Welding

welding banner 3Welding is the fabrication process that fuses like materials togeather by heating them to a suitable temperatures, this can be acomplished by brazing, soldering or welding. The filler metal has a melting point approximately the same or below that of the metals being joined togeather.  Welding is done by melting like metals then add a filler material to the joint, once cooled forming a sturdy joint.  Brazing and soldering is the melting of a filler material that is pulled into the gap between materials joining them togeather.  The brazing filler has a melting point below the materials being joind togeather.

There are many different types of welds, techniques, designs, codes and procedures.

Abbreviations

  • WLD - welded
  • WLDR - welder
  • WLDS - weldess

 

Welding Standards

ISO Standards

  • ISO 693 - Dimensions of seam welding wheel blanks
  • ISO 4850 - Personal eye-protectors for welding and related techniques -- Filters -- Utilisation and transmittance requirements
  • ISO 7286 - Graphical symbols for resistance welding equipment
  • ISO 8167 - Projections for resistance welding
  • ISO 15607 - Specification and qualification of welding procedures for metallic materials -- General rules
  • ISO 17846 - Welding and allied processes -- Health and safety -- Wordless precautionary labels for equipment and consumables used in arc welding and cuttin

 

Welding Associations

 

welding Related Articles

 

Welding processes

  • Arc welding (W)  -  A group of welding processes used to weld metal using heat of an electric arc, with or without filler material.
    • Carbon arc welding (CAW)  -  A process with an electric arc is struck between a carbon electrode and the work piece.
    • Flux cored arc welding (FCAW)  -  This process has a constantly fed electrode that becomes part of the weld.  The flux cored electrode is a composit tubular filler metal surounded with a core of mineral compounds and powdered metals.
    • Gas metal arc welding (GMAW)  -  Also called MIG (metal inert gas) welding.  This process has a constantly fed electrode that becomes part of the weld.  Also a seperate tank adds inert gas to the arc in order to ensure that oxidation does not occur during the menting process.
    • Gas tungsten arc welding (GTAW)  -  Also called TIG welding and heliarc welding.  The arc is created between a non-consumable tungsten electrode and the workpiece.
    • Plasma arc welding (PAW)  -  The arc is created between a non-consumable tungsten electrode and the workpiece.  Plasma gas, usually argon, is added between the electrode and the nozzle.
    • Shielded metal arc welding (SMAW)  -  Also called stick welding.  Is one of the older arc welding method by heating with an arc between a flux covered electrode (filler material) that melts to form a weld pool, which cools and joins the two to metals.
    • Submerged arc welding (SAW)  -  This type of weld is usually used on thick steel with longer welds.  It is created by submerging the electric arc beneath a layer of powdered flux.
  • Oxy-fuel gas welding (OFW)  -  A group of welding processes used to weld metal using heat from a combination of oxygen and a fuel gas.
    • Air-acetylene welding (AAW)  -  Uses air-aceetylene flame without the application of pressure.  Not used very often. 
    • Oxy-acetylene welding (OAW)  -  Uses acetylene as a fuel gas.
    • Oxy-propane welding (OPW)  -  Uses propane as a fuel gas.
    • Oxy-hydrogen welding (OHW)  -  Uses hydrogen as a fuel gas.
    • Pressure gas welding (PSW)  -  Makes a weld simultaneously over the entire surface.  This is done with pressure and without filler material.
  • Resistance welding (RW)  -  A group of welding processes used to weld metal using electric current to force join by pressure of the metals.  The current passed through and heats the metals until they begin to melt at the spot where they are in contact.
    • Resistance flash welding (RFW)  -  Also called butt welding.  The work pieces act as an electrode and the entire cross-section gap is welded.  Two secured work pieces are placed close togeather and a current is applied.  The current creates an arc between the two work pieces, melting both togeather.
    • Resistance projection welding (RPW)  -  The curent is focused from electrode to electrode through the tip of the projection.  This concentrates on specific raised sections or projections of a work piece.  The weld current and force can be forcused into a small area of the projection to produce heat at a specific spot.  During the process the projection collapses making it impossible for further welding since the large surface of the electrode diffuses under current density.
    • Resistance spot welding (RSW)  -  The curent is focused from electrode to electrode and disperced between the two.  Two operlapping work pieces are placed togeather creating a surface between the two.  An electrode is placed on each side of the work piece across from each other.  An electric charge between the two electrodes melts the two pieces togeather from the center out.
    • Resistance seam welding (RESW)  -  The electroces are two copper wheels constantly applying force to the work piece, each rooling on opposite sides of the materials.  The electric charge can be applied in spurts or at a constant feed.
  • Solid-state welding (SSW)  -  A group of welding processes used to weld metal by requiring a temperatures below the melting point of the base metal being joined, without the addition of brazing filter metal.
    • Coextrusion welding (CEW)  -  Dissimilar metals are extruded through the same die.
    • Cold pressure welding (CPW)  -  A pressure is applied at room temperature to cause compress and bond the materials togeather.  This process has no heat or flux and one of the materials must be highly ductile.
    • Diffusion welding (DFW)  -  Uses heat and pressure in a controlled atmosphere, with enough time for diffusion and coalescence to happen.
    • Explosion welding (EXW)  -  Also called explosive cladding.  Combines two metals togeather with an explosive force causing enough energy to form a metallic bond.   
    • Forge welding (FOW)  -  The workpieces are heated to the welding temperature  and hamered togeather to make the weld.
    • Friction welding (FRW)  -  The compressive force contact of workpieces rotating or moving relative to one another to produce heat from the faying surfaces.
    • Friction stir welding (FSW)  -  A rapidly rotating tool traversing a joint between two metals creating friction heating and plastic material displacement welding the seam togeather.
    • Hot pressure welding (HPW)  -  Metals are pressed togeather at elevated temperatures below the melting point in a vacuum or an inert gas atmosphere.
    • Hot isostatic pressure welding (HIPW)  -  A hot inert gas applies pressure inside a pressure vessel.
    • Magnetic pulse welding (MPW)  -  Short electromagnetic pulses produce a high-density magnetic field in the workpiece.  This causes plastic deformation along the workpiece and the two pieces to share electrons at the atomic level.
    • Roll welding (ROW)  -  Also called roll bonding is a cold welding process.  Two or more metals are fed through a cold rolling mill under enough pressure to compress and bond the materials togeather.
    • Ultrasonic welding (USW)  -  Two workpieces are held togeather, the oscillatory shear stresses of ultrasonic frequency causes coalescence or welding.

 

welding Terms

A

  • Alloy  -  A mixture of metals.
  • Annealing  -  A method of heat treating used to relieve stress and increase softening.
  • Arc  -  A gap between the end of the electrode and the base metal.
  • Arc length  -  The distance between the material and the electrode tip.
  • Arc strike  -  Arc strike is an arc initiated (accidental or intentional) on the base metal surface away from the weld zone.
  • Arc time  -  How long a welder can weld without any problems per 8 hours.
  • Arc voltage  - The voltage across the welding arc.
  • Arc welding  -  See welding processes.

B

  • Back weld  - A weld at the back of a groove weld.
  • Backing ring  -  Is inserted between two butt welding joints before welding to allow for complete penetration.
  • Base metal  - A part that all other parts are being brazed, cut, soldered, or welded to.
  • Bevel  - An angle edge cut or ground.
  • Blow hole  -  Formed due to the gas in the liquid metal and the weld can not escape when metal puddles solidify.
  • Bond  -  The junction of the weld metal and the base metal.
  • Brazing  -  The brazing filler metal melts at a temperature having a liquid above 450 deg C and always below the base metal being joined.
  • Burr  -  A sharp thin ridge of roughness left after cutting.
  • Butt joint  -  Joining two metals aligned approximately of lying on the same plane.
  • Buttweld  -  A weld at the butt joint.

C

  • Case hardning  -  Adding carbon to the surface of a mild steel object and heat treating to produce a hard surface.
  • Cold working  -  The permanent crystal distortion of a metal below its lowest temperature of re-crystallization.
  • Combustion  -  A reaction called rapid oxidation or burning produced with the right combination of a fuel, oxygen, and heat.
  • Corrosion  -  The thinning of a pipe wall that is typically caused by a chemical reaction from a corroding fluid or agent and is limited almost exclusively to metal products. 
  • Cover pass  -  The final pass of the weld that forms the face.
  • Current  -  The rate of flow of electricity flowing past a point in a conductor every second.

D

  • Defective weld  -  A weld having one or more defects.
  • Density  -  The ratio of the amount of matter in an object compared to its volume.

E

  • Elastic modulus  -  The ratio of the stress applied to a body or substance to the resulting strain within the elastic limits.
  • Electrode  -  Conducts current through, creating an arc through the tip of the electrode to the metal.  The electrode is a coated metal wire made with a composit material similar to the material being welded.  See stick electrode and MIG electrode.

F

  • Face  -  The outer most portion of the weld or the final pass of a multi-pass weld from the weld face.
  • Faying surfaces  -  Contacting surfacesof faces of two similar or dissimilar materials placed in tightcontact ot form a joint.
  • Field weld  -  A weld made at a location other than the shop or place of construction.
  • Filler material  -  A metal added to make a joint.
  • Flux  -  A chemical compound to hender or stop the formation of oxides and other substances in the moltent metal.
  • Force  -  The push or pull of an object resulting in a change from rest or motion.
  • Full penetration  -  
  • Fume  -  Solid particles formed when a solid vaporizes once and then condenses throught rapid cooling.
  • Fusion  -  The melting togeather of the filler material and base metal or only the base metal.
  • Fusion face  -  The surface of the base metal that is melted during welding.
  • Fusion welding  -  Amy type of welding process that uses fusion.

G

  • Gas welding  -  See solid-state welding processes.
  • Groove  -  A channel or opening created between the surface of the weld joint before welding to achieve necessary penetration.
  • Grove angle  -  The inclined angle between the weld channel or grove face.
  • Grove face  -  Any surface in a weld channel or groove before welding.
  • Groove radius  -  The radius used to form the shape J or U groove weld joint.
  • Groove weld  -  A weld made in a channel or opening between two workpieces.
  • Groove weld types  -  double-bevel-groove, double-flare-bevel-groove, double-flare-V-grove, double-J-groove, double-U-groove, double-V-groove, single-bevel-groove, single-flare-bevel-groove, single-flare-V-groove, single-J-groove, single-U-groove, single-V-groove, square-groove
  • Ground connection  -  A safety connection from the welding machine to the earth.
  • Ground lead  -  A connection from the welding machine to the work.

H

  • Hardfacing  -  A surfacing material added to the surface of impliments/objects to reduce wear from cracking, erosion, impact, and etc.
  • Hardness  -  The property of a material that enables it to resist plastic deformation, usually by penetration.
  • Heat  -  A form of energy that causes physical change in what is being heated. 
  • Heat transfer by conduction  -  It is the flow of energy between two objects, or within one object, where there is a temperature differential.
  • Heat treatment  -  The heating and cooling of metals or alloys.
  • Hot pass  -  A second pass in a multi-pass joint.

I

  • Incomplete weld  -  A defect in the solder joint that causes cracks or damage to the bond.
  • Inductance  -  The measure of an electric conductor or circuit by which an electromotive force is induced in it.
  • Inert gas  -  A gas which does not normally combine chemically with the base metal or filler metal.

J

  • Joint  -  The junction of members or the edge of members that are joined or to be joined.
  • Joint penetration  -  The minimum a groove weld extends from its face into a joint.
    • Complete joint penetration (CJP)  -  Weld completely fills the gap between the two pieces.
    • Partial joint penetration (PJP)  -  Weld fills a portion of the gap between the two pieces.
  • Joint types  - 
    • Butt joint  -  When two plates are butted togeather.
    • Corner joint  -  When two plates are butted togeather creating a L.
    • Edge joint  -  When two plate edges are butted togeather.
    • Lap joint  -  When two flat surfaces overlap each other.
    • Tee joint  -  When two plates are butted togeather creating a T.

K

  • Kinetic energy  -  The energy in moving objects or mass.  If it moves, it has kinetic energy.

L

  • Liquidus  -  The lowest temperature at which a metal or alloy is completely liquid.

M

  • Manual welding  -  the entire welding process is performed and controlled by hand.
  • Mass  -  The amount of matter an object has.
  • Matching weld metal  -  The electrode strength, both yield and tensile strength, is similar to the strength of the base metal.
  • Material hardness  -  The property of a material that enables it to resist plastic deformation, usually by penetration.
  • Maximum fillet weld size  -  There is no size restrictions to a fillet weld.  But if the weld is greater than 1/2" it will take a larger amount of heat to be put into the connection.  Preheating will allow for more even cooling which could help prevent distortion and weld cracking.
  • Melt-thru  -  Complete penetration of a joint weld from one side.
  • Melting range  -  The temperature range between solidus and liquidus of a weld.
  • MIG electrode  -  A constantly fed electrode that becomes part of the weld.
  • MIG welding  -  Also called gas metal arc welding.
  • Minimum fillet weld length  -  When only longitudinal welds are used for connection of bars and plates, their length may not be less than the distance between them.

N

  • Neutral flame  -  Is when oxygen and acetylene are mixed in equal porporttions.  See oxyfuel gas welding.
  • Non-ferrous  -  Contain no iron, is corrosion resistant, lighter in weight, malleability.

O

  • Overlap  -  Liquid metal surface is not melting on the weld.
  • Oxidizing flame  -  Is when an excess amount of oxygen is used.  See oxyfuel gas welding.
  • Oxyfuel gas welding  -  See welding processes.

P

  • Pass  -  A single progression of a welding surfacing operation along a joint, weld deposit, or substrate.
  • Plug weld  -  Joining two pieces of metal through a drilled hole or slot in the top piece which is laid over the bottom piece.
  • Porosity  -  Happens when a contaminent or gas is absorbed into the weld puddle.
  • Prequalified welded joints  -  The fabricator can use these joints with a prequalified procedure and not have to do any additional testing to insure weld joint soundness and strength.
  • Preheat  -  The application of heat to the base metal immediately before welding, brazing, soldering, cutting, or forming.
  • Process qualification  -  The demonstration that welds or other work produced by a specified procedure can meet prescribed standards.
  • Puddle  -  A nonstandard term for weld pool.
  • Pure gas  -  The replacement of air within a piping system with an inert gas.  May be required by the welding process.

Q

  • Quenching  -  The fast cooling of metals or alloys for the process of hardening.  This process can be done with air, oil, or water.  If the metal cools too quickly due to a large flow of heat into the thick base plate, the weld may become brittle, having low fracture toughness.

R

  • Reducing flame  -  Is when an excess amount of acetylene is used.  See oxyfuel gas welding.
  • Reinforcement  -  In branch connections, reinforcement is material around a branch opening that serves to strengthen it.
  • Resistance welding (RW)  -  See welding processes.
  • Reverse ploority  -  The arrangement of direct current arc welding leads with the work as the negative pole and electrode as the positive pole of the welding arc.
  • Root  -  The narrowest point in the gap between the two work pieces to be welded or the point in the gap furthest from the electrode.
  • Root opening  -  A seperation at the joint between the workpieces.
  • Root pass  -  The first weld pass made into the root of the weld.
  • Root penetration  -  The depth that a weld extends into the root of the joint.
  • Root reinforcement  -  The opposite side from which the weld was done.
  • Root surface  -  The exposed surface of a weld on the side other than that from which welding was done.
  • Running a bead  -  The process of making a weld.

S

  • Seal weld  -  A weld commonly used to stop leakage of gasses and liquids from containers and pipelines.
  • Seam weld  -  A continous weld.
  • Second moment of area  -  The resistance of an object to bend around a certain axis of a cross-section area.
  • Shear modulus  -  The ratio of the tangential force per unit area applied to a body or substance to the resulting tangential strain within the elastic limits.
  • Shear stress  - Tends to deform the material by breaking rather than stretching without changing the volume by restraining the object.
  • Shielding gas  -  A gas ueed to block out the atmosphere or contamination in order to prevent oxidization in the moltent well pool.
  • Shrinkage  -  The contractive force that an object undergoes as it cools.
  • Soldering  -  The solder filler metal melts at a temperature having a liquid below 450 deg C and uses a flux is to clean the metal suface allowing the solder to flow easy.
  • Solidus  -  The highest temperature at which a metal or alloy is completely solid.
  • Slag  -  A non-metallic substance that forms in the weld.
  • Slag inclusion  -  It is introduced in the weld, between welds and the surface of the weld.
  • Slot weld  -  When two workpieces are places togeather and one of them have a slot cut in it for access to weld.
  • 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.
  • Spatter  -  Droplets of moltent metal over the surface near an arc weld.
  • Stitch weld  -  A short length of weld over and over.
  • Stick electrode  -  A consumable electrode that becomes part of the weld.
  • Stick welding  -  Also called shielded metal arc welding.
  • Straight ploarity  -  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.
  • Strain  -  The deformation, stretched or compressed, of a material compared to its original length.

  • Stress  -  The force per unit area of cross-section.
  • String bead  -  A type of weld bead made without appreciable weaving motion.
  • Stringer bead  -  A type of weld bead made without appreciable weaving motion.
  • Supplemential steel  -  Structural members that frame between existing building framing steel members and are significantly smaller in size than the existing steel.
  • Surfacing  -  Adding one or more layers of material to a surface to get the desired dimension or properties.

T

  • Tack weld  -  A weld made to hold parts in proper alignment until final welds are made.
  • Temper  -  The amount od hardness that an alloy has after cold working or heat treatment.
  • Temperature  -  Normally described as the amount of heat or cold, but it is neither heat or cold.
  • Tension Strength  -  The capacity of a material to resist a force tending to stretch it.
  • Thermal expansion  - The increase in length, area or volume due to the increase (in some cased decrease) in temperature.
  • Thermal resistance  -  Measures the temperature difference by which an object or material resists a heat flow.
  • Throat of a fillet weld (actual)  -  The shortest distance from the root of a weld to its face.
  • Throat of a fillet weld (theoretical)  -  The perpendicular distance from the beginning of the root of the joint to the hypotenuse of the largest right triangle that can be inscribed within the fillet weld cross section.
  • TIG welding  -  Also called gas tungsten arc welding.
  • Toe of weld  -  The junction between the face of a weld and the base metal.
  • Tungsten electrode  -  A nonconsumable electrode used in arc welding, consisting of a tungsten wire.

U

  • Undercut  -  A groove melted into the base metal adjacent to the toe or root of a weld, and left unfilled by weld metal.  Can cause high stress and structural damage.

V

  • Vertical weld  -  The weld axis and force is approximately vertical.
  • Viscosity  -  The measure of the internal friction/resistance to the flow of a liquid.
  • Voltage  -  The amount of pressure that will cause one ampere of current in one ohm of resistance.
  • Volume  -  The space occupied by a mass.

W

  • Weld crack  -  Cracks can appear on the surface, inside the weld or heat effected zone.
  • Weld design strength  -  AISC-13 Table J2.5 defines the resistance factors and nominal strengths for the base metal and weld metal for various type welds and loading conditions.  The orientation of the applied sterss with respect to the longitudal weld axis determines whether the weld is subject to tension, compression, or shear
  • Weld face  -  The exposed surface of the weld on the side from which welding was done.
  • Weld joint types  -  butt joint, corner joint, edge joint, lap joint, square joint, and tee joint.
    • Butt joint types  -  bevel-groove, flare-bevel-groove, flare-V-groove, J-groove, square-groove, U-groove, and V-groove.
    • Corner joint types  -  bevel-groove, corner-flange, edge, fillet, flair-V-groove, J-groove, spot, square-groove or butt, U-groove, and V-groove.
    • Edge joint types  -  bevel-groove, corner-flange, edge-flange, J-groove, square-groove, U-groove, and V-groove. 
    • Lap joint types  -  bevel-groove, flare-bevel-groove, J-groove, plug, slot, and spot.
  • Weld pool  -  A small body of moltent metal created by the arc of the tourch.
  • Welder certification  -  The act of determining, verifying, or attesting in wrighting that a welder is qualified to produce welds which can meet perscribed standards.
  • Welder performance qualification  -  Demonstration of a welder's ability to produce welds in a manner described in a welding procedure specification that meets prescribed standards.
  • Welding  -  Used to join most all metals whether thin or thick and suitable for high-temperature applications, producing a strong joint than brazing or soldering.
  • Welding defects  -  Blow hole, defect of joint shape, incomplete fusion, overlap, slag inclusion, undercut, weld crack.
  • Welding electrode types  -  arc weld electrode, barr electrode, carbon electrode, flux-cored electrode, metal electrode, stranded electrode, and tungsten electrode.
  • Welding operator  -  One who operates a welding machine or automatic welding equipment.
  • Welding procedure  -  The detailed methods and practices, including all joint welding procedures, involved in making a welded joint.  The parameters of the weld procedure include:
    • Base metal strength
    • Electrode strength and type
    • Heat inlut, current, travel dtime, etc.
    • Weld process
  • Welding procedure qualification  -  Demonstration that welds made in a manner described in the Welding Procedure Specification will meet prescribed standards.
  • Welding procedure specification  -  The written form of the welding procedure for making a specified kind of a welded joint using specified base and filler metals.
  • Wetting  -  The condition in which a liquid filler metal of flux forms a zero angle of contact on a solid base metal surface.

X

Y

  • Yield point  -  The point where an elastic material is permanent change in length with no extra load force.

Z

Display #
Title
Arc Strike
Backing Ring
Bar to Plate Weld - Point Load on CJP Fillet Weld
Bar to Plate Weld - Point Load on PJP Fillet Weld
Bar to Plate Weld - Side Bending Moment on CJP Fillet Weld
Bar to Plate Weld - Side Bending Moment on PJP Fillet Weld
Bar to Plate Weld - Side Bending Moment on PJP Fillet Weld All Around
Bar to Plate Weld - Torsion Moment on CJP Fillet Weld
Elements of a Welding Symbol
Heat Input