GTAW Flashcards
GTAW requires ________ to shield the weld puddle
An inert gas
When is GTAW primarily used?
When high quality welds are mandatory
When is hot wire GTAW used?
When high production welds are required
What positions can the GTAW process be used?
Flat, horizontal and vertical
Which metal requires a full preheat when welded with the GTAW process?
Cast Iron
What is an advantage of GTAW over SMAW?
It can eliminate the need to use a flux
The intensity of the uv light produced by the GTAW process is similar to __________ welding
gas metal arc
The intensity of the uv light produced by the GTAW process is much greater than that produced by ______________ welding
Shielded metal arc welding
When using GTAW, good ventilation is required to prevent _______
An oxygen deficiency
The arc radiation from GTAW reacts with elements in atmospheric air to form _______
Ozone (O3)
Ultraviolet radiation from GTAW can react with chlorinated degreasing solvents to produce _____
Phosgene gas
Pulsing the arc with GTAW is an advantage
penetration on thin metals must be controlled
Welding machines designed for GTAW are ______
Constant current (CC)
An AC/DC _______ would be best suited for GTAW.
rectifier
Power sources recommended for GTAW have a _______volt-amp curve
drooping
What is post-purge control designed to do?
Keep gas flowing for a pre-set time after the arc is extinguished
When using 125 amperes on an AC current _______ is the recommended size of electrode.
2.5 mm or 3/32 inch
What is the recommended current type for welding stainless steel?
DC electrode negative
Which current type produces the deepest penetration?
Direct Current electrode negative
Removal of aluminum oxide occurs during __________
The positive half of the AC cycle
AC high frequency is most suited for GTAW on ________ and _________
aluminum and magnesium
Continuous high frequency current is required when ________
A stabilized AC current is required
A GTAW torch that is too small for the current setting overheats the __________
Torch body
A torch cap is the part of a GTAW torch that _________
Protects the electrode from accidental arc strikes
What do the sealing surfaces between the cap and the torch body of a GTAW torch provide?
Shielding gas seal
What torch part serves the primary purpose of binding the collet onto the electrode?
A torch cap
A collet is a device in the GTAW torch that _________
Positions the electrode and transfers current
The diameter of the nozzle is normally determines by
The size of the puddle and the electrode
To use continuous high frequency current, the nozzle must be constructed of __________
Ceramic
What is the purpose of a regulator when used with GTAW?
To reduce supply pressure to a safe working pressure
Which unit it a flowmeter calibrated in?
liters per minute or cubic feet per hour
What is the purpose of a flowmeter when used with GTAW?
to meter the flow of shielding gas
A floating ball type flowmeter must be used in the ________ position
Veritical
