gas metal arc welding. definition intense heat of an electric arc is used to melt filler material...
TRANSCRIPT
GAS META
L ARC
WELD
ING
DEFINITION
Intense heat of an electric arc is used to melt filler material and base metal while a wire electrode is continuously fed into the arc. A shielding gas protects the weld from contamination.
EQUIPMENT
1. Direct Current
2. Constant Voltage Power Source
3. Wire Feeder w/control system
4. Electrode wire
5. Welding gun
6. Electrical Cable
7. Shielding Gas
TYPES OF METAL TRANSFER
• Short Circuit- molten metal is deposited in repeated short circuits
• Globular- molten metal is transferred across arc in large droplets
• Spray- molten metal is propelled axially across the arc in small droplets
ADVANTAGES
1. High Deposition Rates
2. High Utilization of Filler Material
3. Elimination of Flux/Slag Removal
4. Reduction of Smoke & Fumes
5. Can be Automated
6. Less Skill Required
DISADVANTAGES
1. Cost
2. Metal preparation time
3. Unsuitable for outdoor welding
4. Fast cooling rates
5. Unsuitable for thick metals
6. Shielding gas required
INTERNAL DIAGRAM OF WIRE FEED SYSTEM
TIP DISTANCE DIAGRAM
WELDING TERMINOLOGY
ARC WELDING
Type of welding when weld is produced by heating metal with an arc with or without the use of filler material or pressure
ELECTRODE
A component of the welding circuit through which current is conducted to the arc, molten, slag or base metal
FLUX
Material used to prevent, dissolve or remove oxides and other undesirable materials from a weld
BASE METAL
The metal to be welded, soldered or cut
POROSITY
Cavity formed by gas entrapment during solidification
SPLATTER
Metal particles expelled during welding that does not form as part of the weld
TACK WELD
Weld made to hold part of the weldment in proper alignment until the final welds are made
INERT GAS
A gas that goes not normally combine chemically with the base metal or filler metal. Creates a protective atmosphere.
UNDERCUT
A groove melted into the base metal adjacent to the toe or root of a weld and left unfilled by weld metal
WELD
A localized joining of metal produced by heat
FILLER METAL
The metal to be added in making a welded joint.
READING ELECTRODES
ER-70S-6E=ElectrodeR=Filler Metal Rod70= Tensile Strength
ER-70S-6S= Solid Wire6=Chemical Composition of
the Wire
PRACTICE READING ELECTRODES
WELD ANATOMY