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