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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. How are GMAW guns rated?
Pressure - The rate of flow of a shielding gas
Spatter problems and poor weld appearance
By there current carrying capacity
3

2. What does the abbreviation NEMA stand for?
5.8 to 12.5 L/min
Pressure vessels and the piping industry
To prevent drawing of liquid CO2 (Carbon Dioxide)
National Electrical Manufactures Association

3. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
These terms are quite restrictive and often technically incorrect
...
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
85%

4. What does a flowmeter do and what does it measure?
Minimum distortion due to low heat input
Reducing the gas source pressure to a constant working pressure
Controls the rate of flow of a shielding gas to the gun nozzle
National Electrical Manufactures Association

5. With straight polarity where is 2/3 of the arc energy?
Constant current (CC)
The negative side of a welding unit
Speed of the feed motor and - starting / stopping electrode feed
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

6. What 2 organizations designate specifications for GMAW wires?
National Electrical Manufactures Association
Constant- speed wire feeders and Voltage- sennsing wire feeders
Welding process that joins metals by heating them with an electric arc
AWS and CSA

7. What is the preferred drive roll design for solid wires?
V groove or U groove
Duty cycle
Puddle fluidity
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground

8. What is the key advantage of short circuiting transfer?
Minimum distortion due to low heat input
Penetration and burn - off rate of the electrode
Constant voltage (CV)
Cause flaking - which can clog the liner and contact tube

9. What is the purpose of the pick- up lead on a voltage sensing wire feeder?
Generally not as accurate
Gives arc voltage values to the control system of the feeder
Spatter problems and poor weld appearance
Motor driven generators - Transformer rectifiers - and Inverter designs

10. What is the recommended electrode stick- out for .035 solid wire?
Pressure - The rate of flow of a shielding gas
1/4 inch to 1/2 inch
To limit the short circuiting current so that spatter is reduced
Constant- speed wire feeders and Voltage- sennsing wire feeders

11. What processes are constant current (CC) power sources designed to be used with?
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Speed of the feed motor and - starting / stopping electrode feed
SMAW - GTAW
Higher 26 to 35 arc volts

12. What output on the welding machine is used to rate the duty cycle?
Gives arc voltage values to the control system of the feeder
Minutes of elapsed time continually run (out of 10 minutes)
Generally not as accurate
Reducing the gas source pressure to a constant working pressure

13. What effect does increasing and decreasing the inductance have on the weld?
3
Penetration and burn - off rate of the electrode
Constant current (CC)
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts

14. List 3 wire drive systems and give a short description of each
Motor driven generators - Transformer rectifiers - and Inverter designs
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
5.8 to 12.5 L/min
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

15. What term is used to describe when the workpiece is hooked to the negative pole on the power source?
Cause flaking - which can clog the liner and contact tube
15 feet (4.5 meters)
Reducing the gas source pressure to a constant working pressure
(DCEP) Direct Current Electrode Positive or Reverse polarity

16. List several industries that would use GMAW
Pressure vessels and the piping industry
Spatter problems and poor weld appearance
Insufficient current to melt the wire off cleanly
Constant- speed wire feeders and Voltage- sennsing wire feeders

17. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
Minimum distortion due to low heat input
Constant current (CC)
3
Constant- speed wire feeders and Voltage- sennsing wire feeders

18. 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
When the filler wire is in direct contract with the base metal
The Arc voltage
Shielding the molten weld metal from atmospheric contamination

19. List the basic equipment requirements for the GMAW process
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
If you dont know this check your phone
Duty cycle
V groove or U groove

20. Why must CO2 cylinders be used in the vertical position?
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
To prevent drawing of liquid CO2 (Carbon Dioxide)
National Electrical Manufactures Association

21. What is the purpose of the shielding gas used in GMAW?
Dry ice can form within the flow control openings and cause blockage of shielding gas
...
Shielding the molten weld metal from atmospheric contamination
15 feet (4.5 meters)

22. What type of power source is used with a constant speed wire feeder?
Constant current (CC)
If you dont know this check your phone
Constant voltage (CV)
Penetration and burn - off rate of the electrode

23. List the factors that determine the mode of metal transfer
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
These terms are quite restrictive and often technically incorrect
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Flux cored wires

24. What is the required arc voltage used for short circuit transfer?
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
To prevent drawing of liquid CO2 (Carbon Dioxide)
12 to 22 arc volts

25. A 10 minute cycle of welding time vs cooling time a given machine can handle.
Duty cycle
Controls the rate of flow of a shielding gas to the gun nozzle
1/4 inch to 1/2 inch
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze

26. 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
If you dont know this check your phone
85%
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground

27. List 3 forms compressed gases may be supplied for welding
(DCEP) Direct Current Electrode Positive or Reverse polarity
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
To prevent drawing of liquid CO2 (Carbon Dioxide)
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system

28. What is the maximum distance that hard wire can be successfully pushed?
(DCEP) Direct Current Electrode Positive or Reverse polarity
Higher 26 to 35 arc volts
15 feet (4.5 meters)
SMAW - GTAW

29. What does the term GMAW identify?
Spatter problems and poor weld appearance
Cause flaking - which can clog the liner and contact tube
Wire feed speed
Gas metal arc welding

30. What is a typical flow rate of CO2 for short circuit transfer?
Cause flaking - which can clog the liner and contact tube
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Controls the rate of flow of a shielding gas to the gun nozzle
5.8 to 12.5 L/min

31. Why is the term GMAW preferred over MIG or MAG?
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
These terms are quite restrictive and often technically incorrect
Constant current (CC)
Welding process that joins metals by heating them with an electric arc

32. What controls amperage when using GMAW?
Wire feed speed
Guns
Pressure - The rate of flow of a shielding gas
DCEP (Direct Current Electrode Positive) Reverse Polarity

33. What is the reason glass 'tube' type flowmeters must have the tube mounted truly vertical?
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
...
SMAW - GTAW
When the filler wire is in direct contract with the base metal

34. When using flat drive rolls with too much pressure on copper coated solid wires what problem could take place?
5.8 to 12.5 L/min
(DCEP) Direct Current Electrode Positive or Reverse polarity
Cause flaking - which can clog the liner and contact tube
To prevent leakage - Carbon Dioxide (CO2)

35. Regulators control_____________ flowmeters SHOW____________.
Pressure - The rate of flow of a shielding gas
Speed of the feed motor and - starting / stopping electrode feed
(DCEP) Direct Current Electrode Positive or Reverse polarity
Generally not as accurate

36. What is the effect of too much slope?
Insufficient current to melt the wire off cleanly
The resistace to electrical current flow increases with it. Causing the electrode to heat
Constant- speed wire feeders and Voltage- sennsing wire feeders
Pressure - The rate of flow of a shielding gas

37. List the three methods of metal transfer with GMAW
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Short- circuiting transfer - Globular transfer - Spray transfer
Penetration and burn - off rate of the electrode
1/4 inch to 1/2 inch

38. What power sources are used with the GMAW Process?
Motor driven generators - Transformer rectifiers - and Inverter designs
Generally not as accurate
To prevent drawing of liquid CO2 (Carbon Dioxide)
Penetration and burn - off rate of the electrode

39. What does inductance control?
Wire feed speed - Voltage control
When the filler wire is in direct contract with the base metal
5.8 to 12.5 L/min
The time rate of response for the current rise and fall

40. What type of power source is commonly used with a voltage sensing wire feeder?
Minutes of elapsed time continually run (out of 10 minutes)
Pressure vessels and the piping industry
5.8 to 12.5 L/min
Constant current (CC)

41. How many times per second does short circuiting take place?
20 to 200 times per second
To prevent leakage - Carbon Dioxide (CO2)
Penetration and burn - off rate of the electrode
Duty cycle

42. What current and polarity is generally used with GMAW?
The Arc voltage
DCEP (Direct Current Electrode Positive) Reverse Polarity
By there current carrying capacity
SMAW - GTAW

43. In the GMAW process what does amperage control?
The negative side of a welding unit
Penetration and burn - off rate of the electrode
The Arc voltage
...

44. What is the disadvantage of the gauge preset type of regulator/flowmeter?
3
Generally not as accurate
Controls the rate of flow of a shielding gas to the gun nozzle
To prevent drawing of liquid CO2 (Carbon Dioxide)

45. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
By there current carrying capacity
To prevent leakage - Carbon Dioxide (CO2)
Higher 26 to 35 arc volts
3

46. What does voltage do in an electrical circuit?
These terms are quite restrictive and often technically incorrect
Constant- speed wire feeders and Voltage- sennsing wire feeders
To prevent drawing of liquid CO2 (Carbon Dioxide)
Voltage is the force that overcomes resistance to allow amperage flow

47. Draw a typical volt amp curve for a machine that is designed for GMAW
To limit the short circuiting current so that spatter is reduced
If you dont know this check your phone
5.8 to 12.5 L/min
The resistace to electrical current flow increases with it. Causing the electrode to heat

48. What 2 controls are found on a GMAW set- up?
Wire feed speed - Voltage control
85%
Gives arc voltage values to the control system of the feeder
Pressure vessels and the piping industry

49. What would be an indication that the drive roll pressure is adjusted correctly?
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Pressure vessels and the piping industry
Wire feeds smoothly (yet will slip should a problem occur in the gun)

50. What is another term for electrode holders for GMAW?
Guns
3
Dry ice can form within the flow control openings and cause blockage of shielding gas
Wire feed speed - Voltage control