Equipment for Gas Metal Arc Welding Process

GMAW Equipment

1. PowerPoint
®
Presentation
Chapter 19
GMAW–Equipment
Gas Metal Arc Welding • GMAW
Current Selection • GMAW Welding
Power Sources • GMAW Equipment •
GMAW Welding Wire

2. Chapter 19—GMAW–Equipment
Constant-current (CC)
power sources have a
steep volt-ampere (V-A)
curve, while constant-
voltage (CV) power
sources have a slightly
sloping V-A curve.

3. Chapter 19—GMAW–Equipment
CV power sources are self-correcting with respect to
arc length, which means that arc length remains
constant with changes in electrode extension.

4. Chapter 19—GMAW–Equipment
GMAW equipment
includes a welding gun
cable and gun assembly,
a wire feeder, shielding
gas, and a workpiece
lead with a workpiece
connection.

5. Chapter 19—GMAW–Equipment
Welding gun components
include a handle with a
conductor tube and
trigger, a contact tip, a
gas nozzle, a gas
diffuser, and an insulator.

6. Chapter 19—GMAW–Equipment
Welding guns are
available with curved or
straight conductor
tubes.

7. Chapter 19—GMAW–Equipment
The wire feeder may be
portable, mounted on the
welding machine, or
mounted elsewhere to
facilitate welding in a
large area.

8. Chapter 19—GMAW–Equipment
Drive roll grooves can be
U-shaped, V-shaped, or
knurled depending on the
type of welding wire.

9. Chapter 19—GMAW–Equipment
The wire outlet guide
must be aligned closely
with the groove in the
drive rolls, without
touching it.

10. Chapter 19—GMAW–Equipment
Inert gases do not
react readily with
other materials,
making them useful
as shielding gases for
arc welding.

11. Chapter 19—GMAW–Equipment
Different shielding gases produce different weld bead
contour and penetration characteristics.

12. Chapter 19—GMAW–Equipment
The welding area should be
protected with windbreaks to
prevent gas drifts.

13. Chapter 19—GMAW–Equipment
The American Welding Society (AWS) classification
system for carbon steel electrodes consists of a
series of letters and numbers.

14. Chapter 19—GMAW–Equipment
The American Welding
Society (AWS) has
developed similar
classification systems
for metals other than
carbon steel.

15. Chapter 19—GMAW–Equipment
Welding position and the type of metal to be welded
are factors that must be considered when selecting
welding wire.