Test your basic knowledge |

Gas Metal Arc Welding

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. Draw a typical volt amp curve for a machine that is designed for GMAW
3
To prevent leakage - Carbon Dioxide (CO2)
The resistace to electrical current flow increases with it. Causing the electrode to heat
If you dont know this check your phone

2. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
The resistace to electrical current flow increases with it. Causing the electrode to heat
85%
To prevent drawing of liquid CO2 (Carbon Dioxide)
Higher 26 to 35 arc volts

3. Why is the term GMAW preferred over MIG or MAG?
If you dont know this check your phone
AWS and CSA
Guns
These terms are quite restrictive and often technically incorrect

4. What is a solenoid valve and what actuates it?
The resistace to electrical current flow increases with it. Causing the electrode to heat
National Electrical Manufactures Association
If you dont know this check your phone
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun

5. What power sources are used with the GMAW Process?
If you dont know this check your phone
Motor driven generators - Transformer rectifiers - and Inverter designs
National Electrical Manufactures Association
Spatter problems and poor weld appearance

6. What is the main purpose of 'slope'?
...
To limit the short circuiting current so that spatter is reduced
Short- circuiting transfer - Globular transfer - Spray transfer
20 to 200 times per second

7. What processes are constant current (CC) power sources designed to be used with?
SMAW - GTAW
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Aluminum wire
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun

8. List several industries that would use GMAW
Speed of the feed motor and - starting / stopping electrode feed
Gives arc voltage values to the control system of the feeder
Pressure vessels and the piping industry
Voltage is the force that overcomes resistance to allow amperage flow

9. What is the purpose of a regulator and what does it indicate on its gauges?
The negative side of a welding unit
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Reducing the gas source pressure to a constant working pressure
V groove or U groove

10. What is the effect of too much slope?
SMAW - GTAW
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Insufficient current to melt the wire off cleanly
Reducing the gas source pressure to a constant working pressure

11. List 3 forms compressed gases may be supplied for welding
Controls the rate of flow of a shielding gas to the gun nozzle
Duty cycle
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
85%

12. What is another term for electrode holders for GMAW?
Push type: Wire is fed by a set of drive rolls located in the wire feed unit - Pull type: Drive rolls mounted in the gun itself - Push- pull type: Combination of the two
SMAW - GTAW
Guns
To prevent drawing of liquid CO2 (Carbon Dioxide)

13. A pull type drive system is usually used on what type of material?
If you dont know this check your phone
Push type: Wire is fed by a set of drive rolls located in the wire feed unit - Pull type: Drive rolls mounted in the gun itself - Push- pull type: Combination of the two
AWS and CSA
Aluminum wire

14. What is the key advantage of short circuiting transfer?
Minutes of elapsed time continually run (out of 10 minutes)
Minimum distortion due to low heat input
The resistace to electrical current flow increases with it. Causing the electrode to heat
Aluminum wire

15. In the GMAW process what does amperage control?
Penetration and burn - off rate of the electrode
15 feet (4.5 meters)
Gas metal arc welding
National Electrical Manufactures Association

16. Draw a typical volt/amp curve that would be found with a power source designed for SMAW or GTAW
The resistace to electrical current flow increases with it. Causing the electrode to heat
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Puddle fluidity
If you dont know this check your phone

17. List the basic equipment requirements for the GMAW process
The Arc voltage
If you dont know this check your phone
Wire feed speed - Voltage control
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground

18. What is an advantage of pulsed arc transfer with GMAW?
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
The time rate of response for the current rise and fall
85%

19. Give a brief description of the GMAW process
Welding process that joins metals by heating them with an electric arc
To prevent drawing of liquid CO2 (Carbon Dioxide)
Aluminum wire
...

20. What are the 2 types of wire feeders available?
Wire feed speed - Voltage control
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Constant- speed wire feeders and Voltage- sennsing wire feeders

21. What type of power source is commonly used with a voltage sensing wire feeder?
Constant current (CC)
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
3
Gas metal arc welding

22. What 2 controls are found on a GMAW set- up?
Puddle fluidity
12 to 22 arc volts
Wire feed speed - Voltage control
The time rate of response for the current rise and fall

23. How are GMAW guns rated?
Higher 26 to 35 arc volts
By there current carrying capacity
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Guns

24. With straight polarity where is 2/3 of the arc energy?
The negative side of a welding unit
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
By there current carrying capacity
Aluminum wire

25. What is a typical flow rate of CO2 for short circuit transfer?
DCEP (Direct Current Electrode Positive) Reverse Polarity
Wire feed speed
5.8 to 12.5 L/min
20 to 200 times per second

26. What does inductance control?
The time rate of response for the current rise and fall
Pressure vessels and the piping industry
These terms are quite restrictive and often technically incorrect
The negative side of a welding unit

27. What term is used to describe when the workpiece is hooked to the negative pole on the power source?
3
(DCEP) Direct Current Electrode Positive or Reverse polarity
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts

28. What would be an indication that the drive roll pressure is adjusted correctly?
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
The time rate of response for the current rise and fall
Flux cored wires
Wire feeds smoothly (yet will slip should a problem occur in the gun)

29. What does the wire feeder control?
Cause flaking - which can clog the liner and contact tube
5.8 to 12.5 L/min
Reducing the gas source pressure to a constant working pressure
Speed of the feed motor and - starting / stopping electrode feed

30. How many times per second does short circuiting take place?
20 to 200 times per second
Insufficient current to melt the wire off cleanly
Gas metal arc welding
When the filler wire is in direct contract with the base metal

31. A 10 minute cycle of welding time vs cooling time a given machine can handle.
Duty cycle
Voltage is the force that overcomes resistance to allow amperage flow
Constant current (CC)
Wire feed speed

32. What is the purpose of the pick- up lead on a voltage sensing wire feeder?
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Gives arc voltage values to the control system of the feeder
Constant current (CC)
Minimum distortion due to low heat input

33. List the three methods of metal transfer with GMAW
Controls the rate of flow of a shielding gas to the gun nozzle
If you dont know this check your phone
Short- circuiting transfer - Globular transfer - Spray transfer
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun

34. What 2 organizations designate specifications for GMAW wires?
Flux cored wires
The Arc voltage
...
AWS and CSA

35. What is the purpose of the shielding gas used in GMAW?
Generally not as accurate
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
Shielding the molten weld metal from atmospheric contamination

36. What happens when the electrode extension is increased?
The resistace to electrical current flow increases with it. Causing the electrode to heat
Reducing the gas source pressure to a constant working pressure
Pressure - The rate of flow of a shielding gas
85%

37. What is the maximum distance that hard wire can be successfully pushed?
Speed of the feed motor and - starting / stopping electrode feed
15 feet (4.5 meters)
Wire feed speed
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze

38. What effect does increasing and decreasing the inductance have on the weld?
If you dont know this check your phone
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
By there current carrying capacity
Constant voltage (CV)

39. Why is a line heater required when using GMAW?
Dry ice can form within the flow control openings and cause blockage of shielding gas
20 to 200 times per second
3
The negative side of a welding unit

40. What does the term GMAW identify?
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Gas metal arc welding
Reducing the gas source pressure to a constant working pressure
If you dont know this check your phone

41. What is the preferred drive roll design for solid wires?
V groove or U groove
Constant current (CC)
Push type: Wire is fed by a set of drive rolls located in the wire feed unit - Pull type: Drive rolls mounted in the gun itself - Push- pull type: Combination of the two
12 to 22 arc volts

42. What is the disadvantage of the gauge preset type of regulator/flowmeter?
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
SMAW - GTAW
Generally not as accurate

43. What type of power source is used with a constant speed wire feeder?
Gives arc voltage values to the control system of the feeder
Constant voltage (CV)
DCEP (Direct Current Electrode Positive) Reverse Polarity
The Arc voltage

44. What controls amperage when using GMAW?
Flux cored wires
Wire feed speed
Penetration and burn - off rate of the electrode
If you dont know this check your phone

45. Regulators control_____________ flowmeters SHOW____________.
The Arc voltage
Pressure - The rate of flow of a shielding gas
The time rate of response for the current rise and fall
V groove or U groove

46. What controls the wire speed on a voltage sensing wire feeder?
(DCEP) Direct Current Electrode Positive or Reverse polarity
The Arc voltage
Spatter problems and poor weld appearance
If you dont know this check your phone

47. List the factors that determine the mode of metal transfer
Pressure vessels and the piping industry
15 feet (4.5 meters)
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

48. What output on the welding machine is used to rate the duty cycle?
1/4 inch to 1/2 inch
Insufficient current to melt the wire off cleanly
Controls the rate of flow of a shielding gas to the gun nozzle
Minutes of elapsed time continually run (out of 10 minutes)

49. What wire are knurled drive rolls most commonly used on?
If you dont know this check your phone
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
15 feet (4.5 meters)
Flux cored wires

50. What is the required arc voltage used for short circuit transfer?
To prevent leakage - Carbon Dioxide (CO2)
V groove or U groove
Wire feed speed
12 to 22 arc volts