1 copyright 2004 lincoln global inc. gas metal arc welding gmaw(mig/mag)

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Copyright Copyright 2004 Lincoln Global Inc. 2004 Lincoln Global Inc.

GAS METAL ARC WELDINGGAS METAL ARC WELDING

GMAWGMAW

(MIG/MAG)(MIG/MAG)

22Copyright Copyright 2004 Lincoln Global Inc. 2004 Lincoln Global Inc.

Gas Metal Arc WeldingGas Metal Arc Welding

Principles of the GMAWPrinciples of the GMAWProcessProcess

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Principles of the GMAW ProcessPrinciples of the GMAW Process

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Equipment Components Equipment Components

• Constant Voltage (CV)Constant Voltage (CV)Power Source or Constant Power Source or Constant Current (CC) Power Current (CC) Power SourceSource

• Constant Speed Wire Constant Speed Wire FeederFeeder

• Gun and CablesGun and Cables

• Shielding Gas Kit andShielding Gas Kit andGas CylinderGas Cylinder

• Consumable Wire Consumable Wire ElectrodeElectrode

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Constant VoltageConstant Voltage

• Welding Circuit Consists of Power Source, Wire Welding Circuit Consists of Power Source, Wire Feeder, and Work and Electrode Cables/LeadsFeeder, and Work and Electrode Cables/Leads

• Voltage is Proportional to Arc LengthVoltage is Proportional to Arc Length• Current Changes Dramatically Current Changes Dramatically

to Maintain Constant to Maintain Constant Arc LengthArc Length

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Constant CurrentConstant Current

• Welding Circuit Consists of Power Source, Voltage Welding Circuit Consists of Power Source, Voltage Sensing Wire Feeder, Work and Electrode Sensing Wire Feeder, Work and Electrode Cables/LeadsCables/Leads

• Voltage is Proportional to Arc LengthVoltage is Proportional to Arc Length• Current Remains Constant Current Remains Constant

Even for Changes in Voltage Even for Changes in Voltage Due to Changes in Due to Changes in Arc LengthArc Length

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Duty CycleDuty Cycle

The Duty Cycle of a power source is The Duty Cycle of a power source is

the percentage of a ten (10) the percentage of a ten (10)

minute period that it can operate minute period that it can operate

at the rated output current setting. at the rated output current setting.

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Duty CycleDuty Cycle

Duty CycleDuty Cycle AmperesAmperes Time Time AvailableAvailable

30%30% 250 250 3 Min/10 Min3 Min/10 Min 40%40% 225 225 4 Min/10 Min4 Min/10 Min 50%50% 200 200 5 Min/10 Min5 Min/10 Min 60%60% 190 190 6 Min/10 Min6 Min/10 Min 70%70% 180 180 7 Min/10 Min7 Min/10 Min 80%80% 170 170 8 Min/10 Min8 Min/10 Min 90%90% 155 155 9 Min/10 Min9 Min/10 Min 100%100% 140 140 10 Min/10 Min10 Min/10 Min

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Inductance ControlInductance Control

• ““Fine Adjustment” Controls Fine Adjustment” Controls Arc CharacteristicsArc Characteristics

• Determines the Rate at Which the Determines the Rate at Which the Amperage Rises When a ShortAmperage Rises When a ShortCircuit is ProducedCircuit is Produced

• Also Called Pinch or Arc ControlAlso Called Pinch or Arc Control• Max. Pinch = Min. Inductance Max. Pinch = Min. Inductance • Min. Pinch = Max. InductanceMin. Pinch = Max. Inductance

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Max. Inductance vs. Min. InductanceMax. Inductance vs. Min. Inductance

• Thicker MaterialsThicker Materials• Deeper PenetrationDeeper Penetration• More Fluid Weld PoolMore Fluid Weld Pool• Flatter / Smoother WeldFlatter / Smoother Weld• Reduce SpatterReduce Spatter• Stainless SteelsStainless Steels

• Thin MaterialsThin Materials• Arc Stability On Open GapsArc Stability On Open Gaps• Convex Weld BeadConvex Weld Bead• Increased SpatterIncreased Spatter• Colder ArcColder Arc• Improved Weld Pool ControlImproved Weld Pool Control

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Welding Guns Welding Guns

100 Through 550 Amp GMAW Gun and Cables100 Through 550 Amp GMAW Gun and Cables

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300 and 500 Amp Work Clamps300 and 500 Amp Work Clamps

GC 300

GC 500

Work Clamps Work Clamps

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RECOMMENDED CABLES SIZES FOR ARC WELDINGMachine Size Duty Cycle Copper Cable Sizes for Combined Lengths of Electrode Cable Plus Work Cable

In Amperes (%) Up to 50 Feet 50 - 100 Feet 100 - 150 Feet 150 - 200 Feet 200 - 250 Feet100 20 #8 #4 #3 #2 #1180 20 #5 #4 #3 #2 #1180 30 #4 #4 #3 #2 #1200 50 #3 #3 #2 #1 #1/0200 60 #2 #2 #2 #1 #1/0225 20 #4 #3 #2 #1 #1/0250 30 #3 #3 #2 #1 #1/0300 60 #1/0 #1/0 #1/0 #2/0 #3/0400 60 #2/0 #2/0 #2/0 #3/0 #4/0500 60 #2/0 #2/0 #3/0 #3/0 #4/0

CablesCables

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Flowmeter

Flowgauge

Harris Calorific EquipmentHarris Calorific Equipment

Shielding Gas Kit with HoseShielding Gas Kit with Hose

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The business of The Lincoln Electric Company is manufacturing and selling high The business of The Lincoln Electric Company is manufacturing and selling high quality welding equipment and consumables, and cutting equipment. Our challenge quality welding equipment and consumables, and cutting equipment. Our challenge is to meet the needs of our customers and to exceed their expectations. On is to meet the needs of our customers and to exceed their expectations. On occasion, purchasers may ask Lincoln Electric for advice or information about their occasion, purchasers may ask Lincoln Electric for advice or information about their use of our products. We respond to our customers based on the best information in use of our products. We respond to our customers based on the best information in our possession at that time. Lincoln Electric is not in a position to warrant or our possession at that time. Lincoln Electric is not in a position to warrant or guarantee such advice, and assumes no liability, with respect to such information or guarantee such advice, and assumes no liability, with respect to such information or advice. We expressly disclaim any warranty of any kind, including any warranty of advice. We expressly disclaim any warranty of any kind, including any warranty of fitness for any customer’s particular purpose, with respect to such information or fitness for any customer’s particular purpose, with respect to such information or advice. As a matter of practical consideration, we also cannot assume any advice. As a matter of practical consideration, we also cannot assume any responsibility for updating or correcting any such information or advice once it has responsibility for updating or correcting any such information or advice once it has been given, nor does the provision of information or advice create, expand or alter been given, nor does the provision of information or advice create, expand or alter any warranty with respect to the sale of our products.any warranty with respect to the sale of our products.

Lincoln Electric is a responsive manufacturer, but the selection and use of specific Lincoln Electric is a responsive manufacturer, but the selection and use of specific products sold by Lincoln Electric is solely within the control of, and remains the sole products sold by Lincoln Electric is solely within the control of, and remains the sole responsibility of, the customer.responsibility of, the customer.

Customer Assistance PolicyCustomer Assistance Policy

1 copyright 2004 lincoln global inc. gas metal arc welding gmaw(mig/mag)

Documents

lincoln global

constant arc length

arc lengthvoltage

arc controlalso

arc length current changes

inductance slide

voltage sensing wire

electrode cablesleads