arc welding.pdf

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Arc Welding Methods andProcesses

Arc Welding Methods andProcesses

Harry Sadler

Manager Military and

Shipbuilding Sales

Harry Sadler

Manager Military and

Shipbuilding Sales

2

What is a Fusion Weld?What is a Fusion Weld?

A metal lurg ical bond result ing from thelocalized coalescence of base metal.

This generally requires the addition of

energy and may or may not use a

supplemental filler metal that intermixes

with the base metal.

A metall urgical bond resul ting f rom thelocalized coalescence of base metal.

This generally requires the addition of

energy and may or may not us e a

supplemental filler metal that intermixes

with t he base metal.

3

Cross Section of a Groove WeldCross Section of a Groove Weld

4

What’s the source of energy?What’s the source of energy?

In arc welding, it’s the heat generated by

an electric arc.

In arc welding, it’ s the heat generated by

an electric arc.

5

Reactor Reactor Selects OutputSelects Output

Welding CurrentWelding Current

Bridge Rectifier Bridge Rectifier Changes AC to DCChanges AC to DC

Inductance CoilInductance CoilSmoothes / FiltersSmoothes / Filters

DC OutputDC Output

Transformer Transformer Single Phase InputSingle Phase Input

High VoltsHigh Volts High AmpsHigh Amps

Low AmpsLow Amps Low VoltsLow Volts

Transformer Rectifier Transformer Rectifier

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AC AC -- 50/60 Hz50/60 Hz

High VoltageHigh Voltage

Low AmperageLow Amperage

DCDC -- RippledRippled



DCDC -- SmoothSmooth



AC AC -- 20,000 Hz20,000 Hz



AC AC -- 20,000 Hz20,000 Hz

Low VoltageLow Voltage

High AmperageHigh Amperage

DCDC -- RippledRippled



DCDC -- SmoothSmooth



Inverter Inverter



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F (Hz) Wt (Kg)F (Hz) Wt (Kg) Eff (%)Eff (%)

6060 19.519.5 9090

1,7401,740 3.053.05 969610,00010,000 2.72.7 9797

50,00050,000 1.91.9 98.198.1

100,000100,000 1.71.7 98.298.2

200,000200,000 1.51.5 98.398.3

Alex And erso n, EFW Alex Anderso n, EFW

November 10, 1911November 10, 1911

Paper Presented to AIEEPaper Presented to AIEE

Iron at 200,000 CyclesIron at 200,000 Cycles

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BenefitsBenefits

More Efficient = Lower Cost Operation

Lighter Weight = More Portable

Smaller Size = More Compact

Advanced Desig = Superior Output

More Efficient = Lower Cost Operation

Lighter Weight = More Portable

Smaller Size = More Compact

Advanced Desig = Superior Output

9

DCEP (Reverse) PolarityDCEP (Reverse) Polarity

Direct Current

Heat Conc entrated at

Workpiece

Forceful, Digging Arc

Medium to Deep

Penetration

Direct Current

Heat Concentrated at

Workpiece

Forceful, Digging Arc

Medium to Deep

Penetration

+

_

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DCEN (Straight) PolarityDCEN (Straight) Polarity

DC -


Electrode

Lower Penetration

Increased Deposition

Rates

DC -


Electrode

Lower Penetration

Increased Deposition

Rates

+

_

11

AC Polar ity AC Polar it y

Alternati ng Current

Medium Penetration

Medium Travel

Speeds

Al ternat ing Current

Medium Penetration

Medium Travel

Speeds

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AC AC -- 225225 AC/DC AC/DC -- 225/125225/125

AC AC -- 225C225C

Transformer Welding Power SourcesTransformer Welding Power Sources



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IDEALARC 250IDEALARC 250

R3RR3R -- 400400 R3RR3R -- 500500

Transformer Rectifier Welding Power

Sources

Transformer Rectifier Welding Power

Sources

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Inverter Welding Power SourcesInverter Welding Power SourcesV350V350--PROPRO

V275V275--SS

PWPW--355M355M

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RANGER 10,000RANGER 10,000RANGER GXTRANGER GXT

Engine Driven Power SourcesEngine Driven Power Sources

RANGER 3RANGER 3--PhasePhase

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VANTAGE 500VANTAGE 500

Engine Driven Power SourcesEngine Driven Power Sources

AIR VANTAGE 500 AIR VANTAGE 500

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Constant CurrentConstant Current

Welding Circuit

Consists of Power

Source, Electrode and

Work Cables/Leads

The Power SourceKeeps the Current as

Constant as Possible

even when the Operator

Varies the Arc Length

Voltage is Proportional

to Arc Length

Welding Circuit

Consists of Power

Source, Electrode and

Work Cables/Leads

The Power SourceKeeps the Current as

Constant as Possible

even when the Operator

Varies the Arc Length


to Arc Length

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Constant VoltageConstant Voltage

Welding Circuit

Consists of Power

Source, Wire Feeder,

and Work and Electrode

Cables/Leads


to Arc Length

Current Changes

Dramatically to Maintain

Constant Arc Length

Welding Circuit

Consists of Power

Source, Wire Feeder,

and Work and Electrode

Cables/Leads


to Arc Length

Current Changes

Dramatically to Maintain

Constant Arc Length



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ArcWelding Processes

20

REQUIREMENTS FOR FUSION:

1. Atomic Cleanliness

2. Atomic Closeness

21

SHIELDING OF MOLTEN PUDDLE

Shield from nitrogen, oxygen

Shield with slags

Displace atmosphere with gases

22

Arc Welding Processes

Shielded Metal Arc (SMAW)

Flux Cored Arc (FCAW)

Gas Metal Arc (GMAW)

Submerged Arc (SAW)

Gas Tungsten Arc (GTAW)

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SMAW

24

Shielded Metal Arc (SMAW)

Base metal

Arc stream

Gaseous shield

ElectrodeExtruded covering

Molten pool

Slag

Weld



25

Advantages Advantages

Low Start Up

Costs

Portability

Outdoor

Al l Posi tion

Welding

Variety of

Materials

Mechanical

Properties

Low Start Up

Costs

Portability

Outdoor

Al l Posi tion

Welding

Variety of

Materials

Mechanical

Properties

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LimitationsLimitations

Low Efficiency

(65%)

Operating Factor

Operator Skill

Restarts

Amperage Limi t

Slag

Spatter

Low Efficiency

(65%)

Operating Factor

Operator Skill

Restarts

Amperage Limi t

Slag

Spatter

27

AWS Numbering System-SMAW

E7018Electrode

Tensile Strength (ksi)

Position

Type of coating & current28

FCAW-GFCAW-G

29

FCAW-SFCAW-S

30

FCAW-g



31

FCAW-g

32

Wire FeedersWire Feeders

33


Bead Appearance

Little to No Spatter

High DepositionRates

MechanicalProperties

High Efficiencies(90+%)

Easy Re-strike

Al l Pos it ion Weld ing

Low Hydrogen Weld

Deposits

Bead Appearance

Little to No Spatter


MechanicalProperties

High Efficiencies(90+%)

Easy Re-strike

Al l Posi tion Welding

Low Hydrogen Weld

Deposits34


Smoke and Fumes

Portability

Outdoor Weldability

Potential for Gas

Marks

High Radiated Heat

Slag

Smoke and Fumes

Portability

Outdoor Weldability

Potential for Gas

Marks

High Radiated Heat

Slag

35

FCAW-s

36


Outdoor Usability

Minimize Restarts

No Shielding Gas

Costs


Mechanical Properties

Effective Smoke

Removal

Dirty Steels & Off

Analysi s Steels

Al l Pos it ion Weldi ng

Outdoor Usability

Minimize Restarts

No Shielding Gas

Costs


Mechanical Properties

Effective Smoke

Removal

Dirty Steels & Off

Analysi s Steels

All Posi tion Welding



37


Smoke and FumesSpatter

Slag (Cleaning

Time)

Break Electrode to

Restrike

Smoke and Fumes

Spatter

Slag (Cleaning

Time)

Break Electrode to

Restrike

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E7XTE7XT--YYElectrodeElectrode

70,000 psi Min. Tensile Strength70,000 psi Min. Tensile Strength

Welding Positio nWelding Positi on(0=Flat & Horizon tal, 1= All Positio n)(0=Flat & Horizo ntal, 1= All Positio n)

Tubular (Flux Cored Electrode)Tubular (Flux Cored Electrode)

Usability & Performance CapabilitiesUsability & Performance Capabilit ies

AWS Classif ication AWS Classif ication

39

GMAW

40

Gas Metal Arc Welding (GMAW)

Solid or metal core electrode

Contact tube

Gas nozzleShielding gas

Base metalBase metal

Weld pool

Weld metal

Arc

41


Variety of Metals

Various Thickness

of Materials

High Efficiency

Appl icationsHigh Radiated Heat

Al l Pos it ion Weld ing

Quality Welds

Littl e to No Slag

Low Spatter

Variety of Metals

Various Thickness

of Materials

High Efficiency

Appl icationsHigh Radiated Heat

Al l Posi tion Welding

Quality Welds

Little to No Slag

Low Spatter

42


Cost

Portability

Outdoor Welding

Clean Base MaterialPotential for Cold Lap

Potential for Undercut

Operator Skill

High Radiated Heat

Cost

Portability

Outdoor Welding

Clean Base MaterialPotential for Cold Lap

Potential for Undercut

Operator Skill

High Radiated Heat



43

ER70SER70S--XXElectrodeElectrode

RodRod


SolidSolid

Chemistry, Amount of Deoxidizers (Silicon,Chemistry, Amount of Deoxidizers (Silicon,

Manganese and/or Aluminum, Zirconiu m andManganese and/or Aluminum, Zirconiu m and

Titanium ) X=2,3,4,6,7 or GTitanium ) X=2,3,4,6,7 or G


44

E70CE70C--YYElectrodeElectrode


Metal Core ElectrodeMetal Core Electrode

Usability & Performance CapabilitiesUsability & Performance Capabilit ies


45

SAWSAW

Submerged Arc WeldingSubmerged Arc Welding

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Submerged Arc Welding (SAW)

Contact Tube

SlagFlux

Flux Feed Tube

Flux Hopper

Weld

47

Automatic

SAW

Automatic

SAW

48

Mechanized SAWMechanized SAW

Mechanized

SAW

Mechanized

SAW



49

Mechanized SAW:Mechanized SAW:Mechanized

SAW

Mechanized

SAW

50

Handheld SAWHandheld SAWSemiautomatic

SAW

Semiautomatic

SAW

51


High Deposition

Rates

Typically Deep

Penetration

High Operating Factor

Low Hydrogen Welds

Fast Welding Speeds

High Operator Appeal

High Quality Welds

High Deposition

Rates

Typically Deep

Penetration

High Operating Factor

Low Hydrogen Welds

Fast Welding Speeds

High Operator Appeal

High Quality Welds

52

Limitations continuedLimitations continued

Portability

Downhand Welding

Only

Tight Fit-Up Required

Abrasive Nature of

Flux on Machinery

Housekeeping and

Storage of Flux

Slag

Portability

Downhand Welding

Only

Tight Fit-Up Required

Abrasive Nature of

Flux on Machinery

Housekeeping and

Storage of Flux

Slag

53

FXYZFXYZ--EM12KEM12K--Ni1Ni1FluxFlux

Min. Tensile StrengthMin. Tensile StrengthType of Heat TreatmentType of Heat Treatment

Low Temp Impact StrengthLow Temp Impact Strength

Solid Electrode WireSolid Electrode Wire

Level of ManganeseLevel of Manganese

Nominal Carbon ContentNominal Carbon Content

Silicon Kil led SteelSilicon Kil led Steel

Type and Amount of Alloy in the Weld DepositType and Amount of Alloy in the Weld Deposit


Electrodes & FluxesElectrodes & Fluxes

54

GTAW



55

GTAW

56

GTAW

57

GT AW

58

Process Selection/ApplicationProcess Selection/Application

Typically best left to those doing theTypically best left to those doing the

weldingwelding

SAW: long, big, automaticSAW: long, big, automatic

FCAWFCAW--g:g: semiautosemiauto in shopin shop

FCAWFCAW--s:s: semiautosemiauto in fieldin field

SMAW: small, miscellaneous,SMAW: small, miscellaneous,

repair, tackingrepair, tacking

GMAW:GMAW: semiautosemiauto in shopin shop

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