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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 is the maximum distance that hard wire can be successfully pushed?
Short- circuiting transfer - Globular transfer - Spray transfer
15 feet (4.5 meters)
Cause flaking - which can clog the liner and contact tube
By there current carrying capacity

2. What controls the wire speed on a voltage sensing wire feeder?
To prevent leakage - Carbon Dioxide (CO2)
Voltage is the force that overcomes resistance to allow amperage flow
The Arc voltage
Constant- speed wire feeders and Voltage- sennsing wire feeders

3. List 3 wire drive systems and give a short description of each
If you dont know this check your phone
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
3
Guns

4. A pull type drive system is usually used on what type of material?
...
Cause flaking - which can clog the liner and contact tube
Aluminum wire
Guns

5. When using flat drive rolls with too much pressure on copper coated solid wires what problem could take place?
(DCEP) Direct Current Electrode Positive or Reverse polarity
Cause flaking - which can clog the liner and contact tube
5.8 to 12.5 L/min
Controls the rate of flow of a shielding gas to the gun nozzle

6. What is the main purpose of 'slope'?
1/4 inch to 1/2 inch
To prevent drawing of liquid CO2 (Carbon Dioxide)
To limit the short circuiting current so that spatter is reduced
V groove or U groove

7. What happens when the electrode extension is increased?
Welding process that joins metals by heating them with an electric arc
...
Dry ice can form within the flow control openings and cause blockage of shielding gas
The resistace to electrical current flow increases with it. Causing the electrode to heat

8. What current and polarity is generally used with GMAW?
Generally not as accurate
DCEP (Direct Current Electrode Positive) Reverse Polarity
Flux cored wires
Duty cycle

9. How many times per second does short circuiting take place?
Motor driven generators - Transformer rectifiers - and Inverter designs
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Reducing the gas source pressure to a constant working pressure
20 to 200 times per second

10. What wire are knurled drive rolls most commonly used on?
Controls the rate of flow of a shielding gas to the gun nozzle
85%
Flux cored wires
Duty cycle

11. 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
The Arc voltage
Speed of the feed motor and - starting / stopping electrode feed
Constant voltage (CV)

12. What does the abbreviation NEMA stand for?
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
National Electrical Manufactures Association
...
To prevent leakage - Carbon Dioxide (CO2)

13. How are GMAW guns rated?
By there current carrying capacity
These terms are quite restrictive and often technically incorrect
Minimum distortion due to low heat input
Voltage is the force that overcomes resistance to allow amperage flow

14. What processes are constant current (CC) power sources designed to be used with?
Controls the rate of flow of a shielding gas to the gun nozzle
...
SMAW - GTAW
Welding process that joins metals by heating them with an electric arc

15. Why is a line heater required when using GMAW?
The resistace to electrical current flow increases with it. Causing the electrode to heat
Pressure - The rate of flow of a shielding gas
Dry ice can form within the flow control openings and cause blockage of shielding gas
The Arc voltage

16. Draw a typical volt amp curve for a machine that is designed for GMAW
Short- circuiting transfer - Globular transfer - Spray transfer
Shielding the molten weld metal from atmospheric contamination
Controls the rate of flow of a shielding gas to the gun nozzle
If you dont know this check your phone

17. What does the wire feeder control?
15 feet (4.5 meters)
Puddle fluidity
Speed of the feed motor and - starting / stopping electrode feed
(DCEP) Direct Current Electrode Positive or Reverse polarity

18. What is the recommended electrode stick- out for .035 solid wire?
Aluminum wire
1/4 inch to 1/2 inch
The Arc voltage
Puddle fluidity

19. What does the term GMAW identify?
Generally not as accurate
Gas metal arc welding
SMAW - GTAW
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field

20. What is another term for electrode holders for GMAW?
Gas metal arc welding
Wire feed speed
Guns
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze

21. Why is a fiber washer required and what cylinder gas requires it?
DCEP (Direct Current Electrode Positive) Reverse Polarity
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
To prevent leakage - Carbon Dioxide (CO2)
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field

22. What power sources are used with the GMAW Process?
...
Motor driven generators - Transformer rectifiers - and Inverter designs
Gives arc voltage values to the control system of the feeder
Minutes of elapsed time continually run (out of 10 minutes)

23. When is the metal transferred with short circuit transfer?
When the filler wire is in direct contract with the base metal
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
Motor driven generators - Transformer rectifiers - and Inverter designs

24. What controls amperage when using GMAW?
Wire feed speed
5.8 to 12.5 L/min
V groove or U groove
Pressure - The rate of flow of a shielding gas

25. What are the 2 types of wire feeders available?
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Constant- speed wire feeders and Voltage- sennsing wire feeders
5.8 to 12.5 L/min
SMAW - GTAW

26. What effect does increasing and decreasing the inductance have on the weld?
12 to 22 arc volts
Pressure - The rate of flow of a shielding gas
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

27. What is the disadvantage of the gauge preset type of regulator/flowmeter?
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Puddle fluidity
Generally not as accurate
Duty cycle

28. What is the reason glass 'tube' type flowmeters must have the tube mounted truly vertical?
Speed of the feed motor and - starting / stopping electrode feed
...
The time rate of response for the current rise and fall
The negative side of a welding unit

29. With straight polarity where is 2/3 of the arc energy?
The negative side of a welding unit
Short- circuiting transfer - Globular transfer - Spray transfer
Shielding the molten weld metal from atmospheric contamination
National Electrical Manufactures Association

30. 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
5.8 to 12.5 L/min
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
These terms are quite restrictive and often technically incorrect

31. List the basic equipment requirements for the GMAW process
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Wire feed speed - Voltage control
Duty cycle
Dry ice can form within the flow control openings and cause blockage of shielding gas

32. What does voltage do in an electrical circuit?
To prevent leakage - Carbon Dioxide (CO2)
Voltage is the force that overcomes resistance to allow amperage flow
1/4 inch to 1/2 inch
Puddle fluidity

33. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
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)
Higher 26 to 35 arc volts
AWS and CSA

34. Why is globular transfer generally avoided with GMAW?
Penetration and burn - off rate of the electrode
Guns
Spatter problems and poor weld appearance
If you dont know this check your phone

35. Why must CO2 cylinders be used in the vertical position?
The time rate of response for the current rise and fall
Wire feed speed
By there current carrying capacity
To prevent drawing of liquid CO2 (Carbon Dioxide)

36. A 10 minute cycle of welding time vs cooling time a given machine can handle.
Duty cycle
Dry ice can form within the flow control openings and cause blockage of shielding gas
Pressure vessels and the piping industry
The time rate of response for the current rise and fall

37. What is an advantage of pulsed arc transfer with GMAW?
15 feet (4.5 meters)
Penetration and burn - off rate of the electrode
Duty cycle
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze

38. What is the required arc voltage used for short circuit transfer?
Penetration and burn - off rate of the electrode
The resistace to electrical current flow increases with it. Causing the electrode to heat
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 to 22 arc volts

39. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
85%
Speed of the feed motor and - starting / stopping electrode feed
SMAW - GTAW

40. What is the key advantage of short circuiting transfer?
Wire feed speed - Voltage control
By there current carrying capacity
Minimum distortion due to low heat input
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

41. What is the effect of too much slope?
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
Gives arc voltage values to the control system of the feeder
National Electrical Manufactures Association
Insufficient current to melt the wire off cleanly

42. In the GMAW process what does amperage control?
Aluminum wire
SMAW - GTAW
Penetration and burn - off rate of the electrode
Duty cycle

43. What is the purpose of a regulator and what does it indicate on its gauges?
Reducing the gas source pressure to a constant working pressure
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Constant- speed wire feeders and Voltage- sennsing wire feeders
Penetration and burn - off rate of the electrode

44. What does inductance control?
The time rate of response for the current rise and fall
Controls the rate of flow of a shielding gas to the gun nozzle
Aluminum wire
Duty cycle

45. What term is used to describe when the workpiece is hooked to the negative pole on the power source?
Duty cycle
(DCEP) Direct Current Electrode Positive or Reverse polarity
Gas metal arc welding
By there current carrying capacity

46. What type of power source is commonly used with a voltage sensing wire feeder?
If you dont know this check your phone
5.8 to 12.5 L/min
Constant current (CC)
12 to 22 arc volts

47. What 2 organizations designate specifications for GMAW wires?
AWS and CSA
15 feet (4.5 meters)
Short- circuiting transfer - Globular transfer - Spray transfer
Wire feeds smoothly (yet will slip should a problem occur in the gun)

48. Give a brief description of the GMAW process
Welding process that joins metals by heating them with an electric arc
15 feet (4.5 meters)
The Arc voltage
Minimum distortion due to low heat input

49. What is the preferred drive roll design for solid wires?
Wire feed speed
V groove or U groove
Voltage is the force that overcomes resistance to allow amperage flow
Constant- speed wire feeders and Voltage- sennsing wire feeders

50. What output on the welding machine is used to rate the duty cycle?
To prevent drawing of liquid CO2 (Carbon Dioxide)
Minutes of elapsed time continually run (out of 10 minutes)
National Electrical Manufactures Association
By there current carrying capacity