROD angle.

Stick-Out – The length of nonmelted electrode extending beyond the end of the contact tube in continuous welding processes.

Stitch Welding – The use of intermittent welds to join two or more parts.

Stinger – Another name for the SMAW electrode holder.

Stored Energy Welding – The making of a weld with electrical energy accumulated electrostatically, electromagnetically, or electrochemically at a relatively low rate and made available at the required welding rate.

Straight Polarity – Direct current arc welding where the work is the positive pole.

Stress Corrosion Cracking – Failure of metals by cracking under combined action of corrosion and stress, residual or applied. In brazing, the term applies to the cracking of stressed base metal due to the presence of a liquid filler metal.

Stress Relief Heat Treatment – Uniform heating of a welded component to a temperature sufficient to relieve a major portion of the residual stresses.

Stress Relief Cracking – Cracking in the weld metal or heat affected zone during post-weld heat treatment or high temperature service.

Stringer Bead – A weld bead made without transverse movement of the welding arc.

Stud Welding – A process for attaching a fastener, bolt or nut to a metal base. Fasteners attached during the stud welding process are usually threaded, unthreaded or tapped variety.

Submerged Arc Welding – A process that welds with the heat produced by an electric arc between a bare metal electrode and the work. A blanket of granular fusible flux shields the arc.

Substrate – Any material upon which a thermal-spray deposit is applied.

Surfacing – Welds used to build up worn down equipment to its original form. A good example is a bulldozer bucket tooth.

Synergistic – An action where the total effect of two active components in a mixture is greater than the sum of their individual effects.

Welding Terms Part-9 (Q&R)

Dear Readers,

This continues from Part-8. Successful work execution heavily relies on both written and oral communication. For effective communication, understanding the acronyms and terms used in welding is essential.

Quality Assurance (QA) – The practice involves utilizing a defined set of processes for systematic monitoring and evaluation to ensure product quality.

Quality Control (QC) – The process of confirming that a product meets an established set of specifications. 

Quench – Rapidly cooling the steel to make it harder. The steel has to have enough carbon in it for it to harden.

Radiation – The light emitted during arc welding contains intense ultraviolet radiation (UVR). In the absence of a barrier, this radiation is emitted into the surrounding environment.

Radiography – The weld is x-rayed, and it will show even the minutest weld defects. (Slag inclusion, porosity, or undercut!)

Rake Angle – Slope of a shear knife from end to end.

Rated Load – The amperage and voltage the power source is designed to produce for a given specific duty cycle period. For example, 300 amps, 32 load volts, at 60 percent duty cycle.

Reaction Stress – The residual stress which could not otherwise exist if the members or parts being welded were isolated as free bodies without connection to other parts of the structure.

Reactor (arc welding) – A device used in arc welding circuits for the purpose of minimizing irregularities in the flow of welding current.

Reducing Flame – A gas flame that has a reducing effect, due to the presence of excess fuel.

Regulator – A device used to reduce cylinder pressure to a suitable torch working pressure.

Reinforcement – Weld metal, at the face or root, in excess of the metal necessary to fill the joint.

Residual Stress – Stress remaining in a structure or member, as a result of thermal and/or mechanical treatment. Stress arises in fusion welding primarily because the melted material contracts on cooling from the solidus to room temperature.

Resistance Brazing – A brazing process in which bonding is produced by the heat obtained from resistance to the flow of electric current in a circuit of which the workpiece is a part, and by using a nonferrous filler metal having a melting point above 800 ºF (427 ºC), but below that of the base metals. The filler metal is distributed in the joint by capillary attraction.

Resistance Butt Welding – A group of resistance welding processes in which the weld occurs simultaneously over the entire contact area of the parts being joined.

Resistance Spot Welding (RSW) – Uses electrical current which is passed through the metal. It does not require a filler rod. The process is easy to automate and requires low heat input.

Resistance Welding – A group of welding processes in which fusion is produced by heat obtained from resistance to the flow of electric current in a circuit of which the workpiece is a part and by the application of pressure.

Reverse Polarity – The arrangement of direct current arc welding leads with the work as the negative pole and the electrode as the positive pole of the welding arc.

Robotic Welder – A fully or partially automated machine equipped with a welding head and connected to a welding power source. The movable portion of a robotic welder is normally a robotic arm.

Rockwell Hardness Test – In this test a machine measures hardness by determining the depth of penetration of a penetrator into the specimen under certain arbitrary fixed conditions of test. The penetrator may be either a steel ball or a diamond Sphero cone.

Rods – Same as welding electrode. At site or shop, nobody asks for more "electrodes", they ask for more rods.

Root Crack – A crack at the root of a weld.

Root Edge – The edge of a part to be welded which is adjacent to the root.

Root Face – That portion of the groove face adjacent to the root of the joint.

Root of Joint – That portion of a joint to be welded where the members approach closest to each other. In cross section the root of the joint may be either a point, a line or an area.

Root of Weld – The points, as shown in cross section, at which the back of the weld intersects the base metal surfaces.

Root Opening – A separation at the joint root between the work pieces.

Root Penetration – How far the Filler Metal is penetrating into and through the Root Opening.

Root Reinforcement – Reinforcement of weld at the side other than that from which welding was done.

Root Surface – The exposed surface of a weld on the side other than that from which welding was done.

Welding Terms Part-8 (P)

This is a continuation of Part 7. Welding is a highly technical field that relies on specialized acronyms and abbreviations to ensure effective communication and execution of tasks. The following terms are commonly used in welding work.

Paralleling – Running multiple power generators to form a large capacity power source with redundancy. Often used for mission-critical operations such as oilfield and emergency backup power. 

Parent Metal – Also called "base metal", this is the metal or steel that you are actually welding on.

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.

Peel test – A destructive method of inspection that mechanically separates a lap joint by peeling.

Peening – The mechanical working of metals using impact blows.

Penetration – Is the fusion or depth into the parent metal from its surface, or the amount of fusion through an open-faced joint.

Penetrant Inspection – A non-destructive testing method that detects surface flaws using either fluorescent or dye penetrants. Fluorescent penetrants glow under black light, while dye penetrants produce bright red indications when drawn to the surface by a developer. The process involves cleaning the surface, applying the penetrant, waiting for it to be absorbed, removing excess penetrant, and applying the developer to reveal any defects.

Percussive Welding – A resistance welding process in which a discharge of electrical energy and the application of high pressure occur simultaneously, or with the electrical discharge occurring slightly before the application of pressure.

Perlite – Perlite is the lamellar aggregate of ferrite and iron carbide resulting from the direct transformation of austenite at the lower critical point.

Pilot Arc – A low-current continuous arc between the electrode and the constricting nozzle of a plasma torch that ionizes the gas and facilitates the start of the welding arc.

Pitch – Center-to-center spacing of welds.

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

Plasma Arc Cutting (PAC) – An arc cutting process using a constricted arc to remove the molten metal with a high-velocity jet of ionized gas from the constricting orifice.

Plasma Arc Welding (PAW) – An arc welding process that uses a constricted arc between a non-consumable electrode and the weld pool (transferred arc) or between the electrode and the constricting nozzle (non-transferred arc). Shielding is obtained from the ionized gas issuing from the torch.

Plasma Spraying (PSP) – A thermal spraying process in which a non-transferred arc is used to create an arc plasma for melting and propelling the surfacing material to the substrate.

Plug Weld – A circular weld made through a hole in one member of a lap or T joint.

Poke Welding – A spot welding process in which pressure is applied manually to one electrode. The other electrode is clamped to any part of the metal in much the same manner that arc welding is grounded.

Polarity – When you turn on a welding machine, an electrical circuit is formed. The circuit has either a positive or negative pole, and this property is referred to as polarity. In straight polarity or normal polarity, the workpiece is positive and the tool is negative. When the workpiece is negative and the tool is positive, this type of polarity is commonly known as reversed polarity.

Porosity – A hole-like discontinuity formed by gas entrapment during solidification.

Ports – In a MIG gun, there are small orifices (holes) that allow the flow of shielding gas. The nozzle then directs the gas out over the weld puddle.

Positions of Welding – All welding is accomplished in one of four positions: flat, horizontal, overhead, and vertical. The limiting angles of the various positions depend somewhat on whether the weld is a fillet or groove weld.

Positioner (Rotating Table / Work center) – These are usually found in the bigger, more prestigious fab shops. They can turn, tilt, rotate, revolve, and that allows you to make most of the welds in the flat or horizontal welding positions.

Post-Heating – The application of heat to an assembly after welding, brazing, soldering, thermal spraying, or cutting operation.

Post-weld Heat Treatment (PWHT) – Any heat treatment after welding.

Post-weld Interval – In resistance welding, the heat time between the end of weld time, or weld interval, and the start of hold time. During this interval, the weld is subjected to mechanical and heat treatment.

Power Efficiency – How well an electrical machine uses the incoming electrical power.

Preform – The initial press of a powder metal that forms a compact.

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

Preheat Temperature – The temperature of the base metal immediately before welding is started.

Pressure Controlled Welding – The making of many spot or projection welds in which several electrodes function progressively under the control of a pressure sequencing device.

Pressure Welding – a welding process where pressure is used to make a weld.

Pre-weld Interval – In spot, projection, and upset welding, the time between the end of squeeze time and the start of weld time or weld interval during which the material is preheated. In flash welding, it is the time during which the material is preheated.

Primary Power – Often referred to as the input line voltage and amperage available to the welding machine from the shop's main power line.

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

Procedure Qualification – Demonstration that a fabricating process, such as welding, made by a specific procedure can meet given standards.

Projection Welding – A resistance welding process between two or more surfaces or between the ends of one member and the surface of another. The welds are localized at predetermined points or projections.

Protective atmosphere – A gas envelope surrounding the part to be brazed, welded, or thermal sprayed, with the gas composition controlled with respect to chemical composition, dew point, pressure, flow rate, etc. Examples are inert gases, combusted fuel gases, hydrogen, and vacuum.

Puddle – The puddle is the same as the weld pool. It is the molten filler metal that is combining with the parent metal.

Pull Gun Technique – Same as backhand welding.

Pulse – A current of controlled duration through a welding circuit.

Pulsed Power Welding – Any arc welding method in which the power is cyclically programmed to pulse so that the effective but short-duration values of a parameter can be utilized. Such short-duration values are significantly different from the average value of the parameter. Equivalent terms are pulsed voltage or pulsed current welding.

Pulsed Spray Welding – An arc welding process variation in which the current is pulsed to achieve spray metal transfer at average currents equal to or less than the globular to spray transition current.

Pulsing – Sequencing and controlling the amount of current, the frequency, and the duration of the welding arc.

Push Angle – The travel angle at which the electrode is pointing in the direction of travel.

Push Welding – A technique in welding where the welding gun is pushed forward in the direction of the weld, resulting in better visibility and control over the weld. This technique is commonly used in Gas Metal Arc Welding (GMAW) and is preferred for creating clean, spatter-free welds.

Welding Terms Part-7 (N&O)

Dear Readers,

This is a continuation of Part 6. This article will be a valuable resource for anyone looking to enhance their knowledge of the Welding Works.

Neutral Flame – An oxy-fuel gas flame that is neither oxidizing nor reducing.

Nick Break Test – A method for testing the soundness of welds by nicking each end of the weld, then giving the test specimen a sharp hammer blow to break the weld from nick to nick. Visual inspection will show any weld defects.

Non-Destructive Testing – NDT involves the testing of welds without destroying the welds or parts.

Non-ferrous – Does not come from iron ore. It is mined pretty much in its true form such as copper, aluminum, nickel, etc.

Normalizing – Heating iron-base alloys to approximately 100 ºF (38 ºC) above the critical temperature range followed by cooling to below that range in still air at ordinary temperature.

Nugget – The fused metal zone of a resistance weld.

Nozzle – A brass attachment that is about three inches long and shaped as an open cylinder.

O2 – Oxygen.

OFW – Abbreviation for Oxy-fuel welding. There are three processes in the Oxy group including oxyacetylene, oxyhydrogen and pressure gas welding.

Open-Circuit Voltage – The voltage between the output terminals of the welding machine when no current is flowing in the welding circuit.

Orifice Gas – In plasma arc welding and cutting, the gas is directed into the torch to surround the electrode. It becomes ionized in the arc to form the plasma and issues from the orifice in the torch nozzle as the plasma jet.

Oscillate – Hand (welding holder) movement while dragging (back hand) or pushing (forehand) the weld Puddle.

Ovens – Used to remove dampness from the welding electrodes as moisture in the electrode adversely.

Overfill – Excess deposition of weld metal. Overfill is a waste of time and material and can weaken the steel by placing too much heat on the joint. (Opposite of this is Underfill)

Overhead Position – The position in which welding is performed from the underside of a joint and the face of the weld is approximately horizontal.

Overlap – The protrusion of weld metal beyond the toe, face, or root of the weld.

Oxidizing Flame – An oxy-fuel gas flame having an oxidizing effect (excess oxygen).

Oxyacetylene Cutting – An Oxygen cutting process in which the necessary cutting temperature is maintained by flames obtained from the combustion of acetylene with oxygen.

Oxyacetylene Welding – A welding process in which the required temperature is attained by flames obtained from the combustion of acetylene with oxygen.

Oxy-Arc Cutting – An Oxygen cutting process in which the necessary cutting temperature is maintained through an arc between an electrode and the base metal.

Oxy-City Gas Cutting – An oxygen cutting process in which the necessary cutting temperature is maintained by flames obtained from the combustion of city gas with oxygen.

Oxygen Cutting – A process of cutting ferrous metals by means of the chemical action of oxygen on elements in the base metal at elevated temperatures.

Oxygen Gouging – An application of oxygen cutting in which a chamfer or groove is formed.

Oxy-Hydrogen Cutting – An oxygen cutting process in which the necessary cutting temperature is maintained by flames obtained from the combustion of city gas with oxygen.

Oxy-Hydrogen Welding – A gas welding process in which the required welding temperature is attained by flames obtained from the combustion of hydrogen with oxygen.

Oxy-Natural Gas Cutting – An Oxygen cutting process in which the necessary cutting temperature is maintained by flames obtained by the combustion of natural gas with oxygen.

Oxy-Propane Cutting – An Oxygen cutting process in which the necessary cutting temperature is maintained by flames obtained from the combustion of propane with oxygen.

 

Welding Terms Part-6 (L&M)

     Dear Readers.

This is continuation of Part-5. Welding is a highly technical field requiring specialized acronyms and abbreviations. This article will be a valuable resource for anyone looking to enhance their knowledge of the Welding Works.

Lap Joint – A joint between two overlapping members in parallel planes.

Laser – A device that provides a concentrated coherent light beam. Laser is an acronym for Light Amplification by Stimulated Emission of Radiation.

Laser Beam Cutting – A process that severs material with the heat from a concentrated coherent beam impinging upon the workpiece.

Laser Beam Welding – A process that fuses material with the heat from a concentrated coherent beam impinging upon the members to be joined.

Layer – A stratum of weld metal or surfacing material. The layer may consist of one or more weld beads laid side by side.

Leads – These are the lines from the machine to what you are welding that carry the current.

Leg of Fillet Weld – The distance from the root of the joint to the toe of the fillet weld.

Liquidus – The lowest temperature at which a metal or an alloy is completely liquid.

Local preheating – Preheating a specific portion of a structure.

Local stress relief heat treatment – Stress relief heat treatment of a specific portion of a structure.

Longitudinal sequence – The order in which the increments of a continuous weld are deposited with respect to its length.

Machine Welding – Equipment performs the weld while a person watches to make sure it is working right. They will also visually inspect the completed weld.

Macro Testing – A destructive testing method where the sections of a weld are polished, etched and examined under a microscope for defects.

Mandrel – A metal bar serving as a core around which other metals are cast, forged, or extruded, forming a true, center hole.

Manifold – A multiple header for interconnection of gas or fluid sources with distribution points.

Manual Welding – A welding process where the torch or electrode holder is manipulated by hand.

Mash Seam Welding – A seam weld made in a lap joint in which the thickness at the lap is reduced to approximately the thickness of one of the lapped joints by applying pressure while the metal is in a plastic state.

Mechanical Bond – The adherence of a thermal-spray deposit to a roughened surface by particle interlocking.

Mechanized Welding – Welding with equipment where manual adjustment of controls is required in response to variations in the welding process. The torch or electrode holder is held by a mechanical device.

Melting Point – The temperature at which a metal begins to liquefy.

Melting Rate – How much of the rod (electrode), wire, or TIG rod is melted in a certain amount of time. Or the temperature range between solidus and liquidus.

Melt-Through – Visible reinforcement produced on the opposite side of a welded joint from one side.

Metal-Arc Cutting – The process of cutting metals by melting with the heat of the metal arc. Arc metal cutting is a thermal cutting process that uses an arc between an electrode and the workpiece to melt and remove metal.

Metal-Arc Welding – An arc welding process in which a metal electrode is held so that the heat of the arc fuses both the electrode and the work to form a weld.

Metal Cored Arc Welding – A tubular electrode process where the hollow configuration contains alloying materials.

Metal Cored Electrode – A composite tubular electrode consisting of a metal sheath and a core of various powdered materials, producing no more than slag islands on the face of the weld bead. External shielding is required.

Metal electrode – A fillet or non-filler metal electrode, used in arc welding or cutting consisting 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.

Metallizing – A method of overlay or metal bonding to repair worn parts.

Metallic bond – The principal bond which holds metals together and which is formed between base metals and filler metals in all welding processes.

Method – An orderly arrangement or set form of procedure to be used in the application of welding or allied processes.

Microprocessor – One or more integrated circuits that can be programmed with stored instructions to perform a variety of functions.

MIG – It may be technically called GMAW, but in the shop Mig welding uses a solid steel wire rolled up on a spool and fed through a welding lead with a liner in it. Drivers push, pull or both to feed the wire through the lead to the welding gun.

Mixing Chamber – It is part of a welding or cutting torch in which the gases are mixed for combustion.

Molecular Weight – The sum of the atomic weights of all the constituent atoms in the molecule of an element or compound.

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

Monochromatic – The color of a surface that radiates light, containing an extremely small range of wavelengths.

MQP – Manufacturing Quality Plan. It is a basic test during manufacturing process.

MTC / MTR – Material Test Certificate / Material Test Report.

Multi-Impulse Welding – The making of spot, projection, and upset welds by more than one impulse of current. When alternating current is used each impulse may consist of a fraction of a cycle or a number of cycles.

Multipass Welds – When multiple welds are applied to one project.

Welding Terms Part-5 (I, J & K)

Dear Readers,

This is continuation of Part-4. This article will be a valuable resource for anyone looking to enhance their knowledge of the Welding Works.

Impact Test – A test in which one or more blows are suddenly applied to a specimen. The results are usually expressed in terms of energy absorbed or number of blows of a given intensity required to break the specimen.

IMPREGNATED-TAPE METAL-ARC WELDING – An arc welding process in which fusion is produced by heating with an electric arc between a metal electrode and the work. Shielding is obtained from decomposition of impregnated tape wrapped around the electrode as it is fed to the arc. Pressure is not used, and filler metal is obtained from the electrode.

Inclined Position – In pipe welding, the pipe axis angles 45 degrees to the horizontal position and remains stationary.

Incomplete Fusion – A weld discontinuity where fusion did not occur between weld metal and the joint or adjoining weld beads.

Incomplete Joint Penetration – A condition in a groove weld where weld metal does not extend through the joint thickness.

Indentation – In a spot, seam, or projection weld, the depression on the exterior surface or surfaces of the base metal.

Induction Brazing – A process in which bonding is produced by the heat obtained from the resistance of the work to the flow of induced electric current and by using a nonferrous filler metal having a melting point above 800 ºF (427 ºC), but below that of the base metals. The filler metal is distributed in the joint by capillary attraction.

Induction heating – Induction heating is the process of heating an electrically conducting object (usually a metal) by electromagnetic induction, through heat generated in the object by eddy currents.

Induction Welding – A process in which fusion is produced by heat obtained from resistance of the work to the flow of induced electric current, with or without the application of pressure.

Inert Gas – A gas that normally does not combine chemically with the base metal or filler metal.

Infrared radiation – Electromagnetic energy with wavelengths from 770 to 12000 nanometers.

Intergranular Penetration – The penetration of filler metal along the grain boundaries of a base metal.

Intermetallic – A term used to describe a compound material composed of two or more metals or of a metal and a nonmetal.

Intermittent Weld – An intermittent weld, also called a skip weld, consists of a series of welds placed on a joint, with unwelded spaces between each of the welds.

Inter-pass Temperature – In a multi-pass weld, the temperature of the weld area between passes.

Inverter – A power source for welding machines that is much more efficient than the normal transformers.

Ionization Potential – The voltage required to ionize (add or remove an electron) a material.

ITP – Inspection Test Plan. (Similar to FQP). It's a plan that lists what tests and inspections should be performed throughout each phase of a project.

Jig – Jigs hold the metal or steel you are working on in place as you are fabricating. They can be steel clamped with a vice or C-clamp, bolts tack-welded to a table, or very elaborate frames.

Joined buildup sequence – The order in which the weld beads of a multiple-pass weld are deposited with respect to the cross section of the joint.

Joint – The junction of members or the edges of members that are to be joined or have been joined.

Joint design – The joint geometry together with the required dimensions of the welded joint.

Joint efficiency – The ratio of the strength of a joint to the strength 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.

Joint welding procedure – The materials, detailed methods and practices employed in the welding of a particular joint.

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 leading edge of the molten weld metal. As the heat source progresses, the molten metal fills in behind the hole to form the weld bead.

Kilogram (kg) – The kilogram or kilogramme (SI unit symbol: kg) is the base unit of mass in the International System of Units (SI).

kW (Kilowatts) – A kilowatt is simply 1,000 watts, which is a measure of power. Primary kW is the actual power used by a power source when it is producing its rated output. Secondary kW is the actual power output of a welding power source.

Welding Terms Part-4 (G&H)

Dear Readers,

This is continuation of Part-3. Welders can be found working in manufacturing plants, building job sites, and rebuilding infrastructure such as bridges and highways. Being able to move from industry to industry offers a higher level of job security than many other types of jobs. it’s useful to know some terms of Welding.

Galvanized – An electrochemical process where mild steel is hot-dipped into liquid zinc to make it anti-corrosive.

Gas Carbon-Arc Welding – An arc welding process in which fusion is produced by heating with an electric arc between a carbon electrode and the work. Shielding is obtained from an inert gas such as helium or argon. Pressure and/or filler metal may or may not be used.

Gas Metal Arc Welding (GMAW) – An arc welding process where the arc is between a continuous filler metal electrode and the weld pool. Shielding from an externally supplied gas source is required.

Gas Pocket – A weld cavity caused by the trapping of gases released by the metal when cooling.

Gas Tungsten Arc Welding (GTAW) – An arc welding process where the arc is between a tungsten electrode (non-consumable) and the weld pool. The process is used with an externally supplied shielding gas.

Gas tungsten arc welding-pulsed arc (GTAW-P) – A variation of the gas tungsten arc welding process in which the current is pulsed.

Gas Welding – Welding with the heat from an oxy-fuel flame, with or without the addition of filler metal or pressure.

Globular Transfer – A type of metal transfer in which molten filler metal is transferred across the arc in large droplets.

Goggles – Safety equipment worn to protect the welder’s eyes from harmful radiation while welding and cutting.

Gouging – The forming of a bevel or groove by material removal.

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 type – The geometric configuration of a groove.

Groove Weld – When a very strong weld is needed, such as where two columns are spliced together on a high-rise, it is important to get the maximum penetration and fusion. This is done by cutting a Bevel so that you can weld solid from the Root to the face of the parent metal. Examples: single V, single U, single J, double bevel etc.

Ground Connection – A safety connection from a welding machine frame to the earth. Nothing but earthing.

Ground Lead – When referring to the connection from the welding machine to the work, see preferred term Workpiece Lead.

GTAW – Gas Tungsten Arc Welding. also known as tungsten inert gas (TIG) welding.

Guided Bend Test – A bending test in which the test specimen is bent to a definite shape by means of a jig.

Hammer Welding – A forge welding process.

Hand shield – Also called face Shield. A protective device, used in arc welding, for shielding the eyes, face and neck. A hand shield is equipped with a suitable filter plate and is designed to be held by the hand.

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

Hard Surfacing – The application of a hard, wear-resistant alloy to the surface of a softer metal.

Hardening – This term refers to a process used to increase the hardness of metal, typically iron-based alloys, by heating it above a certain critical temperature range and then rapidly cooling or “quenching” it.

Heat-Affected Zone (HAZ) – That section of the base metal, generally adjacent to the weld zone, whose mechanical properties or microstructure, have been altered by the heat of welding.

Heat Time – The duration of each current impulse in pulse welding.

Heat Treatment – An operation or combination of operations involving the heating and cooling of a metal or an alloy in the solid state for the purpose of obtaining certain desirable conditions or properties.

Helmet – protection equipment worn to protect the welder’s face and neck.

Hermetically Sealed – Airtight. Heterogenous – A mixture of phases such as: liquid-vapor or solid-liquid-vapor.

Hertz – Hertz is often referred to as "cycles per second." In the United States, the frequency or directional change of alternating current is usually 60 hertz.

Hold time – The time that pressure is maintained at the electrodes after the welding current has stopped.

Horizontal Weld – A bead or butt-welding process with its linear direction horizontal or inclined at an angle less than 45 degrees to the horizontal, and the parts welded being vertically or approximately vertically disposed.

Horn – The electrode holding arm of a resistance spot welding machine.

Horn Spacing – In a resistance welding machine, the unobstructed work clearance between horns or platens at right angles to the throat depth. This distance is measured with the horns parallel and horizontal at the end of the downstroke.

Hot Crack – A crack formed at temperatures near the completion of weld solidification.

Hot Pass – In pipe welding, the second pass which goes over the root pass.

Hot Short – A condition that occurs when a metal is heated to that point, prior to melting, where all strength is lost but the shape is still maintained.

Hydrogen Brazing – A method of furnace brazing in a hydrogen atmosphere.