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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 is the purpose of the shielding gas used in GMAW?
Constant voltage (CV)
Shielding the molten weld metal from atmospheric contamination
Reducing the gas source pressure to a constant working pressure
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

2. What effect does increasing and decreasing the inductance have on the weld?
...
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 voltage (CV)
The Arc voltage

3. List 3 forms compressed gases may be supplied for welding
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
85%
Gas metal arc welding

4. What is an advantage of pulsed arc transfer with GMAW?
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Wire feed speed - Voltage control
Pressure - The rate of flow of a shielding gas

5. Regulators control_____________ flowmeters SHOW____________.
Constant- speed wire feeders and Voltage- sennsing wire feeders
Pressure - The rate of flow of a shielding gas
Wire feed speed
Gas metal arc welding

6. Give a brief description of the GMAW process
Short- circuiting transfer - Globular transfer - Spray transfer
Gives arc voltage values to the control system of the feeder
Welding process that joins metals by heating them with an electric arc
Gas metal arc welding

7. A pull type drive system is usually used on what type of material?
The time rate of response for the current rise and fall
15 feet (4.5 meters)
Aluminum wire
Wire feed speed

8. List the factors that determine the mode of metal transfer
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Welding process that joins metals by heating them with an electric arc
Voltage is the force that overcomes resistance to allow amperage flow
(DCEP) Direct Current Electrode Positive or Reverse polarity

9. List 3 wire drive systems and give a short description of each
15 feet (4.5 meters)
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
Reducing the gas source pressure to a constant working pressure

10. What is the key advantage of short circuiting transfer?
Wire feed speed - Voltage control
Pressure - The rate of flow of a shielding gas
AWS and CSA
Minimum distortion due to low heat input

11. What output on the welding machine is used to rate the duty cycle?
SMAW - GTAW
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Minutes of elapsed time continually run (out of 10 minutes)
Pressure vessels and the piping industry

12. Why is the term GMAW preferred over MIG or MAG?
Gas metal arc welding
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
These terms are quite restrictive and often technically incorrect
Flux cored wires

13. Why is a line heater required when using GMAW?
Dry ice can form within the flow control openings and cause blockage of shielding gas
Pressure - The rate of flow of a shielding gas
Gas metal arc welding
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze

14. What would be an indication that the drive roll pressure is adjusted correctly?
SMAW - GTAW
These terms are quite restrictive and often technically incorrect
Aluminum wire
Wire feeds smoothly (yet will slip should a problem occur in the gun)

15. What is the disadvantage of the gauge preset type of regulator/flowmeter?
20 to 200 times per second
The resistace to electrical current flow increases with it. Causing the electrode to heat
15 feet (4.5 meters)
Generally not as accurate

16. What 2 organizations designate specifications for GMAW wires?
Minimum distortion due to low heat input
AWS and CSA
To prevent leakage - Carbon Dioxide (CO2)
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

17. With straight polarity where is 2/3 of the arc energy?
Pressure - The rate of flow of a shielding gas
Constant current (CC)
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

18. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
Pressure vessels and the piping industry
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
Higher 26 to 35 arc volts

19. What controls the wire speed on a voltage sensing wire feeder?
Controls the rate of flow of a shielding gas to the gun nozzle
Generally not as accurate
The Arc voltage
1/4 inch to 1/2 inch

20. What does inductance control?
The time rate of response for the current rise and fall
Constant current (CC)
SMAW - GTAW
By there current carrying capacity

21. What power sources are used with the GMAW Process?
Voltage is the force that overcomes resistance to allow amperage flow
Motor driven generators - Transformer rectifiers - and Inverter designs
85%
These terms are quite restrictive and often technically incorrect

22. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
When the filler wire is in direct contract with the base metal
SMAW - GTAW
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

23. When using flat drive rolls with too much pressure on copper coated solid wires what problem could take place?
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Cause flaking - which can clog the liner and contact tube
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze

24. List the basic equipment requirements for the GMAW process
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Dry ice can form within the flow control openings and cause blockage of shielding gas
Spatter problems and poor weld appearance
Puddle fluidity

25. What does a flowmeter do and what does it measure?
Gives arc voltage values to the control system of the feeder
Minutes of elapsed time continually run (out of 10 minutes)
Controls the rate of flow of a shielding gas to the gun nozzle
Wire feed speed - Voltage control

26. What wire are knurled drive rolls most commonly used on?
5.8 to 12.5 L/min
Minutes of elapsed time continually run (out of 10 minutes)
Flux cored wires
(DCEP) Direct Current Electrode Positive or Reverse polarity

27. Give a description of 'pinch effect'
Flux cored wires
Minimum distortion due to low heat input
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Reducing the gas source pressure to a constant working pressure

28. 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
Wire feed speed
The time rate of response for the current rise and fall
Speed of the feed motor and - starting / stopping electrode feed

29. In the GMAW process what does voltage control?
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Higher 26 to 35 arc volts
Gives arc voltage values to the control system of the feeder
Puddle fluidity

30. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
Insufficient current to melt the wire off cleanly
Aluminum wire
85%
Puddle fluidity

31. In the GMAW process what does amperage control?
SMAW - GTAW
Speed of the feed motor and - starting / stopping electrode feed
Dry ice can form within the flow control openings and cause blockage of shielding gas
Penetration and burn - off rate of the electrode

32. List the three methods of metal transfer with GMAW
The resistace to electrical current flow increases with it. Causing the electrode to heat
Constant current (CC)
...
Short- circuiting transfer - Globular transfer - Spray transfer

33. What controls amperage when using GMAW?
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Wire feed speed
If you dont know this check your phone
Pressure - The rate of flow of a shielding gas

34. How are GMAW guns rated?
If you dont know this check your phone
By there current carrying capacity
Short- circuiting transfer - Globular transfer - Spray transfer
Spatter problems and poor weld appearance

35. What happens when the electrode extension is increased?
Flux cored wires
The resistace to electrical current flow increases with it. Causing the electrode to heat
(DCEP) Direct Current Electrode Positive or Reverse polarity
Penetration and burn - off rate of the electrode

36. List several industries that would use GMAW
Speed of the feed motor and - starting / stopping electrode feed
Motor driven generators - Transformer rectifiers - and Inverter designs
Pressure vessels and the piping industry
National Electrical Manufactures Association

37. When is the metal transferred with short circuit transfer?
Motor driven generators - Transformer rectifiers - and Inverter designs
When the filler wire is in direct contract with the base metal
Spatter problems and poor weld appearance
Cause flaking - which can clog the liner and contact tube

38. What is the required arc voltage used for short circuit transfer?
Wire feed speed
12 to 22 arc volts
Constant current (CC)
...

39. What does the wire feeder control?
To prevent drawing of liquid CO2 (Carbon Dioxide)
3
Speed of the feed motor and - starting / stopping electrode feed
Constant voltage (CV)

40. What does the term GMAW identify?
Gas metal arc welding
Penetration and burn - off rate of the electrode
To limit the short circuiting current so that spatter is reduced
Spatter problems and poor weld appearance

41. What does the abbreviation NEMA stand for?
Voltage is the force that overcomes resistance to allow amperage flow
5.8 to 12.5 L/min
V groove or U groove
National Electrical Manufactures Association

42. What are the 2 types of wire feeders available?
Constant- speed wire feeders and Voltage- sennsing wire feeders
5.8 to 12.5 L/min
Speed of the feed motor and - starting / stopping electrode feed
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system

43. What type of power source is commonly used with a voltage sensing wire feeder?
Constant current (CC)
Controls the rate of flow of a shielding gas to the gun nozzle
If you dont know this check your phone
Constant voltage (CV)

44. What is the recommended electrode stick- out for .035 solid wire?
1/4 inch to 1/2 inch
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
3
Gas metal arc welding

45. What is a typical flow rate of CO2 for short circuit transfer?
5.8 to 12.5 L/min
Pressure - The rate of flow of a shielding gas
85%
To prevent drawing of liquid CO2 (Carbon Dioxide)

46. Draw a typical volt amp curve for a machine that is designed for GMAW
Short- circuiting transfer - Globular transfer - Spray transfer
Wire feeds smoothly (yet will slip should a problem occur in the gun)
The negative side of a welding unit
If you dont know this check your phone

47. What current and polarity is generally used with GMAW?
DCEP (Direct Current Electrode Positive) Reverse Polarity
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
The Arc voltage
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

48. What is the reason glass 'tube' type flowmeters must have the tube mounted truly vertical?
Wire feed speed
By there current carrying capacity
Constant voltage (CV)
...

49. What type of power source is used with a constant speed wire feeder?
Flux cored wires
DCEP (Direct Current Electrode Positive) Reverse Polarity
Short- circuiting transfer - Globular transfer - Spray transfer
Constant voltage (CV)

50. What is the maximum distance that hard wire can be successfully pushed?
15 feet (4.5 meters)
The resistace to electrical current flow increases with it. Causing the electrode to heat
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
The Arc voltage