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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 reason glass 'tube' type flowmeters must have the tube mounted truly vertical?
These terms are quite restrictive and often technically incorrect
Cause flaking - which can clog the liner and contact tube
By there current carrying capacity
...

2. List several industries that would use GMAW
Pressure vessels and the piping industry
The negative side of a welding unit
3
Constant- speed wire feeders and Voltage- sennsing wire feeders

3. A pull type drive system is usually used on what type of material?
Aluminum wire
Spatter problems and poor weld appearance
The Arc voltage
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

4. 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)
Flux cored wires
20 to 200 times per second
Puddle fluidity

5. What processes are constant current (CC) power sources designed to be used with?
SMAW - GTAW
Spatter problems and poor weld appearance
Pressure vessels and the piping industry
Minutes of elapsed time continually run (out of 10 minutes)

6. What 2 organizations designate specifications for GMAW wires?
Flux cored wires
DCEP (Direct Current Electrode Positive) Reverse Polarity
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
AWS and CSA

7. Give a description of 'pinch effect'
Speed of the feed motor and - starting / stopping electrode feed
Generally not as accurate
By there current carrying capacity
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field

8. In the GMAW process what does voltage control?
Constant voltage (CV)
Aluminum wire
Puddle fluidity
Cause flaking - which can clog the liner and contact tube

9. What is the key advantage of short circuiting transfer?
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Gas metal arc welding
Minimum distortion due to low heat input
Pressure vessels and the piping industry

10. A 10 minute cycle of welding time vs cooling time a given machine can handle.
DCEP (Direct Current Electrode Positive) Reverse Polarity
V groove or U groove
Duty cycle
Puddle fluidity

11. What type of power source is commonly used with a voltage sensing wire feeder?
National Electrical Manufactures Association
Insufficient current to melt the wire off cleanly
Constant current (CC)
V groove or U groove

12. What is the maximum distance that hard wire can be successfully pushed?
15 feet (4.5 meters)
Welding process that joins metals by heating them with an electric arc
Aluminum wire
Puddle fluidity

13. What is the purpose of the pick- up lead on a voltage sensing wire feeder?
The resistace to electrical current flow increases with it. Causing the electrode to heat
Wire feed speed - Voltage control
Gives arc voltage values to the control system of the feeder
Generally not as accurate

14. What current and polarity is generally used with GMAW?
Guns
DCEP (Direct Current Electrode Positive) Reverse Polarity
AWS and CSA
Speed of the feed motor and - starting / stopping electrode feed

15. What 2 controls are found on a GMAW set- up?
Controls the rate of flow of a shielding gas to the gun nozzle
Wire feed speed - Voltage control
Minutes of elapsed time continually run (out of 10 minutes)
Short- circuiting transfer - Globular transfer - Spray transfer

16. Why must CO2 cylinders be used in the vertical position?
DCEP (Direct Current Electrode Positive) Reverse Polarity
Aluminum wire
To prevent drawing of liquid CO2 (Carbon Dioxide)
The resistace to electrical current flow increases with it. Causing the electrode to heat

17. With straight polarity where is 2/3 of the arc energy?
...
The negative side of a welding unit
Welding process that joins metals by heating them with an electric arc
12 to 22 arc volts

18. List the basic equipment requirements for the GMAW process
The Arc voltage
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Reducing the gas source pressure to a constant working pressure
20 to 200 times per second

19. What controls amperage when using GMAW?
Welding process that joins metals by heating them with an electric arc
Guns
Wire feed speed
V groove or U groove

20. What wire are knurled drive rolls most commonly used on?
Penetration and burn - off rate of the electrode
Gives arc voltage values to the control system of the feeder
3
Flux cored wires

21. What type of power source is used with a constant speed wire feeder?
To limit the short circuiting current so that spatter is reduced
3
(DCEP) Direct Current Electrode Positive or Reverse polarity
Constant voltage (CV)

22. Draw a typical volt amp curve for a machine that is designed for GMAW
The time rate of response for the current rise and fall
Controls the rate of flow of a shielding gas to the gun nozzle
If you dont know this check your phone
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field

23. When using flat drive rolls with too much pressure on copper coated solid wires what problem could take place?
Puddle fluidity
Cause flaking - which can clog the liner and contact tube
To prevent leakage - Carbon Dioxide (CO2)
Pressure vessels and the piping industry

24. What is the purpose of a regulator and what does it indicate on its gauges?
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
Voltage is the force that overcomes resistance to allow amperage flow
Reducing the gas source pressure to a constant working pressure
Welding process that joins metals by heating them with an electric arc

25. What does the wire feeder control?
Speed of the feed motor and - starting / stopping electrode feed
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
Controls the rate of flow of a shielding gas to the gun nozzle
Puddle fluidity

26. What power sources are used with the GMAW Process?
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Voltage is the force that overcomes resistance to allow amperage flow
Wire feed speed - Voltage control
Motor driven generators - Transformer rectifiers - and Inverter designs

27. List the factors that determine the mode of metal transfer
Duty cycle
The resistace to electrical current flow increases with it. Causing the electrode to heat
When the filler wire is in direct contract with the base metal
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

28. List 3 forms compressed gases may be supplied for welding
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Minimum distortion due to low heat input
Duty cycle
Constant- speed wire feeders and Voltage- sennsing wire feeders

29. What is the preferred drive roll design for solid wires?
The resistace to electrical current flow increases with it. Causing the electrode to heat
Wire feeds smoothly (yet will slip should a problem occur in the gun)
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

30. Draw a typical volt/amp curve that would be found with a power source designed for SMAW or GTAW
Gives arc voltage values to the control system of the feeder
If you dont know this check your phone
20 to 200 times per second
Shielding the molten weld metal from atmospheric contamination

31. What does the term GMAW identify?
Wire feed speed
1/4 inch to 1/2 inch
When the filler wire is in direct contract with the base metal
Gas metal arc welding

32. When is the metal transferred with short circuit transfer?
Motor driven generators - Transformer rectifiers - and Inverter designs
To limit the short circuiting current so that spatter is reduced
When the filler wire is in direct contract with the base metal
Higher 26 to 35 arc volts

33. In the GMAW process what does amperage control?
These terms are quite restrictive and often technically incorrect
Penetration and burn - off rate of the electrode
Flux cored wires
The negative side of a welding unit

34. What term is used to describe when the workpiece is hooked to the negative pole on the power source?
Wire feeds smoothly (yet will slip should a problem occur in the gun)
AWS and CSA
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 or Reverse polarity

35. What is the recommended electrode stick- out for .035 solid 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
1/4 inch to 1/2 inch
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Reducing the gas source pressure to a constant working pressure

36. List 3 wire drive systems and give a short description of each
(DCEP) Direct Current Electrode Positive or Reverse polarity
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
85%
Pressure - The rate of flow of a shielding gas

37. What does voltage do in an electrical circuit?
National Electrical Manufactures Association
12 to 22 arc volts
Voltage is the force that overcomes resistance to allow amperage flow
V groove or U groove

38. What does the abbreviation NEMA stand for?
Pressure vessels and the piping industry
Puddle fluidity
National Electrical Manufactures Association
Reducing the gas source pressure to a constant working pressure

39. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
15 feet (4.5 meters)
Voltage is the force that overcomes resistance to allow amperage flow
85%
Cause flaking - which can clog the liner and contact tube

40. What is another term for electrode holders for GMAW?
Generally not as accurate
Guns
Voltage is the force that overcomes resistance to allow amperage flow
These terms are quite restrictive and often technically incorrect

41. What happens when the electrode extension is increased?
(DCEP) Direct Current Electrode Positive or Reverse polarity
Wire feeds smoothly (yet will slip should a problem occur in the gun)
SMAW - GTAW
The resistace to electrical current flow increases with it. Causing the electrode to heat

42. How are GMAW guns rated?
By there current carrying capacity
...
Higher 26 to 35 arc volts
Duty cycle

43. What does inductance control?
Higher 26 to 35 arc volts
The Arc voltage
The time rate of response for the current rise and fall
If you dont know this check your phone

44. What controls the wire speed on a voltage sensing wire feeder?
DCEP (Direct Current Electrode Positive) Reverse Polarity
Gas metal arc welding
12 to 22 arc volts
The Arc voltage

45. Regulators control_____________ flowmeters SHOW____________.
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Flux cored wires
Pressure - The rate of flow of a shielding gas
The time rate of response for the current rise and fall

46. What is the disadvantage of the gauge preset type of regulator/flowmeter?
Gas metal arc welding
Gives arc voltage values to the control system of the feeder
Aluminum wire
Generally not as accurate

47. List the three methods of metal transfer with GMAW
Cause flaking - which can clog the liner and contact tube
Controls the rate of flow of a shielding gas to the gun nozzle
Short- circuiting transfer - Globular transfer - Spray transfer
Higher 26 to 35 arc volts

48. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
...
If you dont know this check your phone
Higher 26 to 35 arc volts
Puddle fluidity

49. What is the purpose of the shielding gas used in GMAW?
Aluminum wire
If you dont know this check your phone
(DCEP) Direct Current Electrode Positive or Reverse polarity
Shielding the molten weld metal from atmospheric contamination

50. What is a solenoid valve and what actuates it?
Puddle fluidity
...
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Motor driven generators - Transformer rectifiers - and Inverter designs