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