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?
Puddle fluidity
Generally not as accurate
Motor driven generators - Transformer rectifiers - and Inverter designs
Insufficient current to melt the wire off cleanly

2. What does voltage do in an electrical circuit?
The time rate of response for the current rise and fall
Controls the rate of flow of a shielding gas to the gun nozzle
Voltage is the force that overcomes resistance to allow amperage flow
Pressure vessels and the piping industry

3. What power sources are used with the GMAW Process?
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Constant current (CC)
Motor driven generators - Transformer rectifiers - and Inverter designs
3

4. In the GMAW process what does amperage control?
SMAW - GTAW
These terms are quite restrictive and often technically incorrect
If you dont know this check your phone
Penetration and burn - off rate of the electrode

5. What type of power source is commonly used with a voltage sensing wire feeder?
Constant current (CC)
Dry ice can form within the flow control openings and cause blockage of shielding gas
Insufficient current to melt the wire off cleanly
Speed of the feed motor and - starting / stopping electrode feed

6. What does the term GMAW identify?
Gas metal arc welding
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
(DCEP) Direct Current Electrode Positive or Reverse polarity
Constant voltage (CV)

7. What term is used to describe when the workpiece is hooked to the negative pole on the power source?
Gives arc voltage values to the control system of the feeder
Aluminum wire
V groove or U groove
(DCEP) Direct Current Electrode Positive or Reverse polarity

8. 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
Motor driven generators - Transformer rectifiers - and Inverter designs
Dry ice can form within the flow control openings and cause blockage of shielding gas
Gas metal arc welding

9. Give a brief description of the GMAW process
12 to 22 arc volts
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 or Reverse polarity
Welding process that joins metals by heating them with an electric arc

10. What is the main purpose of 'slope'?
To limit the short circuiting current so that spatter is reduced
Wire feed speed - Voltage control
By there current carrying capacity
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground

11. What are the 2 types of wire feeders available?
Penetration and burn - off rate of the electrode
85%
Constant- speed wire feeders and Voltage- sennsing wire feeders
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts

12. 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
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
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

13. What is an advantage of pulsed arc transfer with GMAW?
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
Constant current (CC)
Gas metal arc welding
Pressure vessels and the piping industry

14. What is the maximum distance that hard wire can be successfully pushed?
15 feet (4.5 meters)
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Flux cored wires
Wire feed speed - Voltage control

15. What 2 controls are found on a GMAW set- up?
Wire feed speed - Voltage control
Gives arc voltage values to the control system of the feeder
To limit the short circuiting current so that spatter is reduced
DCEP (Direct Current Electrode Positive) Reverse Polarity

16. How many times per second does short circuiting take place?
Insufficient current to melt the wire off cleanly
The negative side of a welding unit
20 to 200 times per second
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

17. List 3 wire drive systems and give a short description of each
Gives arc voltage values to the control system of the 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
Insufficient current to melt the wire off cleanly
Controls the rate of flow of a shielding gas to the gun nozzle

18. When is the metal transferred with short circuit transfer?
1/4 inch to 1/2 inch
The Arc voltage
When the filler wire is in direct contract with the base metal
Duty cycle

19. A pull type drive system is usually used on what type of material?
Penetration and burn - off rate of the electrode
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
If you dont know this check your phone
Aluminum wire

20. List the basic equipment requirements for the GMAW process
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Shielding the molten weld metal from atmospheric contamination
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
If you dont know this check your phone

21. What does the wire feeder control?
Speed of the feed motor and - starting / stopping electrode feed
Spatter problems and poor weld appearance
Gives arc voltage values to the control system of the feeder
15 feet (4.5 meters)

22. What is the key advantage of short circuiting transfer?
To prevent drawing of liquid CO2 (Carbon Dioxide)
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Duty cycle
Minimum distortion due to low heat input

23. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
DCEP (Direct Current Electrode Positive) Reverse Polarity
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
3
85%

24. What is the required arc voltage used for short circuit transfer?
Generally not as accurate
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Duty cycle
12 to 22 arc volts

25. 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 prevent drawing of liquid CO2 (Carbon Dioxide)
Short- circuiting transfer - Globular transfer - Spray transfer
Spatter problems and poor weld appearance

26. Why is a fiber washer required and what cylinder gas requires it?
The time rate of response for the current rise and fall
To prevent leakage - Carbon Dioxide (CO2)
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Voltage is the force that overcomes resistance to allow amperage flow

27. What is another term for electrode holders for GMAW?
If you dont know this check your phone
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Cause flaking - which can clog the liner and contact tube
Guns

28. What output on the welding machine is used to rate the duty cycle?
Minutes of elapsed time continually run (out of 10 minutes)
Pressure vessels and the piping industry
Reducing the gas source pressure to a constant working pressure
(DCEP) Direct Current Electrode Positive or Reverse polarity

29. What is the preferred drive roll design for solid wires?
Generally not as accurate
V groove or U groove
Pressure - The rate of flow of a shielding gas
DCEP (Direct Current Electrode Positive) Reverse Polarity

30. What is the recommended electrode stick- out for .035 solid wire?
1/4 inch to 1/2 inch
12 to 22 arc volts
National Electrical Manufactures Association
Constant current (CC)

31. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
Higher 26 to 35 arc volts
15 feet (4.5 meters)
Aluminum wire
These terms are quite restrictive and often technically incorrect

32. A 10 minute cycle of welding time vs cooling time a given machine can handle.
V groove or U groove
Duty cycle
(DCEP) Direct Current Electrode Positive or Reverse polarity
The Arc voltage

33. What is the effect of too much slope?
Insufficient current to melt the wire off cleanly
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
Short- circuiting transfer - Globular transfer - Spray transfer

34. With straight polarity where is 2/3 of the arc energy?
The negative side of a welding unit
Gives arc voltage values to the control system of the feeder
3
Guns

35. What type of power source is used with a constant speed wire feeder?
Constant voltage (CV)
National Electrical Manufactures Association
SMAW - GTAW
Constant current (CC)

36. 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
Duty cycle
Constant- speed wire feeders and Voltage- sennsing wire feeders

37. What current and polarity is generally used with GMAW?
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Puddle fluidity
DCEP (Direct Current Electrode Positive) Reverse Polarity
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld

38. What does a flowmeter do and what does it measure?
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
If you dont know this check your phone
Controls the rate of flow of a shielding gas to the gun nozzle
Duty cycle

39. What is the reason glass 'tube' type flowmeters must have the tube mounted truly vertical?
...
If you dont know this check your phone
Dry ice can form within the flow control openings and cause blockage of shielding gas
Minimum distortion due to low heat input

40. What does the abbreviation NEMA stand for?
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- speed wire feeders and Voltage- sennsing wire feeders
SMAW - GTAW

41. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
15 feet (4.5 meters)
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
85%

42. Why is a line heater required when using GMAW?
To prevent drawing of liquid CO2 (Carbon Dioxide)
Constant voltage (CV)
Dry ice can form within the flow control openings and cause blockage of shielding gas
Puddle fluidity

43. How are GMAW guns rated?
Controls the rate of flow of a shielding gas to the gun nozzle
Generally not as accurate
The resistace to electrical current flow increases with it. Causing the electrode to heat
By there current carrying capacity

44. What wire are knurled drive rolls most commonly used on?
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
1/4 inch to 1/2 inch
Puddle fluidity
Flux cored wires

45. Why must CO2 cylinders be used in the vertical position?
To prevent drawing of liquid CO2 (Carbon Dioxide)
V groove or U groove
When the filler wire is in direct contract with the base metal
Welding process that joins metals by heating them with an electric arc

46. Regulators control_____________ flowmeters SHOW____________.
Pressure - The rate of flow of a shielding gas
AWS and CSA
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Voltage is the force that overcomes resistance to allow amperage flow

47. Draw a typical volt amp curve for a machine that is designed for GMAW
20 to 200 times per second
Wire feed speed
Welding process that joins metals by heating them with an electric arc
If you dont know this check your phone

48. What controls amperage when using GMAW?
Wire feed speed
SMAW - GTAW
To prevent leakage - Carbon Dioxide (CO2)
Gas metal arc welding

49. What is the disadvantage of the gauge preset type of regulator/flowmeter?
Constant- speed wire feeders and Voltage- sennsing wire feeders
By there current carrying capacity
Generally not as accurate
Pressure vessels and the piping industry

50. List the factors that determine the mode of metal transfer
Pressure vessels and the piping industry
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
20 to 200 times per second
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld