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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 voltage do in an electrical circuit?
20 to 200 times per second
When the filler wire is in direct contract with the base metal
Short- circuiting transfer - Globular transfer - Spray transfer
Voltage is the force that overcomes resistance to allow amperage flow

2. When is the metal transferred with short circuit transfer?
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Gas metal arc welding
When the filler wire is in direct contract with the base metal
Pressure vessels and the piping industry

3. What happens when the electrode extension is increased?
3
Controls the rate of flow of a shielding gas to the gun nozzle
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

4. Regulators control_____________ flowmeters SHOW____________.
Constant- speed wire feeders and Voltage- sennsing wire feeders
The negative side of a welding unit
Reducing the gas source pressure to a constant working pressure
Pressure - The rate of flow of a shielding gas

5. What 2 organizations designate specifications for GMAW wires?
The time rate of response for the current rise and fall
AWS and CSA
Pressure - The rate of flow of a shielding gas
1/4 inch to 1/2 inch

6. What does the wire feeder control?
Speed of the feed motor and - starting / stopping electrode feed
If you dont know this check your phone
Spatter problems and poor weld appearance
5.8 to 12.5 L/min

7. Why is globular transfer generally avoided with GMAW?
Spatter problems and poor weld appearance
The Arc voltage
20 to 200 times per second
Pressure vessels and the piping industry

8. What is the recommended electrode stick- out for .035 solid wire?
SMAW - GTAW
1/4 inch to 1/2 inch
Pressure vessels and the piping industry
...

9. What is a solenoid valve and what actuates it?
Flux cored wires
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
85%
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun

10. What is the reason glass 'tube' type flowmeters must have the tube mounted truly vertical?
By there current carrying capacity
...
1/4 inch to 1/2 inch
Constant current (CC)

11. What does the term GMAW identify?
Duty cycle
Gas metal arc welding
15 feet (4.5 meters)
12 to 22 arc volts

12. List the basic equipment requirements for the GMAW process
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Spatter problems and poor weld appearance
Wire feed speed - Voltage control
15 feet (4.5 meters)

13. What is the effect of too much slope?
Insufficient current to melt the wire off cleanly
When the filler wire is in direct contract with the base metal
Minimum distortion due to low heat input
The resistace to electrical current flow increases with it. Causing the electrode to heat

14. What is the preferred drive roll design for solid wires?
85%
Welding process that joins metals by heating them with an electric arc
V groove or U groove
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun

15. How many times per second does short circuiting take place?
The time rate of response for the current rise and fall
20 to 200 times per second
Pressure - The rate of flow of a shielding gas
Wire feed speed - Voltage control

16. List 3 forms compressed gases may be supplied for welding
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Welding process that joins metals by heating them with an electric arc
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Puddle fluidity

17. Why must CO2 cylinders be used in the vertical position?
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
1/4 inch to 1/2 inch
Wire feed speed
To prevent drawing of liquid CO2 (Carbon Dioxide)

18. A 10 minute cycle of welding time vs cooling time a given machine can handle.
Minimum distortion due to low heat input
Constant current (CC)
DCEP (Direct Current Electrode Positive) Reverse Polarity
Duty cycle

19. What does the abbreviation NEMA stand for?
12 to 22 arc volts
National Electrical Manufactures Association
1/4 inch to 1/2 inch
When the filler wire is in direct contract with the base metal

20. A pull type drive system is usually used on what type of material?
Aluminum wire
15 feet (4.5 meters)
...
These terms are quite restrictive and often technically incorrect

21. In the GMAW process what does voltage control?
5.8 to 12.5 L/min
Puddle fluidity
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Minutes of elapsed time continually run (out of 10 minutes)

22. List the three methods of metal transfer with GMAW
Short- circuiting transfer - Globular transfer - Spray transfer
To prevent leakage - Carbon Dioxide (CO2)
Dry ice can form within the flow control openings and cause blockage of shielding gas
85%

23. What power sources are used with the GMAW Process?
The time rate of response for the current rise and fall
Constant- speed wire feeders and Voltage- sennsing wire feeders
Motor driven generators - Transformer rectifiers - and Inverter designs
Pressure vessels and the piping industry

24. List the factors that determine the mode of metal transfer
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
3
DCEP (Direct Current Electrode Positive) Reverse Polarity
Flux cored wires

25. With straight polarity where is 2/3 of the arc energy?
Generally not as accurate
Controls the rate of flow of a shielding gas to the gun nozzle
The negative side of a welding unit
Reducing the gas source pressure to a constant working pressure

26. What are the 2 types of wire feeders available?
V groove or U groove
Minutes of elapsed time continually run (out of 10 minutes)
Short- circuiting transfer - Globular transfer - Spray transfer
Constant- speed wire feeders and Voltage- sennsing wire feeders

27. What processes are constant current (CC) power sources designed to be used with?
Constant- speed wire feeders and Voltage- sennsing wire feeders
SMAW - GTAW
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Spatter problems and poor weld appearance

28. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
Reducing the gas source pressure to a constant working pressure
Higher 26 to 35 arc volts
Welding process that joins metals by heating them with an electric arc
These terms are quite restrictive and often technically incorrect

29. What does inductance control?
SMAW - GTAW
Wire feed speed - Voltage control
Generally not as accurate
The time rate of response for the current rise and fall

30. What effect does increasing and decreasing the inductance have on the weld?
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
If you dont know this check your phone
Pressure vessels and the piping industry

31. What does a flowmeter do and what does it measure?
These terms are quite restrictive and often technically incorrect
Controls the rate of flow of a shielding gas to the gun nozzle
If you dont know this check your phone
Wire feed speed - Voltage control

32. Draw a typical volt amp curve for a machine that is designed for GMAW
Pressure vessels and the piping industry
If you dont know this check your phone
The resistace to electrical current flow increases with it. Causing the electrode to heat
Shielding the molten weld metal from atmospheric contamination

33. What is another term for electrode holders for GMAW?
Gas metal arc welding
Guns
By there current carrying capacity
...

34. In the GMAW process what does amperage control?
Penetration and burn - off rate of the electrode
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
These terms are quite restrictive and often technically incorrect

35. Draw a typical volt/amp curve that would be found with a power source designed for SMAW or GTAW
Penetration and burn - off rate of the electrode
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
If you dont know this check your phone
Welding process that joins metals by heating them with an electric arc

36. What is the main purpose of 'slope'?
Guns
Generally not as accurate
To prevent leakage - Carbon Dioxide (CO2)
To limit the short circuiting current so that spatter is reduced

37. What is the disadvantage of the gauge preset type of regulator/flowmeter?
Generally not as accurate
V groove or U groove
15 feet (4.5 meters)
National Electrical Manufactures Association

38. What is a typical flow rate of CO2 for short circuit transfer?
20 to 200 times per second
5.8 to 12.5 L/min
Puddle fluidity
Reducing the gas source pressure to a constant working pressure

39. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
Reducing the gas source pressure to a constant working pressure
3
Gives arc voltage values to the control system of the feeder
(DCEP) Direct Current Electrode Positive or Reverse polarity

40. What type of power source is commonly used with a voltage sensing wire feeder?
National Electrical Manufactures Association
If you dont know this check your phone
Generally not as accurate
Constant current (CC)

41. What is the purpose of the shielding gas used in GMAW?
The resistace to electrical current flow increases with it. Causing the electrode to heat
Aluminum wire
Shielding the molten weld metal from atmospheric contamination
5.8 to 12.5 L/min

42. What term is used to describe when the workpiece is hooked to the negative pole on the power source?
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
SMAW - GTAW
(DCEP) Direct Current Electrode Positive or Reverse polarity
Puddle fluidity

43. What 2 controls are found on a GMAW set- up?
Pressure vessels and the piping industry
Pressure - The rate of flow of a shielding gas
Wire feed speed - Voltage 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

44. What wire are knurled drive rolls most commonly used on?
Flux cored wires
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Dry ice can form within the flow control openings and cause blockage of shielding gas
1/4 inch to 1/2 inch

45. What controls amperage when using GMAW?
Wire feed speed
Generally not as accurate
Spatter problems and poor weld appearance
To prevent leakage - Carbon Dioxide (CO2)

46. How are GMAW guns rated?
Spatter problems and poor weld appearance
Guns
The Arc voltage
By there current carrying capacity

47. When using flat drive rolls with too much pressure on copper coated solid wires what problem could take place?
Flux cored wires
Penetration and burn - off rate of the electrode
When the filler wire is in direct contract with the base metal
Cause flaking - which can clog the liner and contact tube

48. Why is the term GMAW preferred over MIG or MAG?
85%
Constant current (CC)
These terms are quite restrictive and often technically incorrect
Insufficient current to melt the wire off cleanly

49. What is the required arc voltage used for short circuit transfer?
The time rate of response for the current rise and fall
Spatter problems and poor weld appearance
12 to 22 arc volts
To prevent drawing of liquid CO2 (Carbon Dioxide)

50. What is an advantage of pulsed arc transfer with GMAW?
Flux cored wires
Guns
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