Chapter 10 & 11 Study Guide

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

False

The exact shielding gas ________ required for a certain job will vary depending upon the welding conditions.

Flow rate

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

GMA

MIG, MAG, and wire welding are other names for ______

GMAW

______ transfer can be used on thin materials and at a very low current range.

Globular

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

Helium, globular

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

True

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

True

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

True

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

True

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

True

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

On the welder, by changing the wire-feed speed

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

stop welding and make the needed adjustments

GMA welding machines have ______ duty cycle

100 percent

As much as _____ can be added to the argon to increase the power in the arc without affecting the desirable qualities of the spray mode.

80% helium

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

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

Vertical down welds should be used on thin sheet metals

False

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

True

Which of the following gases is the least dense?

Argon

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.

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 _____ of a wire is measured by the diameter of the circle that the wire would make if it were loosely laid on a flat surface

Cast

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

Checking welding guides

GMAW power supplies are _____ type machines

Constant-voltage constant-potential

Shielding gases in the gas metal arc process are used primarily to protect the molten metal from oxidation and ________

Contamination

To make threading electrode wire easier, _____.

Cut off about 12 in. of the end of the wire.

________ is the chief determinant of how effective a gas is for arc shielding.

Density

The _____ rate is the measure of the weld metal deposited

Deposition

The equipment for ___ is more likely to be automated

FCAW and SAW

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

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

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

False

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

False

The short circuiting process works better with a long electrode stickout

False

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 backhand welding?

Is has good bead visibility and makes welds with deeper joint penetration

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 short-circuiting arc metal transfer in the overhead position?

It has less molten weld pool sag

Which of the following is true of globular transfer?

It is used in combination with pulsed-spray transfer

______ is series of ridges cut into the groove

Knurling

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

Linear

Which of the following tasks is done by a machine?

Maintaining the arc in semiautomatic welding processes.

Which is the following deoxidizing elements is weak?

Manganese

MAG is short for _____

Metal active gas welding

_________ is a thin layer of dark gray or black iron oxide formed during the rolling process.

Mill scale

A ______ gap may require _____.

Narrow, more penetration

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

_____ is increased and ____ is decreased as the electrode extension is shortened.

Penetration, buildup

Which of the following tasks are done by the welder?

Providing the joint guidance in machine welding processes

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

Push-type

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

In the pulsed- arc metal transfer current cycle, ______ refers to how the electric current in a transformer takes a few milliseconds to build up the magnetic field to full strength once the coil is energized.

Ramp up

The rate of voltage decreases as the amperage increases within the working range is known as _____

Slope

The major advantages of the vertical down position technique are ____.

Speed, shallow penetration, and good bead appearance.

With the feed running, adjust the _________ so that the rel stops when the feed stops.

Spool drag

______ systems interlock the power supply and wire feeder.

Synergic

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

Ten

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 mill scale?

The porosity it causes is most often confined to the interior of the weld.

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

The axial spray metal transfer process rewuires a current level above a critical amount, called the ______ current.

Transition

GMA spot welding is an excellent process for auto body repair

True

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

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

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

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

True

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.

GMAW is relatively free from spatter because it uses a mode of metal transfer called ________ metal transfer

axial spray

Because of the constant-potential power supply, the welding current will change as the distance between the _________ and the work changes

contact tube

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

decreases

Filler metals and fluxes usually have ______ added to them so that the adverse effects of the mill scale are reduced or eliminated.

deoxidizers

The _______ is the distance from the contact tube to the arc measured along the wire.

electrode extension

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

The ______ refers to the angle between the GMA welding gun and the work as it relates to the direction of travel.

gun angle

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

Often, FCAW and SAW will have a ______ amperage range than GMAW.

higher

The _____ the density of a gas, the _____ will be 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

The relationships between current and voltage with different combinations of arc length or wire-feed speeds are called ______ characteristics.

volt-amperage

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

The ________ rate, measured in inches per minute or pounds per hour, is the rate at which the arc consumes the wire

wire melting