Chapter 16 GTAW and FCAW Flashcards
___________________ rolls are used for solid GMAW electrodes and some metal cored applications.
smooth v-groove
_______________ rolls are used for flux cored and some metal cored electrodes.
knurled v-groove
______________ rolls have ridges in the groove to grip and push the electrode wire.
knurled
Aluminum wire is fed with __________ rolls
smooth u-groove
The wire feeder is the same for all electrodes but the __________ are changed based on the type of the electrode wire.
drive rolls
When the electrode diameter changes, the _____________ must also be changed.
drive rolls
In FCAW, what should you do if the wire exiting the gun is crushed or deformed?
That means the pressure is too high. Reduce the pressure and check again.
When the wire in the feeder becomes tangled it produces a _____________.
bird’s nest
How do you remove a bird’s nest?
By raising the pressure roll and cutting the wire on both sides of the bird’s nest
What part of the welding gun need to be replaced most often?
The contact tube
How is the contact tube replaced?
Select the correct size contact tube for the diameter of electrode you will use. The contact tube is threaded into the adapter or diffuser.
The hole in the center of the contact tube will get _______ due to wear.
larger
________ hours of constant welding with a steel electrode will wear a contact tube enough that it will need to be replaced.
eight
What does the AWS GMAW designation E mean?
E stands for electrode
It means a filler material can be used as an electrode
What does the AWS GMAW designation R mean?
R stands for rod
In the AWS designation, after the E and R the next set of numbers is the ________ of the weld wire after welding.
tensile strength
The tensile strength is measured in _________
thousands of pounds per square inch
Typical value in the electrode designation for carbon steel electrodes are ____ and _____
70 and 80 which represents
70,000 and 80, 000 psi
High-strength steels may require electrodes with tensile strengths of ______
90, 100, 110 or more
In the AWS designation for GMAW, after the E, R and tensile strength comes a letter, either ____ or ____.
S or C
What does the AWS GMAW designation S mean?
Identifies the material as a solid electrode wire
What does the AWS GMAW designation C mean?
Identifies the material as a metal cored electrode.
What does the AWS designation for FCAW, what does T mean?
Tubular electrode
Carbon steel electrodes from GMAW are given different dash numbers to identify their varying compositions. A common GMAW electrode for carbon steel is _________
ER70S-6
FCAW electrodes have a dash number which indicates which three pieces of information about the electrode?
- The polarity to use
- The shielding gas to use, if required
- Whether the electrode can be used for multiple-pass welds.
What is a dash number?
Numerals or letters at the end of the electrode designation, following a dash.
The tension adjusting knob should be adjusted to apply the _____________ pressure needed to properly feed the electrode wire.
minimum
True or False: It is important not to crush flux cored wires.
True
Common GMAW and cored electrode diameters range from ___________
0.030” to 1/16” (0.8 mm to 1.6 mm)
Common FCAW electrodes range from _________
0.045” to 1/16” (1.2 mm to 1.6 mm)
soft electrodes such as _______________ and ________________ electrodes cannot be pushed through a welding cable as far as a large-diameter electrode.
aluminum and magnesium
There are two settings on the welding machine which must be adjusted. What are they?
- voltage
- wire feed speed
The metal transfer method is set by these two variables and the shielding gas selected.
What does adjusting the voltage and wire feed speed do?
determines the arc length and current
What should the wire speed setting be for a carbon or low-alloy steel 0.035” electrode using short circuiting transfer?
160-380 in/min (4.1 - 9.7 M/min)
What should the voltage setting be for a carbon or low-alloy steel 0.035” electrode using short circuiting transfer?
16-22 V
What should the wire speed setting be for a carbon or low-alloy steel 0.035” electrode using spray transfer?
360-520 in/min ( 9.1 - 13.2 M/min)
What should the current setting be for a carbon or low-alloy steel 0.035” electrode using spray transfer?
24-28 V
Flux cored electrodes are designed for one of two position groupings. They may be designed to be used in the flat position to make __________________ or they may be designed to ______________
horizontal fillet welds
weld in all positions
Electrodes for FCAW used for welding in flat positions and horizontal fillet welds are designated by a _____. Those used for welding in all positions are designated by a _____. These are followed by the letter ____
0
1
T
The electrode E70T-X is for use in which position?
Flat or horizontal fillet weld
The electrode E81T-X is for use in which position?
All positions
Gas-shielded flux cored electrodes can be designed to work with 100% ____ or with an _________ mixture.
CO2
argon-CO2
To identify which type of shielding gas is to be used with the electrode, a ____ is added to the designation for CO2 and a _____ is added for mixed gas.
C
M
Which type of shielding gas should be used with the electrode E71T-1C
CO2
Which type of shielding gas should be used with the electrode E71T-1M
Mixed gas
When a single electrode can be used with either shielding gas, it is identified with _____________
Both designations C and M
For example E71T-1M and E71T-1C
How many drive rolls are in a FCAW?
Wire feeders use a 2 roll drive system which works well with welding rolls up to 15 feet long. A 4 roll drive system is used for up to 25 feet.
