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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 main purpose of 'slope'?
Wire feed speed - Voltage control
Generally not as accurate
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
To limit the short circuiting current so that spatter is reduced

2. Why is globular transfer generally avoided with GMAW?
When the filler wire is in direct contract with the base metal
The resistace to electrical current flow increases with it. Causing the electrode to heat
Spatter problems and poor weld appearance
Flux cored wires

3. When is the metal transferred with short circuit transfer?
Dry ice can form within the flow control openings and cause blockage of shielding gas
When the filler wire is in direct contract with the base metal
Spatter problems and poor weld appearance
Higher 26 to 35 arc volts

4. What does the wire feeder control?
Wire feed speed - Voltage control
Speed of the feed motor and - starting / stopping electrode feed
When the filler wire is in direct contract with the base metal
By there current carrying capacity

5. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
If you dont know this check your phone
Spatter problems and poor weld appearance
The resistace to electrical current flow increases with it. Causing the electrode to heat
3

6. Why must CO2 cylinders be used in the vertical position?
To prevent drawing of liquid CO2 (Carbon Dioxide)
15 feet (4.5 meters)
Reducing the gas source pressure to a constant working pressure
(DCEP) Direct Current Electrode Positive or Reverse polarity

7. What does a flowmeter do and what does it measure?
Controls the rate of flow of a shielding gas to the gun nozzle
(DCEP) Direct Current Electrode Positive or Reverse polarity
Duty cycle
20 to 200 times per second

8. Why is the term GMAW preferred over MIG or MAG?
Reducing the gas source pressure to a constant working pressure
(DCEP) Direct Current Electrode Positive or Reverse polarity
Dry ice can form within the flow control openings and cause blockage of shielding gas
These terms are quite restrictive and often technically incorrect

9. 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
Shielding the molten weld metal from atmospheric contamination
85%
12 to 22 arc volts

10. What is the effect of too much slope?
Short- circuiting transfer - Globular transfer - Spray transfer
Constant voltage (CV)
...
Insufficient current to melt the wire off cleanly

11. What wire are knurled drive rolls most commonly used on?
Gives arc voltage values to the control system of the feeder
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
The resistace to electrical current flow increases with it. Causing the electrode to heat

12. What does voltage do in an electrical circuit?
Voltage is the force that overcomes resistance to allow amperage flow
1/4 inch to 1/2 inch
Aluminum wire
Controls the rate of flow of a shielding gas to the gun nozzle

13. What is a typical flow rate of CO2 for short circuit transfer?
12 to 22 arc volts
If you dont know this check your phone
Duty cycle
5.8 to 12.5 L/min

14. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
Controls the rate of flow of a shielding gas to the gun nozzle
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Higher 26 to 35 arc volts
Voltage is the force that overcomes resistance to allow amperage flow

15. List the three methods of metal transfer with GMAW
Generally not as accurate
The Arc voltage
Short- circuiting transfer - Globular transfer - Spray transfer
These terms are quite restrictive and often technically incorrect

16. What type of power source is commonly used with a voltage sensing wire feeder?
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Insufficient current to melt the wire off cleanly
Constant current (CC)

17. What is the reason glass 'tube' type flowmeters must have the tube mounted truly vertical?
By there current carrying capacity
Flux cored wires
Short- circuiting transfer - Globular transfer - Spray transfer
...

18. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
Wire feed speed
To limit the short circuiting current so that spatter is reduced
15 feet (4.5 meters)
85%

19. What is an advantage of pulsed arc transfer with GMAW?
Pressure vessels and the piping industry
National Electrical Manufactures Association
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
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze

20. What is the preferred drive roll design for solid wires?
Dry ice can form within the flow control openings and cause blockage of shielding gas
V groove or U groove
Pressure - The rate of flow of a shielding gas
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun

21. What are the 2 types of wire feeders available?
85%
Minimum distortion due to low heat input
Constant- speed wire feeders and Voltage- sennsing wire feeders
Puddle fluidity

22. Give a brief description of the GMAW process
Welding process that joins metals by heating them with an electric arc
Gas metal arc welding
By there current carrying capacity
V groove or U groove

23. What is the recommended electrode stick- out for .035 solid wire?
3
Pressure vessels and the piping industry
Constant current (CC)
1/4 inch to 1/2 inch

24. What output on the welding machine is used to rate the duty cycle?
Speed of the feed motor and - starting / stopping electrode feed
To prevent leakage - Carbon Dioxide (CO2)
12 to 22 arc volts
Minutes of elapsed time continually run (out of 10 minutes)

25. How many times per second does short circuiting take place?
20 to 200 times per second
Duty cycle
V groove or U groove
Aluminum wire

26. 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
Minutes of elapsed time continually run (out of 10 minutes)
If you dont know this check your phone
Constant- speed wire feeders and Voltage- sennsing wire feeders

27. What is the purpose of the shielding gas used in GMAW?
1/4 inch to 1/2 inch
Shielding the molten weld metal from atmospheric contamination
5.8 to 12.5 L/min
Aluminum wire

28. List 3 forms compressed gases may be supplied for welding
Spatter problems and poor weld appearance
National Electrical Manufactures Association
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Cause flaking - which can clog the liner and contact tube

29. Why is a fiber washer required and what cylinder gas requires it?
These terms are quite restrictive and often technically incorrect
Pressure vessels and the piping industry
(DCEP) Direct Current Electrode Positive or Reverse polarity
To prevent leakage - Carbon Dioxide (CO2)

30. What is the purpose of a regulator and what does it indicate on its gauges?
Gas metal arc welding
National Electrical Manufactures Association
Insufficient current to melt the wire off cleanly
Reducing the gas source pressure to a constant working pressure

31. List the basic equipment requirements for the GMAW process
Minimum distortion due to low heat input
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Gas metal arc welding
Wire feed speed - Voltage control

32. 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
Minutes of elapsed time continually run (out of 10 minutes)
The time rate of response for the current rise and fall
Puddle fluidity

33. Regulators control_____________ flowmeters SHOW____________.
Pressure - The rate of flow of a shielding gas
Reducing the gas source pressure to a constant working pressure
V groove or U groove
Short- circuiting transfer - Globular transfer - Spray transfer

34. In the GMAW process what does voltage control?
Puddle fluidity
Speed of the feed motor and - starting / stopping electrode feed
Pressure vessels and the piping industry
The negative side of a welding unit

35. What processes are constant current (CC) power sources designed to be used with?
Minutes of elapsed time continually run (out of 10 minutes)
Short- circuiting transfer - Globular transfer - Spray transfer
85%
SMAW - GTAW

36. Draw a typical volt/amp curve that would be found with a power source designed for SMAW or GTAW
If you dont know this check your phone
Minimum distortion due to low heat input
To limit the short circuiting current so that spatter is reduced
The resistace to electrical current flow increases with it. Causing the electrode to heat

37. What 2 controls are found on a GMAW set- up?
Wire feed speed - Voltage control
To limit the short circuiting current so that spatter is reduced
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Voltage is the force that overcomes resistance to allow amperage flow

38. What happens when the electrode extension is increased?
If you dont know this check your phone
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Wire feed speed - Voltage control
The resistace to electrical current flow increases with it. Causing the electrode to heat

39. What is another term for electrode holders for GMAW?
Pressure - The rate of flow of a shielding gas
Guns
Controls the rate of flow of a shielding gas to the gun nozzle
The negative side of a welding unit

40. List 3 wire drive systems and give a short description of each
Generally not as accurate
Puddle fluidity
85%
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

41. What controls amperage when using GMAW?
Wire feed speed
Speed of the feed motor and - starting / stopping electrode feed
12 to 22 arc volts
The negative side of a welding unit

42. What is the required arc voltage used for short circuit transfer?
12 to 22 arc volts
Shielding the molten weld metal from atmospheric contamination
To prevent leakage - Carbon Dioxide (CO2)
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system

43. What 2 organizations designate specifications for GMAW wires?
Gives arc voltage values to the control system of the feeder
Spatter problems and poor weld appearance
AWS and CSA
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun

44. What controls the wire speed on a voltage sensing wire feeder?
The Arc voltage
Constant voltage (CV)
Generally not as accurate
Motor driven generators - Transformer rectifiers - and Inverter designs

45. What is the key advantage of short circuiting transfer?
Minimum distortion due to low heat input
The negative side of a welding unit
3
Spatter problems and poor weld appearance

46. A 10 minute cycle of welding time vs cooling time a given machine can handle.
Minimum distortion due to low heat input
Duty cycle
Cause flaking - which can clog the liner and contact tube
(DCEP) Direct Current Electrode Positive or Reverse polarity

47. Give a description of 'pinch effect'
Motor driven generators - Transformer rectifiers - and Inverter designs
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Wire feed speed - Voltage control
AWS and CSA

48. What does the abbreviation NEMA stand for?
If you dont know this check your phone
National Electrical Manufactures Association
Constant voltage (CV)
The resistace to electrical current flow increases with it. Causing the electrode to heat

49. What does the term GMAW identify?
...
To prevent leakage - Carbon Dioxide (CO2)
Gas metal arc welding
Constant- speed wire feeders and Voltage- sennsing wire feeders

50. What is the disadvantage of the gauge preset type of regulator/flowmeter?
Generally not as accurate
Insufficient current to melt the wire off cleanly
Pressure - The rate of flow of a shielding gas
To prevent drawing of liquid CO2 (Carbon Dioxide)