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. What wire are knurled drive rolls most commonly used on?
Generally not as accurate
12 to 22 arc volts
Flux cored wires
5.8 to 12.5 L/min

2. Draw a typical volt amp curve for a machine that is designed for GMAW
15 feet (4.5 meters)
Welding process that joins metals by heating them with an electric arc
Shielding the molten weld metal from atmospheric contamination
If you dont know this check your phone

3. List 3 forms compressed gases may be supplied for welding
Aluminum wire
Shielding the molten weld metal from atmospheric contamination
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
If you dont know this check your phone

4. What is the purpose of the shielding gas used in GMAW?
These terms are quite restrictive and often technically incorrect
Speed of the feed motor and - starting / stopping electrode feed
Shielding the molten weld metal from atmospheric contamination
12 to 22 arc volts

5. What power sources are used with the GMAW Process?
V groove or U groove
The resistace to electrical current flow increases with it. Causing the electrode to heat
Constant voltage (CV)
Motor driven generators - Transformer rectifiers - and Inverter designs

6. What does inductance control?
The time rate of response for the current rise and fall
Insufficient current to melt the wire off cleanly
12 to 22 arc volts
The Arc voltage

7. In the GMAW process what does amperage control?
These terms are quite restrictive and often technically incorrect
Wire feed speed
Voltage is the force that overcomes resistance to allow amperage flow
Penetration and burn - off rate of the electrode

8. What is the recommended electrode stick- out for .035 solid wire?
1/4 inch to 1/2 inch
Cause flaking - which can clog the liner and contact tube
Welding process that joins metals by heating them with an electric arc
Motor driven generators - Transformer rectifiers - and Inverter designs

9. What does a flowmeter do and what does it measure?
When the filler wire is in direct contract with the base metal
Constant voltage (CV)
Aluminum wire
Controls the rate of flow of a shielding gas to the gun nozzle

10. 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
5.8 to 12.5 L/min
Gives arc voltage values to the control system of the feeder
Aluminum wire

11. What is the required arc voltage used for short circuit transfer?
Gives arc voltage values to the control system of the feeder
The resistace to electrical current flow increases with it. Causing the electrode to heat
12 to 22 arc volts
Cause flaking - which can clog the liner and contact tube

12. What controls the wire speed on a voltage sensing wire feeder?
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
The Arc voltage
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

13. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
Duty cycle
3
Constant current (CC)
Motor driven generators - Transformer rectifiers - and Inverter designs

14. What would be an indication that the drive roll pressure is adjusted correctly?
(DCEP) Direct Current Electrode Positive or Reverse polarity
AWS and CSA
To limit the short circuiting current so that spatter is reduced
Wire feeds smoothly (yet will slip should a problem occur in the gun)

15. A 10 minute cycle of welding time vs cooling time a given machine can handle.
Duty cycle
Constant voltage (CV)
The time rate of response for the current rise and fall
These terms are quite restrictive and often technically incorrect

16. Why is a line heater required when using GMAW?
Dry ice can form within the flow control openings and cause blockage of shielding gas
Wire feed speed
Insufficient current to melt the wire off cleanly
Minimum distortion due to low heat input

17. What is the maximum distance that hard wire can be successfully pushed?
By there current carrying capacity
If you dont know this check your phone
The resistace to electrical current flow increases with it. Causing the electrode to heat
15 feet (4.5 meters)

18. What does the wire feeder control?
Speed of the feed motor and - starting / stopping electrode feed
If you dont know this check your phone
These terms are quite restrictive and often technically incorrect
When the filler wire is in direct contract with the base metal

19. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
AWS and CSA
By there current carrying capacity
To limit the short circuiting current so that spatter is reduced
85%

20. 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)
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
15 feet (4.5 meters)

21. When is the metal transferred with short circuit transfer?
Pressure vessels and the piping industry
The negative side of a welding unit
Gas metal arc welding
When the filler wire is in direct contract with the base metal

22. A pull type drive system is usually used on what type of material?
5.8 to 12.5 L/min
Cause flaking - which can clog the liner and contact tube
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
Aluminum wire

23. What current and polarity is generally used with GMAW?
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
DCEP (Direct Current Electrode Positive) Reverse Polarity
Cause flaking - which can clog the liner and contact tube
...

24. Why is the term GMAW preferred over MIG or MAG?
85%
Speed of the feed motor and - starting / stopping electrode feed
Puddle fluidity
These terms are quite restrictive and often technically incorrect

25. What happens when the electrode extension is increased?
Shielding the molten weld metal from atmospheric contamination
The resistace to electrical current flow increases with it. Causing the electrode to heat
Pressure - The rate of flow of a shielding gas
To prevent leakage - Carbon Dioxide (CO2)

26. 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
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Short- circuiting transfer - Globular transfer - Spray transfer

27. List the factors that determine the mode of metal transfer
Aluminum wire
5.8 to 12.5 L/min
Gives arc voltage values to the control system of the feeder
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

28. What is the effect of too much slope?
Constant current (CC)
When the filler wire is in direct contract with the base metal
Insufficient current to melt the wire off cleanly
Minutes of elapsed time continually run (out of 10 minutes)

29. What does the term GMAW identify?
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Constant voltage (CV)
Duty cycle
Gas metal arc welding

30. Give a brief description of the GMAW process
Welding process that joins metals by heating them with an electric arc
Duty cycle
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
15 feet (4.5 meters)

31. What effect does increasing and decreasing the inductance have on the weld?
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
V groove or U groove
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
20 to 200 times per second

32. Why is a fiber washer required and what cylinder gas requires it?
If you dont know this check your phone
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
To prevent leakage - Carbon Dioxide (CO2)
85%

33. What is a typical flow rate of CO2 for short circuit transfer?
5.8 to 12.5 L/min
Voltage is the force that overcomes resistance to allow amperage flow
Guns
85%

34. What is the disadvantage of the gauge preset type of regulator/flowmeter?
Generally not as accurate
1/4 inch to 1/2 inch
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
The resistace to electrical current flow increases with it. Causing the electrode to heat

35. What is the main purpose of 'slope'?
Wire feeds smoothly (yet will slip should a problem occur in the gun)
To prevent drawing of liquid CO2 (Carbon Dioxide)
Gas metal arc welding
To limit the short circuiting current so that spatter is reduced

36. What is the key advantage of short circuiting transfer?
Dry ice can form within the flow control openings and cause blockage of shielding gas
Minimum distortion due to low heat input
If you dont know this check your phone
V groove or U groove

37. What processes are constant current (CC) power sources designed to be used with?
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Guns
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
SMAW - GTAW

38. How are GMAW guns rated?
3
By there current carrying capacity
20 to 200 times per second
...

39. When using flat drive rolls with too much pressure on copper coated solid wires what problem could take place?
Minimum distortion due to low heat input
5.8 to 12.5 L/min
To limit the short circuiting current so that spatter is reduced
Cause flaking - which can clog the liner and contact tube

40. What is the preferred drive roll design for solid wires?
If you dont know this check your phone
Controls the rate of flow of a shielding gas to the gun nozzle
V groove or U groove
Duty cycle

41. In the GMAW process what does voltage control?
Constant- speed wire feeders and Voltage- sennsing wire feeders
Puddle fluidity
12 to 22 arc volts
The Arc voltage

42. What term is used to describe when the workpiece is hooked to the negative pole on the power source?
3
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
(DCEP) Direct Current Electrode Positive or Reverse polarity
Spatter problems and poor weld appearance

43. How many times per second does short circuiting take place?
Generally not as accurate
Wire feed speed - Voltage control
3
20 to 200 times per second

44. Regulators control_____________ flowmeters SHOW____________.
Pressure - The rate of flow of a shielding gas
The resistace to electrical current flow increases with it. Causing the electrode to heat
Gives arc voltage values to the control system of the feeder
If you dont know this check your phone

45. What is another term for electrode holders for GMAW?
To limit the short circuiting current so that spatter is reduced
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Insufficient current to melt the wire off cleanly
Guns

46. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
Higher 26 to 35 arc volts
If you dont know this check your phone
Minimum distortion due to low heat input
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun

47. What is the purpose of the pick- up lead on a voltage sensing wire feeder?
AWS and CSA
Pressure vessels and the piping industry
Gives arc voltage values to the control system of the feeder
To prevent leakage - Carbon Dioxide (CO2)

48. Why must CO2 cylinders be used in the vertical position?
Puddle fluidity
To prevent drawing of liquid CO2 (Carbon Dioxide)
National Electrical Manufactures Association
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field

49. List the basic equipment requirements for the GMAW process
Puddle fluidity
Flux cored wires
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

50. Why is globular transfer generally avoided with GMAW?
Gas metal arc welding
When the filler wire is in direct contract with the base metal
Spatter problems and poor weld appearance
Aluminum wire