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