chapter 11 welding 1
A ____ gap may require ____. a-narrow, more penetration b-narrow, less penetration c-wide, more penetration d-narrow, forehand welding
a
A ________ must be chained securely in place before the valve protection cap is removed. a-Shielding gas cylinder b-Flowmeter regulator c-Cooling water supply hose d-Welding power cable
a
As the electrode extension is shortened, the welding current ____. a-decreases b-increases c-stays the same d-varies erratically
a
When CO2 is being used as a shielding gas and the voltage is set near the maximum, ________. a-excessive spatter may occur b-the welding arc may become too short to control arc blow c-the electrode wire may begin to feed erratically d-the weld penetration will burn through the plate
a
Which of the following is true of mill scale? a- The porosity it causes is most often confined to the interior of the weld. b- It is removed even for noncode welding. c- With GMA welding wire, deoxidizer eliminates the adverse effects of mill scale. d- It increases the chance of rusting.
a
___ is increased and ____ is decreased as the electrode extension is shortened. a-Penetration, buildup b-Buildup, penetration c-Voltage, penetration d-Welding current, penetration
a
Electrode wire has a natural curve that is known as its ____. a-curve b-cast c-diameter d-circle
b
High gas flow rates ____. a-provide better weld coverage b-waste shielding gases c-decrease the venturi effect d-decrease contamination
b
The ____ the density of a gas, the ____ will be the flow rate required for equal arc protection. a-lower, lower b-lower, higher c-higher, higher d-lower, slower
b
The major advantages of the vertical down position technique are ____. a-speed and deep penetration b-speed, shallow penetration, and good bead appearance c-less skill is required to make sound welds d-lack of fusion and overlap
b
The only difference between all GMA welding machines and some FCA welding machines is that all GMA welding machines must have a ______________. a-cooling water system b-shielding gas solenoid c-air cooling fan d-power contactor to start and stop the current
b
The perpendicular welding gun angle produces welds that ______________________. a-have more penetration and less reinforcement b-have a good balance between penetration and reinforcement c-have less penetration and more reinforcement d-are more likely to cause burnthrough than any other welding gun angle
b
____ provide the necessary shielding because they do not form compounds with any other substance. a-Active gases b-Inert gases c-Carbon blends d-Oxygen blends
b
What can be done to keep the spatter to a minimum when using CO2 as the shielding gas? a-Use a leading gun angle with a higher shielding gas flow rate. b-Maintain a very short uniform arc length while welding. c-Make stringer bead welds with little or no weave motion. d-Travel at a slower speed.
b
Adding oxygen or carbon dioxide to an inert gas causes the shielding gas to become ____, which may cause ____ in some ferrous materials. a-inert, oxidizing b-oxidizing, spatter c-oxidizing, porosity d-inert, porosity
c
In GMA welding, the voltage is set ____ and the amperage is set ____. a-on the welder, on the welder b-by changing the wire-feed speed, on the welder c-on the welder, by changing the wire-feed speed d-by changing the wire-feed speed, by changing the wire-feed speed
c
Slight changes in ____ can be used to control the weld as the groove spacing changes. a-penetration b-V-groove c-welding gun angle d-stick out
c
The correct flow rate of a shielding gas can be set by ____. a-checking the pressure of the gas b-multiplying the nozzle size by the amperage c-checking welding guides d-checking the density of the gas
c
The major skill required to make acceptable GMA welds consistently is_______________. a-to use a longer arc length with a slower wire feed speed b-to only weld in the flat or vertical down positions when possible c-the ability to set up the equipment and weldment d-to keep the welding gun nozzle high enough so you can always see all of the weld pool
c
Too light of a feed roller pressure can _______________. a-prevent damage to the welding wire b-be used to prevent bird-nesting c-cause erratic wire feeding d-help to reduce the roller's wear
c
Because of the constant-potential power supply, the welding current will change as the distance between the ____________________ and the work changes.
contact tube
Shielding gases in the gas metal arc process are used primarily to protect the molten metal from oxidation and ___________
contamination
A weld that is high and has little or no fusion is too "cold." To correct this, ____. a-change welding technique b-change the weave pattern c-increase travel speed d-stop welding and make the needed adjustments
d
The longer the ____, the greater the ____ to the welding current. a-electrode extension, distance b-arc, distance c-distance, arc d-electrode extension, resistance
d
What can be done to counteract the loss of certain alloying elements such as chromium, vanadium, aluminum, titanium, manganese or silicon? a-Do not use oxygen in the shielding gas. b-Use less oxygen in the shielding gas. c-Add a deoxidizer to the shielding gas. d-Add a deoxidizer to the filler wire.
d
Which of the following gases is the least dense? a-Oxygen b-Carbon dioxide c-Argon d-Helium
d
What can a welder do to make the necessary adjustments in the setup and manipulation to achieve a good weld? a-Keep the welding station clean and free from scrap that can get in the way of your seeing the weld. b-Do not make changes to the welding setup that was working for the last welder. c-Use a mixture of argon with 2% oxygen as the shielding gas. d-Make a few test welds.
d
__________________ is the chief determinant of how effective a gas is for arc shielding.
density
Filler metals and fluxes usually have ____________________ added to them so that the adverse effects of the mill scale are reduced or eliminated.
deoxidizers
The exact shielding gas ____________________ required for a certain job will vary depending upon the welding conditions.
flow rate