Test your basic knowledge |

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 controls the wire speed on a voltage sensing wire feeder?
(DCEP) Direct Current Electrode Positive or Reverse polarity
20 to 200 times per second
The Arc voltage
If you dont know this check your phone

2. What is a typical flow rate of CO2 for short circuit transfer?
5.8 to 12.5 L/min
15 feet (4.5 meters)
Shielding the molten weld metal from atmospheric contamination
Gives arc voltage values to the control system of the feeder

3. What power sources are used with the GMAW Process?
When the filler wire is in direct contract with the base metal
Motor driven generators - Transformer rectifiers - and Inverter designs
20 to 200 times per second
DCEP (Direct Current Electrode Positive) Reverse Polarity

4. What is the key advantage of short circuiting transfer?
When the filler wire is in direct contract with the base metal
If you dont know this check your phone
Minimum distortion due to low heat input
Spatter problems and poor weld appearance

5. What is the reason glass 'tube' type flowmeters must have the tube mounted truly vertical?
...
Spatter problems and poor weld appearance
Aluminum wire
Flux cored wires

6. List several industries that would use GMAW
Flux cored wires
Pressure vessels and the piping industry
V groove or U groove
SMAW - GTAW

7. What is the preferred drive roll design for solid wires?
To prevent leakage - Carbon Dioxide (CO2)
V groove or U groove
Motor driven generators - Transformer rectifiers - and Inverter designs
To prevent drawing of liquid CO2 (Carbon Dioxide)

8. Draw a typical volt/amp curve that would be found with a power source designed for SMAW or GTAW
Gas metal arc welding
Pressure vessels and the piping industry
If you dont know this check your phone
Aluminum wire

9. What is a solenoid valve and what actuates it?
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Controls the rate of flow of a shielding gas to the gun nozzle
Flux cored wires
Constant voltage (CV)

10. A 10 minute cycle of welding time vs cooling time a given machine can handle.
...
1/4 inch to 1/2 inch
Duty cycle
The time rate of response for the current rise and fall

11. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
Minutes of elapsed time continually run (out of 10 minutes)
By there current carrying capacity
Speed of the feed motor and - starting / stopping electrode feed
3

12. Why must CO2 cylinders be used in the vertical position?
These terms are quite restrictive and often technically incorrect
5.8 to 12.5 L/min
To prevent drawing of liquid CO2 (Carbon Dioxide)
20 to 200 times per second

13. What does the wire feeder control?
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Speed of the feed motor and - starting / stopping electrode feed
Constant- speed wire feeders and Voltage- sennsing wire feeders
15 feet (4.5 meters)

14. What is the maximum distance that hard wire can be successfully pushed?
Wire feed speed
15 feet (4.5 meters)
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Aluminum wire

15. How are GMAW guns rated?
Controls the rate of flow of a shielding gas to the gun nozzle
By there current carrying capacity
Penetration and burn - off rate of the electrode
Pressure - The rate of flow of a shielding gas

16. What is the effect of too much slope?
Voltage is the force that overcomes resistance to allow amperage flow
When the filler wire is in direct contract with the base metal
Gives arc voltage values to the control system of the feeder
Insufficient current to melt the wire off cleanly

17. List the three methods of metal transfer with GMAW
3
Gas metal arc welding
AWS and CSA
Short- circuiting transfer - Globular transfer - Spray transfer

18. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
85%
To prevent drawing of liquid CO2 (Carbon Dioxide)
SMAW - GTAW
Insufficient current to melt the wire off cleanly

19. What term is used to describe when the workpiece is hooked to the negative pole on the power source?
The negative side of a welding unit
Wire feed speed - Voltage control
If you dont know this check your phone
(DCEP) Direct Current Electrode Positive or Reverse polarity

20. Why is globular transfer generally avoided with GMAW?
85%
Spatter problems and poor weld appearance
The Arc voltage
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze

21. When is the metal transferred with short circuit transfer?
Speed of the feed motor and - starting / stopping electrode feed
Wire feeds smoothly (yet will slip should a problem occur in the gun)
When the filler wire is in direct contract with the base metal
To prevent leakage - Carbon Dioxide (CO2)

22. Regulators control_____________ flowmeters SHOW____________.
Reducing the gas source pressure to a constant working pressure
Controls the rate of flow of a shielding gas to the gun nozzle
The Arc voltage
Pressure - The rate of flow of a shielding gas

23. What would be an indication that the drive roll pressure is adjusted correctly?
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Gives arc voltage values to the control system of the feeder
Gas metal arc welding

24. What does voltage do in an electrical circuit?
The Arc voltage
The time rate of response for the current rise and fall
If you dont know this check your phone
Voltage is the force that overcomes resistance to allow amperage flow

25. A pull type drive system is usually used on what type of material?
Aluminum wire
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
DCEP (Direct Current Electrode Positive) 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

26. What is the main purpose of 'slope'?
The negative side of a welding unit
To limit the short circuiting current so that spatter is reduced
Motor driven generators - Transformer rectifiers - and Inverter designs
Wire feed speed - Voltage control

27. When using flat drive rolls with too much pressure on copper coated solid wires what problem could take place?
Welding process that joins metals by heating them with an electric arc
Cause flaking - which can clog the liner and contact tube
Short- circuiting transfer - Globular transfer - Spray transfer
When the filler wire is in direct contract with the base metal

28. What is the disadvantage of the gauge preset type of regulator/flowmeter?
Constant voltage (CV)
Generally not as accurate
20 to 200 times per second
Wire feeds smoothly (yet will slip should a problem occur in the gun)

29. What output on the welding machine is used to rate the duty cycle?
Minutes of elapsed time continually run (out of 10 minutes)
V groove or U groove
Dry ice can form within the flow control openings and cause blockage of shielding gas
Constant voltage (CV)

30. What is the required arc voltage used for short circuit transfer?
When the filler wire is in direct contract with the base metal
(DCEP) Direct Current Electrode Positive or Reverse polarity
These terms are quite restrictive and often technically incorrect
12 to 22 arc volts

31. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
Pressure vessels and the piping industry
Gas metal arc welding
15 feet (4.5 meters)
Higher 26 to 35 arc volts

32. What controls amperage when using GMAW?
Wire feed speed
AWS and CSA
Insufficient current to melt the wire off cleanly
If you dont know this check your phone

33. With straight polarity where is 2/3 of the arc energy?
Controls the rate of flow of a shielding gas to the gun nozzle
Dry ice can form within the flow control openings and cause blockage of shielding gas
Guns
The negative side of a welding unit

34. Why is the term GMAW preferred over MIG or MAG?
Flux cored wires
Insufficient current to melt the wire off cleanly
These terms are quite restrictive and often technically incorrect
To prevent drawing of liquid CO2 (Carbon Dioxide)

35. List 3 wire drive systems and give a short description of each
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
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
DCEP (Direct Current Electrode Positive) Reverse Polarity
Gas metal arc welding

36. What 2 controls are found on a GMAW set- up?
If you dont know this check your phone
Minutes of elapsed time continually run (out of 10 minutes)
1/4 inch to 1/2 inch
Wire feed speed - Voltage control

37. Why is a line heater required when using GMAW?
Voltage is the force that overcomes resistance to allow amperage flow
Duty cycle
If you dont know this check your phone
Dry ice can form within the flow control openings and cause blockage of shielding gas

38. What is the recommended electrode stick- out for .035 solid wire?
Dry ice can form within the flow control openings and cause blockage of shielding gas
1/4 inch to 1/2 inch
AWS and CSA
Spatter problems and poor weld appearance

39. What current and polarity is generally used with GMAW?
Speed of the feed motor and - starting / stopping electrode feed
Aluminum wire
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
DCEP (Direct Current Electrode Positive) Reverse Polarity

40. In the GMAW process what does amperage control?
20 to 200 times per second
Penetration and burn - off rate of the electrode
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

41. List the basic equipment requirements for the GMAW process
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Controls the rate of flow of a shielding gas to the gun nozzle
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Minutes of elapsed time continually run (out of 10 minutes)

42. What is an advantage of pulsed arc transfer with GMAW?
To prevent leakage - Carbon Dioxide (CO2)
Flux cored wires
To prevent drawing of liquid CO2 (Carbon Dioxide)
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze

43. What does the term GMAW identify?
The resistace to electrical current flow increases with it. Causing the electrode to heat
Gas metal arc welding
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Wire feeds smoothly (yet will slip should a problem occur in the gun)

44. What is the purpose of a regulator and what does it indicate on its gauges?
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Pressure vessels and the piping industry
Reducing the gas source pressure to a constant working pressure
The negative side of a welding unit

45. List the factors that determine the mode of metal transfer
The negative side of a welding unit
Shielding the molten weld metal from atmospheric contamination
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
...

46. Give a brief description of the GMAW process
To prevent drawing of liquid CO2 (Carbon Dioxide)
12 to 22 arc volts
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
Welding process that joins metals by heating them with an electric arc

47. Give a description of 'pinch effect'
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
12 to 22 arc volts
These terms are quite restrictive and often technically incorrect

48. What type of power source is commonly used with a voltage sensing wire feeder?
To limit the short circuiting current so that spatter is reduced
Cause flaking - which can clog the liner and contact tube
Constant current (CC)
If you dont know this check your phone

49. Draw a typical volt amp curve for a machine that is designed for GMAW
Short- circuiting transfer - Globular transfer - Spray transfer
Wire feed speed
If you dont know this check your phone
20 to 200 times per second

50. Why is a fiber washer required and what cylinder gas requires it?
Motor driven generators - Transformer rectifiers - and Inverter designs
To prevent leakage - Carbon Dioxide (CO2)
1/4 inch to 1/2 inch
Cause flaking - which can clog the liner and contact tube