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