Review Questions - GTAW Flashcards
Gas Tungsten Arc Welding
Purging is used during QTAW to:
- protect the root from oxygen and nitrogen
- protect the tungsten
- protect the weld pool surface
- protect the work lead connection
protect the root from oxygen and nitrogen
Which of the following is used as a shielding gas for GTAW?
- oxygen
- nitrogen
- phosgene
- argon
argon
When is a gas lens used with GTAW?
- to improve shielding of the weld pool
- to increase weld cooling rate
- to prevent laminar flow of shielding gas
- to control weld pool shrinkage
to improve shielding of the weld pool
Which type of current is used for GTAW of stainless steel?
- DCEP
- ACHF
- DCEN
- ACPG
DCEN
What is a suitable shielding gas flow rate for GTAW on DCEN using a #6 gas cup?
- 5 l/min (11cfh)
- 10 l/min (22 cfh)
- 15 l/min (33 cfh)
- 20 l/min (44 cfh)
5 l/min (11cfh)
Which of the following desgnates an “unalloyed” tungsten?
- EWZr-1
- EWP
- EWCe-1
- EWTh-2
EWP
Post flow of shielding gas when GTA welding is used to:
- protect the weld pool while cooling
- melt the electrode end
- freeze the weld pool
- protect the hot gas cup
protect the weld pool while cooling
The GTAW process can be performed:
- with plastic filler rods
- without shielding gas
- without filler metal
- without electricity
without filler metal
what colour band ewould identify 2% thoriated tungsten?
- orange
- red
- yellow
- green
red
What unit of calibration is used for Flow Meters?
- PSI
- LPM/CFH
- FPM
- CFM/LPH
LPM/CFH
liters per minute or cubic feet per hour
What is an Autogenous weld?
- a weld produced by an automated welder
- a weld that has a high degree of felxibility
- a weld produced without the use of a filler metal
- a weld produced by submerged arc welding
a weld produced without the use of a filler metal
how would you reduce suck back on a root weld using GTAW?
- increase weld amperage
- change polarity
- increase purge pressure
- reduce weld amperage
reduce weld amperage
A flow meter would be installed with the site glass in which postion?
- horizontal
- 4º to the vertical
- down
- upright
upright
Which tungsten would you expect to see balled after striking an arc?
- pure tugnsten using AC
- 2% thiriated using DC electrode negative
- 2% ceriated tugnsten using AC with a balance control of 60-70%
- any tungsten when excessive DC+ (positive) current is used
pure tugnsten using AC
Why is argon used a a shielding and purging gas?
- Argon is lighter than air
- argon poses no health risk to the welder
- argon is heavier than air
- argon is a reactive gas and increases the arc temperature
argon is heavier than air