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. What type of power source is used with a constant speed wire feeder?
Reducing the gas source pressure to a constant working pressure
Welding process that joins metals by heating them with an electric arc
When the filler wire is in direct contract with the base metal
Constant voltage (CV)

2. Why is a fiber washer required and what cylinder gas requires it?
To prevent drawing of liquid CO2 (Carbon Dioxide)
To prevent leakage - Carbon Dioxide (CO2)
Controls the rate of flow of a shielding gas to the gun nozzle
The time rate of response for the current rise and fall

3. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
85%
The resistace to electrical current flow increases with it. Causing the electrode to heat
...
Controls the rate of flow of a shielding gas to the gun nozzle

4. Why is globular transfer generally avoided with GMAW?
Wire feed speed
Wire feed speed - Voltage control
Spatter problems and poor weld appearance
Voltage is the force that overcomes resistance to allow amperage flow

5. When is the metal transferred with short circuit transfer?
1/4 inch to 1/2 inch
Shielding the molten weld metal from atmospheric contamination
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
When the filler wire is in direct contract with the base metal

6. What is a typical flow rate of CO2 for short circuit transfer?
Spatter problems and poor weld appearance
V groove or U groove
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
5.8 to 12.5 L/min

7. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
Duty cycle
Higher 26 to 35 arc volts
The Arc voltage
Minimum distortion due to low heat input

8. In the GMAW process what does amperage control?
Penetration and burn - off rate of the electrode
To limit the short circuiting current so that spatter is reduced
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Controls the rate of flow of a shielding gas to the gun nozzle

9. A 10 minute cycle of welding time vs cooling time a given machine can handle.
(DCEP) Direct Current Electrode Positive or Reverse polarity
Guns
Duty cycle
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

10. What is the reason glass 'tube' type flowmeters must have the tube mounted truly vertical?
...
The resistace to electrical current flow increases with it. Causing the electrode to heat
Aluminum wire
Controls the rate of flow of a shielding gas to the gun nozzle

11. What does inductance control?
3
The time rate of response for the current rise and fall
To prevent drawing of liquid CO2 (Carbon Dioxide)
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field

12. What current and polarity is generally used with GMAW?
DCEP (Direct Current Electrode Positive) Reverse Polarity
1/4 inch to 1/2 inch
Cause flaking - which can clog the liner and contact tube
Duty cycle

13. What is the purpose of the pick- up lead on a voltage sensing wire feeder?
Spatter problems and poor weld appearance
Gives arc voltage values to the control system of the feeder
Higher 26 to 35 arc volts
Controls the rate of flow of a shielding gas to the gun nozzle

14. What is a solenoid valve and what actuates it?
Guns
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
AWS and CSA
Constant voltage (CV)

15. What output on the welding machine is used to rate the duty cycle?
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
When the filler wire is in direct contract with the base metal
...
Minutes of elapsed time continually run (out of 10 minutes)

16. What is an advantage of pulsed arc transfer with GMAW?
Pressure vessels and the piping industry
Constant current (CC)
DCEP (Direct Current Electrode Positive) Reverse Polarity
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze

17. How many times per second does short circuiting take place?
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Constant voltage (CV)
20 to 200 times per second

18. What 2 controls are found on a GMAW set- up?
3
Wire feed speed - Voltage control
To prevent drawing of liquid CO2 (Carbon Dioxide)
Gas metal arc welding

19. What are the 2 types of wire feeders available?
SMAW - GTAW
Constant- speed wire feeders and Voltage- sennsing wire feeders
By there current carrying capacity
Short- circuiting transfer - Globular transfer - Spray transfer

20. What is the purpose of the shielding gas used in GMAW?
Generally not as accurate
Shielding the molten weld metal from atmospheric contamination
Puddle fluidity
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground

21. What happens when the electrode extension is increased?
Guns
The resistace to electrical current flow increases with it. Causing the electrode to heat
Reducing the gas source pressure to a constant working pressure
Insufficient current to melt the wire off cleanly

22. What does a flowmeter do and what does it measure?
Controls the rate of flow of a shielding gas to the gun nozzle
The Arc voltage
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Constant current (CC)

23. How are GMAW guns rated?
By there current carrying capacity
Guns
Dry ice can form within the flow control openings and cause blockage of shielding gas
Cause flaking - which can clog the liner and contact tube

24. What is the recommended electrode stick- out for .035 solid wire?
1/4 inch to 1/2 inch
Generally not as accurate
Cause flaking - which can clog the liner and contact tube
Controls the rate of flow of a shielding gas to the gun nozzle

25. Why is the term GMAW preferred over MIG or MAG?
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
These terms are quite restrictive and often technically incorrect
Wire feed speed
To limit the short circuiting current so that spatter is reduced

26. Draw a typical volt amp curve for a machine that is designed for GMAW
If you dont know this check your phone
The negative side of a welding unit
To limit the short circuiting current so that spatter is reduced
AWS and CSA

27. List 3 forms compressed gases may be supplied for welding
National Electrical Manufactures Association
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Constant voltage (CV)
Pressure vessels and the piping industry

28. What power sources are used with the GMAW Process?
National Electrical Manufactures Association
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
Motor driven generators - Transformer rectifiers - and Inverter designs
(DCEP) Direct Current Electrode Positive or Reverse polarity

29. What is the required arc voltage used for short circuit transfer?
Generally not as accurate
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
12 to 22 arc volts

30. What is the purpose of a regulator and what does it indicate on its gauges?
Flux cored wires
Reducing the gas source pressure to a constant working pressure
Penetration and burn - off rate of the electrode
Constant current (CC)

31. What term is used to describe when the workpiece is hooked to the negative pole on the power source?
The negative side of a welding unit
Gas metal arc welding
(DCEP) Direct Current Electrode Positive or Reverse polarity
...

32. What is the preferred drive roll design for solid wires?
V groove or U groove
...
Higher 26 to 35 arc volts
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze

33. Draw a typical volt/amp curve that would be found with a power source designed for SMAW or GTAW
Wire feed speed
DCEP (Direct Current Electrode Positive) Reverse Polarity
If you dont know this check your phone
Higher 26 to 35 arc volts

34. When using flat drive rolls with too much pressure on copper coated solid wires what problem could take place?
Constant voltage (CV)
Cause flaking - which can clog the liner and contact tube
The time rate of response for the current rise and fall
Reducing the gas source pressure to a constant working pressure

35. What is the disadvantage of the gauge preset type of regulator/flowmeter?
Generally not as accurate
15 feet (4.5 meters)
If you dont know this check your phone
Shielding the molten weld metal from atmospheric contamination

36. What does the abbreviation NEMA stand for?
...
If you dont know this check your phone
National Electrical Manufactures Association
Constant voltage (CV)

37. What is another term for electrode holders for GMAW?
Penetration and burn - off rate of the electrode
(DCEP) Direct Current Electrode Positive or Reverse polarity
Guns
5.8 to 12.5 L/min

38. What would be an indication that the drive roll pressure is adjusted correctly?
Higher 26 to 35 arc volts
If you dont know this check your phone
Minimum distortion due to low heat input
Wire feeds smoothly (yet will slip should a problem occur in the gun)

39. What does voltage do in an electrical circuit?
Pressure vessels and the piping industry
Voltage is the force that overcomes resistance to allow amperage flow
Reducing the gas source pressure to a constant working pressure
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

40. Give a brief description of the GMAW process
1/4 inch to 1/2 inch
Welding process that joins metals by heating them with an electric arc
Controls the rate of flow of a shielding gas to the gun nozzle
Flux cored wires

41. What is the maximum distance that hard wire can be successfully pushed?
Speed of the feed motor and - starting / stopping electrode feed
The resistace to electrical current flow increases with it. Causing the electrode to heat
15 feet (4.5 meters)
Wire feed speed - Voltage control

42. What 2 organizations designate specifications for GMAW wires?
15 feet (4.5 meters)
Spatter problems and poor weld appearance
Pressure - The rate of flow of a shielding gas
AWS and CSA

43. A pull type drive system is usually used on what type of material?
Aluminum wire
To prevent drawing of liquid CO2 (Carbon Dioxide)
Minutes of elapsed time continually run (out of 10 minutes)
AWS and CSA

44. What type of power source is commonly used with a voltage sensing wire feeder?
Gas metal arc welding
Constant- speed wire feeders and Voltage- sennsing wire feeders
The time rate of response for the current rise and fall
Constant current (CC)

45. Regulators control_____________ flowmeters SHOW____________.
Pressure - The rate of flow of a shielding gas
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
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

46. What is the key advantage of short circuiting transfer?
Minimum distortion due to low heat input
Controls the rate of flow of a shielding gas to the gun nozzle
SMAW - GTAW
85%

47. What does the wire feeder control?
Higher 26 to 35 arc volts
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Speed of the feed motor and - starting / stopping electrode feed
Pressure - The rate of flow of a shielding gas

48. List the three methods of metal transfer with GMAW
Generally not as accurate
Short- circuiting transfer - Globular transfer - Spray transfer
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
Pressure vessels and the piping industry

49. What is the main purpose of 'slope'?
The resistace to electrical current flow increases with it. Causing the electrode to heat
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
To limit the short circuiting current so that spatter is reduced
(DCEP) Direct Current Electrode Positive or Reverse polarity

50. Why must CO2 cylinders be used in the vertical position?
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
To prevent drawing of liquid CO2 (Carbon Dioxide)
Cause flaking - which can clog the liner and contact tube
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground