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