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