29207-15 GTAW - Equipment and Filler Metals

If you see the label "TIG" on a welding machine, that machine is considered to be what kind of a welding machine?

• Stick

• FCAW

• GMAW

• GTAW

In the atmosphere near the weld, the UV radiation from the GTAW process can ionize _____.

• dust

• helium

• oxygen

• hydrogen

GTAW is most commonly performed using _____.

• constant voltage

• alternating current with low frequency

• direct current electrode positive (DCEP)

• direct current electrode negative (DCEN)

A high-voltage, high-frequency current used in GTAW work creates an arc that can jump a gap of about _____.

• 1/4 inch (6.4 mm)

• 1/2 inch (12.7 mm)

• 3/4 inch (19.1 mm)

• 1 inch (25.4 mm)

One of the advanced features associated with the GTAW process is the high-frequency intensity controls that provide better _____.

• arc starting

• arc ending

• craters

• welds

Setting the amperage at 200 amps for a welding machine that is rated 300 amps at 60-percent duty cycle will _____.

• reduce the shielding gas flow rate by 30 percent

• cause excessive nozzle vibration

• increase the duty cycle to 100 percent

• allow welding current to be pulsed

On a GTAW torch, to change an electrode or adjust its stickout, the welder loosens the _____.

• electrode back cap

• nozzle gasket

• retaining cup

• gas nozzle

Of the various types of tungsten electrodes available, the tungsten electrodes that are used for AC welding are _____.

• lanthanated

• pure

• irradiated

• thoriated

The two principal shielding gases used for GTAW are _____.

• argon and helium

• nitrogen and oxygen

• argon and carbon dioxide

• hydrogen and carbon dioxide

When welding with GTAW in a cross draft situation, better shielding is provided by _____.

• argon

• helium

• hydrogen

• carbon dioxide