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Test your basic knowledge |
Gas Metal Arc Welding
Start Test
Study First
Subject
:
engineering
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 output on the welding machine is used to rate the duty cycle?
Puddle fluidity
3
Minutes of elapsed time continually run (out of 10 minutes)
20 to 200 times per second
2. What happens when the electrode extension is increased?
Gives arc voltage values to the control system of the feeder
Minimum distortion due to low heat input
Motor driven generators - Transformer rectifiers - and Inverter designs
The resistace to electrical current flow increases with it. Causing the electrode to heat
3. What does a flowmeter do and what does it measure?
Gives arc voltage values to the control system of the feeder
Higher 26 to 35 arc volts
Dry ice can form within the flow control openings and cause blockage of shielding gas
Controls the rate of flow of a shielding gas to the gun nozzle
4. What is the minimum % value of argon that must be present to use the spray transfer method of GMAW?
Puddle fluidity
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
85%
5. 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
Higher 26 to 35 arc volts
Aluminum wire
5.8 to 12.5 L/min
6. What is the disadvantage of the gauge preset type of regulator/flowmeter?
Short- circuiting transfer - Globular transfer - Spray transfer
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
Generally not as accurate
(DCEP) Direct Current Electrode Positive or Reverse polarity
7. What is an advantage of pulsed arc transfer with GMAW?
Constant voltage (CV)
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
85%
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
8. A machine with a 70% duty cycle can run at its max for 7 minutes with a cooling cycle of only _ minutes.
Constant voltage (CV)
3
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
9. Why is a line heater required when using GMAW?
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
Dry ice can form within the flow control openings and cause blockage of shielding gas
10. 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
The Arc voltage
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
11. What controls amperage when using GMAW?
Wire feed speed
Pressure - The rate of flow of a shielding gas
Aluminum wire
When the filler wire is in direct contract with the base metal
12. What is the purpose of the pick- up lead on a voltage sensing wire feeder?
Shielding the molten weld metal from atmospheric contamination
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Gives arc voltage values to the control system of the feeder
20 to 200 times per second
13. What would be an indication that the drive roll pressure is adjusted correctly?
15 feet (4.5 meters)
Controls the rate of flow of a shielding gas to the gun nozzle
Insufficient current to melt the wire off cleanly
Wire feeds smoothly (yet will slip should a problem occur in the gun)
14. A 10 minute cycle of welding time vs cooling time a given machine can handle.
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Duty cycle
V groove or U groove
...
15. With straight polarity where is 2/3 of the arc energy?
The negative side of a welding unit
To limit the short circuiting current so that spatter is reduced
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Cause flaking - which can clog the liner and contact tube
16. List several industries that would use GMAW
Guns
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
Pressure vessels and the piping industry
17. When is the metal transferred with short circuit transfer?
Aluminum wire
To prevent drawing of liquid CO2 (Carbon Dioxide)
When the filler wire is in direct contract with the base metal
Gas metal arc welding
18. What is the required arc voltage used for short circuit transfer?
By there current carrying capacity
Short- circuiting transfer - Globular transfer - Spray transfer
To prevent drawing of liquid CO2 (Carbon Dioxide)
12 to 22 arc volts
19. Regulators control_____________ flowmeters SHOW____________.
Shielding the molten weld metal from atmospheric contamination
Pressure - The rate of flow of a shielding gas
Cause flaking - which can clog the liner and contact tube
Flux cored wires
20. A pull type drive system is usually used on what type of material?
Aluminum wire
Heat input is less than spray transfer - resulting in less distortion - Used in all positions due to controlling the weld metal freeze
These terms are quite restrictive and often technically incorrect
Minutes of elapsed time continually run (out of 10 minutes)
21. How are GMAW guns rated?
By there current carrying capacity
Gas metal arc welding
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
If you dont know this check your phone
22. What does the abbreviation NEMA stand for?
The negative side of a welding unit
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
When the filler wire is in direct contract with the base metal
National Electrical Manufactures Association
23. What 2 controls are found on a GMAW set- up?
Wire feed speed - Voltage control
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
Penetration and burn - off rate of the electrode
24. What is the recommended electrode stick- out for .035 solid wire?
Generally not as accurate
Dry ice can form within the flow control openings and cause blockage of shielding gas
...
1/4 inch to 1/2 inch
25. Why must CO2 cylinders be used in the vertical position?
To limit the short circuiting current so that spatter is reduced
Motor driven generators - Transformer rectifiers - and Inverter designs
To prevent drawing of liquid CO2 (Carbon Dioxide)
V groove or U groove
26. What type of power source is used with a constant speed 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
Motor driven generators - Transformer rectifiers - and Inverter designs
Constant voltage (CV)
Guns
27. What is the maximum distance that hard wire can be successfully pushed?
15 feet (4.5 meters)
AWS and CSA
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
Motor driven generators - Transformer rectifiers - and Inverter designs
28. Give a brief description of the GMAW process
Shielding the molten weld metal from atmospheric contamination
Welding process that joins metals by heating them with an electric arc
Penetration and burn - off rate of the electrode
Reducing the gas source pressure to a constant working pressure
29. What does the wire feeder control?
Reducing the gas source pressure to a constant working pressure
Speed of the feed motor and - starting / stopping electrode feed
Puddle fluidity
12 to 22 arc volts
30. What does inductance control?
Flux cored wires
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
The time rate of response for the current rise and fall
Controls the rate of flow of a shielding gas to the gun nozzle
31. Is the arc voltage for spray transfer higher or lower than that used for short circuit transfer?
Higher 26 to 35 arc volts
Minutes of elapsed time continually run (out of 10 minutes)
If you dont know this check your phone
AWS and CSA
32. How many times per second does short circuiting take place?
Welding process that joins metals by heating them with an electric arc
20 to 200 times per second
Shielding the molten weld metal from atmospheric contamination
Constant voltage (CV)
33. What is the preferred drive roll design for solid wires?
Speed of the feed motor and - starting / stopping electrode feed
To prevent leakage - Carbon Dioxide (CO2)
V groove or U groove
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
34. What 2 organizations designate specifications for GMAW wires?
DCEP (Direct Current Electrode Positive) Reverse Polarity
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
Reducing the gas source pressure to a constant working pressure
AWS and CSA
35. Draw a typical volt amp curve for a machine that is designed for GMAW
If you dont know this check your phone
Wire feed speed - Voltage control
Speed of the feed motor and - starting / stopping electrode feed
(DCEP) Direct Current Electrode Positive or Reverse polarity
36. What is the effect of too much slope?
Constant- speed wire feeders and Voltage- sennsing wire feeders
12 to 22 arc volts
(DCEP) Direct Current Electrode Positive or Reverse polarity
Insufficient current to melt the wire off cleanly
37. What type of power source is commonly used with a voltage sensing wire feeder?
DCEP (Direct Current Electrode Positive) Reverse Polarity
Minutes of elapsed time continually run (out of 10 minutes)
Constant current (CC)
Insufficient current to melt the wire off cleanly
38. What controls the wire speed on a voltage sensing wire feeder?
Welding Current - Filler wire diameter - arc length - type of shielding - position of the weld
If you dont know this check your phone
...
The Arc voltage
39. Why is globular transfer generally avoided with GMAW?
Spatter problems and poor weld appearance
Dry ice can form within the flow control openings and cause blockage of shielding gas
Generally not as accurate
Shielding the molten weld metal from atmospheric contamination
40. What does the term GMAW identify?
Welding process that joins metals by heating them with an electric arc
Spatter problems and poor weld appearance
Gas metal arc welding
Penetration and burn - off rate of the electrode
41. What is the key advantage of short circuiting transfer?
If you dont know this check your phone
Minimum distortion due to low heat input
These terms are quite restrictive and often technically incorrect
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
42. What is a solenoid valve and what actuates it?
When the filler wire is in direct contract with the base metal
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
By there current carrying capacity
85%
43. What processes are constant current (CC) power sources designed to be used with?
85%
Wire feed speed
SMAW - GTAW
...
44. Why is the term GMAW preferred over MIG or MAG?
These terms are quite restrictive and often technically incorrect
Generally not as accurate
To prevent drawing of liquid CO2 (Carbon Dioxide)
Gas metal arc welding
45. 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
Voltage is the force that overcomes resistance to allow amperage flow
Cause flaking - which can clog the liner and contact tube
DCEP (Direct Current Electrode Positive) Reverse Polarity
46. List 3 forms compressed gases may be supplied for welding
Increasing inductance increases puddle fluidity - improves penatration - makes the bead flatter and smoother - and reduces spatter. To much inductance though will create erratic starts
Dry ice can form within the flow control openings and cause blockage of shielding gas
Motor driven generators - Transformer rectifiers - and Inverter designs
Compressed gas cylinder - Liquid filled cylinder - or a Liquid bulk system
47. What does voltage do in an electrical circuit?
Constant voltage (CV)
If you dont know this check your phone
Voltage is the force that overcomes resistance to allow amperage flow
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
48. Give a description of 'pinch effect'
AWS and CSA
When the filler wire is in direct contract with the base metal
Gas metal arc welding
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
49. List the basic equipment requirements for the GMAW process
Power source - wire feeder - welding gun - Spooled filler wire - Shielding gas - and a ground
Molten metal is separated from the end of the filler wire by a squeezing force created by a magnetic field
Guns
Electricaly operated valves that control the flow of shielding gas to the weld zone. The control switch located on the gun
50. What power sources are used with the GMAW Process?
Motor driven generators - Transformer rectifiers - and Inverter designs
Higher 26 to 35 arc volts
Generally not as accurate
The time rate of response for the current rise and fall