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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. List 3 wire drive systems and give a short description of each
Aluminum wire
3
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
1/4 inch to 1/2 inch

2. What output on the welding machine is used to rate the duty cycle?
Wire feed speed - Voltage control
Minutes of elapsed time continually run (out of 10 minutes)
AWS and CSA
By there current carrying capacity

3. What processes are constant current (CC) power sources designed to be used with?
SMAW - GTAW
Minimum distortion due to low heat input
Spatter problems and poor weld appearance
Wire feeds smoothly (yet will slip should a problem occur in the gun)

4. What type of power source is used with a constant speed wire feeder?
Constant voltage (CV)
Constant current (CC)
Wire feed speed
5.8 to 12.5 L/min

5. In the GMAW process what does voltage control?
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
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Puddle fluidity
Constant- speed wire feeders and Voltage- sennsing wire feeders

6. What would be an indication that the drive roll pressure is adjusted correctly?
If you dont know this check your phone
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Pressure vessels and the piping industry
Controls the rate of flow of a shielding gas to the gun nozzle

7. Why must CO2 cylinders be used in the vertical position?
5.8 to 12.5 L/min
Gives arc voltage values to the control system of the feeder
By there current carrying capacity
To prevent drawing of liquid CO2 (Carbon Dioxide)

8. What controls amperage when using GMAW?
The resistace to electrical current flow increases with it. Causing the electrode to heat
AWS and CSA
Wire feed speed
V groove or U groove

9. Draw a typical volt/amp curve that would be found with a power source designed for SMAW or GTAW
SMAW - GTAW
If you dont know this check your phone
Constant- speed wire feeders and Voltage- sennsing wire feeders
15 feet (4.5 meters)

10. What term is used to describe when the workpiece is hooked to the negative pole on the power source?
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
V groove or U groove
...
(DCEP) Direct Current Electrode Positive or Reverse polarity

11. What is the reason glass 'tube' type flowmeters must have the tube mounted truly vertical?
V groove or U groove
Gas metal arc welding
Flux cored wires
...

12. What does a flowmeter do and what does it measure?
Controls the rate of flow of a shielding gas to the gun nozzle
Pressure vessels and the piping industry
Voltage is the force that overcomes resistance to allow amperage flow
These terms are quite restrictive and often technically incorrect

13. Give a brief description of the GMAW process
Motor driven generators - Transformer rectifiers - and Inverter designs
These terms are quite restrictive and often technically incorrect
Higher 26 to 35 arc volts
Welding process that joins metals by heating them with an electric arc

14. Why is the term GMAW preferred over MIG or MAG?
20 to 200 times per second
1/4 inch to 1/2 inch
15 feet (4.5 meters)
These terms are quite restrictive and often technically incorrect

15. What is the main purpose of 'slope'?
To limit the short circuiting current so that spatter is reduced
Minimum distortion due to low heat input
Duty cycle
15 feet (4.5 meters)

16. What is the purpose of the shielding gas used in GMAW?
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Wire feed speed
Shielding the molten weld metal from atmospheric contamination
Guns

17. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
85%
15 feet (4.5 meters)
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Reducing the gas source pressure to a constant working pressure

18. Why is globular transfer generally avoided with GMAW?
Guns
Spatter problems and poor weld appearance
V groove or U groove
Duty cycle

19. When using flat drive rolls with too much pressure on copper coated solid wires what problem could take place?
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Cause flaking - which can clog the liner and contact tube
Wire feed speed
AWS and CSA

20. What is the maximum distance that hard wire can be successfully pushed?
Shielding the molten weld metal from atmospheric contamination
15 feet (4.5 meters)
...
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system

21. What 2 organizations designate specifications for GMAW wires?
AWS and CSA
To prevent leakage - Carbon Dioxide (CO2)
Puddle fluidity
If you dont know this check your phone

22. What is the key advantage of short circuiting transfer?
Gives arc voltage values to the control system of the feeder
Wire feed speed - Voltage control
Minimum distortion due to low heat input
Gas metal arc welding

23. Draw a typical volt amp curve for a machine that is designed for GMAW
Dry ice can form within the flow control openings and cause blockage of shielding gas
Insufficient current to melt the wire off cleanly
Flux cored wires
If you dont know this check your phone

24. List the three methods of metal transfer with GMAW
AWS and CSA
Short- circuiting transfer - Globular transfer - Spray transfer
Shielding the molten weld metal from atmospheric contamination
The time rate of response for the current rise and fall

25. What is the recommended electrode stick- out for .035 solid wire?
1/4 inch to 1/2 inch
When the filler wire is in direct contract with the base metal
Gas metal arc welding
Constant current (CC)

26. What power sources are used with the GMAW Process?
Pressure - The rate of flow of a shielding gas
Motor driven generators - Transformer rectifiers - and Inverter designs
Pressure vessels and the piping industry
1/4 inch to 1/2 inch

27. What is the purpose of a regulator and what does it indicate on its gauges?
Reducing the gas source pressure to a constant working pressure
85%
To limit the short circuiting current so that spatter is reduced
If you dont know this check your phone

28. What is another term for electrode holders for GMAW?
3
Guns
DCEP (Direct Current Electrode Positive) Reverse Polarity
Constant current (CC)

29. What are the 2 types of wire feeders available?
Gives arc voltage values to the control system of the feeder
Dry ice can form within the flow control openings and cause blockage of shielding gas
15 feet (4.5 meters)
Constant- speed wire feeders and Voltage- sennsing wire feeders

30. What is the purpose of the pick- up lead on a voltage sensing wire feeder?
Spatter problems and poor weld appearance
Reducing the gas source pressure to a constant working pressure
Constant current (CC)
Gives arc voltage values to the control system of the feeder

31. List 3 forms compressed gases may be supplied for welding
Speed of the feed motor and - starting / stopping electrode feed
The time rate of response for the current rise and fall
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Constant voltage (CV)

32. What does inductance control?
Wire feed speed
Voltage is the force that overcomes resistance to allow amperage flow
The time rate of response for the current rise and fall
Cause flaking - which can clog the liner and contact tube

33. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
If you dont know this check your phone
85%
Higher 26 to 35 arc volts
Aluminum wire

34. Why is a line heater required when using GMAW?
Constant current (CC)
AWS and CSA
Penetration and burn - off rate of the electrode
Dry ice can form within the flow control openings and cause blockage of shielding gas

35. List the factors that determine the mode of metal transfer
SMAW - GTAW
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
Higher 26 to 35 arc volts

36. With straight polarity where is 2/3 of the arc energy?
Minutes of elapsed time continually run (out of 10 minutes)
Reducing the gas source pressure to a constant working pressure
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
The negative side of a welding unit

37. When is the metal transferred with short circuit transfer?
When the filler wire is in direct contract with the base metal
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
The resistace to electrical current flow increases with it. Causing the electrode to heat

38. What is the disadvantage of the gauge preset type of regulator/flowmeter?
To limit the short circuiting current so that spatter is reduced
Gives arc voltage values to the control system of the feeder
Generally not as accurate
Minutes of elapsed time continually run (out of 10 minutes)

39. What is an advantage of pulsed arc transfer with GMAW?
1/4 inch to 1/2 inch
The Arc voltage
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

40. What happens when the electrode extension is increased?
1/4 inch to 1/2 inch
Pressure - The rate of flow of a shielding gas
AWS and CSA
The resistace to electrical current flow increases with it. Causing the electrode to heat

41. What 2 controls are found on a GMAW set- up?
Wire feed speed - Voltage control
These terms are quite restrictive and often technically incorrect
85%
To prevent drawing of liquid CO2 (Carbon Dioxide)

42. In the GMAW process what does amperage control?
85%
Penetration and burn - off rate of the electrode
Motor driven generators - Transformer rectifiers - and Inverter designs
Shielding the molten weld metal from atmospheric contamination

43. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
3
Constant- speed wire feeders and Voltage- sennsing wire feeders
If you dont know this check your phone
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system

44. Give a description of 'pinch effect'
Higher 26 to 35 arc volts
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Aluminum wire
Voltage is the force that overcomes resistance to allow amperage flow

45. What current and polarity is generally used with GMAW?
SMAW - GTAW
DCEP (Direct Current Electrode Positive) Reverse Polarity
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
To limit the short circuiting current so that spatter is reduced

46. What is a solenoid valve and what actuates it?
Penetration and burn - off rate of the electrode
By there current carrying capacity
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
The Arc voltage

47. What does the abbreviation NEMA stand for?
20 to 200 times per second
5.8 to 12.5 L/min
The time rate of response for the current rise and fall
National Electrical Manufactures Association

48. What wire are knurled drive rolls most commonly used on?
Penetration and burn - off rate of the electrode
Flux cored wires
These terms are quite restrictive and often technically incorrect
AWS and CSA

49. What is the required arc voltage used for short circuit transfer?
Constant current (CC)
V groove or U groove
12 to 22 arc volts
DCEP (Direct Current Electrode Positive) Reverse Polarity

50. List the basic equipment requirements for the GMAW process
(DCEP) Direct Current Electrode Positive or Reverse polarity
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Pressure - The rate of flow of a shielding gas
Spatter problems and poor weld appearance