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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. What does a flowmeter do and what does it measure?
Insufficient current to melt the wire off cleanly
...
Controls the rate of flow of a shielding gas to the gun nozzle
Flux cored wires

2. What is another term for electrode holders for GMAW?
National Electrical Manufactures Association
20 to 200 times per second
Penetration and burn - off rate of the electrode
Guns

3. Give a description of 'pinch effect'
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Duty cycle
Dry ice can form within the flow control openings and cause blockage of shielding gas
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze

4. A pull type drive system is usually used on what type of material?
(DCEP) Direct Current Electrode Positive or Reverse polarity
Aluminum wire
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
Duty cycle

5. What does the term GMAW identify?
Short- circuiting transfer - Globular transfer - Spray transfer
Gas metal arc welding
Guns
Flux cored wires

6. Why must CO2 cylinders be used in the vertical position?
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
To prevent drawing of liquid CO2 (Carbon Dioxide)
(DCEP) Direct Current Electrode Positive or Reverse polarity
Minimum distortion due to low heat input

7. What are the 2 types of wire feeders available?
Wire feed speed
The negative side of a welding unit
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Constant- speed wire feeders and Voltage- sennsing wire feeders

8. What happens when the electrode extension is increased?
85%
1/4 inch to 1/2 inch
The resistace to electrical current flow increases with it. Causing the electrode to heat
By there current carrying capacity

9. What does the abbreviation NEMA stand for?
5.8 to 12.5 L/min
Reducing the gas source pressure to a constant working pressure
National Electrical Manufactures Association
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field

10. What is the reason glass 'tube' type flowmeters must have the tube mounted truly vertical?
(DCEP) Direct Current Electrode Positive or Reverse polarity
...
Minutes of elapsed time continually run (out of 10 minutes)
Aluminum wire

11. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
The Arc voltage
3
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts

12. What does inductance control?
The time rate of response for the current rise and fall
These terms are quite restrictive and often technically incorrect
...
Higher 26 to 35 arc volts

13. List the three methods of metal transfer with GMAW
Short- circuiting transfer - Globular transfer - Spray transfer
Welding process that joins metals by heating them with an electric arc
Wire feed speed - Voltage control
These terms are quite restrictive and often technically incorrect

14. When is the metal transferred with short circuit transfer?
Insufficient current to melt the wire off cleanly
When the filler wire is in direct contract with the base metal
Motor driven generators - Transformer rectifiers - and Inverter designs
Pressure vessels and the piping industry

15. What type of power source is used with a constant speed wire feeder?
By there current carrying capacity
Welding process that joins metals by heating them with an electric arc
Constant current (CC)
Constant voltage (CV)

16. What is the preferred drive roll design for solid wires?
Wire feed speed - Voltage control
Higher 26 to 35 arc volts
Constant voltage (CV)
V groove or U groove

17. What is the recommended electrode stick- out for .035 solid wire?
12 to 22 arc volts
1/4 inch to 1/2 inch
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
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze

18. List several industries that would use GMAW
Shielding the molten weld metal from atmospheric contamination
Pressure vessels and the piping industry
The Arc voltage
15 feet (4.5 meters)

19. What is an advantage of pulsed arc transfer with GMAW?
Dry ice can form within the flow control openings and cause blockage of shielding gas
Gas metal arc welding
Minutes of elapsed time continually run (out of 10 minutes)
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze

20. What effect does increasing and decreasing the inductance have on the weld?
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
Speed of the feed motor and - starting / stopping electrode feed
Aluminum wire
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun

21. Regulators control_____________ flowmeters SHOW____________.
Higher 26 to 35 arc volts
Pressure - The rate of flow of a shielding gas
20 to 200 times per second
To prevent leakage - Carbon Dioxide (CO2)

22. What is the purpose of a regulator and what does it indicate on its gauges?
Cause flaking - which can clog the liner and contact tube
Reducing the gas source pressure to a constant working pressure
Minimum distortion due to low heat input
Spatter problems and poor weld appearance

23. 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
Voltage is the force that overcomes resistance to allow amperage flow
To limit the short circuiting current so that spatter is reduced
5.8 to 12.5 L/min

24. What is the maximum distance that hard wire can be successfully pushed?
15 feet (4.5 meters)
Gives arc voltage values to the control system of the feeder
Constant voltage (CV)
Puddle fluidity

25. What is the key advantage of short circuiting transfer?
3
Minimum distortion due to low heat input
Penetration and burn - off rate of the electrode
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

26. How are GMAW guns rated?
By there current carrying capacity
Constant- speed wire feeders and Voltage- sennsing wire feeders
Dry ice can form within the flow control openings and cause blockage of shielding gas
DCEP (Direct Current Electrode Positive) Reverse Polarity

27. What controls amperage when using GMAW?
Spatter problems and poor weld appearance
Wire feed speed
Higher 26 to 35 arc volts
By there current carrying capacity

28. With straight polarity where is 2/3 of the arc energy?
Aluminum wire
Gas metal arc welding
Wire feeds smoothly (yet will slip should a problem occur in the gun)
The negative side of a welding unit

29. Why is a fiber washer required and what cylinder gas requires it?
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Aluminum wire
When the filler wire is in direct contract with the base metal
To prevent leakage - Carbon Dioxide (CO2)

30. What is a typical flow rate of CO2 for short circuit transfer?
5.8 to 12.5 L/min
AWS and CSA
Shielding the molten weld metal from atmospheric contamination
Spatter problems and poor weld appearance

31. Why is the term GMAW preferred over MIG or MAG?
By there current carrying capacity
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
These terms are quite restrictive and often technically incorrect

32. What wire are knurled drive rolls most commonly used on?
Constant current (CC)
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
Flux cored wires
The negative side of a welding unit

33. What current and polarity is generally used with GMAW?
DCEP (Direct Current Electrode Positive) Reverse Polarity
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Dry ice can form within the flow control openings and cause blockage of shielding gas
Spatter problems and poor weld appearance

34. What is the required arc voltage used for short circuit transfer?
Constant current (CC)
Minutes of elapsed time continually run (out of 10 minutes)
Constant voltage (CV)
12 to 22 arc volts

35. What 2 organizations designate specifications for GMAW wires?
AWS and CSA
To limit the short circuiting current so that spatter is reduced
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

36. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
Welding process that joins metals by heating them with an electric arc
Insufficient current to melt the wire off cleanly
85%
AWS and CSA

37. What power sources are used with the GMAW Process?
Motor driven generators - Transformer rectifiers - and Inverter designs
Generally not as accurate
Insufficient current to melt the wire off cleanly
Dry ice can form within the flow control openings and cause blockage of shielding gas

38. What is the purpose of the pick- up lead on a voltage sensing wire feeder?
To prevent drawing of liquid CO2 (Carbon Dioxide)
Insufficient current to melt the wire off cleanly
The negative side of a welding unit
Gives arc voltage values to the control system of the feeder

39. What is the effect of too much slope?
SMAW - GTAW
Insufficient current to melt the wire off cleanly
Voltage is the force that overcomes resistance to allow amperage flow
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts

40. How many times per second does short circuiting take place?
Higher 26 to 35 arc volts
20 to 200 times per second
Shielding the molten weld metal from atmospheric contamination
1/4 inch to 1/2 inch

41. What controls the wire speed on a voltage sensing wire feeder?
Speed of the feed motor and - starting / stopping electrode feed
15 feet (4.5 meters)
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
The Arc voltage

42. What 2 controls are found on a GMAW set- up?
When the filler wire is in direct contract with the base metal
Aluminum wire
By there current carrying capacity
Wire feed speed - Voltage control

43. List 3 forms compressed gases may be supplied for welding
Wire feed speed - Voltage control
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
These terms are quite restrictive and often technically incorrect
Shielding the molten weld metal from atmospheric contamination

44. In the GMAW process what does amperage control?
Motor driven generators - Transformer rectifiers - and Inverter designs
3
Penetration and burn - off rate of the electrode
Pressure - The rate of flow of a shielding gas

45. What output on the welding machine is used to rate the duty cycle?
The time rate of response for the current rise and fall
12 to 22 arc volts
Speed of the feed motor and - starting / stopping electrode feed
Minutes of elapsed time continually run (out of 10 minutes)

46. What term is used to describe when the workpiece is hooked to the negative pole on the power source?
The negative side of a welding unit
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
(DCEP) Direct Current Electrode Positive or Reverse polarity
Duty cycle

47. What is a solenoid valve and what actuates it?
Speed of the feed motor and - starting / stopping electrode feed
By there current carrying capacity
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
DCEP (Direct Current Electrode Positive) Reverse Polarity

48. A 10 minute cycle of welding time vs cooling time a given machine can handle.
Aluminum wire
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
20 to 200 times per second
Duty cycle

49. What is the purpose of the shielding gas used in GMAW?
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Gives arc voltage values to the control system of the feeder
Shielding the molten weld metal from atmospheric contamination
Motor driven generators - Transformer rectifiers - and Inverter designs

50. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Higher 26 to 35 arc volts
Motor driven generators - Transformer rectifiers - and Inverter designs
20 to 200 times per second