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. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
Wire feeds smoothly (yet will slip should a problem occur in the gun)
15 feet (4.5 meters)
Higher 26 to 35 arc volts
Duty cycle

2. What wire are knurled drive rolls most commonly used on?
DCEP (Direct Current Electrode Positive) Reverse Polarity
Wire feed speed
...
Flux cored wires

3. What is the purpose of a regulator and what does it indicate on its gauges?
Short- circuiting transfer - Globular transfer - Spray transfer
Reducing the gas source pressure to a constant working pressure
Constant current (CC)
Voltage is the force that overcomes resistance to allow amperage flow

4. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
SMAW - GTAW
Spatter problems and poor weld appearance
Duty cycle
85%

5. What is the required arc voltage used for short circuit transfer?
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
Aluminum wire
12 to 22 arc volts
Gives arc voltage values to the control system of the feeder

6. What type of power source is used with a constant speed wire feeder?
Constant voltage (CV)
1/4 inch to 1/2 inch
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Pressure vessels and the piping industry

7. What is the purpose of the shielding gas used in GMAW?
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Shielding the molten weld metal from atmospheric contamination
National Electrical Manufactures Association
The negative side of a welding unit

8. What is another term for electrode holders for GMAW?
Speed of the feed motor and - starting / stopping electrode feed
Controls the rate of flow of a shielding gas to the gun nozzle
Pressure vessels and the piping industry
Guns

9. What power sources are used with the GMAW Process?
Motor driven generators - Transformer rectifiers - and Inverter designs
The resistace to electrical current flow increases with it. Causing the electrode to heat
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Constant- speed wire feeders and Voltage- sennsing wire feeders

10. When is the metal transferred with short circuit transfer?
Duty cycle
V groove or U groove
(DCEP) Direct Current Electrode Positive or Reverse polarity
When the filler wire is in direct contract with the base metal

11. Why is the term GMAW preferred over MIG or MAG?
These terms are quite restrictive and often technically incorrect
Minutes of elapsed time continually run (out of 10 minutes)
The negative side of a welding unit
Minimum distortion due to low heat input

12. What type of power source is commonly used with a voltage sensing wire feeder?
If you dont know this check your phone
Gives arc voltage values to the control system of the feeder
Constant current (CC)
To limit the short circuiting current so that spatter is reduced

13. Draw a typical volt amp curve for a machine that is designed for GMAW
Welding process that joins metals by heating them with an electric arc
If you dont know this check your phone
Duty cycle
Speed of the feed motor and - starting / stopping electrode feed

14. What is the key advantage of short circuiting transfer?
Penetration and burn - off rate of the electrode
Shielding the molten weld metal from atmospheric contamination
Minimum distortion due to low heat input
Generally not as accurate

15. What term is used to describe when the workpiece is hooked to the negative pole on the power source?
When the filler wire is in direct contract with the base metal
(DCEP) Direct Current Electrode Positive or Reverse polarity
20 to 200 times per second
The Arc voltage

16. What is the reason glass 'tube' type flowmeters must have the tube mounted truly vertical?
Insufficient current to melt the wire off cleanly
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
If you dont know this check your phone
...

17. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
By there current carrying capacity
3
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

18. What does voltage do in an electrical circuit?
Constant current (CC)
Constant- speed wire feeders and Voltage- sennsing wire feeders
Voltage is the force that overcomes resistance to allow amperage flow
Gas metal arc welding

19. When using flat drive rolls with too much pressure on copper coated solid wires what problem could take place?
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
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
5.8 to 12.5 L/min

20. In the GMAW process what does amperage control?
5.8 to 12.5 L/min
Penetration and burn - off rate of the electrode
The Arc voltage
SMAW - GTAW

21. List the factors that determine the mode of metal transfer
Flux cored wires
Wire feed speed - Voltage control
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Shielding the molten weld metal from atmospheric contamination

22. Why must CO2 cylinders be used in the vertical position?
3
SMAW - GTAW
To prevent drawing of liquid CO2 (Carbon Dioxide)
Flux cored wires

23. What happens when the electrode extension is increased?
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
...
Puddle fluidity
The resistace to electrical current flow increases with it. Causing the electrode to heat

24. Draw a typical volt/amp curve that would be found with a power source designed for SMAW or GTAW
Wire feed speed - Voltage control
Flux cored wires
Penetration and burn - off rate of the electrode
If you dont know this check your phone

25. What is the recommended electrode stick- out for .035 solid wire?
1/4 inch to 1/2 inch
If you dont know this check your phone
The negative side of a welding unit
Constant- speed wire feeders and Voltage- sennsing wire feeders

26. Give a description of 'pinch effect'
If you dont know this check your phone
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
To prevent leakage - Carbon Dioxide (CO2)
5.8 to 12.5 L/min

27. List the three methods of metal transfer with GMAW
By there current carrying capacity
Short- circuiting transfer - Globular transfer - Spray transfer
Spatter problems and poor weld appearance
Motor driven generators - Transformer rectifiers - and Inverter designs

28. What effect does increasing and decreasing the inductance have on the weld?
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
DCEP (Direct Current Electrode Positive) Reverse Polarity
Guns
Voltage is the force that overcomes resistance to allow amperage flow

29. With straight polarity where is 2/3 of the arc energy?
Motor driven generators - Transformer rectifiers - and Inverter designs
The negative side of a welding unit
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Wire feeds smoothly (yet will slip should a problem occur in the gun)

30. Why is a line heater required when using GMAW?
1/4 inch to 1/2 inch
Dry ice can form within the flow control openings and cause blockage of shielding gas
V groove or U groove
Voltage is the force that overcomes resistance to allow amperage flow

31. In the GMAW process what does voltage control?
Puddle fluidity
SMAW - GTAW
Constant voltage (CV)
12 to 22 arc volts

32. What 2 organizations designate specifications for GMAW wires?
Puddle fluidity
Reducing the gas source pressure to a constant working pressure
AWS and CSA
Spatter problems and poor weld appearance

33. What is a typical flow rate of CO2 for short circuit transfer?
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Minimum distortion due to low heat input
5.8 to 12.5 L/min
Speed of the feed motor and - starting / stopping electrode feed

34. What is the purpose of the pick- up lead on a voltage sensing wire feeder?
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
When the filler wire is in direct contract with the base metal
Dry ice can form within the flow control openings and cause blockage of shielding gas
Gives arc voltage values to the control system of the feeder

35. What output on the welding machine is used to rate the duty cycle?
Gas metal arc welding
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Minutes of elapsed time continually run (out of 10 minutes)
Spatter problems and poor weld appearance

36. Give a brief description of the GMAW process
If you dont know this check your phone
By there current carrying capacity
3
Welding process that joins metals by heating them with an electric arc

37. What is the effect of too much slope?
The time rate of response for the current rise and fall
Shielding the molten weld metal from atmospheric contamination
Short- circuiting transfer - Globular transfer - Spray transfer
Insufficient current to melt the wire off cleanly

38. Regulators control_____________ flowmeters SHOW____________.
Insufficient current to melt the wire off cleanly
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
85%
Pressure - The rate of flow of a shielding gas

39. How many times per second does short circuiting take place?
Penetration and burn - off rate of the electrode
20 to 200 times per second
When the filler wire is in direct contract with the base metal
Wire feeds smoothly (yet will slip should a problem occur in the gun)

40. What processes are constant current (CC) power sources designed to be used with?
20 to 200 times per second
SMAW - GTAW
Gives arc voltage values to the control system of the feeder
Welding process that joins metals by heating them with an electric arc

41. List several industries that would use GMAW
Voltage is the force that overcomes resistance to allow amperage flow
By there current carrying capacity
(DCEP) Direct Current Electrode Positive or Reverse polarity
Pressure vessels and the piping industry

42. What controls the wire speed on a voltage sensing wire feeder?
Pressure vessels and the piping industry
The Arc voltage
Dry ice can form within the flow control openings and cause blockage of shielding gas
12 to 22 arc volts

43. What is the maximum distance that hard wire can be successfully pushed?
SMAW - GTAW
15 feet (4.5 meters)
Constant- speed wire feeders and Voltage- sennsing wire feeders
Penetration and burn - off rate of the electrode

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

45. A 10 minute cycle of welding time vs cooling time a given machine can handle.
20 to 200 times per second
Pressure vessels and the piping industry
Constant voltage (CV)
Duty cycle

46. What does the wire feeder control?
Voltage is the force that overcomes resistance to allow amperage flow
Speed of the feed motor and - starting / stopping electrode feed
The Arc voltage
3

47. What does the abbreviation NEMA stand for?
National Electrical Manufactures Association
5.8 to 12.5 L/min
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Shielding the molten weld metal from atmospheric contamination

48. A pull type drive system is usually used on what type of material?
85%
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Aluminum wire
Higher 26 to 35 arc volts

49. List 3 forms compressed gases may be supplied for welding
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
These terms are quite restrictive and often technically incorrect
Constant- speed wire feeders and Voltage- sennsing wire feeders

50. What are the 2 types of wire feeders available?
Wire feed speed - Voltage control
Cause flaking - which can clog the liner and contact tube
When the filler wire is in direct contract with the base metal
Constant- speed wire feeders and Voltage- sennsing wire feeders