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Gas Metal Arc Welding

Instructions:

Answer 50 questions in 15 minutes.
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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. Regulators control_____________ flowmeters SHOW____________.
15 feet (4.5 meters)
SMAW - GTAW
Pressure - The rate of flow of a shielding gas
Wire feed speed

2. What are the 2 types of wire feeders available?
Dry ice can form within the flow control openings and cause blockage of shielding gas
Pressure - The rate of flow of a shielding gas
Constant- speed wire feeders and Voltage- sennsing wire feeders
Minimum distortion due to low heat input

3. Give a brief description of the GMAW process
5.8 to 12.5 L/min
Minimum distortion due to low heat input
Welding process that joins metals by heating them with an electric arc
Wire feeds smoothly (yet will slip should a problem occur in the gun)

4. What is the maximum distance that hard wire can be successfully pushed?
15 feet (4.5 meters)
Cause flaking - which can clog the liner and contact tube
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
1/4 inch to 1/2 inch

5. Why must CO2 cylinders be used in the vertical position?
To prevent drawing of liquid CO2 (Carbon Dioxide)
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Pressure vessels and the piping industry
DCEP (Direct Current Electrode Positive) Reverse Polarity

6. What is the disadvantage of the gauge preset type of regulator/flowmeter?
Minutes of elapsed time continually run (out of 10 minutes)
DCEP (Direct Current Electrode Positive) Reverse Polarity
Constant current (CC)
Generally not as accurate

7. What controls amperage when using GMAW?
Wire feed speed
Short- circuiting transfer - Globular transfer - Spray transfer
Cause flaking - which can clog the liner and contact tube
Minutes of elapsed time continually run (out of 10 minutes)

8. Draw a typical volt/amp curve that would be found with a power source designed for SMAW or GTAW
Duty cycle
If you dont know this check your phone
Aluminum wire
National Electrical Manufactures Association

9. 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)
Pressure - The rate of flow of a shielding gas
Constant voltage (CV)
3

10. In the GMAW process what does amperage control?
Constant voltage (CV)
Penetration and burn - off rate of the electrode
Minimum distortion due to low heat input
By there current carrying capacity

11. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
Pressure vessels and the piping industry
85%
Duty cycle
3

12. What effect does increasing and decreasing the inductance have on the weld?
Penetration and burn - off rate of the electrode
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)
To prevent leakage - Carbon Dioxide (CO2)

13. List 3 forms compressed gases may be supplied for welding
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Aluminum wire
Shielding the molten weld metal from atmospheric contamination
Reducing the gas source pressure to a constant working pressure

14. What 2 controls are found on a GMAW set- up?
Wire feed speed - Voltage control
3
Higher 26 to 35 arc volts
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground

15. What is the effect of too much slope?
When the filler wire is in direct contract with the base metal
To limit the short circuiting current so that spatter is reduced
Speed of the feed motor and - starting / stopping electrode feed
Insufficient current to melt the wire off cleanly

16. What output on the welding machine is used to rate the duty cycle?
Minutes of elapsed time continually run (out of 10 minutes)
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
If you dont know this check your phone
1/4 inch to 1/2 inch

17. With straight polarity where is 2/3 of the arc energy?
Wire feed speed
The negative side of a welding unit
Gas metal arc welding
V groove or U groove

18. What is the key advantage of short circuiting transfer?
Constant voltage (CV)
Short- circuiting transfer - Globular transfer - Spray transfer
Minimum distortion due to low heat input
Speed of the feed motor and - starting / stopping electrode feed

19. What is the reason glass 'tube' type flowmeters must have the tube mounted truly vertical?
Pressure - The rate of flow of a shielding gas
...
Wire feed speed - Voltage control
When the filler wire is in direct contract with the base metal

20. In the GMAW process what does voltage control?
Guns
Constant- speed wire feeders and Voltage- sennsing wire feeders
Puddle fluidity
The Arc voltage

21. What power sources are used with the GMAW Process?
12 to 22 arc volts
Controls the rate of flow of a shielding gas to the gun nozzle
Motor driven generators - Transformer rectifiers - and Inverter designs
Constant- speed wire feeders and Voltage- sennsing wire feeders

22. What controls the wire speed on a voltage sensing wire feeder?
The Arc voltage
Controls the rate of flow of a shielding gas to the gun nozzle
If you dont know this check your phone
...

23. What is the main purpose of 'slope'?
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Motor driven generators - Transformer rectifiers - and Inverter designs
To prevent drawing of liquid CO2 (Carbon Dioxide)
To limit the short circuiting current so that spatter is reduced

24. What does the term GMAW identify?
Gas metal arc welding
3
Constant voltage (CV)
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun

25. List the three methods of metal transfer with GMAW
Short- circuiting transfer - Globular transfer - Spray transfer
Welding process that joins metals by heating them with an electric arc
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
1/4 inch to 1/2 inch

26. What does the abbreviation NEMA stand for?
National Electrical Manufactures Association
By there current carrying capacity
(DCEP) Direct Current Electrode Positive or Reverse polarity
Constant voltage (CV)

27. Why is the term GMAW preferred over MIG or MAG?
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
These terms are quite restrictive and often technically incorrect
Gives arc voltage values to the control system of the feeder
85%

28. How many times per second does short circuiting take place?
20 to 200 times per second
1/4 inch to 1/2 inch
5.8 to 12.5 L/min
Speed of the feed motor and - starting / stopping electrode feed

29. What does voltage do in an electrical circuit?
Voltage is the force that overcomes resistance to allow amperage flow
Dry ice can form within the flow control openings and cause blockage of shielding gas
DCEP (Direct Current Electrode Positive) Reverse Polarity
(DCEP) Direct Current Electrode Positive or Reverse polarity

30. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Higher 26 to 35 arc volts
Dry ice can form within the flow control openings and cause blockage of shielding gas
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system

31. 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
(DCEP) Direct Current Electrode Positive or Reverse polarity
Cause flaking - which can clog the liner and contact tube
20 to 200 times per second

32. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
Higher 26 to 35 arc volts
1/4 inch to 1/2 inch
...
3

33. List the basic equipment requirements for the GMAW process
Controls the rate of flow of a shielding gas to the gun nozzle
85%
Constant current (CC)
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground

34. What 2 organizations designate specifications for GMAW wires?
Motor driven generators - Transformer rectifiers - and Inverter designs
By there current carrying capacity
To prevent leakage - Carbon Dioxide (CO2)
AWS and CSA

35. A pull type drive system is usually used on what type of material?
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
SMAW - GTAW
Aluminum wire
1/4 inch to 1/2 inch

36. What processes are constant current (CC) power sources designed to be used with?
The resistace to electrical current flow increases with it. Causing the electrode to heat
Voltage is the force that overcomes resistance to allow amperage flow
Speed of the feed motor and - starting / stopping electrode feed
SMAW - GTAW

37. How are GMAW guns rated?
3
V groove or U groove
By there current carrying capacity
AWS and CSA

38. Why is a line heater required when using GMAW?
Constant- speed wire feeders and Voltage- sennsing wire feeders
Spatter problems and poor weld appearance
To prevent leakage - Carbon Dioxide (CO2)
Dry ice can form within the flow control openings and cause blockage of shielding gas

39. What is the purpose of the pick- up lead on a voltage sensing wire feeder?
To prevent drawing of liquid CO2 (Carbon Dioxide)
Gives arc voltage values to the control system of the feeder
Constant current (CC)
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

40. When is the metal transferred with short circuit transfer?
1/4 inch to 1/2 inch
Short- circuiting transfer - Globular transfer - Spray transfer
When the filler wire is in direct contract with the base metal
3

41. What is another term for electrode holders for GMAW?
V groove or U groove
Guns
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Gives arc voltage values to the control system of the feeder

42. What is the purpose of a regulator and what does it indicate on its gauges?
The resistace to electrical current flow increases with it. Causing the electrode to heat
Reducing the gas source pressure to a constant working pressure
Higher 26 to 35 arc volts
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system

43. What term is used to describe when the workpiece is hooked to the negative pole on the power source?
To prevent drawing of liquid CO2 (Carbon Dioxide)
(DCEP) Direct Current Electrode Positive or Reverse polarity
Motor driven generators - Transformer rectifiers - and Inverter designs
Minutes of elapsed time continually run (out of 10 minutes)

44. What current and polarity is generally used with GMAW?
DCEP (Direct Current Electrode Positive) Reverse Polarity
Wire feed speed - Voltage control
5.8 to 12.5 L/min
Speed of the feed motor and - starting / stopping electrode feed

45. A 10 minute cycle of welding time vs cooling time a given machine can handle.
Duty cycle
Guns
Higher 26 to 35 arc volts
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

46. What is an advantage of pulsed arc transfer with GMAW?
Gas metal arc welding
These terms are quite restrictive and often technically incorrect
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

47. List several industries that would use GMAW
15 feet (4.5 meters)
Pressure vessels and the piping industry
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
Short- circuiting transfer - Globular transfer - Spray transfer

48. Why is globular transfer generally avoided with GMAW?
Spatter problems and poor weld appearance
Constant current (CC)
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
The negative side of a welding unit

49. What is the preferred drive roll design for solid wires?
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
AWS and CSA
V groove or U groove
Gives arc voltage values to the control system of the feeder

50. What is a solenoid valve and what actuates it?
To prevent drawing of liquid CO2 (Carbon Dioxide)
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
SMAW - GTAW
1/4 inch to 1/2 inch