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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 output on the welding machine is used to rate the duty cycle?
5.8 to 12.5 L/min
Minutes of elapsed time continually run (out of 10 minutes)
V groove or U groove
These terms are quite restrictive and often technically incorrect

2. Regulators control_____________ flowmeters SHOW____________.
To prevent leakage - Carbon Dioxide (CO2)
Pressure - The rate of flow of a shielding gas
...
National Electrical Manufactures Association

3. When is the metal transferred with short circuit transfer?
Controls the rate of flow of a shielding gas to the gun nozzle
Spatter problems and poor weld appearance
National Electrical Manufactures Association
When the filler wire is in direct contract with the base metal

4. What is the purpose of the pick- up lead on a voltage sensing wire feeder?
Constant current (CC)
Gives arc voltage values to the control system of the feeder
Minimum distortion due to low heat input
By there current carrying capacity

5. What is another term for electrode holders for GMAW?
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Wire feed speed
Penetration and burn - off rate of the electrode
Guns

6. What is the maximum distance that hard wire can be successfully pushed?
15 feet (4.5 meters)
Shielding the molten weld metal from atmospheric contamination
Speed of the feed motor and - starting / stopping electrode feed
Wire feed speed

7. What does the wire feeder control?
85%
Constant- speed wire feeders and Voltage- sennsing wire feeders
Speed of the feed motor and - starting / stopping electrode feed
The resistace to electrical current flow increases with it. Causing the electrode to heat

8. List the factors that determine the mode of metal transfer
The Arc voltage
By there current carrying capacity
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Puddle fluidity

9. What 2 controls are found on a GMAW set- up?
Dry ice can form within the flow control openings and cause blockage of shielding gas
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
85%
Wire feed speed - Voltage control

10. List several industries that would use GMAW
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Pressure vessels and the piping industry
Generally not as accurate
Gas metal arc welding

11. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
85%
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Constant- speed wire feeders and Voltage- sennsing wire feeders
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts

12. What happens when the electrode extension is increased?
12 to 22 arc volts
The resistace to electrical current flow increases with it. Causing the electrode to heat
Generally not as accurate
Welding process that joins metals by heating them with an electric arc

13. What 2 organizations designate specifications for GMAW wires?
AWS and CSA
Controls the rate of flow of a shielding gas to the gun nozzle
Shielding the molten weld metal from atmospheric contamination
V groove or U groove

14. List 3 forms compressed gases may be supplied for welding
Constant voltage (CV)
Motor driven generators - Transformer rectifiers - and Inverter designs
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
To prevent drawing of liquid CO2 (Carbon Dioxide)

15. What is the key advantage of short circuiting transfer?
Minimum distortion due to low heat input
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
If you dont know this check your phone
The negative side of a welding unit

16. In the GMAW process what does voltage control?
Puddle fluidity
Shielding the molten weld metal from atmospheric contamination
Insufficient current to melt the wire off cleanly
12 to 22 arc volts

17. What type of power source is commonly used with a voltage sensing wire feeder?
Constant current (CC)
Gas metal arc welding
Motor driven generators - Transformer rectifiers - and Inverter designs
If you dont know this check your phone

18. What controls amperage when using GMAW?
Flux cored wires
Higher 26 to 35 arc volts
Wire feed speed
(DCEP) Direct Current Electrode Positive or Reverse polarity

19. What processes are constant current (CC) power sources designed to be used with?
Flux cored wires
SMAW - GTAW
Speed of the feed motor and - starting / stopping electrode feed
To prevent leakage - Carbon Dioxide (CO2)

20. A 10 minute cycle of welding time vs cooling time a given machine can handle.
Guns
Duty cycle
Penetration and burn - off rate of the electrode
DCEP (Direct Current Electrode Positive) Reverse Polarity

21. What is an advantage of pulsed arc transfer with GMAW?
When the filler wire is in direct contract with the base metal
Duty cycle
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

22. Draw a typical volt/amp curve that would be found with a power source designed for SMAW or GTAW
Minutes of elapsed time continually run (out of 10 minutes)
Puddle fluidity
...
If you dont know this check your phone

23. What controls the wire speed on a voltage sensing wire feeder?
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Constant voltage (CV)
The Arc voltage
5.8 to 12.5 L/min

24. What would be an indication that the drive roll pressure is adjusted correctly?
(DCEP) Direct Current Electrode Positive or Reverse polarity
15 feet (4.5 meters)
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Constant current (CC)

25. A pull type drive system is usually used on what type of material?
Pressure - The rate of flow of a shielding gas
5.8 to 12.5 L/min
Aluminum wire
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

26. What is the purpose of the shielding gas used in GMAW?
V groove or U groove
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Gives arc voltage values to the control system of the feeder
Shielding the molten weld metal from atmospheric contamination

27. Give a brief description of the GMAW process
20 to 200 times per second
Voltage is the force that overcomes resistance to allow amperage flow
Welding process that joins metals by heating them with an electric arc
The time rate of response for the current rise and fall

28. List 3 wire drive systems and give a short description of each
Wire feed speed - 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
Constant- speed wire feeders and Voltage- sennsing wire feeders
5.8 to 12.5 L/min

29. What does the term GMAW identify?
5.8 to 12.5 L/min
Cause flaking - which can clog the liner and contact tube
Gas metal arc welding
Minimum distortion due to low heat input

30. Why is a line heater required when using GMAW?
Dry ice can form within the flow control openings and cause blockage of shielding gas
Spatter problems and poor weld appearance
Constant voltage (CV)
Speed of the feed motor and - starting / stopping electrode feed

31. In the GMAW process what does amperage control?
The Arc voltage
Gas metal arc welding
When the filler wire is in direct contract with the base metal
Penetration and burn - off rate of the electrode

32. What is a typical flow rate of CO2 for short circuit transfer?
Shielding the molten weld metal from atmospheric contamination
Wire feed speed
Flux cored wires
5.8 to 12.5 L/min

33. How are GMAW guns rated?
By there current carrying capacity
Aluminum wire
V groove or U groove
Dry ice can form within the flow control openings and cause blockage of shielding gas

34. Give a description of 'pinch effect'
If you dont know this check your phone
12 to 22 arc volts
Pressure vessels and the piping industry
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field

35. What wire are knurled drive rolls most commonly used on?
Spatter problems and poor weld appearance
Flux cored wires
85%
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

36. What is the recommended electrode stick- out for .035 solid wire?
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
20 to 200 times per second
The negative side of a welding unit
1/4 inch to 1/2 inch

37. What is the disadvantage of the gauge preset type of regulator/flowmeter?
Duty cycle
Generally not as accurate
Pressure vessels and the piping industry
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

38. What power sources are used with the GMAW Process?
Guns
Constant- speed wire feeders and Voltage- sennsing wire feeders
Motor driven generators - Transformer rectifiers - and Inverter designs
Shielding the molten weld metal from atmospheric contamination

39. What is the reason glass 'tube' type flowmeters must have the tube mounted truly vertical?
If you dont know this check your phone
Motor driven generators - Transformer rectifiers - and Inverter designs
Short- circuiting transfer - Globular transfer - Spray transfer
...

40. What does a flowmeter do and what does it measure?
Controls the rate of flow of a shielding gas to the gun nozzle
Minutes of elapsed time continually run (out of 10 minutes)
National Electrical Manufactures Association
Pressure vessels and the piping industry

41. What does voltage do in an electrical circuit?
Voltage is the force that overcomes resistance to allow amperage flow
SMAW - GTAW
Motor driven generators - Transformer rectifiers - and Inverter designs
V groove or U groove

42. What is the preferred drive roll design for solid wires?
Duty cycle
Speed of the feed motor and - starting / stopping electrode feed
Spatter problems and poor weld appearance
V groove or U groove

43. Why is the term GMAW preferred over MIG or MAG?
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Constant current (CC)
12 to 22 arc volts
These terms are quite restrictive and often technically incorrect

44. What type of power source is used with a constant speed wire feeder?
To prevent leakage - Carbon Dioxide (CO2)
20 to 200 times per second
Higher 26 to 35 arc volts
Constant voltage (CV)

45. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
3
Gives arc voltage values to the control system of the feeder
Flux cored wires
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun

46. Why must CO2 cylinders be used in the vertical position?
Higher 26 to 35 arc volts
Pressure vessels and the piping industry
Welding process that joins metals by heating them with an electric arc
To prevent drawing of liquid CO2 (Carbon Dioxide)

47. When using flat drive rolls with too much pressure on copper coated solid wires what problem could take place?
...
The negative side of a welding unit
Cause flaking - which can clog the liner and contact tube
Wire feeds smoothly (yet will slip should a problem occur in the gun)

48. What is the purpose of a regulator and what does it indicate on its gauges?
15 feet (4.5 meters)
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
Wire feed speed - Voltage control

49. What term is used to describe when the workpiece is hooked to the negative pole on the power source?
These terms are quite restrictive and often technically incorrect
(DCEP) Direct Current Electrode Positive or Reverse polarity
Minimum distortion due to low heat input
Wire feed speed

50. What does the abbreviation NEMA stand for?
Aluminum wire
By there current carrying capacity
National Electrical Manufactures Association
Motor driven generators - Transformer rectifiers - and Inverter designs