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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 the abbreviation NEMA stand for?
National Electrical Manufactures Association
1/4 inch to 1/2 inch
The Arc voltage
The resistace to electrical current flow increases with it. Causing the electrode to heat

2. Why is a fiber washer required and what cylinder gas requires it?
Aluminum wire
15 feet (4.5 meters)
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

3. What does voltage do in an electrical circuit?
Speed of the feed motor and - starting / stopping electrode feed
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
Constant- speed wire feeders and Voltage- sennsing wire feeders

4. What is the key advantage of short circuiting transfer?
1/4 inch to 1/2 inch
Minimum distortion due to low heat input
...
By there current carrying capacity

5. What is a solenoid valve and what actuates it?
When the filler wire is in direct contract with the base metal
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
Voltage is the force that overcomes resistance to allow amperage flow

6. What effect does increasing and decreasing the inductance have on the weld?
National Electrical Manufactures Association
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
Gas metal arc welding
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun

7. List 3 forms compressed gases may be supplied for welding
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
SMAW - GTAW
By there current carrying capacity
Penetration and burn - off rate of the electrode

8. What is the preferred drive roll design for solid wires?
To prevent leakage - Carbon Dioxide (CO2)
V groove or U groove
Higher 26 to 35 arc volts
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. In the GMAW process what does voltage control?
Puddle fluidity
V groove or U groove
Gas metal arc welding
Motor driven generators - Transformer rectifiers - and Inverter designs

10. What power sources are used with the GMAW Process?
The resistace to electrical current flow increases with it. Causing the electrode to heat
The negative side of a welding unit
Motor driven generators - Transformer rectifiers - and Inverter designs
Cause flaking - which can clog the liner and contact tube

11. What type of power source is used with a constant speed wire feeder?
Constant voltage (CV)
The Arc voltage
To prevent drawing of liquid CO2 (Carbon Dioxide)
The negative side of a welding unit

12. What current and polarity is generally used with GMAW?
20 to 200 times per second
DCEP (Direct Current Electrode Positive) Reverse Polarity
Duty cycle
Constant voltage (CV)

13. What is the recommended electrode stick- out for .035 solid wire?
Penetration and burn - off rate of the electrode
SMAW - GTAW
1/4 inch to 1/2 inch
The negative side of a welding unit

14. What 2 controls are found on a GMAW set- up?
85%
Voltage is the force that overcomes resistance to allow amperage flow
Constant- speed wire feeders and Voltage- sennsing wire feeders
Wire feed speed - Voltage control

15. What term is used to describe when the workpiece is hooked to the negative pole on the power source?
(DCEP) Direct Current Electrode Positive or Reverse polarity
To limit the short circuiting current so that spatter is reduced
These terms are quite restrictive and often technically incorrect
Insufficient current to melt the wire off cleanly

16. What controls amperage when using GMAW?
SMAW - GTAW
To prevent drawing of liquid CO2 (Carbon Dioxide)
Wire feed speed
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground

17. List the basic equipment requirements for the GMAW process
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
To limit the short circuiting current so that spatter is reduced
Penetration and burn - off rate of the electrode
Duty cycle

18. How many times per second does short circuiting take place?
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
20 to 200 times per second
...
These terms are quite restrictive and often technically incorrect

19. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
3
Insufficient current to melt the wire off cleanly
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
15 feet (4.5 meters)

20. What is the disadvantage of the gauge preset type of regulator/flowmeter?
Wire feed speed
Generally not as accurate
DCEP (Direct Current Electrode Positive) Reverse Polarity
Penetration and burn - off rate of the electrode

21. What processes are constant current (CC) power sources designed to be used with?
Wire feed speed - Voltage control
SMAW - GTAW
Aluminum wire
Reducing the gas source pressure to a constant working pressure

22. What is the purpose of a regulator and what does it indicate on its gauges?
Aluminum wire
Reducing the gas source pressure to a constant working pressure
3
When the filler wire is in direct contract with the base metal

23. What does a flowmeter do and what does it measure?
Controls the rate of flow of a shielding gas to the gun nozzle
Wire feeds smoothly (yet will slip should a problem occur in the gun)
To limit the short circuiting current so that spatter is reduced
To prevent drawing of liquid CO2 (Carbon Dioxide)

24. What type of power source is commonly used with a voltage sensing wire feeder?
3
5.8 to 12.5 L/min
National Electrical Manufactures Association
Constant current (CC)

25. List 3 wire drive systems and give a short description of each
Generally not as accurate
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
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Gas metal arc welding

26. Draw a typical volt/amp curve that would be found with a power source designed for SMAW or GTAW
Dry ice can form within the flow control openings and cause blockage of shielding gas
If you dont know this check your phone
20 to 200 times per second
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun

27. Why is a line heater required when using GMAW?
20 to 200 times per second
Dry ice can form within the flow control openings and cause blockage of shielding gas
AWS and CSA
Constant voltage (CV)

28. Give a brief description of the GMAW process
V groove or U groove
Welding process that joins metals by heating them with an electric arc
To limit the short circuiting current so that spatter is reduced
Wire feed speed

29. How are GMAW guns rated?
If you dont know this check your phone
Pressure - The rate of flow of a shielding gas
Aluminum wire
By there current carrying capacity

30. What happens when the electrode extension is increased?
To prevent leakage - Carbon Dioxide (CO2)
The resistace to electrical current flow increases with it. Causing the electrode to heat
Minutes of elapsed time continually run (out of 10 minutes)
20 to 200 times per second

31. What controls the wire speed on a voltage sensing wire feeder?
Cause flaking - which can clog the liner and contact tube
The Arc voltage
Constant voltage (CV)
These terms are quite restrictive and often technically incorrect

32. What output on the welding machine is used to rate the duty cycle?
Motor driven generators - Transformer rectifiers - and Inverter designs
Minutes of elapsed time continually run (out of 10 minutes)
Aluminum wire
...

33. Why must CO2 cylinders be used in the vertical position?
AWS and CSA
To prevent drawing of liquid CO2 (Carbon Dioxide)
SMAW - GTAW
Guns

34. What is an advantage of pulsed arc transfer with GMAW?
Guns
Motor driven generators - Transformer rectifiers - and Inverter designs
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Cause flaking - which can clog the liner and contact tube

35. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
85%
Reducing the gas source pressure to a constant working pressure
Puddle fluidity
The negative side of a welding unit

36. What is the effect of too much slope?
Penetration and burn - off rate of the electrode
Insufficient current to melt the wire off cleanly
Guns
Cause flaking - which can clog the liner and contact tube

37. In the GMAW process what does amperage control?
Penetration and burn - off rate of the electrode
Controls the rate of flow of a shielding gas to the gun nozzle
Pressure vessels and the piping industry
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

38. What is the required arc voltage used for short circuit transfer?
5.8 to 12.5 L/min
Short- circuiting transfer - Globular transfer - Spray transfer
12 to 22 arc volts
Reducing the gas source pressure to a constant working pressure

39. Why is globular transfer generally avoided with GMAW?
Spatter problems and poor weld appearance
15 feet (4.5 meters)
20 to 200 times per second
Welding process that joins metals by heating them with an electric arc

40. What is the maximum distance that hard wire can be successfully pushed?
Constant current (CC)
15 feet (4.5 meters)
Speed of the feed motor and - starting / stopping electrode feed
When the filler wire is in direct contract with the base metal

41. List the factors that determine the mode of metal transfer
85%
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Dry ice can form within the flow control openings and cause blockage of shielding gas
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system

42. What is the main purpose of 'slope'?
...
Constant current (CC)
Wire feeds smoothly (yet will slip should a problem occur in the gun)
To limit the short circuiting current so that spatter is reduced

43. A pull type drive system is usually used on what type of material?
Aluminum wire
Dry ice can form within the flow control openings and cause blockage of shielding gas
Controls the rate of flow of a shielding gas to the gun nozzle
...

44. What would be an indication that the drive roll pressure is adjusted correctly?
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
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Pressure - The rate of flow of a shielding gas

45. With straight polarity where is 2/3 of the arc energy?
The negative side of a welding unit
12 to 22 arc volts
Minimum distortion due to low heat input
85%

46. Give a description of 'pinch effect'
...
Pressure vessels and the piping industry
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Constant voltage (CV)

47. What is the purpose of the shielding gas used in GMAW?
Shielding the molten weld metal from atmospheric contamination
Voltage is the force that overcomes resistance to allow amperage flow
When the filler wire is in direct contract with the base metal
National Electrical Manufactures Association

48. A 10 minute cycle of welding time vs cooling time a given machine can handle.
Shielding the molten weld metal from atmospheric contamination
Gas metal arc welding
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Duty cycle

49. What wire are knurled drive rolls most commonly used on?
5.8 to 12.5 L/min
These terms are quite restrictive and often technically incorrect
Flux cored wires
Higher 26 to 35 arc volts

50. List the three methods of metal transfer with GMAW
Flux cored wires
Short- circuiting transfer - Globular transfer - Spray transfer
To limit the short circuiting current so that spatter is reduced
Reducing the gas source pressure to a constant working pressure