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. In the GMAW process what does voltage control?
Higher 26 to 35 arc volts
12 to 22 arc volts
V groove or U groove
Puddle fluidity

2. List 3 wire drive systems and give a short description of each
The time rate of response for the current rise and fall
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
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Wire feed speed

3. What does the wire feeder control?
Speed of the feed motor and - starting / stopping electrode feed
These terms are quite restrictive and often technically incorrect
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
Generally not as accurate

4. How are GMAW guns rated?
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
SMAW - GTAW
Constant current (CC)
By there current carrying capacity

5. What processes are constant current (CC) power sources designed to be used with?
3
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
SMAW - GTAW

6. What is another term for electrode holders for GMAW?
These terms are quite restrictive and often technically incorrect
Guns
Aluminum wire
Cause flaking - which can clog the liner and contact tube

7. Why must CO2 cylinders be used in the vertical position?
Duty cycle
To prevent drawing of liquid CO2 (Carbon Dioxide)
Wire feed speed
(DCEP) Direct Current Electrode Positive or Reverse polarity

8. What is the key advantage of short circuiting transfer?
20 to 200 times per second
Voltage is the force that overcomes resistance to allow amperage flow
Minimum distortion due to low heat input
Guns

9. List the basic equipment requirements for the GMAW process
If you dont know this check your phone
Speed of the feed motor and - starting / stopping electrode feed
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Spatter problems and poor weld appearance

10. What wire are knurled drive rolls most commonly used on?
The Arc voltage
(DCEP) Direct Current Electrode Positive or Reverse polarity
Reducing the gas source pressure to a constant working pressure
Flux cored wires

11. A pull type drive system is usually used on what type of material?
1/4 inch to 1/2 inch
Flux cored wires
Aluminum wire
3

12. A 10 minute cycle of welding time vs cooling time a given machine can handle.
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Guns
Duty cycle
If you dont know this check your phone

13. What does the abbreviation NEMA stand for?
The Arc voltage
SMAW - GTAW
National Electrical Manufactures Association
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground

14. What output on the welding machine is used to rate the duty cycle?
5.8 to 12.5 L/min
Minutes of elapsed time continually run (out of 10 minutes)
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
...

15. What is the reason glass 'tube' type flowmeters must have the tube mounted truly vertical?
...
Pressure - The rate of flow of a shielding gas
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Aluminum wire

16. What controls the wire speed on a voltage sensing wire feeder?
Constant- speed wire feeders and Voltage- sennsing wire feeders
If you dont know this check your phone
The Arc voltage
Insufficient current to melt the wire off cleanly

17. With straight polarity where is 2/3 of the arc energy?
To prevent drawing of liquid CO2 (Carbon Dioxide)
By there current carrying capacity
The negative side of a welding unit
Gives arc voltage values to the control system of the feeder

18. What 2 controls are found on a GMAW set- up?
Wire feed speed - Voltage control
Dry ice can form within the flow control openings and cause blockage of shielding gas
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
3

19. What is the effect of too much slope?
Penetration and burn - off rate of the electrode
Insufficient current to melt the wire off cleanly
Wire feed speed
Welding process that joins metals by heating them with an electric arc

20. Draw a typical volt amp curve for a machine that is designed for GMAW
5.8 to 12.5 L/min
The resistace to electrical current flow increases with it. Causing the electrode to heat
Gives arc voltage values to the control system of the feeder
If you dont know this check your phone

21. What does a flowmeter do and what does it measure?
Controls the rate of flow of a shielding gas to the gun nozzle
Short- circuiting transfer - Globular transfer - Spray transfer
Minutes of elapsed time continually run (out of 10 minutes)
If you dont know this check your phone

22. What is the purpose of the pick- up lead on a voltage sensing wire feeder?
Reducing the gas source pressure to a constant working pressure
Short- circuiting transfer - Globular transfer - Spray transfer
The resistace to electrical current flow increases with it. Causing the electrode to heat
Gives arc voltage values to the control system of the feeder

23. List the three methods of metal transfer with GMAW
Short- circuiting transfer - Globular transfer - Spray transfer
Constant current (CC)
To prevent drawing of liquid CO2 (Carbon Dioxide)
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts

24. What is the disadvantage of the gauge preset type of regulator/flowmeter?
85%
SMAW - GTAW
Wire feed speed - Voltage control
Generally not as accurate

25. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
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
3
SMAW - GTAW

26. What is the purpose of the shielding gas used in GMAW?
Wire feeds smoothly (yet will slip should a problem occur in the gun)
By there current carrying capacity
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Shielding the molten weld metal from atmospheric contamination

27. What is the required arc voltage used for short circuit transfer?
12 to 22 arc volts
AWS and CSA
The negative side of a welding unit
These terms are quite restrictive and often technically incorrect

28. What 2 organizations designate specifications for GMAW wires?
Duty cycle
Flux cored wires
Voltage is the force that overcomes resistance to allow amperage flow
AWS and CSA

29. Why is the term GMAW preferred over MIG or MAG?
Constant voltage (CV)
Reducing the gas source pressure to a constant working pressure
12 to 22 arc volts
These terms are quite restrictive and often technically incorrect

30. What does the term GMAW identify?
Short- circuiting transfer - Globular transfer - Spray transfer
To prevent drawing of liquid CO2 (Carbon Dioxide)
Gas metal arc welding
Pressure vessels and the piping industry

31. Why is a line heater required when using GMAW?
Gas metal arc welding
To prevent leakage - Carbon Dioxide (CO2)
Dry ice can form within the flow control openings and cause blockage of shielding gas
Generally not as accurate

32. What does inductance control?
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Wire feed speed - Voltage control
Penetration and burn - off rate of the electrode
The time rate of response for the current rise and fall

33. What effect does increasing and decreasing the inductance have on the weld?
Welding process that joins metals by heating them with an electric arc
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
Guns
Controls the rate of flow of a shielding gas to the gun nozzle

34. What controls amperage when using GMAW?
Speed of the feed motor and - starting / stopping electrode feed
5.8 to 12.5 L/min
Motor driven generators - Transformer rectifiers - and Inverter designs
Wire feed speed

35. What happens when the electrode extension is increased?
The Arc voltage
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
The resistace to electrical current flow increases with it. Causing the electrode to heat

36. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
85%
Gives arc voltage values to the control system of the feeder
Puddle fluidity
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts

37. What type of power source is used with a constant speed wire feeder?
Flux cored wires
Puddle fluidity
Constant voltage (CV)
15 feet (4.5 meters)

38. What are the 2 types of wire feeders available?
Flux cored wires
Constant- speed wire feeders and Voltage- sennsing wire feeders
Aluminum wire
Puddle fluidity

39. What term is used to describe when the workpiece is hooked to the negative pole on the power source?
Controls the rate of flow of a shielding gas to the gun nozzle
Constant current (CC)
(DCEP) Direct Current Electrode Positive or Reverse polarity
When the filler wire is in direct contract with the base metal

40. What is the recommended electrode stick- out for .035 solid wire?
Reducing the gas source pressure to a constant working pressure
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
To prevent drawing of liquid CO2 (Carbon Dioxide)
1/4 inch to 1/2 inch

41. What is the main purpose of 'slope'?
Minimum distortion due to low heat input
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Welding process that joins metals by heating them with an electric arc
To limit the short circuiting current so that spatter is reduced

42. What is an advantage of pulsed arc transfer with GMAW?
3
When the filler wire is in direct contract with the base metal
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Reducing the gas source pressure to a constant working pressure

43. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
Higher 26 to 35 arc volts
Gives arc voltage values to the control system of the feeder
Minimum distortion due to low heat input
Pressure vessels and the piping industry

44. What is the maximum distance that hard wire can be successfully pushed?
15 feet (4.5 meters)
Pressure vessels and the piping industry
Controls the rate of flow of a shielding gas to the gun nozzle
Minutes of elapsed time continually run (out of 10 minutes)

45. List 3 forms compressed gases may be supplied for welding
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
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
Reducing the gas source pressure to a constant working pressure

46. List several industries that would use GMAW
Pressure vessels and the piping industry
Penetration and burn - off rate of the electrode
Minimum distortion due to low heat input
AWS and CSA

47. What does voltage do in an electrical circuit?
...
Voltage is the force that overcomes resistance to allow amperage flow
When the filler wire is in direct contract with the base metal
Constant- speed wire feeders and Voltage- sennsing wire feeders

48. What is the purpose of a regulator and what does it indicate on its gauges?
The time rate of response for the current rise and fall
Short- circuiting transfer - Globular transfer - Spray transfer
Reducing the gas source pressure to a constant working pressure
3

49. When using flat drive rolls with too much pressure on copper coated solid wires what problem could take place?
Cause flaking - which can clog the liner and contact tube
Gas metal arc welding
(DCEP) Direct Current Electrode Positive or Reverse polarity
Shielding the molten weld metal from atmospheric contamination

50. What power sources are used with the GMAW Process?
1/4 inch to 1/2 inch
Cause flaking - which can clog the liner and contact tube
Minimum distortion due to low heat input
Motor driven generators - Transformer rectifiers - and Inverter designs