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