120103K Flashcards
(36 cards)
Describe and explain the principles of operation of SAW
Submerged arc welding is an arc welding process in which metals are joined using an
electric arc established between a continuously fed bare metal consumable electrode or electrodes and the work. Shielding is provided by a granular, fusible flux material usually brought to the work area using a flux feed system.
What position(s) can SAW be used in?
flat and horizontal positions
Name four (4) types of materials that SAW can be used on.
1) carbon
2) alloy steels
3) stainless steels
4) nickel alloys
List the seven (7) basic equipment components required for a SAW set-up and briefly
explain their functions.
- The welding power source provides welding current.
- The welding head assembly includes the wire feeder, torch assembly and travel
carriage (machine and automatic operation). - The fixtures and positioners position the work piece for welding.
- Spooled filler wire provides filler metal for the weld.
- The flux provides shielding, shapes the bead and allows alloys to be added.
- The flux feed and recovery equipment conveys flux to the weld zone and collects
unused flux. - The work lead connection completes the welding current circuit to the work
piece
What are the advantages of using a screw-type work clamp with SAW?
- It provides a strong and positive contact to the work.
- It minimizes heat build-up.
What type(s) of output slope do SAW power sources use?
CC and CV
What duty cycle rating is recommended for most SAW power sources?
100%
SAW may be used in the _____________ or automatic operation modes
semi-automatic
What is the advantage of using an ac power source for SAW?
It minimizes arc blow with multiple wire set-ups.
What will usually result if the drive roll pressure is set too low?
The wire electrode will slip and feed erratically.
How will the arc react if the flux layer is too shallow?
The weld will be flashing and will likely result in porosity.
Helix is ______?
the space between two unrestrained loops of wire
What type(s) of drive rolls are normally used with SAW?
knurled or V-groove
What type of wire feed set-up is used with CV power sources?
constant speed
List the six (6) main SAW operating variables and their effects.
- Amperage controls penetration and rate of deposit.
- Voltage affects arc length.
- Travel speed affects the penetration and weld bead profile
- Electrode diameter has a direct effect on the weld bead shape, depth of
penetration and weld metal deposition rates. - Electrode extension affects rate of metal deposition and affects flux layer depth.
- Width and depth of flux layer has an influence on arc action, bead appearance and weld metal soundness.
To increase arc length when you are welding with SAW, you would:
increase arc voltage.
When using SAW, an increase in the arc voltage produces a ______
wider arc stream and shallower penetration.
When is DCEN used with SAW?
when shallower penetration is required
Why are wire cast and helix requirements placed in CSA and AWS specifications for
SAW filler metals?
They ensure that the electrode wire will feed smoothly to the weld zone
What diameters are SAW electrode wires available in?
1.6 mm to 6.4 mm (1/16” to 1/4”)
What is the main difference between the CSA and AWS classification systems for
SAW electrode wires?
CSA uses the metric system to measure tensile strength values.
Using the AWS classification for the F7AZ-EL12K flux/wire designation, what does the F represent?
designates a flux
Using the AWS classification for the F7AZ-EL12K flux/wire designation, what does the 7 represent?
minimum tensile strength x 10 000 psi (70 000 psi)
Using the AWS classification for the F7AZ-EL12K flux/wire designation, what does the A represent?
as-welded condition
