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