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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. In the GMAW process what does voltage control?
Flux cored wires
Puddle fluidity
Aluminum wire
V groove or U groove

2. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
85%
The resistace to electrical current flow increases with it. Causing the electrode to heat
Shielding the molten weld metal from atmospheric contamination
Gas metal arc welding

3. What type of power source is used with a constant speed wire feeder?
1/4 inch to 1/2 inch
Constant- speed wire feeders and Voltage- sennsing wire feeders
By there current carrying capacity
Constant voltage (CV)

4. What is the preferred drive roll design for solid wires?
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
V groove or U groove
To limit the short circuiting current so that spatter is reduced

5. What power sources are used with the GMAW Process?
Motor driven generators - Transformer rectifiers - and Inverter designs
Constant current (CC)
Puddle fluidity
Constant- speed wire feeders and Voltage- sennsing wire feeders

6. A 10 minute cycle of welding time vs cooling time a given machine can handle.
These terms are quite restrictive and often technically incorrect
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
Duty cycle

7. How many times per second does short circuiting take place?
These terms are quite restrictive and often technically incorrect
20 to 200 times per second
Shielding the molten weld metal from atmospheric contamination
Wire feeds smoothly (yet will slip should a problem occur in the gun)

8. What wire are knurled drive rolls most commonly used on?
Flux cored wires
The Arc voltage
To limit the short circuiting current so that spatter is reduced
Duty cycle

9. List the factors that determine the mode of metal transfer
The resistace to electrical current flow increases with it. Causing the electrode to heat
These terms are quite restrictive and often technically incorrect
Higher 26 to 35 arc volts
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

10. What type of power source is commonly used with a voltage sensing wire feeder?
Constant current (CC)
Cause flaking - which can clog the liner and contact tube
SMAW - GTAW
Penetration and burn - off rate of the electrode

11. Regulators control_____________ flowmeters SHOW____________.
Pressure - The rate of flow of a shielding gas
Short- circuiting transfer - Globular transfer - Spray transfer
(DCEP) Direct Current Electrode Positive or Reverse polarity
Pressure vessels and the piping industry

12. How are GMAW guns rated?
Pressure - The rate of flow of a shielding gas
By there current carrying capacity
To prevent leakage - Carbon Dioxide (CO2)
V groove or U groove

13. What is the purpose of a regulator and what does it indicate on its gauges?
Minimum distortion due to low heat input
Aluminum wire
Reducing the gas source pressure to a constant working pressure
SMAW - GTAW

14. What does inductance control?
DCEP (Direct Current Electrode Positive) Reverse Polarity
Duty cycle
The time rate of response for the current rise and fall
Minutes of elapsed time continually run (out of 10 minutes)

15. Draw a typical volt/amp curve that would be found with a power source designed for SMAW or GTAW
Speed of the feed motor and - starting / stopping electrode feed
If you dont know this check your phone
AWS and CSA
85%

16. List 3 wire drive systems and give a short description of each
Cause flaking - which can clog the liner and contact tube
Motor driven generators - Transformer rectifiers - and Inverter designs
Shielding the molten weld metal from atmospheric contamination
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

17. What happens when the electrode extension is increased?
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
The resistace to electrical current flow increases with it. Causing the electrode to heat
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
Shielding the molten weld metal from atmospheric contamination

18. List several industries that would use GMAW
Gives arc voltage values to the control system of the feeder
...
Controls the rate of flow of a shielding gas to the gun nozzle
Pressure vessels and the piping industry

19. Why is a fiber washer required and what cylinder gas requires it?
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
To prevent leakage - Carbon Dioxide (CO2)
85%
Motor driven generators - Transformer rectifiers - and Inverter designs

20. What is the key advantage of short circuiting transfer?
Gives arc voltage values to the control system of the feeder
Minimum distortion due to low heat input
To prevent drawing of liquid CO2 (Carbon Dioxide)
The resistace to electrical current flow increases with it. Causing the electrode to heat

21. What is the maximum distance that hard wire can be successfully pushed?
Welding process that joins metals by heating them with an electric arc
15 feet (4.5 meters)
Constant- speed wire feeders and Voltage- sennsing wire feeders
Short- circuiting transfer - Globular transfer - Spray transfer

22. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
V groove or U groove
Wire feed speed - Voltage control
Gives arc voltage values to the control system of the feeder
3

23. With straight polarity where is 2/3 of the arc energy?
The negative side of a welding unit
To prevent drawing of liquid CO2 (Carbon Dioxide)
Gives arc voltage values to the control system of the feeder
Speed of the feed motor and - starting / stopping electrode feed

24. What effect does increasing and decreasing the inductance have on the weld?
Gives arc voltage values to the control system of the feeder
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 time rate of response for the current rise and fall

25. When is the metal transferred with short circuit transfer?
DCEP (Direct Current Electrode Positive) Reverse Polarity
The time rate of response for the current rise and fall
Insufficient current to melt the wire off cleanly
When the filler wire is in direct contract with the base metal

26. Why is globular transfer generally avoided with GMAW?
Spatter problems and poor weld appearance
Constant voltage (CV)
By there current carrying capacity
Gas metal arc welding

27. List 3 forms compressed gases may be supplied for welding
When the filler wire is in direct contract with the base metal
Shielding the molten weld metal from atmospheric contamination
By there current carrying capacity
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system

28. What does a flowmeter do and what does it measure?
20 to 200 times per second
These terms are quite restrictive and often technically incorrect
Controls the rate of flow of a shielding gas to the gun nozzle
Constant voltage (CV)

29. What is another term for electrode holders for GMAW?
Constant current (CC)
The Arc voltage
By there current carrying capacity
Guns

30. What 2 controls are found on a GMAW set- up?
Minimum distortion due to low heat input
Wire feed speed - Voltage control
To prevent leakage - Carbon Dioxide (CO2)
Higher 26 to 35 arc volts

31. What is the main purpose of 'slope'?
The Arc voltage
V groove or U groove
3
To limit the short circuiting current so that spatter is reduced

32. Why is the term GMAW preferred over MIG or MAG?
These terms are quite restrictive and often technically incorrect
Cause flaking - which can clog the liner and contact tube
To prevent drawing of liquid CO2 (Carbon Dioxide)
Generally not as accurate

33. What is the recommended electrode stick- out for .035 solid wire?
1/4 inch to 1/2 inch
85%
V groove or U groove
3

34. What is an advantage of pulsed arc transfer with GMAW?
If you dont know this check your phone
The negative side of a welding unit
Pressure - The rate of flow of a shielding gas
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze

35. What 2 organizations designate specifications for GMAW wires?
DCEP (Direct Current Electrode Positive) Reverse Polarity
AWS and CSA
To limit the short circuiting current so that spatter is reduced
Minutes of elapsed time continually run (out of 10 minutes)

36. 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)
Pressure - The rate of flow of a shielding gas
AWS and CSA
The Arc voltage

37. What does the term GMAW identify?
Voltage is the force that overcomes resistance to allow amperage flow
Gas metal arc welding
The negative side of a welding unit
Wire feed speed

38. What output on the welding machine is used to rate the duty cycle?
Aluminum wire
Voltage is the force that overcomes resistance to allow amperage flow
Minutes of elapsed time continually run (out of 10 minutes)
By there current carrying capacity

39. 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
Controls the rate of flow of a shielding gas to the gun nozzle
Duty cycle
Gives arc voltage values to the control system of the feeder

40. What current and polarity is generally used with GMAW?
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
Higher 26 to 35 arc volts
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system

41. What is the required arc voltage used for short circuit transfer?
Reducing the gas source pressure to a constant working pressure
These terms are quite restrictive and often technically incorrect
Wire feed speed
12 to 22 arc volts

42. Why must CO2 cylinders be used in the vertical position?
Gas metal arc welding
To prevent drawing of liquid CO2 (Carbon Dioxide)
Minimum distortion due to low heat input
To prevent leakage - Carbon Dioxide (CO2)

43. When using flat drive rolls with too much pressure on copper coated solid wires what problem could take place?
Constant- speed wire feeders and Voltage- sennsing wire feeders
Duty cycle
Dry ice can form within the flow control openings and cause blockage of shielding gas
Cause flaking - which can clog the liner and contact tube

44. Give a brief description of the GMAW process
Welding process that joins metals by heating them with an electric arc
Constant current (CC)
1/4 inch to 1/2 inch
12 to 22 arc volts

45. What does voltage do in an electrical circuit?
The resistace to electrical current flow increases with it. Causing the electrode to heat
Voltage is the force that overcomes resistance to allow amperage flow
85%
National Electrical Manufactures Association

46. What controls the wire speed on a voltage sensing wire feeder?
The Arc voltage
Motor driven generators - Transformer rectifiers - and Inverter designs
If you dont know this check your phone
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun

47. What are the 2 types of wire feeders available?
The time rate of response for the current rise and fall
These terms are quite restrictive and often technically incorrect
To prevent drawing of liquid CO2 (Carbon Dioxide)
Constant- speed wire feeders and Voltage- sennsing wire feeders

48. List the three methods of metal transfer with GMAW
Puddle fluidity
National Electrical Manufactures Association
Short- circuiting transfer - Globular transfer - Spray transfer
Wire feed speed

49. What is a solenoid valve and what actuates it?
AWS and CSA
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
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

50. What does the abbreviation NEMA stand for?
By there current carrying capacity
Reducing the gas source pressure to a constant working pressure
National Electrical Manufactures Association
Generally not as accurate