SMAW Flashcards
What steels can be welded with SMAW?
All types
What size electrode has the greatest percentage of waste?
Smaller
A “drooping” or “sloping” volt-ampere curve is typical of a constant current (CC) machine.
True or false
True
The phenomenon of deflection of an arc from its normal path because of magnetic forces is called what?
Arc blow
What controls the weld puddle, the electrode deposition rate, and depth of penetration, greatly depends on voltage and current?
Weld heat input
What is a benefit of the twist type electrode holder?
It holds the electrode tightly, allowing the welder to bend the electrode as they choose.
What is a benefit of the alligator jaw electrode holder?
Releasing the electrode is easier, reducing the chances of a stray arc
What is the most common electrode length?
350 mm (14 in.)
When welding in a damp environment, which electrode grouping is least likely to be negatively affected by moisture in the atmosphere?
Fast-freeze
When completing an open root weld on a flat V-groove butt joint, which electrode grouping would be the best choice?
Fast freeze
When welding in only flat and horizontal positions on a heavy structure, which electrode grouping would give the highest weld metal deposition rate and weld bead profile with the smoothest finish?
Fast fill
What type of electrode coating is a product of wood pulp or cotton?
Cellulose
Which electrode group is best for flat and horizontal surfaces?
Fast fill
Which electrode group is not suited for out of position welding?
Fast fill
Which electrode group has a deep-penetrating, forceful arc?
Fast freeze
Which electrode group produces welds with excellent notch toughness and high ductility?
Low hydrogen
Which electrode group has high deposition rates?
Fast fill
Which electrode group is well suited to welding sheet metal?
Fill freeze
Which electrode group is suitable for welding in the vertical or overhead position?
Fast freeze
What is the intended result of a PWHT?
Improved atmospheric absorption
Can be used for higher temperature and higher pressure service applications, especially in corrosion resistance situations.
What metal alloy?
Chrome-moly
Which metal alloy reduces softening at elevated temperatures?
Carbon-moly
A convex and coarsely rippled bead.
EXXXxx-15 or EXXXxx-16
EXXXxx-15
A finely rippled bead.
EXXXxx-15 or EXXXxx-16
EXXXxx-16
A more penetrating arc.
EXXXxx-15 or EXXXxx-16
EXXXxx-15
A smoother arc.
EXXXxx-15 or EXXXxx-16
EXXXxx-16
Less spatter.
EXXXxx-15 or EXXXxx-16
EXXXxx-16
What is the typical work angle when using a SMAW electrode?
One-half (1/2) the included joint angle.
When vertical-down welding with SMAW, what technique will help to avoid slag inclusions?
Travel at higher speeds
Which is not a characteristic of the continuously fed electrode with GMAW?
A) can be used semi automatic, machine, or fully automated
B) improves weld deposit rates
C) provides internal gas shielding, so external gas shielding is not required
D) reduces frequency of stopping and restarting
C) provides internal gas shielding, so external gas shielding is not required
With GMAW, the higher deposition rate results from the absence of electrode covering and higher current density.
True or false
True
What is not one of the purposes of the flux inside FCAW wires?
A) to add alloying elements
B) to generate shielding gases
C) to prevent slag formations
D) to stabilize the arc
C) to prevent slag formations
What is a disadvantage of the FCAW process?
A) increased need for a draft free environment
B) frequent changing of electrodes
C) low weld metal deposition rates
D) need for interpass slag removal
D) need for interpass slag removal
What type of power source is typically used with GMAW and FCAW welding?
CV
If there is no change in wire feed speed, what will an increase in arc voltage do?
Increase arc length
With wire process welding, how is current (amperage) controlled?
By changing the wire feed speed
Which type of drive rolls are most often used for FCAW and MCAW?
Knurled
Which type of drive rolls are most often used for aluminum wires?
U
Which part of the welding gun transfers the current to the wire electrode?
Contact tip
Shielding gas flow rates are measured in either litres per hour (L/h) or cubic feet per minute (cfm).
True or false
False
What does the term pinch effect refer to?
The buildup of magnetic fields around the molten droplet at the end of the electrode
What does excessive current cause?
Spatter
Droplet transfer rate and mode of transfer are controlled by what?
The current density
What gas mixture is required to achieve spray transfer?
A minimum of 85% argon
Which shielding gas transfers the greatest amount of heat to the weld puddle?
CO2
Which shielding gas causes a deep, finger shaped penetration profile?
Argon
What percentage of oxygen added to argon improves weld beam contour and penetration?
1-5%
The most common general GMAW electrode used is what?
ER70S-6
The system of classification for carbon steel FCAW electrodes, CSA W48, is based on whether the electrode is self-shielded or gas-shielded.
True or false
True
MCAW electrodes contain no fluxes and are filled with metal powders and arc stabilizers.
True or False
True
ER309L filler wire is used in the joining of what?
Carbon steel to stainless steel
What can excessive travel speed lead to?
Lower heat input
What can insufficient travel speed lead to when using GMAW?
Burn-through
What travel angle is optimal for open root applications with GMAW?
Pull (backhand) 5-15•
Which of the following is not an advantage of short-circuiting transfer?
A) can be used for all position welding
B) can easily weld non-ferrous metals and alloys
C) is good for welding thinner materials
D) the low heat input reduces distortion
B) can easily weld non-ferrous metals and alloys
One of the benefits of globular transfer is the low amount of spatter formed.
True or false
False
When foot welding with GMAW in 1 GR position, where should the welding torch be positioned?
Between 12 and 2 o’clock
