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