Campbell Hausfeld WG3000, WG2045, WG2044, WG2040 manual Arc Welding Basics

Wire Feed Arc Welder

Welding Guidelines (Continued)

Arc Welding Basics

Five basic techniques affect weld quality. These are: wire selection, heat setting, weld angle, wire speed, and travel speed. An understanding of these techniques is necessary for effective welds.

HEAT SETTING

The correct heat involves the adjustment of the welding machine to the required setting. Heat or voltage is regulated by a switch on the welder. The heat setting used depends on the size (diameter) and type of wire, position of the weld, and the thickness of the work piece. Consult specifications listed on the welder. It is suggested that the welder practice with scrap metal to adjust settings, and compare welds with Figure 15.

WIRE TYPE AND SIZE

The correct choice of wire type involves a variety of factors, such as welding position, work piece material type, thickness, and condition of surface to be welded. The American Welding Society, AWS, has set up certain requirements for each type of wire.

FLUX-CORED WIRE

E - 7 0 T - GS

Weld strength, times 10,000 pounds per square inch Welding positions (0 for flat or horizontal, 1 for any position)

proper penetration and bead formation. As different welding positions and weld joints become necessary, nozzle angle becomes an increasingly important factor in obtaining a satisfactory weld. Weld angle involves two positions - travel angle and work angle.

Travel angle is the angle in the line of welding and may vary from 5º to 45º from the vertical, depending on welding conditions.

5º - 45º

WORK ANGLE

5º - 45º

TRAVEL ANGLE

Figure 14 - Weld Angle

Work angle is the angle from horizontal, measured at right angles to the line of welding. For most

applications, a 45º travel angle and 45º work angle is sufficient. For specific applications, consult an arc welding handbook.

WIRE SPEED

The wire speed is controlled by the knob on the front panel. The speed needs to be “tuned” to the rate at which the wire is being melted in the arc. Tuning is one of the most critical functions in wire feed welding. Tuning should be performed on a scrap piece of metal the same type and thickness as that to be welded. Begin welding with one hand “dragging” the gun nozzle across the scrap piece while adjusting the wire speed with the other hand. Too slow of speed will cause sputtering and the wire will burn up into the contact tip. Too fast a speed will also cause a sputtering sound and the wire will push into the plate before melting. A smooth buzzing sound indicates the wire speed is properly tuned. Repeat the tuning procedure each time there is a change in heat setting, wire diameter or type, or work piece material type or thickness. For Aluminum, wire speed is typically set higher (7-9 speed range).

TRAVEL SPEED

The travel speed is the rate at which the torch is moved across the weld area.

Tubular flux core wire

Flux type

AWS E71T-GS or E71T-11 is recommended for this welder.

SOLID WIRE

ER - 70 S - 6

Weld strength, times 1,000 PSI

Solid wire

Wire composition

ER-70S6 is recommended for this welder.

WELD ANGLE

Weld angle is the angle at which the nozzle is held during the welding process. Using the correct angle ensures

Base

Metal

Normal Heat,

Wire Speed,

Travel Speed

Heat Too Low

Heat Too High

Wire Speed

Too Fast

Figure 15 - Weld Appearance

Travel Speed

Too Fast

Travel Speed

Too Slow

Wire Speed Too Slow

www.chpower.com

8