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. List the factors that determine the mode of metal transfer
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Constant voltage (CV)
The resistace to electrical current flow increases with it. Causing the electrode to heat
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

2. What 2 organizations designate specifications for GMAW wires?
AWS and CSA
Constant- speed wire feeders and Voltage- sennsing wire feeders
DCEP (Direct Current Electrode Positive) Reverse Polarity
By there current carrying capacity

3. 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)
Minimum distortion due to low heat input
Spatter problems and poor weld appearance
If you dont know this check your phone

4. What is the purpose of a regulator and what does it indicate on its gauges?
Pressure vessels and the piping industry
Reducing the gas source pressure to a constant working pressure
To prevent drawing of liquid CO2 (Carbon Dioxide)
The resistace to electrical current flow increases with it. Causing the electrode to heat

5. What type of power source is used with a constant speed wire feeder?
Flux cored wires
These terms are quite restrictive and often technically incorrect
Constant voltage (CV)
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze

6. What is the reason glass 'tube' type flowmeters must have the tube mounted truly vertical?
...
Wire feed speed
These terms are quite restrictive and often technically incorrect
Wire feeds smoothly (yet will slip should a problem occur in the gun)

7. Why is a fiber washer required and what cylinder gas requires it?
Constant current (CC)
Aluminum wire
To prevent leakage - Carbon Dioxide (CO2)
3

8. List 3 forms compressed gases may be supplied for welding
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
Constant voltage (CV)
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system

9. List the three methods of metal transfer with GMAW
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Constant current (CC)
If you dont know this check your phone
Short- circuiting transfer - Globular transfer - Spray transfer

10. What is the recommended electrode stick- out for .035 solid wire?
Minutes of elapsed time continually run (out of 10 minutes)
1/4 inch to 1/2 inch
85%
The resistace to electrical current flow increases with it. Causing the electrode to heat

11. What power sources are used with the GMAW Process?
Dry ice can form within the flow control openings and cause blockage of shielding gas
Higher 26 to 35 arc volts
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Motor driven generators - Transformer rectifiers - and Inverter designs

12. What 2 controls are found on a GMAW set- up?
Generally not as accurate
Shielding the molten weld metal from atmospheric contamination
Wire feed speed - Voltage control
The time rate of response for the current rise and fall

13. 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
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
(DCEP) Direct Current Electrode Positive or Reverse polarity

14. What wire are knurled drive rolls most commonly used on?
Flux cored wires
Penetration and burn - off rate of the electrode
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
(DCEP) Direct Current Electrode Positive or Reverse polarity

15. What is the maximum distance that hard wire can be successfully pushed?
15 feet (4.5 meters)
Spatter problems and poor weld appearance
V groove or U groove
Constant- speed wire feeders and Voltage- sennsing wire feeders

16. A pull type drive system is usually used on what type of material?
Constant current (CC)
12 to 22 arc volts
...
Aluminum wire

17. What does a flowmeter do and what does it measure?
Penetration and burn - off rate of the electrode
Controls the rate of flow of a shielding gas to the gun nozzle
By there current carrying capacity
Constant current (CC)

18. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
Higher 26 to 35 arc volts
Short- circuiting transfer - Globular transfer - Spray transfer
85%
Dry ice can form within the flow control openings and cause blockage of shielding gas

19. A 10 minute cycle of welding time vs cooling time a given machine can handle.
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Duty cycle
To prevent leakage - Carbon Dioxide (CO2)

20. Why is globular transfer generally avoided with GMAW?
Shielding the molten weld metal from atmospheric contamination
Wire feed speed - Voltage control
Spatter problems and poor weld appearance
If you dont know this check your phone

21. What type of power source is commonly used with a voltage sensing wire feeder?
Short- circuiting transfer - Globular transfer - Spray transfer
Constant current (CC)
AWS and CSA
The resistace to electrical current flow increases with it. Causing the electrode to heat

22. What controls the wire speed on a voltage sensing wire feeder?
Wire feed speed
The Arc voltage
If you dont know this check your phone
National Electrical Manufactures Association

23. What would be an indication that the drive roll pressure is adjusted correctly?
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Gas metal arc welding
Cause flaking - which can clog the liner and contact tube
Higher 26 to 35 arc volts

24. What does the abbreviation NEMA stand for?
National Electrical Manufactures Association
Speed of the feed motor and - starting / stopping electrode feed
Generally not as accurate
The Arc voltage

25. What is the purpose of the shielding gas used in GMAW?
Pressure vessels and the piping industry
SMAW - GTAW
Shielding the molten weld metal from atmospheric contamination
Gas metal arc welding

26. What is the effect of too much slope?
12 to 22 arc volts
To limit the short circuiting current so that spatter is reduced
Insufficient current to melt the wire off cleanly
Spatter problems and poor weld appearance

27. What is another term for electrode holders for GMAW?
Guns
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
Gives arc voltage values to the control system of the feeder

28. List several industries that would use GMAW
Pressure - The rate of flow of a shielding gas
(DCEP) Direct Current Electrode Positive or Reverse polarity
Constant current (CC)
Pressure vessels and the piping industry

29. What is the disadvantage of the gauge preset type of regulator/flowmeter?
Generally not as accurate
Guns
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Higher 26 to 35 arc volts

30. 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
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Minimum distortion due to low heat input

31. List the basic equipment requirements for the GMAW process
15 feet (4.5 meters)
Duty cycle
Puddle fluidity
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground

32. What controls amperage when using GMAW?
Insufficient current to melt the wire off cleanly
Flux cored wires
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Wire feed speed

33. What current and polarity is generally used with GMAW?
Motor driven generators - Transformer rectifiers - and Inverter designs
Short- circuiting transfer - Globular transfer - Spray transfer
DCEP (Direct Current Electrode Positive) Reverse Polarity
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts

34. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
3
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
12 to 22 arc volts
Pressure - The rate of flow of a shielding gas

35. 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
Controls the rate of flow of a shielding gas to the gun nozzle
When the filler wire is in direct contract with the base metal

36. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
Penetration and burn - off rate of the electrode
If you dont know this check your phone
Wire feed speed
Higher 26 to 35 arc volts

37. Give a description of 'pinch effect'
V groove or U groove
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
3
Controls the rate of flow of a shielding gas to the gun nozzle

38. What is the main purpose of 'slope'?
Constant- speed wire feeders and Voltage- sennsing wire feeders
15 feet (4.5 meters)
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
To limit the short circuiting current so that spatter is reduced

39. How are GMAW guns rated?
By there current carrying capacity
Cause flaking - which can clog the liner and contact tube
National Electrical Manufactures Association
These terms are quite restrictive and often technically incorrect

40. What does the wire feeder control?
Gas metal arc welding
85%
Speed of the feed motor and - starting / stopping electrode feed
V groove or U groove

41. With straight polarity where is 2/3 of the arc energy?
Duty cycle
Cause flaking - which can clog the liner and contact tube
V groove or U groove
The negative side of a welding unit

42. What is the preferred drive roll design for solid wires?
Voltage is the force that overcomes resistance to allow amperage flow
Insufficient current to melt the wire off cleanly
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
V groove or U groove

43. 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
Motor driven generators - Transformer rectifiers - and Inverter designs
Speed of the feed motor and - starting / stopping electrode feed
Duty cycle

44. List 3 wire drive systems and give a short description of each
12 to 22 arc volts
If you dont know this check your phone
When the filler wire is in direct contract with the base metal
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

45. What output on the welding machine is used to rate the duty cycle?
Generally not as accurate
3
To limit the short circuiting current so that spatter is reduced
Minutes of elapsed time continually run (out of 10 minutes)

46. What is the required arc voltage used for short circuit transfer?
12 to 22 arc volts
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
V groove or U groove
If you dont know this check your phone

47. Regulators control_____________ flowmeters SHOW____________.
20 to 200 times per second
Duty cycle
Short- circuiting transfer - Globular transfer - Spray transfer
Pressure - The rate of flow of a shielding gas

48. What effect does increasing and decreasing the inductance have on the weld?
To prevent drawing of liquid CO2 (Carbon Dioxide)
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)
By there current carrying capacity

49. What are the 2 types of wire feeders available?
Puddle fluidity
Constant- speed wire feeders and Voltage- sennsing wire feeders
Minimum distortion due to low heat input
Penetration and burn - off rate of the electrode

50. What is a solenoid valve and what actuates it?
(DCEP) Direct Current Electrode Positive or Reverse polarity
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze