Mid term study guide

____ is a type of welding.

Gas tungsten arc welding

Which of the following is true of perpendicular welding technique?

It has a good balance between penetration and reinforcement and is used on automated welding.

____ is a series of ridges cut into the groove.

Knurling

Which of the following is true of shielded metal arc welding?

Metal as thin as 1/16 inch to several feet thick can be welded using the same machine.

____ is formed when ultraviolet radiation decomposes chlorinated hydrocarbon.

Phosgene

____ respirators are air-purifying respirators that use a blower to force the ambient air through air-purifying elements to the inlet covering.

Powered air-purifying

A disadvantage of the perpendicular technique is limited visibility of the weld.

True

Constant-potential and voltage are terms that have the same meaning.

True

Slight changes in the welding gun angle can be used to control the weld as the groove spacing changes.

True

The highest paid welders are those who have the education and skills to read blueprints and do the required work to produce a weldment to strict specifications.

True

____ fire extinguishers are used for combustible metals such as zinc and magnesium.

Type D

____ can cause an arc to move during a weld.

Uneven flux lines

____ controls the maximum gap the electrons can jump to form the arc.

Voltage

In generators the welding current is produced on the ____.

armature

The shielded metal arc welding machine's voltage output ____ as its current ____.

decreases, increases

Welding shop supervisors ____.

demonstrate good management skills by planning jobs and assigning workers

Welding engineers ____.

design, specify, and oversee the construction of complex weldments

Electrons flow through a conductor ____.

from negative to positive

Resistance to the flow of electrons produces ____.

heat

In the pulsed-arc metal transfer current cycle, ____ is the peak current that flows across the arc during the high current pulse.

high pulse current

In selecting the joining process, one consideration relates to the ____, such as whether the parts are made out of a standard metal or an exotic alloy.

materials to be joined

MAG is short for ____.

metal active gas welding

In FCAW ____ % of the electrode is used.

nearly 100

In alternators the welding current is produced on the ____.

stator

____ is a gas that is produced by the ultraviolet radiation in the air in the vicinity of welding operations.

Ozone

Which of the following is true of GMA spot welding?

The burning back of the thin material allows the thicker metal to be melted.

Which of the following is true of axial spray metal transfer?

There are hundreds of drops per second crossing from the wire to the base metal.

Any cold liquid you drink can be poured on a first or second degree burn.

True

GTA welding is the cleanest of all the manual welding processes.

True

Hammer welding preceded resistance welding.

True

In a standard welding transformer, the size of the iron core is determined by ____.

the length of time it takes for the magnetic field to build up and collapse

FCA welding deposition rates of more than ____ lb./hr. of weld metal are possible.

25

____ all help remove oxides and/or nitrides in the weld.

Aluminum, silicon, and titanium

____ controls the size of the arc.

Amperage

Which of the following is a carbide former?

Chromium

3/4 inch equals 28 millimeters.

False

A formal apprenticeship is usually required to become a general welder.

False

An advantage of FCAW is that it is confined to ferrous

False

Both earmuffs and earplugs protect the outer ear from burns.

False

FCAW electrodes have a mineral-based flux that becomes liquid at high temperatures.

False

FCAW represented about 20% of the total amount of welding done in 2005.

False

Generally seventeen months of training are required to learn to weld.

False

Hot-rolled steel has a thin copper layer which is formed during the rolling process.

False

In semiautomatic or automatic processes, the welder is required to work harder because of the greater demands on travel speed and current.

False

The welding area should be ventilated and forced ventilation is best, but natural ventilation is sometimes required.

False

To treat a third degree burn, apply ointments or antibiotic cream.

False

When first introduced, SMAW was immediately accepted because it was more productive than GTAW and produced higher quality welds than GMAW.

False

When using extension cords on portable power tools, the size of the conductors must be small enough to enable a drop in voltage.

False

____ welding is the most modern.

Fusion

Which of the following is a similarity between FCAW and GMAW?

Higher electrode feed speeds produce higher currents.

Pressure and heat are both necessary to create a weld.

False

Scrap metal and electrode stubs are difficult and costly to recycle.

False

The Industrial Revolution, from 1750 to 1850, introduced a method of joining pieces of iron together known as forced welding.

False

The flux within the electrode will remove or control weld quality problems caused by surface contaminators.

False

The heat produced during GMA welding is sufficient to force 100% penetration consistently, making it ideal for industrial applications.

False

The lime-based flux is acidic.

False

The lower the density of a gas, the lower the flow rate required for equal arc protection.

False

Even though ____ welding is slower and requires a higher skill level as compared to other manual welding processes, it is still in demand because it can be used to make extremely high-quality welds in applications where weld integrity is critical.

GTA

____ welding can be used to weld metal ranging in thickness from thin-gauge sheet metal to heavy plate by making only a few changes in the welding setup.

Gas metal arc

Which of the following is true of wire electrodes?

Some wire electrodes require storage in an electric rod oven.

The heat produced during axial spray welding using large diameter wire or high current may be intense enough to shatter the filter lens in a welding helmet.

True

The rutile-based flux is acidic.

True

Too much visible light can cause temporary night blindness.

True

Welding and cutting lead-bearing alloys or metals whose surfaces have been painted with lead-based paint can generate lead oxide fumes.

True

Wire should not be discarded on the floor because it can work its way into a filter screen on the welding power source.

True

A(n) ____ produces AC, and a(n) ____ produces DC.

alternator, generator

The amount of heat produced by a welding arc is determined by the ____.

amperage

In the flux classification system, the letter "G" is used to indicate ____.

an unspecified classification

Atmospheric contamination of molten weld metal occurs ____.

as it travels across the arc gap and within the pool before it solidifies

General work clothing should ____.

be tightly woven and a dark color

A ____ is the symbol for a Type C fire extinguisher.

blue circle

The shielding gas used on carbon steel is ____.

carbon dioxide, or a mixture of carbon dioxide and argon

The correct flow rate of a shielding gas can be set by ____.

checking welding guides

Welders' helpers ____.

clean slag from the welds, and help position weldments

Open circuit voltage ____.

is the voltage at the electrode before striking an arc

The best material to use for special protective clothing is ____.

leather

The major classifications of welding machines are ____.

multiple coil, movable coil, movable core, and inverter

The ____ machine allows the selection of different current settings by tapping into the secondary coil at a different turn value.

multiple-coil

Stored oxygen and fuel gas cylinders ____.

must be separated by 20 feet

A ____ gap may require ____.

narrow, more penetration

Welding cables made of aluminum wire must be ____ would be required for copper.

one size larger than

The base of a ladder should be set out a distance equal to ____ the height to the point of support.

one-fourth of

Welder assemblers ____

position all the parts in their proper places and make ready for the tack welders

In FCAW, atmospheric shielding is ____.

provided by flux sealed within the tubular electrode, but extra shielding may be supplied through a nozzle as in GMAW

The heat produced by a rectifier ____.

reduces the power efficiency of the welding machine

An advantage of ____ welding is that a variety of metal types and metal thicknesses can be joined with one machine.

shielded metal arc

A 60% duty cycle means that the machine can be used a total of ____ minutes out of every ten minutes at the maximum rated current.

six

A transformer with more turns of wire in the primary winding than in the secondary winding is known as a ____.

step-down transformer

To test a grinding stone for cracks ____.

tap the stone in four places and listen for a ring

Mixtures of argon with less than ____ percent carbon dioxide may not have enough arc voltage to give desired results.

ten

The temperature of a welding arc is dependent on the ____, arc length, and atmosphere.

voltage

The most popular electrode diameters range from ____ to ____.

.035 inch, 3/32 inch

The amount of reactive gas required to produce the desired effects is quite small.

True

Burns can be caused by ultraviolet light rays.

True

Damage to your hearing caused by high sound levels is permanent and may not be detected until later in life.

True

Gas metal arc welding and flux cored arc welding are very different welding processes, but they use very similar welding equipment.

True

In some instances, pressure alone may be sufficient to force separate pieces of material to combine and form one piece.

True

In the beginning, the GMAW process was used to weld aluminum using argon gas for shielding.

True

Sometimes the shielding gas is referred to as the shielding medium.

True

The FCA welding power supply is the same type that is required for GMAW.

True