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 key advantage of short circuiting transfer?
If you dont know this check your phone
Minutes of elapsed time continually run (out of 10 minutes)
Constant- speed wire feeders and Voltage- sennsing wire feeders
Minimum distortion due to low heat input

2. How many times per second does short circuiting take place?
SMAW - GTAW
Motor driven generators - Transformer rectifiers - and Inverter designs
20 to 200 times per second
To limit the short circuiting current so that spatter is reduced

3. Why is globular transfer generally avoided with GMAW?
V groove or U groove
Duty cycle
AWS and CSA
Spatter problems and poor weld appearance

4. List 3 wire drive systems and give a short description of each
Constant current (CC)
The negative side of a welding unit
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 feed speed - Voltage control

5. List the factors that determine the mode of metal transfer
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
Minimum distortion due to low heat input
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Insufficient current to melt the wire off cleanly

6. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
Pressure - The rate of flow of a shielding gas
Gas metal arc welding
5.8 to 12.5 L/min
85%

7. A pull type drive system is usually used on what type of material?
Aluminum wire
To limit the short circuiting current so that spatter is reduced
Wire feed speed - Voltage control
Reducing the gas source pressure to a constant working pressure

8. What processes are constant current (CC) power sources designed to be used with?
Insufficient current to melt the wire off cleanly
Guns
SMAW - GTAW
20 to 200 times per second

9. Regulators control_____________ flowmeters SHOW____________.
Minutes of elapsed time continually run (out of 10 minutes)
Wire feed speed
Pressure - The rate of flow of a shielding gas
Short- circuiting transfer - Globular transfer - Spray transfer

10. When using flat drive rolls with too much pressure on copper coated solid wires what problem could take place?
To prevent leakage - Carbon Dioxide (CO2)
Cause flaking - which can clog the liner and contact tube
Minutes of elapsed time continually run (out of 10 minutes)
1/4 inch to 1/2 inch

11. What is another term for electrode holders for GMAW?
85%
When the filler wire is in direct contract with the base metal
Guns
15 feet (4.5 meters)

12. What power sources are used with the GMAW Process?
These terms are quite restrictive and often technically incorrect
Motor driven generators - Transformer rectifiers - and Inverter designs
Speed of the feed motor and - starting / stopping electrode feed
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field

13. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
If you dont know this check your phone
Higher 26 to 35 arc volts
Controls the rate of flow of a shielding gas to the gun nozzle
The Arc voltage

14. With straight polarity where is 2/3 of the arc energy?
The negative side of a welding unit
The Arc voltage
To prevent drawing of liquid CO2 (Carbon Dioxide)
Pressure vessels and the piping industry

15. What output on the welding machine is used to rate the duty cycle?
Cause flaking - which can clog the liner and contact tube
Puddle fluidity
Minutes of elapsed time continually run (out of 10 minutes)
If you dont know this check your phone

16. What does voltage do in an electrical circuit?
Pressure - The rate of flow of a shielding gas
Short- circuiting transfer - Globular transfer - Spray transfer
Voltage is the force that overcomes resistance to allow amperage flow
Spatter problems and poor weld appearance

17. What is a solenoid valve and what actuates it?
AWS and CSA
V groove or U groove
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Spatter problems and poor weld appearance

18. Why is a line heater required when using GMAW?
If you dont know this check your phone
Dry ice can form within the flow control openings and cause blockage of shielding gas
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
SMAW - GTAW

19. What does a flowmeter do and what does it measure?
Controls the rate of flow of a shielding gas to the gun nozzle
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
Minutes of elapsed time continually run (out of 10 minutes)

20. What is the reason glass 'tube' type flowmeters must have the tube mounted truly vertical?
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
The resistace to electrical current flow increases with it. Causing the electrode to heat

21. What is the recommended electrode stick- out for .035 solid wire?
Gas metal arc welding
Minutes of elapsed time continually run (out of 10 minutes)
Insufficient current to melt the wire off cleanly
1/4 inch to 1/2 inch

22. What is the preferred drive roll design for solid wires?
Puddle fluidity
V groove or U groove
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
These terms are quite restrictive and often technically incorrect

23. Why must CO2 cylinders be used in the vertical position?
Pressure - The rate of flow of a shielding gas
Spatter problems and poor weld appearance
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
To prevent drawing of liquid CO2 (Carbon Dioxide)

24. What controls amperage when using GMAW?
Constant voltage (CV)
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Puddle fluidity
Wire feed speed

25. What current and polarity is generally used with GMAW?
20 to 200 times per second
15 feet (4.5 meters)
Welding process that joins metals by heating them with an electric arc
DCEP (Direct Current Electrode Positive) Reverse Polarity

26. When is the metal transferred with short circuit transfer?
Speed of the feed motor and - starting / stopping electrode feed
Constant- speed wire feeders and Voltage- sennsing wire feeders
When the filler wire is in direct contract with the base metal
The time rate of response for the current rise and fall

27. What type of power source is commonly used with a voltage sensing wire feeder?
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
The time rate of response for the current rise and fall
Constant current (CC)
...

28. What controls the wire speed on a voltage sensing wire feeder?
1/4 inch to 1/2 inch
Welding process that joins metals by heating them with an electric arc
The Arc voltage
Gives arc voltage values to the control system of the feeder

29. What is a typical flow rate of CO2 for short circuit transfer?
Controls the rate of flow of a shielding gas to the gun nozzle
The negative side of a welding unit
5.8 to 12.5 L/min
Generally not as accurate

30. What 2 organizations designate specifications for GMAW wires?
AWS and CSA
Gas metal arc welding
Higher 26 to 35 arc volts
To prevent leakage - Carbon Dioxide (CO2)

31. Give a description of 'pinch effect'
(DCEP) Direct Current Electrode Positive or Reverse polarity
Short- circuiting transfer - Globular transfer - Spray transfer
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
By there current carrying capacity

32. In the GMAW process what does amperage control?
Penetration and burn - off rate of the electrode
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
By there current carrying capacity
Guns

33. What is the maximum distance that hard wire can be successfully pushed?
1/4 inch to 1/2 inch
Constant current (CC)
15 feet (4.5 meters)
Flux cored wires

34. Why is the term GMAW preferred over MIG or MAG?
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
These terms are quite restrictive and often technically incorrect
National Electrical Manufactures Association
Reducing the gas source pressure to a constant working pressure

35. What does the abbreviation NEMA stand for?
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
(DCEP) Direct Current Electrode Positive or Reverse polarity
To prevent leakage - Carbon Dioxide (CO2)
National Electrical Manufactures Association

36. What does inductance control?
The time rate of response for the current rise and fall
1/4 inch to 1/2 inch
Gas metal arc welding
Penetration and burn - off rate of the electrode

37. 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
The negative side of a welding unit
When the filler wire is in direct contract with the base metal
By there current carrying capacity

38. List several industries that would use GMAW
Aluminum wire
Constant current (CC)
Pressure vessels and the piping industry
Constant voltage (CV)

39. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
3
These terms are quite restrictive and often technically incorrect
Minimum distortion due to low heat input

40. A 10 minute cycle of welding time vs cooling time a given machine can handle.
The Arc voltage
AWS and CSA
Constant- speed wire feeders and Voltage- sennsing wire feeders
Duty cycle

41. Draw a typical volt amp curve for a machine that is designed for GMAW
15 feet (4.5 meters)
The negative side of a welding unit
Generally not as accurate
If you dont know this check your phone

42. List 3 forms compressed gases may be supplied for welding
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
1/4 inch to 1/2 inch
The resistace to electrical current flow increases with it. Causing the electrode to heat
Minimum distortion due to low heat input

43. What is the purpose of the shielding gas used in GMAW?
Insufficient current to melt the wire off cleanly
Gas metal arc welding
AWS and CSA
Shielding the molten weld metal from atmospheric contamination

44. What term is used to describe when the workpiece is hooked to the negative pole on the power source?
Guns
(DCEP) Direct Current Electrode Positive or Reverse polarity
V groove or U groove
Cause flaking - which can clog the liner and contact tube

45. What is the purpose of a regulator and what does it indicate on its gauges?
Wire feeds smoothly (yet will slip should a problem occur in the gun)
If you dont know this check your phone
15 feet (4.5 meters)
Reducing the gas source pressure to a constant working pressure

46. What wire are knurled drive rolls most commonly used on?
V groove or U groove
Flux cored wires
(DCEP) Direct Current Electrode Positive or Reverse polarity
Pressure - The rate of flow of a shielding gas

47. What does the wire feeder control?
These terms are quite restrictive and often technically incorrect
(DCEP) Direct Current Electrode Positive or Reverse polarity
Speed of the feed motor and - starting / stopping electrode feed
If you dont know this check your phone

48. What would be an indication that the drive roll pressure is adjusted correctly?
Flux cored wires
Wire feeds smoothly (yet will slip should a problem occur in the gun)
Voltage is the force that overcomes resistance to allow amperage flow
Cause flaking - which can clog the liner and contact tube

49. What does the term GMAW identify?
Dry ice can form within the flow control openings and cause blockage of shielding gas
If you dont know this check your phone
DCEP (Direct Current Electrode Positive) Reverse Polarity
Gas metal arc welding

50. Why is a fiber washer required and what cylinder gas requires it?
To prevent leakage - Carbon Dioxide (CO2)
Minimum distortion due to low heat input
To limit the short circuiting current so that spatter is reduced
Gives arc voltage values to the control system of the feeder

Test your basic knowledge |

Gas Metal Arc Welding

Link to This Test

Related Subjects