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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 does voltage do in an electrical circuit?
To prevent leakage - Carbon Dioxide (CO2)
Voltage is the force that overcomes resistance to allow amperage flow
The resistace to electrical current flow increases with it. Causing the electrode to heat
5.8 to 12.5 L/min

2. What is the preferred drive roll design for solid wires?
1/4 inch to 1/2 inch
AWS and CSA
When the filler wire is in direct contract with the base metal
V groove or U groove

3. What is the recommended electrode stick- out for .035 solid wire?
1/4 inch to 1/2 inch
(DCEP) Direct Current Electrode Positive or Reverse polarity
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts

4. What does the abbreviation NEMA stand for?
National Electrical Manufactures Association
Flux cored wires
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
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5. What 2 controls are found on a GMAW set- up?
Constant current (CC)
Insufficient current to melt the wire off cleanly
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

6. What controls the wire speed on a voltage sensing wire feeder?
DCEP (Direct Current Electrode Positive) Reverse Polarity
Constant voltage (CV)
15 feet (4.5 meters)
The Arc voltage

7. What power sources are used with the GMAW Process?
These terms are quite restrictive and often technically incorrect
Motor driven generators - Transformer rectifiers - and Inverter designs
85%
DCEP (Direct Current Electrode Positive) Reverse Polarity

8. What does inductance control?
Minutes of elapsed time continually run (out of 10 minutes)
Dry ice can form within the flow control openings and cause blockage of shielding gas
12 to 22 arc volts
The time rate of response for the current rise and fall

9. What is the reason glass 'tube' type flowmeters must have the tube mounted truly vertical?
...
Duty cycle
Puddle fluidity
Reducing the gas source pressure to a constant working pressure

10. What does the wire feeder control?
When the filler wire is in direct contract with the base metal
12 to 22 arc volts
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Speed of the feed motor and - starting / stopping electrode feed

11. List the basic equipment requirements for the GMAW process
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
Minimum distortion due to low heat input
1/4 inch to 1/2 inch

12. What output on the welding machine is used to rate the duty cycle?
Voltage is the force that overcomes resistance to allow amperage flow
Pressure - The rate of flow of a shielding gas
To limit the short circuiting current so that spatter is reduced
Minutes of elapsed time continually run (out of 10 minutes)

13. What controls amperage when using GMAW?
Gives arc voltage values to the control system of the feeder
Minimum distortion due to low heat input
(DCEP) Direct Current Electrode Positive or Reverse polarity
Wire feed speed

14. What is the main purpose of 'slope'?
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20 to 200 times per second
To limit the short circuiting current so that spatter is reduced
National Electrical Manufactures Association

15. Why is a line heater required when using GMAW?
Dry ice can form within the flow control openings and cause blockage of shielding gas
To limit the short circuiting current so that spatter is reduced
1/4 inch to 1/2 inch
15 feet (4.5 meters)

16. What type of power source is commonly used with a voltage sensing wire feeder?
5.8 to 12.5 L/min
Generally not as accurate
Motor driven generators - Transformer rectifiers - and Inverter designs
Constant current (CC)

17. When is the metal transferred with short circuit transfer?
When the filler wire is in direct contract with the base metal
Duty cycle
Cause flaking - which can clog the liner and contact tube
85%

18. What is the required arc voltage used for short circuit transfer?
To prevent leakage - Carbon Dioxide (CO2)
Dry ice can form within the flow control openings and cause blockage of shielding gas
Insufficient current to melt the wire off cleanly
12 to 22 arc volts

19. List several industries that would use GMAW
3
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
Constant current (CC)
Pressure vessels and the piping industry

20. With straight polarity where is 2/3 of the arc energy?
AWS and CSA
The negative side of a welding unit
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Speed of the feed motor and - starting / stopping electrode feed

21. Why is a fiber washer required and what cylinder gas requires it?
To prevent leakage - Carbon Dioxide (CO2)
When the filler wire is in direct contract with the base metal
To prevent drawing of liquid CO2 (Carbon Dioxide)
Aluminum wire

22. In the GMAW process what does voltage control?
(DCEP) Direct Current Electrode Positive or Reverse polarity
Insufficient current to melt the wire off cleanly
Welding process that joins metals by heating them with an electric arc
Puddle fluidity

23. What term is used to describe when the workpiece is hooked to the negative pole on the power source?
(DCEP) Direct Current Electrode Positive or Reverse polarity
Minutes of elapsed time continually run (out of 10 minutes)
Flux cored wires
3

24. 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
12 to 22 arc volts
Guns
3

25. When using flat drive rolls with too much pressure on copper coated solid wires what problem could take place?
12 to 22 arc volts
Cause flaking - which can clog the liner and contact tube
Shielding the molten weld metal from atmospheric contamination
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26. What does the term GMAW identify?
Constant voltage (CV)
Gas metal arc welding
The negative side of a welding unit
Higher 26 to 35 arc volts

27. What does a flowmeter do and what does it measure?
(DCEP) Direct Current Electrode Positive or Reverse polarity
1/4 inch to 1/2 inch
Higher 26 to 35 arc volts
Controls the rate of flow of a shielding gas to the gun nozzle

28. What happens when the electrode extension is increased?
Constant current (CC)
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
The resistace to electrical current flow increases with it. Causing the electrode to heat
Gas metal arc welding

29. A 10 minute cycle of welding time vs cooling time a given machine can handle.
Constant current (CC)
The Arc voltage
Duty cycle
Aluminum wire

30. What is another term for electrode holders for GMAW?
Spatter problems and poor weld appearance
Constant- speed wire feeders and Voltage- sennsing wire feeders
Short- circuiting transfer - Globular transfer - Spray transfer
Guns

31. What is the disadvantage of the gauge preset type of regulator/flowmeter?
Speed of the feed motor and - starting / stopping electrode feed
The time rate of response for the current rise and fall
Generally not as accurate
Motor driven generators - Transformer rectifiers - and Inverter designs

32. What effect does increasing and decreasing the inductance have on the weld?
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

33. In the GMAW process what does amperage control?
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Constant- speed wire feeders and Voltage- sennsing wire feeders
Penetration and burn - off rate of the electrode
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system

34. How many times per second does short circuiting take place?
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
20 to 200 times per second
DCEP (Direct Current Electrode Positive) Reverse Polarity
Minimum distortion due to low heat input

35. Why is globular transfer generally avoided with GMAW?
Puddle fluidity
Motor driven generators - Transformer rectifiers - and Inverter designs
Spatter problems and poor weld appearance
Duty cycle

36. Give a brief description of the GMAW process
Short- circuiting transfer - Globular transfer - Spray transfer
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Welding process that joins metals by heating them with an electric arc
Gas metal arc welding

37. List the factors that determine the mode of metal transfer
Voltage is the force that overcomes resistance to allow amperage flow
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Constant- speed wire feeders and Voltage- sennsing wire feeders
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun

38. What is a typical flow rate of CO2 for short circuit transfer?
Constant- speed wire feeders and Voltage- sennsing wire feeders
5.8 to 12.5 L/min
Wire feed speed - Voltage control
By there current carrying capacity

39. What is the key advantage of short circuiting transfer?
Minimum distortion due to low heat input
Duty cycle
Gives arc voltage values to the control system of the feeder
Short- circuiting transfer - Globular transfer - Spray transfer

40. What 2 organizations designate specifications for GMAW wires?
AWS and CSA
By there current carrying capacity
20 to 200 times per second
Shielding the molten weld metal from atmospheric contamination

41. What is a solenoid valve and what actuates it?
5.8 to 12.5 L/min
The Arc voltage
Voltage is the force that overcomes resistance to allow amperage flow
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun

42. List 3 forms compressed gases may be supplied for welding
Reducing the gas source pressure to a constant working pressure
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Constant current (CC)
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field

43. What would be an indication that the drive roll pressure is adjusted correctly?
Wire feeds smoothly (yet will slip should a problem occur in the gun)
(DCEP) Direct Current Electrode Positive or Reverse polarity
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Guns

44. What wire are knurled drive rolls most commonly used on?
The time rate of response for the current rise and fall
Flux cored wires
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
15 feet (4.5 meters)

45. What is the purpose of a regulator and what does it indicate on its gauges?
Voltage is the force that overcomes resistance to allow amperage flow
Reducing the gas source pressure to a constant working pressure
Pressure - The rate of flow of a shielding gas
Constant- speed wire feeders and Voltage- sennsing wire feeders

46. What type of power source is used with a constant speed wire feeder?
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Constant voltage (CV)
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
5.8 to 12.5 L/min

47. What are the 2 types of wire feeders available?
Cause flaking - which can clog the liner and contact tube
The resistace to electrical current flow increases with it. Causing the electrode to heat
If you dont know this check your phone
Constant- speed wire feeders and Voltage- sennsing wire feeders

48. A pull type drive system is usually used on what type of material?
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DCEP (Direct Current Electrode Positive) Reverse Polarity
Cause flaking - which can clog the liner and contact tube
Aluminum wire

49. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
Welding process that joins metals by heating them with an electric arc
Constant voltage (CV)
85%
Motor driven generators - Transformer rectifiers - and Inverter designs

50. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
3
Controls the rate of flow of a shielding gas to the gun nozzle
Pressure - The rate of flow of a shielding gas
Penetration and burn - off rate of the electrode