Welding

Pataasin ang iyong marka sa homework at exams ngayon gamit ang Quizwiz!

3/4 inch equals 28 millimeters.

False

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

Ozone

____ is formed when ultraviolet radiation decomposes chlorinated hydrocarbon.

Phosgene

____ cutting uses a stiff, highly ionized, extremely hot column of gas to almost instantly vaporize the metal being cut.

Plasma arc

____ are usually either hydraulic or flywheel operated.

Power punches

____ 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

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

True

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

True

____ fire extinguishers are used for electrical fires.

Type C

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

Type D

____ welding is the most modern.

Fusion

Gauges that do not read ____ when the pressure is released must be repaired or replaced.

0 psig

Hoses are available in four sizes: ____.

3/16 in., 1/4 in., 5/16 in., 3/8 in.

Which of the following is true of the tee joint?

A large percentage of the welding heat is reflected back on the torch.

If the current is set too high, the electrode covering is discolored more than ____ from the end of the electrode.

1/8 in. to 1/4 in.

In axial spray metal transfer, the shielding gas is usually a mixture of ____.

95% to 98% argon and 2% to 5% oxygen

____ controls the size of the arc.

Amperage

____ relies on capillary action to draw filler metal into the joint, whereas ____ does not need capillary action.

Brazing, braze welding

____ alloys have excellent wetting, flow, and strength characteristics, but they are expensive.

Cadmium-silver

____ electrodes have a forceful arc with little slag left on the weld bead.

E6010 and E6011

____ have rutile-based fluxes with a thick slag left on the weld bead.

E6012 and E6013

The equipment for ____ is more likely to be automated.

FCAW and SAW

Acetylene can be used in any tip.

False

As a fillet weld is made on a lap joint, the buildup should be less than the thickness of the plate.

False

As the slope increases, both the short-circuit current and pinch effect are increased.

False

Body position changes should never be made during electrode changes.

False

Chrome plating causes spatter to stick to the tip, prolonging cleanup.

False

Electrodes with mineral-based fluxes should be the first choice.

False

Helium is not considered to be an inert gas.

False

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

False

If the current is set too low or too high, you should change the settings during welding.

False

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

False

In silver brazing, using an oxyacetylene torch will reduce the possibility the alloy will overheat.

False

It is possible to make acceptable welds with the wrong type of power supply.

False

Large welding lead sizes make electrode manipulation easier.

False

Low carbon steels are difficult to cut.

False

Materials that are round or covered in rust require less preheat flame.

False

Oxygen need not be completely mixed with the fuel gas before they leave the tip and create the flame.

False

SMAW is a rarely used welding process because of its cost and lack of flexibility.

False

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

False

Shielded metal arc welding often continues for long periods of time.

False

Straight or dedicated cutting torches are usually shorter than combination torches.

False

Tensile strength is not affected by the spacing between the parts being joined.

False

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

False

The flat tee joint is easier to make than the butt or lap joint.

False

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

False

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

False

The oxyfuel (OF) gas processes are the least vresatile of the welding processes.

False

The rooms that are used for manifolds cannot be used for cylinder storage.

False

The short-circuiting process works better with a long electrode stickout.

False

The temperature of a welding arc does not exceed 1,100 degrees Fahrenheit.

False

The use of fluxes eliminates the need for good joint cleaning.

False

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

False

Tin-lead may be used for water or food-handling equipment.

False

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

False

Today, oxyacetylene welding is frequently used on thick plate.

False

Vertical down welds should never be used on thin sheet metals.

False

Welding with the current set too high results in poor fusion and poor arc stability.

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 BCuP silver brazing alloys on clean copper, it is necessary to use a flux.

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 was introduced first.

Forge or hammer

Electrons flow through a conductor ____.

From negative to positive

While less likely to be automated, ____ welding equipment can be automated easily.

GMA

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

____ is a type of welding.

Gas tungsten arc welding

Which of the following is true of welding mild steel pipe and tubing?

Gas welding is seldom used to manufacture piping systems.

Which of the following gases is the least dense?

Helium

Which of the following is true of axial spray transfers using high current settings?

High current settings may cause the weld to be difficult to control in out-of-position welds.

____ provide the necessary shielding because they do not form compounds with any other substance.

Inert gases

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.

Which of the following is true of backhand welding?

It has good bead visibility and makes welds with deeper joint penetration.

Which of the following is true of globular transfer?

It is used in combination with pulsed-spray transfer.

Which of the following is important when choosing general work clothing?

It should be tightly woven and a dark color

The ____ pattern works well on flat lap joints, all vertical joints, and horizontal butt and lap welds.

J

Which of the following deoxidizing elements is weak?

Manganese

____ machines are adjusted by turning a handwheel that moves the internal parts closer together or farther apart.

Movable coil

What is the paste range of an alloy of 61.9% tin and 38.1% lead?

No paste range

Which of the following tasks are done by the welder?

Providing the joint guidance in machine welding processes.

____ contains little or no unoxidized iron.

Soft slag

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 pull-type feed systems?

The gun is heavier and more difficult to use

Which of the following is true of welding cables?

The welding cables should be sufficiently long to reach the work station

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.

Which of the following is a function of fluxes used in brazing and soldering?

They must remove oxides that form from heating parts

Which of the following is true of soldering and brazing fluxes?

They will remove light surface oxides.

A brazed joint can be made that has a tensile strength four to five times higher than the filler metal itself.

True

A cutting torch should never be used to cut open a sealed container.

True

A properly sized electrode holder can overheat if its jaws are dirty or loose.

True

A slight forward torch angle keeps the tip clean for a longer period of time.

True

A tiny movement such as a heartbeat can cause a ripple in the cut.

True

Alternators can be smaller in size and lighter in weight than generators and still produce the same amount of power.

True

Arc welding machines may be stacked to save space as long as there is enough room between them for air to circulate.

True

As the weld progresses, the electrode becomes shorter.

True

Electrodes with cellulose-based fluxes do not have heavy slags.

True

GMA spot welding is an excellent process for auto body repair.

True

Goggles or other suitable eye protection must be used for flame cutting.

True

If an electrode holder becomes hot, you should never dip it in water to cool it off. Correct!

True

If cadmium is overheated, the fumes can be hazardous unless the area is properly ventilated.

True

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

True

More amperage is required to melt the wire the faster it is fed.

True

More people use the oxyfuel cutting torch than any other welding process.

True

Pulsed-arc welding systems were developed in the 1960s.

True

Rectifiers must be connected to a heat sink and cool air blown over them.

True

Shorter arcs are best suited for use on thin metal or thin-to-thick metal joints.

True

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

True

Surfaces on worn parts are often built up again with braze metal.

True

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

True

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 maximum safe open circuit voltage for welders is 80 volts.

True

The same equipment may be used for semiautomatic GMAW, FCAW, and SAW.

True

The thin copper coating on a steel wire electrode either burns off or is diluted into the weld pool with no significant effect to the weld bead.

True

The weave pattern selected for a flat butt joint is not as critical as the pattern selection for other joints and positions.

True

Tin-lead and tin-antimony solders have a low melting temperature.

True

Using excessive flux in a joint may result in flux being trapped in the joint, weakening the joint, or causing the joint to leak or fail.

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

Which of the following determines the amount of preheat flame required to make a cut?

Type of fuel gas and material thickness, shape, and surface condition

____ light is dangerous because the welder cannot feel the light while being exposed to it, and it may pass through clothing.

Ultraviolet

____ 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

____ is a measurement of the amount of electrical energy or power in the arc.

Wattage

Which of the following is correct?

Watts = Volts X Amps

_____ must be able to interpret blueprints and welding procedures.

Welder assemblers

Globular transfer occurs at a rate of ____ drops per second.

a few

To prevent the loss of certain alloying elements, ____.

add a deoxidizer to the filler wire

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

amperage

The three units used to measure an electrical current are ____.

amps, watts, and volts

The ____ is the distance the arc must jump from the end of the electrode to the plate or weld pool surface.

arc length

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

In generators the welding current is produced on the ____.

armature

Welding cables should ____.

be sufficiently long to reach the work station

Students will find it easier to start with ____ joints.

butt

The shielding gas used on carbon steel is ____.

carbon dioxide, or a mixture of carbon dioxide and argon

Electrode wire has a natural curve that is known as its ____.

cast

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

checking welding guides

To prevent ____ use as little leading angle as possible.

cold lap and slag inclusions

GMAW power supplies are ____ type machines.

constant-voltage constant-potential

Most cutting tips are made of ____.

copper alloy

The compatibility of the base materials to the filler metal will determine the ____.

corrosion resistance

To treat third degree burn ___.

cover the burned area with thick, sterile, non-fluffy dressing

The ____ determines the thickness of the metal that can be cut.

cutting tip diameter

As the electrode extension is shortened, the welding current ____.

decreases

Welding shop supervisors

demonstrate good management skills by planning jobs and assigning workers

In ____ processing, the entire surface of the part can be covered with the filler metal at the same time that it is being joined.

dip

Some electrodes may not remove the deposits ahead of the molten weld pool, resulting in ____.

discontinuities within the weld

The longer the ____, the greater the ____ to the welding current.

electrode extension, resistance

The purpose of the ____ is to provide a steady and reliable supply of wire to the weld.

electrode feed unit

Any system of ventilation should draw the fumes or smoke away before it rises past the level of the welder's ____.

face

For most soldered or brazed joints, ____ is usually fairly low.

fatigue resistance

The most commonly used welding processes are _____.

gas metal arc welding and flux cored arc welding

Oxyacetylene welding is also referred to as ____.

gas welding or torch welding

Welding shop owners ____.

have a high degree of skill and knowledge of small business management

Burns ____.

have a high risk of infection because of the dead tissue

Resistance to the flow of electrons produces ____.

heat

With the addition of ____ to the argon gas, the transfer becomes progressively more ____.

helium, globular

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

The ____ method of heating uses a high-frequency electrical current to establish a corresponding current on the surface of the part.

induction

The size of a hose is the ____ of the hose.

inside diameter

Open circuit voltage ____.

is the voltage at the electrode before striking an arc

The space produced during the cutting process is the ____.

kerf

Small molten weld pools are ____ large ones to drip.

less likely than

The torch pressure is always ____ the working pressure shown on the gauge.

less than

A machine cutting torch is sometimes referred to as a(n) ____.

line burner

An advantage of the ____ feed system is that the bulky system of gears is eliminated.

linear

Which of the following metals are easy to cut using oxyfuel gas cutting?

low carbon steels

The ____ the density of a gas, the ____ will be the flow rate required for equal arc protection.

lower, higher

The symptom of acute exposure to high concentrations of cadmium fumes is ____.

lung irritation

The rhythm of moving the torch helps ____.

make the bead uniform

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

At any one voltage setting, ____ amperage is required to melt the wire the ____ it is fed.

more, faster

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

Soldering fluxes are chemical compounds such as ____.

muriatic acid

Fluxes that are active at room temperature ____.

must be neutralized after completing the job

Stored oxygen and fuel gas cylinders ____.

must be separated by 20 feet

A ____ gap may require ____.

narrow, more penetration

Tack welders ____.

often help the welder by making small welds to hold parts in place

In GMA welding, the voltage is set ____ and the amperage is set ____.

on the welder, by changing the wire-feed speed

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

one size larger than

Acetylene is used in tips having ____ preheat holes.

one to six

To correct a(n) ____ problem, a welder can use a smaller electrode at a lower current setting.

overheating

In the pulsed-arc metal transfer current cycle, ____ refers to the surging electrical current passing through the transformer like a wave on water.

overshoot

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 ____ flame has a very high temperature near the inner cone, but it has little heat in the outer flame, resulting in localized overheating.

oxyacetylene

When metal is burned away, ____.

oxygen forms an iron oxide

Welder assemblers

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

In the ____ feed system, the electrode must have enough strength to be pushed through the conduit without kinking.

push-type

In selecting the joining process, one consideration relates to the ____, such as whether the weld will be used on a piece of furniture, or to repair a piece of equipment, or to join a pipeline.

quality requirements

In the pulsed-arc metal transfer current cycle, ____ is a function of the time it takes the magnetic field in the transformer to collapse once the coil is de-energized.

ramp down

The space between plates in a square butt joint is called the ____.

root gap

A work clamp ____.

should be carefully touched occasionally to determine if it is hot

On thick metal, a ____ diameter filler rod may be used to ____.

small, increase penetration

If a process is ____, the base material or materials are not melted.

solid

Welding with the current set too high results in ____.

spatter

If arc length is shortened, metal transferring across the gap may short out the electrode, causing it to ____.

stick to the plate

When drilling, if the metal shavings coming out of the hole become long,

stop downward pressure

A weld that is high and has little or no fusion is too "cold." To correct this, ____.

stop welding and make the needed adjustments

To make threading electrode wire easier, ____.

straighten about 12 in. of the end of the wire and cut off any kinks

The straight step pattern can be used for ____.

stringer beads

A ____ may oversee the actual work for the engineer by providing the engineer with progress reports as well as chemical, physical, and mechanical test results.

technician

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

ten

The spacing between the parts being joined greatly affects the ____ of the finished part.

tensile strength

An arc will jump ____.

the closest metal conductor

If the cutting stream is too fast, ____.

the cut may be incomplete

If the pressure setting is too high, ____.

the sides of the kerf may be dished

The selection of the correct size of welding electrode is determined by ____.

the thickness and size of the metal

If an excessive amount of preheat flame is used, ____.

the top edge may be melted or rounded off

The mixing chamber may be located in ____.

the torch body or the tip

When cutting pipe freehand, if the pipe is larger than three inches in diameter, ____.

the torch tip is always pointed toward the center of the pipe

Large diameter electrodes may overheat the metal if ____.

they are used with thin or small pieces of metal

The strongest joints are obtained when the parts use lap or scarf joints where the joining area is equal to ____ times the thickness of the thinnest joint member.

three

A welded tee joint can be strong if it is welded on both sides, even without having deep penetration.

true

If a large cutting tip pops when the acetylene is turned off, ____.

turn the oxygen off first

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

voltage

High gas flow rates ____.

waste shielding gases

Forced ventilation is always required when ___.

welding on metals that contain zinc, lead, beryllium, cadmium, mercury, copper, or austenitic manganese or other materials that give off hazardous fumes

The symptoms of lead poisoning include ____.

metallic taste, loss of appetite, nausea, abdominal cramps, and insomnia

When mixing oxygen and fuel gas, one method uses equal or balanced pressure and mixes gases in a(n) ____.

mixing chamber

A(n) ____ flame is the most commonly used flame because it adds nothing to the weld metal.

neutral

In a horizontal stringer bead, the weld bead will tend to sag downward, and as a result there may be a(n) ____ on the bottom edge.

overlap

A(n) ____ flame has an excess of oxygen.

oxidizing

A(n) ____ flame has the highest temperature.

oxidizing

Some joints, such as the lap joint, may never need 100% ____; however, they do need 100% ____.

penetration, fusion

The purpose of the ____ valve is to prevent gases from accidentally flowing through the torch and into the wrong hose.

reverse flow

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

shielded metal arc

To test a grinding stone for cracks ____.

tap the stone in four places and listen for a ring

In a vertical weld, the ____ will constantly be solidifying, forming a new shelf to support the molten weld pool.

trailing edge

There are ____ basic methods for mixing oxygen and fuel gas to form a hot, uniform flame.

two

When taping hoses together, the hoses should be wrapped for about ____ in. out of every ____ in.

two, twelve

If a nut or bolt is too tight to loosen with a wrench, ____.

use a longer wrench

The ____ has a right and a left side.

vertical tee joint

The ____ pressure gauge shows the pressure at the regulator.

working

The combination welding and cutting torch offers more flexibility because a cutting head, welding tip, or heating tip can be attached quickly to the same torch body.

True

The flat butt joint is a welded joint and one of the easiest to make.

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

The possibility of being burned increases greatly when welding in the overhead position.

True

There are no internal or external moving parts on a regulator or a gauge that require oiling.

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

When heating the two clean sheets in the process of welding a lap joint, caution must be exercised to ensure that both sheets start melting at the same time.

True

Small amounts of total penetration usually will not cause a burnout.

True

The acetylene valve should never be opened more than one and one-half turns.

True

GMA and ____ welding are the first choice for many welding fabricators because these processes are cost effective, produce high- quality welds, and are flexible and versatile.

FCA

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

False

A reverse flow valve will stop the flame from a flashback from continuing through the hoses.

False

All regulators can be used interchangeably on different types of gas or for different pressure ranges.

False

Both earmuffs and earplugs protect the outer ear from burns.

False

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

False

If the tip's flame produces too much heat, you should lower the flame size.

False

Mild steel is one of the more difficult metals to gas weld.

False

Out-of-position welds are no more difficult than flat welds.

False

Pressure and heat are both necessary to create a weld.

False

Regulators that creep excessively or beyond the safe working pressure may be used with caution until they are repaired.

False

Which of the following is true of mild steel welds?

It is possible to make welds with 100% integrity.

____ seal tips must be tightened with a wrench.

Metal-to-metal

____ of a tee joint enables a larger weld to be made than either the butt or lap joint.

Surface tension in the molten weld pool

Which of the following is true about overhead welding?

The direction that you choose to weld is a matter of personal preference.

Which of the following is true of horizontal welds?

They must rely on some part of the weld bead to support the molten weld pool.

A vertical weld is the most common out-of-position weld that a welder is required to perform.

True

All regulators work the same way.

True

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

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

Hammer welding preceded resistance welding.

True

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

True

No industrial standard tip size identification system exists.

True

Which of the following is true of making a proper stop?

You should slightly taper down the molten weld pool by flashing the torch off.

To obtain the absolute pressure, ____.

add the atmospheric pressure to the gauge pressure

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

blue circle

Often the number of sparks in the air increases just before a ____ takes place.

burn-through

Welders' helpers ____.

clean slag from the welds, and help position weldments

Welding engineers ____.

design, specify, and oversee the construction of complex weldments

The ____ gauge is used to indicate the amount of gas that remains in a cylinder.

high-pressure

The symptoms of exposure to zinc oxide fumes include ____.

influenza symptoms


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