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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. Give a description of 'pinch effect'
Gas metal arc welding
Dry ice can form within the flow control openings and cause blockage of shielding gas
Aluminum wire
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field

2. What controls amperage when using GMAW?
Flux cored wires
Pressure vessels and the piping industry
Higher 26 to 35 arc volts
Wire feed speed

3. When using flat drive rolls with too much pressure on copper coated solid wires what problem could take place?
20 to 200 times per second
Cause flaking - which can clog the liner and contact tube
Reducing the gas source pressure to a constant working pressure
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

4. What term is used to describe when the workpiece is hooked to the negative pole on the power source?
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
SMAW - GTAW
Short- circuiting transfer - Globular transfer - Spray transfer
(DCEP) Direct Current Electrode Positive or Reverse polarity

5. What is the maximum distance that hard wire can be successfully pushed?
5.8 to 12.5 L/min
15 feet (4.5 meters)
Cause flaking - which can clog the liner and contact tube
To prevent leakage - Carbon Dioxide (CO2)

6. What is the recommended electrode stick- out for .035 solid wire?
Constant current (CC)
Minimum distortion due to low heat input
1/4 inch to 1/2 inch
When the filler wire is in direct contract with the base metal

7. What is the main purpose of 'slope'?
Constant current (CC)
Minutes of elapsed time continually run (out of 10 minutes)
To limit the short circuiting current so that spatter is reduced
Flux cored wires

8. What is the key advantage of short circuiting transfer?
Minimum distortion due to low heat input
The time rate of response for the current rise and fall
20 to 200 times per second
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts

9. What does voltage do in an electrical circuit?
Flux cored wires
The Arc voltage
Voltage is the force that overcomes resistance to allow amperage flow
These terms are quite restrictive and often technically incorrect

10. Regulators control_____________ flowmeters SHOW____________.
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Pressure - The rate of flow of a shielding gas
These terms are quite restrictive and often technically incorrect
Welding process that joins metals by heating them with an electric arc

11. In the GMAW process what does amperage control?
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
Penetration and burn - off rate of the electrode
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
12 to 22 arc volts

12. A pull type drive system is usually used on what type of material?
Welding process that joins metals by heating them with an electric arc
Pressure - The rate of flow of a shielding gas
DCEP (Direct Current Electrode Positive) Reverse Polarity
Aluminum wire

13. List 3 wire drive systems and give a short description of each
15 feet (4.5 meters)
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
Flux cored wires

14. What is the reason glass 'tube' type flowmeters must have the tube mounted truly vertical?
Shielding the molten weld metal from atmospheric contamination
...
Pressure vessels and the piping industry
Gives arc voltage values to the control system of the feeder

15. List several industries that would use GMAW
To limit the short circuiting current so that spatter is reduced
To prevent drawing of liquid CO2 (Carbon Dioxide)
Wire feed speed - Voltage control
Pressure vessels and the piping industry

16. With straight polarity where is 2/3 of the arc energy?
The negative side of a welding unit
15 feet (4.5 meters)
Short- circuiting transfer - Globular transfer - Spray transfer
The time rate of response for the current rise and fall

17. Why is a fiber washer required and what cylinder gas requires it?
Reducing the gas source pressure to a constant working pressure
Gas metal arc welding
Guns
To prevent leakage - Carbon Dioxide (CO2)

18. List 3 forms compressed gases may be supplied for welding
Penetration and burn - off rate of the electrode
Aluminum wire
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Welding process that joins metals by heating them with an electric arc

19. What is the preferred drive roll design for solid wires?
...
Gives arc voltage values to the control system of the feeder
V groove or U groove
Aluminum wire

20. What is another term for electrode holders for GMAW?
Insufficient current to melt the wire off cleanly
To prevent drawing of liquid CO2 (Carbon Dioxide)
Constant current (CC)
Guns

21. What does the wire feeder control?
Speed of the feed motor and - starting / stopping electrode feed
The Arc voltage
Motor driven generators - Transformer rectifiers - and Inverter designs
Shielding the molten weld metal from atmospheric contamination

22. What is a typical flow rate of CO2 for short circuit transfer?
To limit the short circuiting current so that spatter is reduced
1/4 inch to 1/2 inch
5.8 to 12.5 L/min
Gives arc voltage values to the control system of the feeder

23. What output on the welding machine is used to rate the duty cycle?
Minutes of elapsed time continually run (out of 10 minutes)
Constant current (CC)
Spatter problems and poor weld appearance
Short- circuiting transfer - Globular transfer - Spray transfer

24. Give a brief description of the GMAW process
Welding process that joins metals by heating them with an electric arc
Penetration and burn - off rate of the electrode
1/4 inch to 1/2 inch
Gas metal arc welding

25. What is the purpose of the shielding gas used in GMAW?
Higher 26 to 35 arc volts
Voltage is the force that overcomes resistance to allow amperage flow
Motor driven generators - Transformer rectifiers - and Inverter designs
Shielding the molten weld metal from atmospheric contamination

26. Draw a typical volt amp curve for a machine that is designed for GMAW
Constant voltage (CV)
Speed of the feed motor and - starting / stopping electrode feed
Controls the rate of flow of a shielding gas to the gun nozzle
If you dont know this check your phone

27. How are GMAW guns rated?
Controls the rate of flow of a shielding gas to the gun nozzle
By there current carrying capacity
To limit the short circuiting current so that spatter is reduced
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts

28. Why is globular transfer generally avoided with GMAW?
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Wire feed speed - Voltage control
Spatter problems and poor weld appearance
Wire feed speed

29. List the factors that determine the mode of metal transfer
Short- circuiting transfer - Globular transfer - Spray transfer
Controls the rate of flow of a shielding gas to the gun nozzle
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
85%

30. What does the term GMAW identify?
Puddle fluidity
Gives arc voltage values to the control system of the feeder
Gas metal arc welding
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground

31. What is the effect of too much slope?
Insufficient current to melt the wire off cleanly
Constant- speed wire feeders and Voltage- sennsing wire feeders
V groove or U groove
The resistace to electrical current flow increases with it. Causing the electrode to heat

32. Why must CO2 cylinders be used in the vertical position?
To prevent drawing of liquid CO2 (Carbon Dioxide)
Puddle fluidity
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
12 to 22 arc volts

33. A 10 minute cycle of welding time vs cooling time a given machine can handle.
Generally not as accurate
Duty cycle
Short- circuiting transfer - Globular transfer - Spray transfer
To prevent drawing of liquid CO2 (Carbon Dioxide)

34. Why is a line heater required when using GMAW?
Constant- speed wire feeders and Voltage- sennsing wire feeders
AWS and CSA
Dry ice can form within the flow control openings and cause blockage of shielding gas
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field

35. What controls the wire speed on a voltage sensing wire feeder?
The Arc voltage
Pressure - The rate of flow of a shielding gas
Constant- speed wire feeders and Voltage- sennsing wire feeders
Guns

36. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
Spatter problems and poor weld appearance
Higher 26 to 35 arc volts
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

37. What is the required arc voltage used for short circuit transfer?
Higher 26 to 35 arc volts
If you dont know this check your phone
12 to 22 arc volts
Spatter problems and poor weld appearance

38. 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
Guns
20 to 200 times per second
If you dont know this check your phone

39. What is a solenoid valve and what actuates it?
15 feet (4.5 meters)
SMAW - GTAW
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Short- circuiting transfer - Globular transfer - Spray transfer

40. What effect does increasing and decreasing the inductance have on the weld?
Flux cored wires
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
Reducing the gas source pressure to a constant working pressure

41. Why is the term GMAW preferred over MIG or MAG?
20 to 200 times per second
Short- circuiting transfer - Globular transfer - Spray transfer
These terms are quite restrictive and often technically incorrect
The time rate of response for the current rise and fall

42. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
1/4 inch to 1/2 inch
85%
To prevent leakage - Carbon Dioxide (CO2)
(DCEP) Direct Current Electrode Positive or Reverse polarity

43. What does the abbreviation NEMA stand for?
National Electrical Manufactures Association
Constant voltage (CV)
15 feet (4.5 meters)
3

44. How many times per second does short circuiting take place?
Controls the rate of flow of a shielding gas to the gun nozzle
Wire feed speed
20 to 200 times per second
If you dont know this check your phone

45. When is the metal transferred with short circuit transfer?
Constant voltage (CV)
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
AWS and CSA
When the filler wire is in direct contract with the base metal

46. What is the purpose of the pick- up lead on a voltage sensing wire feeder?
Shielding the molten weld metal from atmospheric contamination
Gives arc voltage values to the control system of the feeder
Penetration and burn - off rate of the electrode
Duty cycle

47. What type of power source is commonly used with a voltage sensing wire feeder?
Constant current (CC)
The time rate of response for the current rise and fall
Gas metal arc welding
Generally not as accurate

48. What would be an indication that the drive roll pressure is adjusted correctly?
Spatter problems and poor weld appearance
Wire feeds smoothly (yet will slip should a problem occur in the gun)
15 feet (4.5 meters)
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun

49. What happens when the electrode extension is increased?
Speed of the feed motor and - starting / stopping electrode feed
Shielding the molten weld metal from atmospheric contamination
The resistace to electrical current flow increases with it. Causing the electrode to heat
The Arc voltage

50. What 2 controls are found on a GMAW set- up?
Flux cored wires
Spatter problems and poor weld appearance
SMAW - GTAW
Wire feed speed - Voltage control