Review Questions - GTAW

Question 1

Purging is used during QTAW to:

1. protect the root from oxygen and nitrogen
2. protect the tungsten
3. protect the weld pool surface
4. protect the work lead connection

Answer 1

protect the root from oxygen and nitrogen

Question 2

Which of the following is used as a shielding gas for GTAW?

1. oxygen
2. nitrogen
3. phosgene
4. argon

Answer 2

argon

Question 3

When is a gas lens used with GTAW?

1. to improve shielding of the weld pool
2. to increase weld cooling rate
3. to prevent laminar flow of shielding gas
4. to control weld pool shrinkage

Answer 3

to improve shielding of the weld pool

Question 4

Which type of current is used for GTAW of stainless steel?

1. DCEP
2. ACHF
3. DCEN
4. ACPG

Answer 4

DCEN

Question 5

What is a suitable shielding gas flow rate for GTAW on DCEN using a #6 gas cup?

1. 5 l/min (11cfh)
2. 10 l/min (22 cfh)
3. 15 l/min (33 cfh)
4. 20 l/min (44 cfh)

Answer 5

5 l/min (11cfh)

Question 6

Which of the following desgnates an “unalloyed” tungsten?

1. EWZr-1
2. EWP
3. EWCe-1
4. EWTh-2

Answer 6

EWP

Question 7

Post flow of shielding gas when GTA welding is used to:

1. protect the weld pool while cooling
2. melt the electrode end
3. freeze the weld pool
4. protect the hot gas cup

Answer 7

protect the weld pool while cooling

Question 8

The GTAW process can be performed:

1. with plastic filler rods
2. without shielding gas
3. without filler metal
4. without electricity

Answer 8

without filler metal

Question 9

what colour band ewould identify 2% thoriated tungsten?

1. orange
2. red
3. yellow
4. green

Answer 9

red

Question 10

What unit of calibration is used for Flow Meters?

1. PSI
2. LPM/CFH
3. FPM
4. CFM/LPH

Answer 10

LPM/CFH

liters per minute or cubic feet per hour

Question 11

What is an Autogenous weld?

1. a weld produced by an automated welder
2. a weld that has a high degree of felxibility
3. a weld produced without the use of a filler metal
4. a weld produced by submerged arc welding

Answer 11

a weld produced without the use of a filler metal

Question 12

how would you reduce suck back on a root weld using GTAW?

1. increase weld amperage
2. change polarity
3. increase purge pressure
4. reduce weld amperage

Answer 12

reduce weld amperage

Question 13

A flow meter would be installed with the site glass in which postion?

1. horizontal
2. 4º to the vertical
3. down
4. upright

Answer 13

upright

Question 14

Which tungsten would you expect to see balled after striking an arc?

1. pure tugnsten using AC
2. 2% thiriated using DC electrode negative
3. 2% ceriated tugnsten using AC with a balance control of 60-70%
4. any tungsten when excessive DC+ (positive) current is used

Answer 14

pure tugnsten using AC

Question 15

Why is argon used a a shielding and purging gas?

1. Argon is lighter than air
2. argon poses no health risk to the welder
3. argon is heavier than air
4. argon is a reactive gas and increases the arc temperature

Answer 15

argon is heavier than air