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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. With straight polarity where is 2/3 of the arc energy?
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Gives arc voltage values to the control system of the feeder
The negative side of a welding unit
The resistace to electrical current flow increases with it. Causing the electrode to heat

2. Why is the term GMAW preferred over MIG or MAG?
Cause flaking - which can clog the liner and contact tube
The time rate of response for the current rise and fall
Spatter problems and poor weld appearance
These terms are quite restrictive and often technically incorrect

3. List several industries that would use GMAW
Voltage is the force that overcomes resistance to allow amperage flow
(DCEP) Direct Current Electrode Positive or Reverse polarity
Pressure vessels and the piping industry
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4. What does voltage do in an electrical circuit?
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Flux cored wires
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Voltage is the force that overcomes resistance to allow amperage flow

5. When is the metal transferred with short circuit transfer?
Cause flaking - which can clog the liner and contact tube
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When the filler wire is in direct contract with the base metal
The Arc voltage

6. List the three methods of metal transfer with GMAW
Controls the rate of flow of a shielding gas to the gun nozzle
Cause flaking - which can clog the liner and contact tube
Short- circuiting transfer - Globular transfer - Spray transfer
By there current carrying capacity

7. Why is globular transfer generally avoided with GMAW?
Spatter problems and poor weld appearance
Minutes of elapsed time continually run (out of 10 minutes)
Constant voltage (CV)
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

8. What are the 2 types of wire feeders available?
These terms are quite restrictive and often technically incorrect
Constant- speed wire feeders and Voltage- sennsing wire feeders
To prevent drawing of liquid CO2 (Carbon Dioxide)
Insufficient current to melt the wire off cleanly

9. What is the main purpose of 'slope'?
V groove or U groove
By there current carrying capacity
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
To limit the short circuiting current so that spatter is reduced

10. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
Constant current (CC)
Motor driven generators - Transformer rectifiers - and Inverter designs
...
85%

11. List the basic equipment requirements for the GMAW process
5.8 to 12.5 L/min
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
Insufficient current to melt the wire off cleanly

12. What does the abbreviation NEMA stand for?
Penetration and burn - off rate of the electrode
(DCEP) Direct Current Electrode Positive or Reverse polarity
Controls the rate of flow of a shielding gas to the gun nozzle
National Electrical Manufactures Association

13. What term is used to describe when the workpiece is hooked to the negative pole on the power source?
The resistace to electrical current flow increases with it. Causing the electrode to heat
(DCEP) Direct Current Electrode Positive or Reverse polarity
Minutes of elapsed time continually run (out of 10 minutes)
V groove or U groove

14. What is the maximum distance that hard wire can be successfully pushed?
15 feet (4.5 meters)
Gives arc voltage values to the control system of the feeder
Constant current (CC)
To limit the short circuiting current so that spatter is reduced

15. What would be an indication that the drive roll pressure is adjusted correctly?
20 to 200 times per second
Aluminum wire
Wire feeds smoothly (yet will slip should a problem occur in the gun)
To prevent leakage - Carbon Dioxide (CO2)

16. A pull type drive system is usually used on what type of material?
Generally not as accurate
Voltage is the force that overcomes resistance to allow amperage flow
Minutes of elapsed time continually run (out of 10 minutes)
Aluminum wire

17. What does the term GMAW identify?
These terms are quite restrictive and often technically incorrect
The negative side of a welding unit
Gas metal arc welding
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

18. In the GMAW process what does amperage control?
Minutes of elapsed time continually run (out of 10 minutes)
Penetration and burn - off rate of the electrode
These terms are quite restrictive and often technically incorrect
15 feet (4.5 meters)

19. What is the effect of too much slope?
3
Penetration and burn - off rate of the electrode
85%
Insufficient current to melt the wire off cleanly

20. What current and polarity is generally used with GMAW?
Pressure vessels and the piping industry
DCEP (Direct Current Electrode Positive) Reverse Polarity
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
Minimum distortion due to low heat input

21. Draw a typical volt/amp curve that would be found with a power source designed for SMAW or GTAW
Pressure - The rate of flow of a shielding gas
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5.8 to 12.5 L/min
Constant voltage (CV)

22. Draw a typical volt amp curve for a machine that is designed for GMAW
To prevent leakage - Carbon Dioxide (CO2)
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Gives arc voltage values to the control system of the feeder
To prevent drawing of liquid CO2 (Carbon Dioxide)

23. What output on the welding machine is used to rate the duty cycle?
Minutes of elapsed time continually run (out of 10 minutes)
SMAW - GTAW
Higher 26 to 35 arc volts
Voltage is the force that overcomes resistance to allow amperage flow

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
Generally not as accurate
SMAW - GTAW
To prevent leakage - Carbon Dioxide (CO2)

25. What does inductance control?
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Wire feeds smoothly (yet will slip should a problem occur in the gun)
The time rate of response for the current rise and fall
V groove or U groove

26. Give a brief description of the GMAW process
Pressure vessels and the piping industry
AWS and CSA
Welding process that joins metals by heating them with an electric arc
Short- circuiting transfer - Globular transfer - Spray transfer

27. What is the disadvantage of the gauge preset type of regulator/flowmeter?
Insufficient current to melt the wire off cleanly
Generally not as accurate
Reducing the gas source pressure to a constant working pressure
Dry ice can form within the flow control openings and cause blockage of shielding gas

28. What is the reason glass 'tube' type flowmeters must have the tube mounted truly vertical?
Pressure vessels and the piping industry
85%
...
Aluminum wire

29. What is the key advantage of short circuiting transfer?
Minimum distortion due to low heat input
5.8 to 12.5 L/min
National Electrical Manufactures Association
Higher 26 to 35 arc volts

30. What is the purpose of the pick- up lead on a voltage sensing wire feeder?
Gives arc voltage values to the control system of the feeder
National Electrical Manufactures Association
Flux cored wires
Generally not as accurate

31. What is a typical flow rate of CO2 for short circuit transfer?
To prevent drawing of liquid CO2 (Carbon Dioxide)
Penetration and burn - off rate of the electrode
5.8 to 12.5 L/min
AWS and CSA

32. What is another term for electrode holders for GMAW?
National Electrical Manufactures Association
These terms are quite restrictive and often technically incorrect
12 to 22 arc volts
Guns

33. In the GMAW process what does voltage control?
Pressure - The rate of flow of a shielding gas
Constant- speed wire feeders and Voltage- sennsing wire feeders
Puddle fluidity
Insufficient current to melt the wire off cleanly

34. What processes are constant current (CC) power sources designed to be used with?
SMAW - GTAW
15 feet (4.5 meters)
To limit the short circuiting current so that spatter is reduced
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground

35. Why must CO2 cylinders be used in the vertical position?
National Electrical Manufactures Association
To prevent drawing of liquid CO2 (Carbon Dioxide)
Motor driven generators - Transformer rectifiers - and Inverter designs
Short- circuiting transfer - Globular transfer - Spray transfer

36. What is the required arc voltage used for short circuit transfer?
12 to 22 arc volts
15 feet (4.5 meters)
The resistace to electrical current flow increases with it. Causing the electrode to heat
Dry ice can form within the flow control openings and cause blockage of shielding gas

37. What does a flowmeter do and what does it measure?
The resistace to electrical current flow increases with it. Causing the electrode to heat
3
Generally not as accurate
Controls the rate of flow of a shielding gas to the gun nozzle

38. Give a description of 'pinch effect'
Flux cored wires
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
To prevent leakage - Carbon Dioxide (CO2)
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field

39. What happens when the electrode extension is increased?
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
These terms are quite restrictive and often technically incorrect
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

40. Regulators control_____________ flowmeters SHOW____________.
Pressure - The rate of flow of a shielding gas
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V groove or U groove
15 feet (4.5 meters)

41. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
Welding process that joins metals by heating them with an electric arc
1/4 inch to 1/2 inch
Speed of the feed motor and - starting / stopping electrode feed
Higher 26 to 35 arc volts

42. What does the wire feeder control?
Gas metal arc welding
Voltage is the force that overcomes resistance to allow amperage flow
The time rate of response for the current rise and fall
Speed of the feed motor and - starting / stopping electrode feed

43. What wire are knurled drive rolls most commonly used on?
Aluminum wire
The negative side of a welding unit
Flux cored wires
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system

44. What type of power source is used with a constant speed wire feeder?
1/4 inch to 1/2 inch
Constant voltage (CV)
Puddle fluidity
If you dont know this check your phone

45. List 3 wire drive systems and give a short description of each
...
To limit the short circuiting current so that spatter is reduced
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
Controls the rate of flow of a shielding gas to the gun nozzle

46. When using flat drive rolls with too much pressure on copper coated solid wires what problem could take place?
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Cause flaking - which can clog the liner and contact tube
1/4 inch to 1/2 inch

47. What 2 organizations designate specifications for GMAW wires?
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
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
AWS and CSA
Controls the rate of flow of a shielding gas to the gun nozzle

48. What controls amperage when using GMAW?
(DCEP) Direct Current Electrode Positive or Reverse polarity
The resistace to electrical current flow increases with it. Causing the electrode to heat
Wire feed speed
To prevent drawing of liquid CO2 (Carbon Dioxide)

49. How are GMAW guns rated?
AWS and CSA
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
The negative side of a welding unit
By there current carrying capacity

50. What type of power source is commonly used with a voltage sensing wire feeder?
Minimum distortion due to low heat input
...
Constant current (CC)
Wire feed speed - Voltage control