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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. What type of power source is used with a constant speed wire feeder?
...
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
Constant voltage (CV)

2. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
Higher 26 to 35 arc volts
These terms are quite restrictive and often technically incorrect
5.8 to 12.5 L/min
Constant- speed wire feeders and Voltage- sennsing wire feeders

3. What 2 organizations designate specifications for GMAW wires?
AWS and CSA
Reducing the gas source pressure to a constant working pressure
20 to 200 times per second
12 to 22 arc volts

4. What does the wire feeder control?
Speed of the feed motor and - starting / stopping electrode feed
When the filler wire is in direct contract with the base metal
Generally not as accurate
If you dont know this check your phone

5. Why is globular transfer generally avoided with GMAW?
Minutes of elapsed time continually run (out of 10 minutes)
Wire feed speed
3
Spatter problems and poor weld appearance

6. Why is a fiber washer required and what cylinder gas requires it?
To prevent leakage - Carbon Dioxide (CO2)
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Higher 26 to 35 arc volts
15 feet (4.5 meters)

7. When is the metal transferred with short circuit transfer?
1/4 inch to 1/2 inch
If you dont know this check your phone
SMAW - GTAW
When the filler wire is in direct contract with the base metal

8. A pull type drive system is usually used on what type of material?
Puddle fluidity
Aluminum wire
Higher 26 to 35 arc volts
12 to 22 arc volts

9. List the basic equipment requirements for the GMAW process
To prevent leakage - Carbon Dioxide (CO2)
Higher 26 to 35 arc volts
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground

10. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Generally not as accurate
85%
Wire feed speed

11. What is an advantage of pulsed arc transfer with GMAW?
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Spatter problems and poor weld appearance
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
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

12. What does the abbreviation NEMA stand for?
Voltage is the force that overcomes resistance to allow amperage flow
DCEP (Direct Current Electrode Positive) Reverse Polarity
20 to 200 times per second
National Electrical Manufactures Association

13. What is the purpose of a regulator and what does it indicate on its gauges?
Motor driven generators - Transformer rectifiers - and Inverter designs
By there current carrying capacity
Reducing the gas source pressure to a constant working pressure
Short- circuiting transfer - Globular transfer - Spray transfer

14. What does a flowmeter do and what does it measure?
SMAW - GTAW
85%
The time rate of response for the current rise and fall
Controls the rate of flow of a shielding gas to the gun nozzle

15. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
Controls the rate of flow of a shielding gas to the gun nozzle
Gives arc voltage values to the control system of the feeder
3
Short- circuiting transfer - Globular transfer - Spray transfer

16. What processes are constant current (CC) power sources designed to be used with?
Pressure - The rate of flow of a shielding gas
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
Pressure vessels and the piping industry
SMAW - GTAW

17. Draw a typical volt amp curve for a machine that is designed for GMAW
To prevent leakage - Carbon Dioxide (CO2)
DCEP (Direct Current Electrode Positive) Reverse Polarity
If you dont know this check your phone
Aluminum wire

18. What term is used to describe when the workpiece is hooked to the negative pole on the power source?
SMAW - GTAW
(DCEP) Direct Current Electrode Positive or Reverse polarity
Shielding the molten weld metal from atmospheric contamination
Generally not as accurate

19. List 3 wire drive systems and give a short description of each
Dry ice can form within the flow control openings and cause blockage of shielding gas
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
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

20. List the factors that determine the mode of metal transfer
Constant- speed wire feeders and Voltage- sennsing wire feeders
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
...
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system

21. In the GMAW process what does amperage control?
By there current carrying capacity
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Penetration and burn - off rate of the electrode
V groove or U groove

22. What happens when the electrode extension is increased?
The resistace to electrical current flow increases with it. Causing the electrode to heat
Dry ice can form within the flow control openings and cause blockage of shielding gas
(DCEP) Direct Current Electrode Positive or Reverse polarity
Guns

23. What is a typical flow rate of CO2 for short circuit transfer?
Cause flaking - which can clog the liner and contact tube
12 to 22 arc volts
The negative side of a welding unit
5.8 to 12.5 L/min

24. Give a brief description of the GMAW process
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Reducing the gas source pressure to a constant working pressure
(DCEP) Direct Current Electrode Positive or Reverse polarity
Welding process that joins metals by heating them with an electric arc

25. What is the key advantage of short circuiting transfer?
Minimum distortion due to low heat input
To prevent leakage - Carbon Dioxide (CO2)
Higher 26 to 35 arc volts
AWS and CSA

26. What current and polarity is generally used with GMAW?
V groove or U groove
The time rate of response for the current rise and fall
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

27. What effect does increasing and decreasing the inductance have on the weld?
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
Minutes of elapsed time continually run (out of 10 minutes)
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun

28. List 3 forms compressed gases may be supplied for welding
By there current carrying capacity
Aluminum wire
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system

29. What is the maximum distance that hard wire can be successfully pushed?
AWS and CSA
Puddle fluidity
5.8 to 12.5 L/min
15 feet (4.5 meters)

30. In the GMAW process what does voltage control?
Higher 26 to 35 arc volts
Welding process that joins metals by heating them with an electric arc
Guns
Puddle fluidity

31. What would be an indication that the drive roll pressure is adjusted correctly?
(DCEP) Direct Current Electrode Positive or Reverse polarity
...
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Wire feeds smoothly (yet will slip should a problem occur in the gun)

32. What is the disadvantage of the gauge preset type of regulator/flowmeter?
By there current carrying capacity
Welding process that joins metals by heating them with an electric arc
National Electrical Manufactures Association
Generally not as accurate

33. 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
Aluminum wire
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

34. What power sources are used with the GMAW Process?
Motor driven generators - Transformer rectifiers - and Inverter designs
Shielding the molten weld metal from atmospheric contamination
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
DCEP (Direct Current Electrode Positive) Reverse Polarity

35. What controls amperage when using GMAW?
To prevent leakage - Carbon Dioxide (CO2)
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
Wire feed speed

36. What is the main purpose of 'slope'?
Voltage is the force that overcomes resistance to allow amperage flow
To limit the short circuiting current so that spatter is reduced
To prevent leakage - Carbon Dioxide (CO2)
Pressure - The rate of flow of a shielding gas

37. What is a solenoid valve and what actuates it?
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
National Electrical Manufactures Association
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

38. Regulators control_____________ flowmeters SHOW____________.
To prevent drawing of liquid CO2 (Carbon Dioxide)
Voltage is the force that overcomes resistance to allow amperage flow
Pressure - The rate of flow of a shielding gas
85%

39. A 10 minute cycle of welding time vs cooling time a given machine can handle.
Minimum distortion due to low heat input
The Arc voltage
Controls the rate of flow of a shielding gas to the gun nozzle
Duty cycle

40. Why is a line heater required when using GMAW?
To limit the short circuiting current so that spatter is reduced
Generally not as accurate
Dry ice can form within the flow control openings and cause blockage of shielding gas
Flux cored wires

41. What output on the welding machine is used to rate the duty cycle?
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
20 to 200 times per second
Penetration and burn - off rate of the electrode
Minutes of elapsed time continually run (out of 10 minutes)

42. What is another term for electrode holders for GMAW?
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
Guns
AWS and CSA

43. List the three methods of metal transfer with GMAW
Generally not as accurate
Short- circuiting transfer - Globular transfer - Spray transfer
Motor driven generators - Transformer rectifiers - and Inverter designs
The negative side of a welding unit

44. Draw a typical volt/amp curve that would be found with a power source designed for SMAW or GTAW
The resistace to electrical current flow increases with it. Causing the electrode to heat
To prevent drawing of liquid CO2 (Carbon Dioxide)
DCEP (Direct Current Electrode Positive) Reverse Polarity
If you dont know this check your phone

45. What is the reason glass 'tube' type flowmeters must have the tube mounted truly vertical?
...
When the filler wire is in direct contract with the base metal
DCEP (Direct Current Electrode Positive) Reverse Polarity
Shielding the molten weld metal from atmospheric contamination

46. What does voltage do in an electrical circuit?
Voltage is the force that overcomes resistance to allow amperage flow
Guns
National Electrical Manufactures Association
Wire feeds smoothly (yet will slip should a problem occur in the gun)

47. With straight polarity where is 2/3 of the arc energy?
Penetration and burn - off rate of the electrode
The time rate of response for the current rise and fall
Spatter problems and poor weld appearance
The negative side of a welding unit

48. When using flat drive rolls with too much pressure on copper coated solid wires what problem could take place?
Gas metal arc welding
Cause flaking - which can clog the liner and contact tube
To prevent drawing of liquid CO2 (Carbon Dioxide)
The time rate of response for the current rise and fall

49. What is the purpose of the shielding gas used in GMAW?
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Shielding the molten weld metal from atmospheric contamination
The negative side of a welding unit
Pressure - The rate of flow of a shielding gas

50. What 2 controls are found on a GMAW set- up?
Motor driven generators - Transformer rectifiers - and Inverter designs
Wire feed speed - Voltage control
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Voltage is the force that overcomes resistance to allow amperage flow