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 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
Pressure vessels and the piping industry
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Flux cored wires

2. A 10 minute cycle of welding time vs cooling time a given machine can handle.
The resistace to electrical current flow increases with it. Causing the electrode to heat
Duty cycle
Spatter problems and poor weld appearance
To limit the short circuiting current so that spatter is reduced

3. When is the metal transferred with short circuit transfer?
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
When the filler wire is in direct contract with the base metal
Shielding the molten weld metal from atmospheric contamination
3

4. Give a description of 'pinch effect'
Motor driven generators - Transformer rectifiers - and Inverter designs
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
These terms are quite restrictive and often technically incorrect
Guns

5. What output on the welding machine is used to rate the duty cycle?
Minutes of elapsed time continually run (out of 10 minutes)
Motor driven generators - Transformer rectifiers - and Inverter designs
Aluminum wire
15 feet (4.5 meters)

6. With straight polarity where is 2/3 of the arc energy?
Constant voltage (CV)
The negative side of a welding unit
Pressure vessels and the piping industry
V groove or U groove

7. What does inductance control?
Flux cored wires
Speed of the feed motor and - starting / stopping electrode feed
Wire feeds smoothly (yet will slip should a problem occur in the gun)
The time rate of response for the current rise and fall

8. Draw a typical volt/amp curve that would be found with a power source designed for SMAW or GTAW
If you dont know this check your phone
Puddle fluidity
Higher 26 to 35 arc volts
Reducing the gas source pressure to a constant working pressure

9. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
Higher 26 to 35 arc volts
Insufficient current to melt the wire off cleanly
Speed of the feed motor and - starting / stopping electrode feed
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun

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

11. List the three methods of metal transfer with GMAW
Short- circuiting transfer - Globular transfer - Spray transfer
Penetration and burn - off rate of the electrode
Welding process that joins metals by heating them with an electric arc
Guns

12. What 2 organizations designate specifications for GMAW wires?
The Arc voltage
The time rate of response for the current rise and fall
Dry ice can form within the flow control openings and cause blockage of shielding gas
AWS and CSA

13. What is the purpose of a regulator and what does it indicate on its gauges?
Reducing the gas source pressure to a constant working pressure
Cause flaking - which can clog the liner and contact tube
Controls the rate of flow of a shielding gas to the gun nozzle
To limit the short circuiting current so that spatter is reduced

14. What controls amperage when using GMAW?
Wire feed speed
When the filler wire is in direct contract with the base metal
3
Cause flaking - which can clog the liner and contact tube

15. Give a brief description of the GMAW process
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
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
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts

16. What is the key advantage of short circuiting transfer?
(DCEP) Direct Current Electrode Positive or Reverse polarity
The resistace to electrical current flow increases with it. Causing the electrode to heat
Minimum distortion due to low heat input
Gas metal arc welding

17. What 2 controls are found on a GMAW set- up?
Puddle fluidity
When the filler wire is in direct contract with the base metal
Wire feed speed - Voltage control
Speed of the feed motor and - starting / stopping electrode feed

18. 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
Pressure - The rate of flow of a shielding gas
Gives arc voltage values to the control system of the feeder
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground

19. Why is a fiber washer required and what cylinder gas requires it?
Pressure vessels and the piping industry
To prevent leakage - Carbon Dioxide (CO2)
The negative side of a welding unit
Speed of the feed motor and - starting / stopping electrode feed

20. What does the term GMAW identify?
Gas metal arc welding
...
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
If you dont know this check your phone

21. List the factors that determine the mode of metal transfer
Insufficient current to melt the wire off cleanly
Pressure - The rate of flow of a shielding gas
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
85%

22. 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
Gas metal arc welding
5.8 to 12.5 L/min
Wire feed speed

23. What is another term for electrode holders for GMAW?
The Arc voltage
Guns
Shielding the molten weld metal from atmospheric contamination
Wire feed speed - Voltage control

24. What does voltage do in an electrical circuit?
Voltage is the force that overcomes resistance to allow amperage flow
The Arc voltage
Short- circuiting transfer - Globular transfer - Spray transfer
Flux cored wires

25. What is a solenoid valve and what actuates it?
Controls the rate of flow of a shielding gas to the gun nozzle
Constant- speed wire feeders and Voltage- sennsing wire feeders
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Penetration and burn - off rate of the electrode

26. What would be an indication that the drive roll pressure is adjusted correctly?
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Spatter problems and poor weld appearance
Gives arc voltage values to the control system of the feeder
Minimum distortion due to low heat input

27. List 3 forms compressed gases may be supplied for welding
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
The Arc voltage
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Higher 26 to 35 arc volts

28. List the basic equipment requirements for the GMAW process
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
5.8 to 12.5 L/min
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
Cause flaking - which can clog the liner and contact tube

29. How are GMAW guns rated?
By there current carrying capacity
Wire feeds smoothly (yet will slip should a problem occur in the gun)
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

30. What is the maximum distance that hard wire can be successfully pushed?
15 feet (4.5 meters)
5.8 to 12.5 L/min
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

31. What is the required arc voltage used for short circuit transfer?
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
1/4 inch to 1/2 inch
Wire feed speed - Voltage control
12 to 22 arc volts

32. When using flat drive rolls with too much pressure on copper coated solid wires what problem could take place?
20 to 200 times per second
DCEP (Direct Current Electrode Positive) Reverse Polarity
Cause flaking - which can clog the liner and contact tube
When the filler wire is in direct contract with the base metal

33. What does the wire feeder control?
(DCEP) Direct Current Electrode Positive or Reverse polarity
Speed of the feed motor and - starting / stopping electrode feed
To prevent drawing of liquid CO2 (Carbon Dioxide)
Guns

34. What does the abbreviation NEMA stand for?
12 to 22 arc volts
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
By there current carrying capacity
National Electrical Manufactures Association

35. What are the 2 types of wire feeders available?
Dry ice can form within the flow control openings and cause blockage of shielding gas
Higher 26 to 35 arc volts
Flux cored wires
Constant- speed wire feeders and Voltage- sennsing wire feeders

36. Regulators control_____________ flowmeters SHOW____________.
Minimum distortion due to low heat input
Pressure - The rate of flow of a shielding gas
The Arc voltage
Puddle fluidity

37. What is the purpose of the shielding gas used in GMAW?
Minutes of elapsed time continually run (out of 10 minutes)
Wire feed speed
Shielding the molten weld metal from atmospheric contamination
Cause flaking - which can clog the liner and contact tube

38. What controls the wire speed on a voltage sensing wire feeder?
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
By there current carrying capacity
The Arc voltage
Generally not as accurate

39. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
Insufficient current to melt the wire off cleanly
Wire feed speed
The resistace to electrical current flow increases with it. Causing the electrode to heat
85%

40. What is the disadvantage of the gauge preset type of regulator/flowmeter?
20 to 200 times per second
Generally not as accurate
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
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. In the GMAW process what does voltage control?
National Electrical Manufactures Association
Puddle fluidity
Motor driven generators - Transformer rectifiers - and Inverter designs
To limit the short circuiting current so that spatter is reduced

42. What does a flowmeter do and what does it measure?
Welding process that joins metals by heating them with an electric arc
Controls the rate of flow of a shielding gas to the gun nozzle
85%
Wire feed speed - Voltage control

43. What type of power source is commonly used with a voltage sensing wire feeder?
Pressure vessels and the piping industry
Constant current (CC)
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
Insufficient current to melt the wire off cleanly

44. What is the recommended electrode stick- out for .035 solid wire?
To prevent leakage - Carbon Dioxide (CO2)
1/4 inch to 1/2 inch
Minutes of elapsed time continually run (out of 10 minutes)
Constant- speed wire feeders and Voltage- sennsing wire feeders

45. What is the effect of too much slope?
The Arc voltage
SMAW - GTAW
Insufficient current to melt the wire off cleanly
Flux cored wires

46. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
Wire feeds smoothly (yet will slip should a problem occur in the gun)
3
Reducing the gas source pressure to a constant working pressure
To prevent leakage - Carbon Dioxide (CO2)

47. Why is the term GMAW preferred over MIG or MAG?
Generally not as accurate
The Arc voltage
These terms are quite restrictive and often technically incorrect
Aluminum wire

48. Why is a line heater required when using GMAW?
Dry ice can form within the flow control openings and cause blockage of shielding gas
20 to 200 times per second
To prevent drawing of liquid CO2 (Carbon Dioxide)
The negative side of a welding unit

49. What is the main purpose of 'slope'?
The Arc voltage
Constant voltage (CV)
To limit the short circuiting current so that spatter is reduced
When the filler wire is in direct contract with the base metal

50. What processes are constant current (CC) power sources designed to be used with?
The time rate of response for the current rise and fall
15 feet (4.5 meters)
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
SMAW - GTAW