Welding Chapter 11 and 12 Test
___ rapidly expand and push the surrounding air away from the molten weld pool.
Gas formers
A weld that is high and has little or no fusion is too "cold." To correct this, ______.
stop welding and make the needed adjustments
Which of the following is true of wire electrodes?
storage in an electric rod
To make threading electrode wire easier, _____.
straighten about 12 in. (305 mm) of the end of the wire and cut off any kinks
Mixtures of argon with less than ____ percent carbon dioxide may not have enough arc voltage to give desired results.
ten
The American Welding Society defines ____ as the linear rate at which the arc is moved along the weld joint.
travel speed
The most popular electrode diameters range from ____ to ____.
.035 inch, 3/32 inch
FCA welding deposition rates of more than ____ lbs/hr. of weld metal are positive.
25
What can be done to counteract the loss of certain alloying elements such as chromium, vanadium, aluminum, titanium, manganese or silicon?
Add a deoxidizer to the filler wire
_____ all help remove oxides, and/or nitrides in the weld.
Aluminum, silicon, and titanium
Which of the following is a similarity between FCAW and GMAW?
Both use CP welding power supplies
_____ can be added to improve hardness, strength, creep resistance, and corrosion resistance.
Carbon, chromium, and vanadium
How is the amperage adjusted on a FCA welding machine?
Changes in the wire feed speed automatically change the amperage
From 75% to 95% of the weight of ____ electrodes is metal, whereas ____ have a maximum of 75% filler metal.
FCAW, SMAW
______ provide the necessary shielding because they do not form compounds with any other substance.
Inert gas
Which of the following is true of short-circuiting arc metal transfer in the overhead position?
It has less molten weld pool sag
Which of the following is true of making high- quality welds?
It is affected by the weather
Which of the following is true of lime-based flux?
It is generally unsuitable out of position
______ is increased and ____ is decreased as the electrode extension is shortened.
Penetration, buildup
_____ are added to the flux and form a slag.
Potassium, sodium, and zirconium
_____ helps the weld by protecting the hot metal from the effects of the atmosphere.
Slag
The major advantages of the vertical down position technique are _____.
Speed, shallow penetration, and good bead appearance
Which of the following is true of FCAW?
The addition of deoxidizers eliminates most of the pre cleaning required
Which of the following is true of mill scale?
The porosity it causes is most often confined to the interior of the weld
If the voltage and wire feed speed are not changed but a larger wire size is used, the _____.
amperage would automatically go up
In the flux classification system, the letter "G" is used to indicate _____.
an unspecified classification
When used as pure gases for welding ferrous metals, ______ may produce an erratic arc action, promote undercutting, and result in other flaws.
argon and helium
Atmospheric contamination of molten weld occurs ____.
as it travels across the arc gap and within the pool before it solidifies
An electrode specifically designed for use with 100% CO2 will have higher levels of ___ to compensate for the losses to oxidation.
silicon and manganese
Electrode wire has a natural curve that is known as its _____.
cast
Too light of a feed roller pressure can _______.
cause erratic wire feeding
The correct flow rate of shielding gas can be set by _____.
check welding guides
As the electrode extension as shortened, the welding current _____.
decreases
The longer the ____, the greater the _____ to the welding current.
electrode extension, resistance
The addition of ____ gives FCAW the high level of reliability needed for welding on boilers, pressure vessels, and structural steel.
flux
The wire feed speed on charts are generally given in ______.
inches per minute
The main limitation of flux cored arc welding is that _____.
it is confined to ferrous metals and nickel-bases alloys
The _____ density of a gas, the ____ will be the flow rate required for equal arc protection.
lower, higher
At any one voltage setting, ____ amperage is required to melt the wire the ___ it is fed.
more, faster
A ____ gap may require_____.
narrow, more penetration
In FCAW ____ % of the electrode is used.
nearly 100
In GMA welding, the voltage is set ____ and the amperage is set ____.
on the welder, by changing the wire-feed speed
Adding oxygen or carbon dioxide to an inert gas causes the shielding gas to become ____, which may cause ____ in some ferrous materials.
oxidizing, porosity
The major atmospheric contaminations come from _____.
oxygen and nitrogen
In FCAW, atmospheric shielding is _____.
provided by flux sealed within the tubular electrode, but extra shielding may be supplied through a nozzle
When the electrode provides all of the the shielding, it is called ______.
self shielding
A _____ must be chained securely in place before the valve protection cap is removed.
shielding gas cylinder
The only difference between all GMA welding machines and some FCA welding machines is that all GMA welding machines must have a _______.
shielding gas solenoid
High gas flow rates _____.
waste shielding gases
Slight changes in ___ can be used to control the weld as the groove spacing changes.
welding gun angle