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