01 mig (gmaw/fcaw) basic welding technique – Tweco 350 4R Wirefeeder User Manual

Page 39

Basic weldinG Guide

weldskill 250, 350

Manual 0-5182

6-1

Basic Welding Guide

SECTION 6:

BASIC WELDING GUIDE

6.01 MIG (GMAW/FCAW) Basic Welding Technique

Two different welding processes are covered in this section (GMAW and FCAW), with the intention of providing

the very basic concepts in using the MIG mode of welding, where a welding gun is hand held, and the electrode

(welding wire) is fed into a weld puddle, and the arc is shielded by an inert welding grade shielding gas or inert

welding grade shielding gas mixture.
GAS METAL ARC WELDING (GMAW): This process, also known as MIG welding, CO

welding, Micro Wire

Welding, short arc welding, dip transfer welding, wire welding etc., is an electric arc welding process which

fuses together the parts to be welded by heating them with an arc between a solid continuous, consumable

electrode and the work. Shielding is obtained from an externally supplied welding grade shielding gas or welding

grade shielding gas mixture. The process is normally applied semiautomatically; however the process may be

operated automatically and can be machine operated. The process can be used to weld thin and fairly thick

steels, and some non-ferrous metals in all positions.

Art # A-8991_AB

Shielding Gas

Molten Weld Metal

Solidified

Weld Metal

Nozzle

Electrode

Arc

Base Metal

GMAW Process

Figure 6-1

FLUX CORED ARC WELDING (FCAW): This is an electric arc welding process which fuses together the parts to

be welded by heating them with an arc between a continuous flux filled electrode wire and the work. Shielding

is obtained through decomposition of the flux within the tubular wire. Additional shielding may or may not be

obtained from an externally supplied gas or gas mixture. The process is normally applied semiautomatically;

however the process may be applied automatically or by machine. It is commonly used to weld large diameter

electrodes in the flat and horizontal position and small electrode diameters in all positions. The process is used

to a lesser degree for welding stainless steel and for overlay work.

Art # A-08992_AB

Molten

Slag

Nozzle

(Optional)

FCAW Process

Flux Cored