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Test your basic knowledge |

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. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
3
Higher 26 to 35 arc volts
5.8 to 12.5 L/min
Duty cycle

2. When using flat drive rolls with too much pressure on copper coated solid wires what problem could take place?
Cause flaking - which can clog the liner and contact tube
5.8 to 12.5 L/min
Constant current (CC)
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

3. What wire are knurled drive rolls most commonly used on?
The time rate of response for the current rise and fall
Flux cored wires
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
National Electrical Manufactures Association

4. In the GMAW process what does amperage control?
Spatter problems and poor weld appearance
Wire feed speed - Voltage control
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Penetration and burn - off rate of the electrode

5. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
SMAW - GTAW
85%
AWS and CSA
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

6. What is an advantage of pulsed arc transfer with GMAW?
Constant current (CC)
Speed of the feed motor and - starting / stopping electrode feed
Penetration and burn - off rate of the electrode
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze

7. How many times per second does short circuiting take place?
3
1/4 inch to 1/2 inch
20 to 200 times per second
Gas metal arc welding

8. What term is used to describe when the workpiece is hooked to the negative pole on the power source?
Higher 26 to 35 arc volts
By there current carrying capacity
(DCEP) Direct Current Electrode Positive or Reverse polarity
Minutes of elapsed time continually run (out of 10 minutes)

9. What 2 organizations designate specifications for GMAW wires?
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
AWS and CSA
National Electrical Manufactures Association
When the filler wire is in direct contract with the base metal

10. What is the maximum distance that hard wire can be successfully pushed?
DCEP (Direct Current Electrode Positive) Reverse Polarity
15 feet (4.5 meters)
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
20 to 200 times per second

11. 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
Reducing the gas source pressure to a constant working pressure
Gives arc voltage values to the control system of the feeder

12. What does the abbreviation NEMA stand for?
SMAW - GTAW
5.8 to 12.5 L/min
Pressure vessels and the piping industry
National Electrical Manufactures Association

13. What is the main purpose of 'slope'?
SMAW - GTAW
Pressure vessels and the piping industry
To limit the short circuiting current so that spatter is reduced
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun

14. What is another term for electrode holders for GMAW?
Speed of the feed motor and - starting / stopping electrode feed
Wire feed speed
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Guns

15. What is the purpose of a regulator and what does it indicate on its gauges?
If you dont know this check your phone
Reducing the gas source pressure to a constant working pressure
12 to 22 arc volts
Generally not as accurate

16. Why is a fiber washer required and what cylinder gas requires it?
Penetration and burn - off rate of the electrode
To prevent leakage - Carbon Dioxide (CO2)
Shielding the molten weld metal from atmospheric contamination
Constant current (CC)

17. List the factors that determine the mode of metal transfer
Constant voltage (CV)
Gives arc voltage values to the control system of the feeder
Penetration and burn - off rate of the electrode
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

18. What is the purpose of the pick- up lead on a voltage sensing wire feeder?
Shielding the molten weld metal from atmospheric contamination
(DCEP) Direct Current Electrode Positive or Reverse polarity
Gives arc voltage values to the control system of the feeder
...

19. What is a typical flow rate of CO2 for short circuit transfer?
5.8 to 12.5 L/min
Higher 26 to 35 arc volts
The time rate of response for the current rise and fall
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field

20. Regulators control_____________ flowmeters SHOW____________.
12 to 22 arc volts
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
Minimum distortion due to low heat input
Pressure - The rate of flow of a shielding gas

21. List the basic equipment requirements for the GMAW process
Cause flaking - which can clog the liner and contact tube
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
V groove or U groove

22. What does inductance control?
The time rate of response for the current rise and fall
...
Spatter problems and poor weld appearance
If you dont know this check your phone

23. What does the term GMAW identify?
Constant voltage (CV)
Gas metal arc welding
5.8 to 12.5 L/min
Shielding the molten weld metal from atmospheric contamination

24. What is the effect of too much slope?
Insufficient current to melt the wire off cleanly
If you dont know this check your phone
5.8 to 12.5 L/min
Reducing the gas source pressure to a constant working pressure

25. List the three methods of metal transfer with GMAW
Minimum distortion due to low heat input
By there current carrying capacity
Penetration and burn - off rate of the electrode
Short- circuiting transfer - Globular transfer - Spray transfer

26. A pull type drive system is usually used on what type of material?
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Aluminum wire
SMAW - GTAW
Gas metal arc welding

27. What is the key advantage of short circuiting transfer?
Insufficient current to melt the wire off cleanly
By there current carrying capacity
Minimum distortion due to low heat input
AWS and CSA

28. What happens when the electrode extension is increased?
The resistace to electrical current flow increases with it. Causing the electrode to heat
Wire feed speed
Cause flaking - which can clog the liner and contact tube
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field

29. List 3 wire drive systems and give a short description of each
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
3
National Electrical Manufactures Association
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun

30. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
Higher 26 to 35 arc volts
Reducing the gas source pressure to a constant working pressure
1/4 inch to 1/2 inch
Pressure vessels and the piping industry

31. What would be an indication that the drive roll pressure is adjusted correctly?
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
Cause flaking - which can clog the liner and contact tube
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Minimum distortion due to low heat input

32. What is the recommended electrode stick- out for .035 solid wire?
Speed of the feed motor and - starting / stopping electrode feed
1/4 inch to 1/2 inch
3
Gas metal arc welding

33. A 10 minute cycle of welding time vs cooling time a given machine can handle.
Gas metal arc welding
National Electrical Manufactures Association
Constant voltage (CV)
Duty cycle

34. What are the 2 types of wire feeders available?
Constant current (CC)
Constant- speed wire feeders and Voltage- sennsing wire feeders
Welding process that joins metals by heating them with an electric arc
Cause flaking - which can clog the liner and contact tube

35. What output on the welding machine is used to rate the duty cycle?
The resistace to electrical current flow increases with it. Causing the electrode to heat
Minutes of elapsed time continually run (out of 10 minutes)
To limit the short circuiting current so that spatter is reduced
Constant current (CC)

36. What current and polarity is generally used with GMAW?
DCEP (Direct Current Electrode Positive) Reverse Polarity
5.8 to 12.5 L/min
To prevent drawing of liquid CO2 (Carbon Dioxide)
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system

37. With straight polarity where is 2/3 of the arc energy?
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
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
The negative side of a welding unit
20 to 200 times per second

38. How are GMAW guns rated?
If you dont know this check your phone
The Arc voltage
Generally not as accurate
By there current carrying capacity

39. Why is a line heater required when using GMAW?
1/4 inch to 1/2 inch
These terms are quite restrictive and often technically incorrect
Dry ice can form within the flow control openings and cause blockage of shielding gas
Higher 26 to 35 arc volts

40. What does the wire feeder control?
3
Speed of the feed motor and - starting / stopping electrode feed
Wire feed speed
1/4 inch to 1/2 inch

41. What 2 controls are found on a GMAW set- up?
5.8 to 12.5 L/min
To limit the short circuiting current so that spatter is reduced
Wire feed speed - Voltage control
Pressure vessels and the piping industry

42. What does a flowmeter do and what does it measure?
Controls the rate of flow of a shielding gas to the gun nozzle
Welding process that joins metals by heating them with an electric arc
3
AWS and CSA

43. List several industries that would use GMAW
Cause flaking - which can clog the liner and contact tube
Pressure vessels and the piping industry
The negative side of a welding unit
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field

44. What controls amperage when using GMAW?
Wire feed speed
Penetration and burn - off rate of the electrode
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
By there current carrying capacity

45. Why is globular transfer generally avoided with GMAW?
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Spatter problems and poor weld appearance
Insufficient current to melt the wire off cleanly
The resistace to electrical current flow increases with it. Causing the electrode to heat

46. What processes are constant current (CC) power sources designed to be used with?
The time rate of response for the current rise and fall
Dry ice can form within the flow control openings and cause blockage of shielding gas
SMAW - GTAW
Insufficient current to melt the wire off cleanly

47. What type of power source is used with a constant speed wire feeder?
85%
The resistace to electrical current flow increases with it. Causing the electrode to heat
Constant voltage (CV)
To prevent drawing of liquid CO2 (Carbon Dioxide)

48. What is the preferred drive roll design for solid wires?
20 to 200 times per second
National Electrical Manufactures Association
12 to 22 arc volts
V groove or U groove

49. What effect does increasing and decreasing the inductance have on the weld?
Controls the rate of flow of a shielding gas to the gun nozzle
Minimum distortion due to low heat input
Spatter problems and poor weld appearance
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts

50. In the GMAW process what does voltage control?
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Reducing the gas source pressure to a constant working pressure
Puddle fluidity
Welding process that joins metals by heating them with an electric arc