PowerPoint Presentation - TIG Welding Introduction€¦ · PPT file · Web view · 2013-06-11TIG...

TIG Welding TIG Welding IntroductionIntroduction

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OutlineOutline► Background/Advantages & Disadvantages/Advantages & Disadvantages► SafetySafety► Preparation for TIG WeldingPreparation for TIG Welding► Techniques for Basic Weld JointsTechniques for Basic Weld Joints► TIG Shielding GasesTIG Shielding Gases► Welding ParametersWelding Parameters► Tungsten Electrode SelectionTungsten Electrode Selection► ConclusionConclusion

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ConclusionConclusion► TIG welding is an exciting skill that proves itself TIG welding is an exciting skill that proves itself

useful in countless applicationsuseful in countless applications► Because it welds more metal and metal alloys than Because it welds more metal and metal alloys than

any other process, TIG welding should be regarded any other process, TIG welding should be regarded as an important tool where experience is the teacheras an important tool where experience is the teacher

► Welding parameters and tungsten electrode Welding parameters and tungsten electrode selection tables are recommended values and should selection tables are recommended values and should be used as a guidelinebe used as a guideline

► Information presented here is only the tip of the Information presented here is only the tip of the iceberg, and further research and hands-on iceberg, and further research and hands-on involvement should be pursued to be comprehensiveinvolvement should be pursued to be comprehensive

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BackgroundBackground►What is TIG?What is TIG?

Tungsten Inert GasTungsten Inert Gas►Also referred to as GTAWAlso referred to as GTAW

Gas Shielded Tungsten WeldingGas Shielded Tungsten Welding► In TIG welding, a tungsten electrode In TIG welding, a tungsten electrode

heats the metal you are welding and heats the metal you are welding and gas (most typically Argon) protects the gas (most typically Argon) protects the weld from airborne contaminantsweld from airborne contaminants

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BackgroundBackground►TIG welding uses a non-consumable TIG welding uses a non-consumable

tungstentungsten►Filler metal, when required, is added Filler metal, when required, is added

by handby hand►Shielding gas protects the weld and Shielding gas protects the weld and

tungstentungsten

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AdvantagesAdvantages► Welds more metals Welds more metals

and metal alloys than and metal alloys than any other processany other process

► High quality and High quality and precisionprecision

► Pin point controlPin point control► Aesthetic weld beadsAesthetic weld beads► No sparks or spatterNo sparks or spatter► No flux or slagNo flux or slag► No smoke or fumesNo smoke or fumes

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DisadvantagesDisadvantages► Lower filler metal Lower filler metal

deposition ratesdeposition rates► Good hand-eye Good hand-eye

coordination a required coordination a required skillskill

► Brighter UV rays than Brighter UV rays than other processesother processes

► Slower travel speeds Slower travel speeds than other processesthan other processes

► Equipment costs tend Equipment costs tend to be higher than other to be higher than other processesprocesses

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SafetySafety► Electric shock can kill.Electric shock can kill.

Always wear dry insulating glovesAlways wear dry insulating gloves Insulate yourself from work and groundInsulate yourself from work and ground Do not touch live electrical partsDo not touch live electrical parts Keep all panels and covers securely in placeKeep all panels and covers securely in place

► Fumes and gases can be hazardous to your Fumes and gases can be hazardous to your health.health. Keep your head out of the fumesKeep your head out of the fumes Ventilate area, or use breathing deviceVentilate area, or use breathing device

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SafetySafety► Welding can cause fire or explosion.Welding can cause fire or explosion.

Do not weld near flammable materialDo not weld near flammable material Watch for fire; keep extinguisher nearbyWatch for fire; keep extinguisher nearby Do not locate unit over combustible surfacesDo not locate unit over combustible surfaces Do not weld on closed containersDo not weld on closed containers

► Arc rays can burn eyes and skin; Noise Arc rays can burn eyes and skin; Noise can damage hearing.can damage hearing. Wear welding helmet with correct shade of Wear welding helmet with correct shade of

filterfilter Wear correct eye, ear, and body protectionWear correct eye, ear, and body protection

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SafetySafety► Hot parts can cause injury.Hot parts can cause injury.

Allow cooling period before touching welded Allow cooling period before touching welded metalmetal

Wear protective gloves and clothingWear protective gloves and clothing► Magnetic fields from high currents can Magnetic fields from high currents can

affect pacemaker operation.affect pacemaker operation.► Flying metal can injure eyes.Flying metal can injure eyes.

Welding, chipping, wire brushing, and Welding, chipping, wire brushing, and grinding cause sparks and flying metal; wear grinding cause sparks and flying metal; wear approved safety glasses with side shieldsapproved safety glasses with side shields

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SafetySafety► Welding current can damage electronic parts Welding current can damage electronic parts

in vehicles.in vehicles. Disconnect both battery cables before welding on Disconnect both battery cables before welding on

a vehiclea vehicle Place work clamp as close to the weld as possiblePlace work clamp as close to the weld as possible

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Techniques for Basic Weld Techniques for Basic Weld JointsJoints

Arc LengthArc Length► Arc length normally one electrode diameter, Arc length normally one electrode diameter,

when AC welding with a balled end when AC welding with a balled end electrodeelectrode

► When DC welding with a pointed electrode, When DC welding with a pointed electrode, arc length may be much less than electrode arc length may be much less than electrode diameterdiameter

*Figure copied from “TIG Handbook”

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Gas Cup SizeGas Cup Size► Inside diameter of gas Inside diameter of gas

cup should be at least cup should be at least three times the three times the tungsten diameter to tungsten diameter to provide adequate provide adequate shielding gas shielding gas coveragecoverage

► Picture on right shows Picture on right shows example of gas cup example of gas cup size and torch positionsize and torch position

1-Workpiece, 2-Work clamp, 3-Torch, 4-Filler rod, 5-Gas cup, 6-Tungsten electrode


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Electrode ExtensionElectrode Extension► Refers to distance the tungsten extends out Refers to distance the tungsten extends out

beyond the gas cupbeyond the gas cup► May vary from flush with the gas cup to no May vary from flush with the gas cup to no

more than the inside diameter of the gas cupmore than the inside diameter of the gas cup► Longer the extension, the more likely it may Longer the extension, the more likely it may

contact something by accidentcontact something by accident► General rule would be to start with an General rule would be to start with an

extension of one electrode diameterextension of one electrode diameter

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Arc Starting with High Arc Starting with High FrequencyFrequency

► Torch position on left shows Torch position on left shows recommended method of starting recommended method of starting the arc with high frequency when the arc with high frequency when the torch is held manuallythe torch is held manually

► By resting gas cup on base metal By resting gas cup on base metal there is little danger of touching there is little danger of touching the electrode to the workthe electrode to the work

► After arc is initiated, torch can be After arc is initiated, torch can be raised to proper welding angleraised to proper welding angle


ENBE 499 16


Manual Torch MovementManual Torch Movement


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Manual Torch MovementManual Torch Movement► Torch and filler rod must be moved Torch and filler rod must be moved

progressively and smoothly so the weld pool, progressively and smoothly so the weld pool, the hot filler rod end, and the solidifying weld the hot filler rod end, and the solidifying weld are not exposed to air that will contaminate are not exposed to air that will contaminate the weld metal area or heat affected zonethe weld metal area or heat affected zone

► When arc is turned off, postflow of shielding When arc is turned off, postflow of shielding gas should shield the weld pool, electrode, gas should shield the weld pool, electrode, and hot end of the filler rodand hot end of the filler rod

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Butt Weld and Butt Weld and Stringer BeadStringer Bead

► Be sure to center Be sure to center weld pool on weld pool on adjoining edgesadjoining edges

► When finishing a butt When finishing a butt weld, torch angle weld, torch angle may be decreased to may be decreased to aid in filling the aid in filling the cratercrater

Torch and rod position for welding the butt weld and stringer bead


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Lap JointLap Joint► Pool is formed so that Pool is formed so that

the edge of the the edge of the overlapping piece and overlapping piece and the flat surface of the the flat surface of the second piece flow second piece flow togethertogether

► Torch angle is important Torch angle is important because the edge will because the edge will become molten before become molten before the flat surfacethe flat surface

► Enough filler metal must Enough filler metal must be added to fill the joint be added to fill the joint as illustrated on the rightas illustrated on the right

Torch and rod position for welding the lap joint


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T-JointT-Joint► Edge will heat up and Edge will heat up and

melt soonermelt sooner► Torch angle illustrated Torch angle illustrated

will direct more heat will direct more heat onto the flat surfaceonto the flat surface

► Electrode may need to Electrode may need to be extended further be extended further beyond the cup in order beyond the cup in order to hold a short arcto hold a short arc

Torch and rod position for welding the T-joint


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Corner JointCorner Joint► Both edges of the Both edges of the

adjoining pieces adjoining pieces should be melted and should be melted and the pool kept on the the pool kept on the joint centerlinejoint centerline

► Sufficient filler metal Sufficient filler metal is necessary to is necessary to create a convex bead create a convex bead as shownas shown

Torch and rod position for welding the corner joint


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TIG Shielding GasesTIG Shielding Gases►ArgonArgon►HeliumHelium►Argon/Helium MixturesArgon/Helium Mixtures

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TIG Shielding GasesTIG Shielding GasesArgonArgon

► Good arc startingGood arc starting► Good cleaning actionGood cleaning action► Good arc stabilityGood arc stability► Focused arc coneFocused arc cone► Lower arc voltagesLower arc voltages► 10-30 CFH flow rates10-30 CFH flow rates

HeliumHelium► Faster travel speedsFaster travel speeds► Increased penetrationIncreased penetration► Difficult arc startingDifficult arc starting► Less cleaning actionLess cleaning action► Less low amp stabilityLess low amp stability► Flared arc coneFlared arc cone► Higher arc voltagesHigher arc voltages► Higher flow rates (2x)Higher flow rates (2x)► Higher cost than argonHigher cost than argon

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TIG Shielding GasesTIG Shielding GasesArgon/Helium MixturesArgon/Helium Mixtures► Improved travel speeds over pure argonImproved travel speeds over pure argon► Improved penetration over pure argonImproved penetration over pure argon► Cleaning properties closer to pure argonCleaning properties closer to pure argon► Improved arc starting over pure heliumImproved arc starting over pure helium► Improved arc stability over pure heliumImproved arc stability over pure helium► Arc cone shape more focused than pure heliumArc cone shape more focused than pure helium► Arc voltages between pure argon and pure heliumArc voltages between pure argon and pure helium► Higher flow rates than pure argonHigher flow rates than pure argon► Costs higher than pure argonCosts higher than pure argon

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Welding ParametersWelding Parameters

Aluminum weld parameters


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Aluminum with advanced squarewave weld parameters


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Stainless steel weld parameters


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Titanium weld parameters


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Mild steel weld parameters


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Tungsten Electrode SelectionTungsten Electrode Selection

Guide to selecting a tungsten electrode based on amperage range

*Figure copied from “Guidelines to Gas Tungsten Arc Welding (GTAW)”

PowerPoint Presentation - TIG Welding Introduction€¦ · PPT file · Web view · 2013-06-11TIG...

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