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8/14/2019 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
6
AC AC -- 50/60 Hz50/60 Hz
High VoltageHigh Voltage
Low AmperageLow Amperage
DCDC -- RippledRippled
High VoltageHigh Voltage
Low AmperageLow Amperage
DCDC -- SmoothSmooth
High VoltageHigh Voltage
Low AmperageLow Amperage
AC AC -- 20,000 Hz20,000 Hz
High VoltageHigh Voltage
Low AmperageLow Amperage
AC AC -- 20,000 Hz20,000 Hz
Low VoltageLow Voltage
High AmperageHigh Amperage
DCDC -- RippledRippled
Low VoltageLow Voltage
High AmperageHigh Amperage
DCDC -- SmoothSmooth
Low VoltageLow Voltage
High AmperageHigh Amperage
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
8
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
+
_
10
DCEN (Straight) PolarityDCEN (Straight) Polarity
DC -
Heat Concentrated at
Electrode
Lower Penetration
Increased Deposition
Rates
DC -
Heat Concentrated at
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
12
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
14
Inverter Welding Power SourcesInverter Welding Power SourcesV350V350--PROPRO
V275V275--SS
PWPW--355M355M
15
RANGER 10,000RANGER 10,000RANGER GXTRANGER GXT
Engine Driven Power SourcesEngine Driven Power Sources
RANGER 3RANGER 3--PhasePhase
16
VANTAGE 500VANTAGE 500
Engine Driven Power SourcesEngine Driven Power Sources
AIR VANTAGE 500 AIR VANTAGE 500
17
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
Voltage is Proportional
to Arc Length
18
Constant VoltageConstant Voltage
Welding Circuit
Consists of Power
Source, Wire Feeder,
and Work and Electrode
Cables/Leads
Voltage is Proportional
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
Voltage is Proportional
to Arc Length
Current Changes
Dramatically to Maintain
Constant Arc Length
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ArcWelding Processes
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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)
23
SMAW
24
Shielded Metal Arc (SMAW)
Base metal
Arc stream
Gaseous shield
ElectrodeExtruded covering
Molten pool
Slag
Weld
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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
26
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
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FCAW-g
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Wire FeedersWire Feeders
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Advantages Advantages
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
High DepositionRates
MechanicalProperties
High Efficiencies(90+%)
Easy Re-strike
Al l Posi tion Welding
Low Hydrogen Weld
Deposits34
LimitationsLimitations
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
Advantages Advantages
Outdoor Usability
Minimize Restarts
No Shielding Gas
Costs
High DepositionRates
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
High DepositionRates
Mechanical Properties
Effective Smoke
Removal
Dirty Steels & Off
Analysi s Steels
All Posi tion Welding
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LimitationsLimitations
Smoke and FumesSpatter
Slag (Cleaning
Time)
Break Electrode to
Restrike
Smoke and Fumes
Spatter
Slag (Cleaning
Time)
Break Electrode to
Restrike
38
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
Advantages Advantages
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
LimitationsLimitations
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
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ER70SER70S--XXElectrodeElectrode
RodRod
70,000 psi Min. Tensile Strength70,000 psi Min. Tensile Strength
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
AWS Classif ication AWS Classif ication
44
E70CE70C--YYElectrodeElectrode
70,000 psi Min. Tensile Strength70,000 psi Min. Tensile Strength
Metal Core ElectrodeMetal Core Electrode
Usability & Performance CapabilitiesUsability & Performance Capabilit ies
AWS Classif ication AWS Classif ication
45
SAWSAW
Submerged Arc WeldingSubmerged Arc Welding
46
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
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Mechanized SAW:Mechanized SAW:Mechanized
SAW
Mechanized
SAW
50
Handheld SAWHandheld SAWSemiautomatic
SAW
Semiautomatic
SAW
51
Advantages Advantages
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
AWS Classif ication AWS Classif ication
Electrodes & FluxesElectrodes & Fluxes
54
GTAW
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GTAW
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GTAW
57
GT AW
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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