456A GMAW MIG 2

Question 1

What is the difference between push (forehand) and pull (backhand) gun angle in GMAW?

Accepted Answer

Push angle tilts the gun in the direction of travel for less penetration and wider bead; pull angle tilts away from travel direction for deeper penetration and narrower bead

Answer

There is no difference in technique

Answer

Push is for vertical; pull is for horizontal

Answer

Push is for thick metal; pull is for thin metal

Question 2

What is the purpose of anti-spatter compound in GMAW welding?

Accepted Answer

To coat the nozzle, workpiece surface, and fixtures to prevent spatter from adhering, making cleanup easier

Answer

To improve the weld's mechanical properties

Answer

To reduce the shielding gas consumption

Answer

To lubricate the wire feed mechanism

Question 3

What causes excessive spatter in GMAW welding?

Accepted Answer

Voltage set too high or too low for the wire feed speed, contaminated base metal, wrong shielding gas, excessive stick-out, or moisture on the wire

Answer

Using too much shielding gas

Answer

The room temperature is too high

Answer

Using the correct parameters

Question 4

What is pulsed GMAW and what are its advantages?

Accepted Answer

An electronically controlled process that alternates between high peak current (for droplet transfer) and low background current (to maintain the arc), allowing spray-type transfer at lower average heat input

Answer

A manual on-off technique by the welder

Answer

A process using pulsed shielding gas

Answer

The same as short-circuit transfer

Question 5

What is the correct procedure for setting up a GMAW machine for a new welding job?

Accepted Answer

Select correct wire size and type, install matching drive rolls and contact tip, set gas type and flow rate, adjust wire feed speed and voltage per the manufacturer's chart, and make test welds

Answer

Just turn it on and start welding

Answer

Only adjust the voltage

Answer

Only change the wire spool

Question 6

In GMAW, what does a constant voltage (CV) power source do differently from a constant current (CC) source?

Accepted Answer

CV maintains a set voltage and allows amperage to vary with arc length changes (self-regulating); CC maintains set amperage and allows voltage to vary — GMAW uses CV

Answer

CV provides constant amperage; CC provides constant voltage

Answer

There is no difference for GMAW

Answer

CV is for AC only; CC is for DC only