Lincoln Electric High-Speed and High-Deposition Welding manual Horizontal Fillet Weld

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W A V E F O R M C O N T R O L T E C H N O L O G Y T M

APPLICATION

Tandem MIG

8/16

High-Speed and High-Deposition Welding

 

Comparing High-Deposition Tandem MIG

To Single Wire GMAW Process

Reduced Heat Input and Improved Bead Profiles

Problem - Single Wire GMAW

A single wire GMAW process has a useable weld metal deposition rate based on wire feed speed and wire diameter. In an attempt to increase weld metal deposit rates, rather than push a given wire diameter to unstable wire feed speeds, it is often common practice to increase the wire diameter and operate within stable wire feed ranges. The increase in wire diameter increases the required current draw associated with a given weld metal deposit rate. Increased current draw produces higher heat inputs leading to part distortion and a large fluid weld pool that is difficult to control.

Solution - Tandem MIG

With the Tandem MIG process the two smaller diameter electrodes produce a lower heat input and improved weld pool control when compared to a larger single electrode process attempting to perform similar welds. When compared to larger diameter electrode processes,Tandem MIG typically reduces heat input by as much as 30-50%. The trail electrode in the Tandem MIG process is operated in a special Tandem MIG pulse mode designed to cool the weld pool created by the lead electrode. The combination of lower total heat input and the cooling affect of the trail electrode, allows the trail electrode to be used to help control weld bead contour. This provides the ability to better stack horizontal weld beads and produce flatter horizontal fillets while working at higher deposition rates.

REDUCED HEAT INPUT EXAMPLE

5/16” Horizontal Fillet Weld

 

CURRENT

ARC

DEPOSIT

TRAVEL SPEED

HEAT INPUT

PROCESS

DRAW

VOLTAGE

RATE

(ipm)

Kj/in

 

(amps)

(DC+)

(lbs./hr)

 

 

 

 

 

 

 

 

 

GMAW - 1/16” dia. - ER70S - 6

470

31

17.8

17.7

49.4

 

 

 

 

 

 

FCAW - 3/32” dia. - ER70T - 1

435

29.5

15.8

15.7

49.0

 

 

 

 

 

 

GMAW - 3/32” dia. - ER70C - 6M

500

34

16.2

16.1

63.3

 

 

 

 

 

 

 

 

Tandem MIG

 

 

 

 

 

 

 

 

 

Lead .045” dia. ER70S - 6

300

23

 

 

 

 

 

 

23.3

23.1

33.5

Trail .045” dia. ER70S - 6

250

24

 

 

 

 

 

 

 

 

 

T h e

f u t u r e

o f

w e l d i n g

i s

h e r e .

®

 

 

 

 

 

 

 

 

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Contents Tandem Migtm What Is It? Tandem MIGHow Does It Work? Using Tandem MIG Flat and Horizontal Lap Welds 1.5 mm 5 mmFlat and Horizontal Fillet Welds 3 mm 6 mm Joggle Joints 1.5 mm 4 mmFlat and Horizontal Fillet Welds 6 mm and Larger Bevel and V Groove JointsU Groove Butt Welds Earth Moving Equipment Heavy Plate FabricationBetter Weld Metal Follow Characteristics Problem Single Wire GmawSolution Tandem MIG Comparing High-Speed Tandem MIGHigher Deposition rates Comparing High-Deposition Tandem MIGTravel Speed Comparison Reduced Heat Input and Improved Bead Profiles Horizontal Fillet WeldDeposition Rate Comparison Torch Positioning Lead ArcTrail Arc Joint Selection Shielding GasWork Lead Connection Configuring Tandem MIG Configuring Tandem MIG Models AD1201 1 and AD1201Power Feed 10R Wire Feeder Lincoln Welding Systems Featuring Tandem MIGPower Wave 455M Power Wave 655RAccu-Trak SuperArc/SuperGlideAccu-Pak