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 are the 2 types of wire feeders available?
These terms are quite restrictive and often technically incorrect
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Welding process that joins metals by heating them with an electric arc
Constant- speed wire feeders and Voltage- sennsing wire feeders

2. List the three methods of metal transfer with GMAW
Short- circuiting transfer - Globular transfer - Spray transfer
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Puddle fluidity
The Arc voltage

3. In the GMAW process what does voltage control?
Constant current (CC)
Puddle fluidity
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Wire feed speed

4. When using flat drive rolls with too much pressure on copper coated solid wires what problem could take place?
Constant- speed wire feeders and Voltage- sennsing wire feeders
Reducing the gas source pressure to a constant working pressure
Wire feed speed - Voltage control
Cause flaking - which can clog the liner and contact tube

5. What happens when the electrode extension is increased?
The resistace to electrical current flow increases with it. Causing the electrode to heat
...
National Electrical Manufactures Association
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

6. List the factors that determine the mode of metal transfer
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
AWS and CSA
The resistace to electrical current flow increases with it. Causing the electrode to heat
Reducing the gas source pressure to a constant working pressure

7. 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
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Wire feed speed

8. What is the effect of too much slope?
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Constant voltage (CV)
Insufficient current to melt the wire off cleanly
To prevent drawing of liquid CO2 (Carbon Dioxide)

9. What does the term GMAW identify?
Flux cored wires
Gas metal arc welding
Constant- speed wire feeders and Voltage- sennsing wire feeders
Penetration and burn - off rate of the electrode

10. Give a brief description of the GMAW process
Minutes of elapsed time continually run (out of 10 minutes)
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Wire feed speed
Welding process that joins metals by heating them with an electric arc

11. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
Wire feed speed - Voltage control
Higher 26 to 35 arc volts
To limit the short circuiting current so that spatter is reduced
Pressure vessels and the piping industry

12. A pull type drive system is usually used on what type of material?
SMAW - GTAW
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Aluminum wire
1/4 inch to 1/2 inch

13. List several industries that would use GMAW
Constant- speed wire feeders and Voltage- sennsing wire feeders
Pressure vessels and the piping industry
Flux cored wires
Guns

14. What 2 organizations designate specifications for GMAW wires?
The resistace to electrical current flow increases with it. Causing the electrode to heat
AWS and CSA
85%
Welding process that joins metals by heating them with an electric arc

15. What effect does increasing and decreasing the inductance have on the weld?
85%
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
Constant voltage (CV)

16. What power sources are used with the GMAW Process?
The Arc voltage
15 feet (4.5 meters)
Motor driven generators - Transformer rectifiers - and Inverter designs
Speed of the feed motor and - starting / stopping electrode feed

17. What processes are constant current (CC) power sources designed to be used with?
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
The Arc voltage
Duty cycle
SMAW - GTAW

18. When is the metal transferred with short circuit transfer?
When the filler wire is in direct contract with the base metal
Wire feed speed - Voltage control
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
The Arc voltage

19. What is the preferred drive roll design for solid wires?
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
To prevent drawing of liquid CO2 (Carbon Dioxide)
Guns
V groove or U groove

20. What is the purpose of the pick- up lead on a voltage sensing wire feeder?
Gives arc voltage values to the control system of the feeder
To limit the short circuiting current so that spatter is reduced
85%
AWS and CSA

21. With straight polarity where is 2/3 of the arc energy?
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Cause flaking - which can clog the liner and contact tube
The negative side of a welding unit
Penetration and burn - off rate of the electrode

22. What is the purpose of a regulator and what does it indicate on its gauges?
The Arc voltage
Pressure - The rate of flow of a shielding gas
Spatter problems and poor weld appearance
Reducing the gas source pressure to a constant working pressure

23. Regulators control_____________ flowmeters SHOW____________.
Constant current (CC)
Pressure - The rate of flow of a shielding gas
Aluminum wire
Cause flaking - which can clog the liner and contact tube

24. What type of power source is commonly used with a voltage sensing wire feeder?
...
20 to 200 times per second
Constant current (CC)
15 feet (4.5 meters)

25. What is the recommended electrode stick- out for .035 solid wire?
Speed of the feed motor and - starting / stopping electrode feed
1/4 inch to 1/2 inch
Insufficient current to melt the wire off cleanly
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze

26. What current and polarity is generally used with GMAW?
Minutes of elapsed time continually run (out of 10 minutes)
DCEP (Direct Current Electrode Positive) Reverse Polarity
Short- circuiting transfer - Globular transfer - Spray transfer
Gas metal arc welding

27. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
These terms are quite restrictive and often technically incorrect
If you dont know this check your phone
V groove or U groove
85%

28. What wire are knurled drive rolls most commonly used on?
The negative side of a welding unit
Generally not as accurate
Motor driven generators - Transformer rectifiers - and Inverter designs
Flux cored wires

29. What would be an indication that the drive roll pressure is adjusted correctly?
To limit the short circuiting current so that spatter is reduced
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Shielding the molten weld metal from atmospheric contamination

30. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
3
5.8 to 12.5 L/min
Wire feed speed - Voltage control
Speed of the feed motor and - starting / stopping electrode feed

31. Give a description of 'pinch effect'
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Cause flaking - which can clog the liner and contact tube
The negative side of a welding unit
Generally not as accurate

32. What controls amperage when using GMAW?
Wire feed speed
Pressure - The rate of flow of a shielding gas
AWS and CSA
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field

33. What does the abbreviation NEMA stand for?
Welding process that joins metals by heating them with an electric arc
When the filler wire is in direct contract with the base metal
National Electrical Manufactures Association
The time rate of response for the current rise and fall

34. What is a typical flow rate of CO2 for short circuit transfer?
Wire feed speed
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
5.8 to 12.5 L/min
(DCEP) Direct Current Electrode Positive or Reverse polarity

35. Why must CO2 cylinders be used in the vertical position?
National Electrical Manufactures Association
To limit the short circuiting current so that spatter is reduced
To prevent drawing of liquid CO2 (Carbon Dioxide)
Constant- speed wire feeders and Voltage- sennsing wire feeders

36. How are GMAW guns rated?
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
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
Duty cycle

37. What output on the welding machine is used to rate the duty cycle?
V groove or U groove
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Minutes of elapsed time continually run (out of 10 minutes)
3

38. How many times per second does short circuiting take place?
SMAW - GTAW
20 to 200 times per second
Wire feed speed - Voltage control
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun

39. What is another term for electrode holders for GMAW?
15 feet (4.5 meters)
Puddle fluidity
Guns
The resistace to electrical current flow increases with it. Causing the electrode to heat

40. What is the purpose of the shielding gas used in GMAW?
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Insufficient current to melt the wire off cleanly
Shielding the molten weld metal from atmospheric contamination
If you dont know this check your phone

41. A 10 minute cycle of welding time vs cooling time a given machine can handle.
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
Controls the rate of flow of a shielding gas to the gun nozzle
15 feet (4.5 meters)
Duty cycle

42. Why is globular transfer generally avoided with GMAW?
To limit the short circuiting current so that spatter is reduced
Guns
These terms are quite restrictive and often technically incorrect
Spatter problems and poor weld appearance

43. In the GMAW process what does amperage control?
Higher 26 to 35 arc volts
Constant current (CC)
Penetration and burn - off rate of the electrode
Minimum distortion due to low heat input

44. What is an advantage of pulsed arc transfer with GMAW?
Aluminum wire
Welding process that joins metals by heating them with an electric arc
Puddle fluidity
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze

45. What is the reason glass 'tube' type flowmeters must have the tube mounted truly vertical?
...
The Arc voltage
Puddle fluidity
Controls the rate of flow of a shielding gas to the gun nozzle

46. What is the main purpose of 'slope'?
Puddle fluidity
To limit the short circuiting current so that spatter is reduced
...
Penetration and burn - off rate of the electrode

47. What controls the wire speed on a voltage sensing wire feeder?
If you dont know this check your phone
12 to 22 arc volts
Minimum distortion due to low heat input
The Arc voltage

48. What type of power source is used with a constant speed wire feeder?
Constant voltage (CV)
20 to 200 times per second
The time rate of response for the current rise and fall
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts

49. Draw a typical volt/amp curve that would be found with a power source designed for SMAW or GTAW
20 to 200 times per second
If you dont know this check your phone
(DCEP) Direct Current Electrode Positive or Reverse polarity
Gives arc voltage values to the control system of the feeder

50. Why is the term GMAW preferred over MIG or MAG?
Flux cored wires
National Electrical Manufactures Association
Constant- speed wire feeders and Voltage- sennsing wire feeders
These terms are quite restrictive and often technically incorrect