Welding Final Study Guide

The metal added to a weld joint is the ____ metal

Filler

What is the difference between a fillet weld and a groove weld

Fillet welds are made at an intersection of a surface and an edge whereas groove welds are made between 2 butted pieces or in a groove

What does GMAW stand for? Can the terms GMAW and MIG be interchanged?

GMAW: (Gas metal arc welding) Another term that is often used to describe GMAW is MIG: (Metal inert gas) However, because some of the gases used in GMAW are not inert, MIG is an inaccurate term

transfer deposits more metal for a given size electrode wire

Globular

Which GMAW metal transfer methods are recommended for out-of-position welding?

Globular Transfer

The electrode type and diameter is given in a welding procedure specification

True

Which of the following does the welder actually observe and control to obtain a good-quality weld bead?

Nozzle-to-work distance

List 2 reasons why it costs more to make a weld if the groove angle is too large

the groove angle has to be large enough to allow the torch tip or electrode to reach near the bottom of the joint

List two names other than GTAW that are used to refer to the gas tungsten arc welding process

tungsten inert gas and heliarc welding

List two shielding gases used in FCAW-G

-Argon -CO2

List three shielding gases commonly used in GMAW

-Argon -Carbon Dioxide -Helium

Which of the following part(s) of the torch must also be changed when a different size tungsten electrode is used?

-Collet -Collet Body

List 4 purposes of an electrode covering

-Creates a flux to clean impurities from the metal -Creates slag covering to protect the molten bead as it cools -Provides additional filler metal to the weld -Determines the current type and polarity specifications of the electrode

List two gases that are added to argon to eliminate the undercutting that occurs when pure argon is used with GMAW to weld steel

-Oxygen -Carbon dioxide

List two advantages of backhand welding over forehand welding

-The backhand method produces a narrower weld bead with deep penetration. -Less motion is used rather than forehand.

Name five pieces of protective clothing that are to be worn for out-of-position welding

-Wear flame-resistant clothing -Wear a cap to protect your hair from hot metal and sparks -Wear earplugs or earmuffs to prevent hot metal from splattering into your ears -Gauntlet gloves and leathers -Wear high top, hard toe shoes

List four factors that a welder must consider before selecting the electrode and shielding gas

-What type of base metal is to be welded? -How thick is the base metal? -In what position will the welding be done? -What type of metal transfer will be used?

The entire whip motion should take only _____ seconds

1-2

The electrode should extend _____ beyond the end of the contact tube for spray transfer with GMAW

1/2″-1″ (13 mm-25 mm)

2 butt joints are tacked together. one has 1/16" opening and other has 1/8" opening. which is larger?

1/8"

One grove weld has 45 degrees grove angle and the other has a 60 degree angle. which weld would take less time to complete

45 degree would require less metal and time to complete

Determine the trial amperage for a 7/32" electrode

90A+30A+30A+30A= 180A

Spray transfer requires the use of shielding gas that contains at least __% argon

98%

Which type of welding machine is used for GMAW: a constant voltage machine or a constant current machine?

A constant voltage machine is used for GMAW

What is used to prevent the current from stopping during the electrode positive half cycle when AC welding?

A high-frequency, high-voltage, very-low-current generator in series with the welding transformer can keep the positive half cycle from being totally rectified

Which joint does not require any special edge preparation?

A lap joint

Which Aws electrode specification number provides information about electrodes to weld nickel and nickel alloy?

AWS A5.11 provides information about electrodes to weld nickel and nickel alloy

List four advantages and two disadvantages of FCAW

Advantages: -FCAW eliminates many of the starts and stops that occur with SMAW. -Welding speeds are faster than SMAW. -Flux cored electrodes add alloying elements to the weld pool. -Flux cored electrodes provide shielding gas to protect the weld pool. Disadvantages: -FCAW equipment cost more than SMAW equipment. -Rapid air movement, such as a strong wind can blow the shielding gas away, resulting in a weld defect.

List four advantages and two disadvantages of GMAW as compared to SMAW

Advantages: -Welding speeds are faster than with shielded metal arc welding (SMAW) -Deeper penetration is possible with GMAW than with SMAW -A continuous electrode is used so that longer welds can be made without stopping to change electrodes. -This eliminates many of the starts and stops that occur with SMAW. -No Slag is produced in GMAW. Very little splatter is created. Disadvantages: -GMAW equipment cost more than SMAW equipment. -Some weld joints are hard to reach with the welding gun.

The metal to be welded is called the ___ metal

Base metal

Why is a post flow of shielding gas used with GTAW?

Because if you stopped welding and the shielding gas also stopped, oxygen and other gases could contaminate the weld

Why must the weld pool be kept ahead of the slag when welding downhill?

Because slag in the weld causes inclusions that will weaken the completed weld

Why should electrodes be kept in their shipping containers until they are used?

Because the shipping containers provide safe storage for the electrodes and keeps them from getting damp or damaged

List the 5 basic weld joints

Butt welds, Lap welds, Corner welds, T-welds and Edge joints

The weld pool shape for a fillet weld is a(n) ____ shape.

C

Which of the following welding techniques is not used for FCAW?

DCEN

Which type of current is most commonly used for GMAW welding, DCEN or DCEP?

DCEP (direct current electrode positive) is used for GMAW welding.

What electrode, shielding gas, and flow rate are recommended for gas metal arc welding of 1/8″ (3 mm) 308 stainless steel using short circuit transfer?

Electrode: ___1/4"- ½" (6mm-13mm)______ Shielding gas: ___98%_Ar--2% O2______ Flow rate: ___35 cfm or 15L/min_______

An example of an electrode designed especially for making welds in the flat and horizontal fillet positions is _____

Electrodes with a "2" in the second-to-last digit, such as E6027 or E7024, are designed for making welds in the Flat position

Which of the following does not require shielding gas?

FCAW-S

An E7013 electrode would be a good electrode to use for steel with a tensile strength of 88,000 psi

False

True or False? Flux and shielding gas are used to protect the weld from the atmosphere during GMAW

False

True or False? Gloves worn for GTAW are thick leather to protect the welder from the intense heat and rays of the arc

False

True or False? On a lap joint, greater strength is obtained by welding downhill

False

What does increasing the voltage do?

Increases pool width

The opening at the root pass of a butt weld is a(n) _____ shape

Keyhole

List three advantages of using smaller diameter electrodes for out-of-position welding

Lower amperage can be used, A smaller weld pool is created, The molten metal in the pool is easier to control

List two ways to reduce spatter

Lower the amperage by decreasing wire feed speed or increasing the voltage

Which of the following is not a function of a GMAW gun?

Maintain the correct voltage

What does increasing the contact tube-to-work distance do?

Preheats the electrode more

The slag on a ---- weld bead contains flux and metallic salts

SMAW

Describe 2 ways to store SMAW electrodes

SMAW electrodes can be kept in an electrode drying oven or an electrode dispenser is good for short term storage

What does a flowmeter control?

Shielding gas flowing to the gun

What welding lens shade is recommended for high-current GMAW/FCAW?

The best welding lens shade would be #11-#14

Will the current of the welding machine increase or decrease if the arc voltage increases while welding?

The current will increase if the arc voltage increases

What part of a wire feeder is used to pull the electrode wire off the spool and push it to the gun?

The drive rolls or the drive wheels push the wire off the spool and through the gun

Describe what is indicated by each of the characters in the E6013 electrode designation

The first 3 numerals indicate the tensile strength. The last 2 numerals at the right indicate the recommended electrical polarity

Describe a flux cored electrode

The flux core of the electrode creates a shielding gas as it melts

When welding horizontally, why is the lowest weld bead in each layer made first on a multiple-pass V-groove butt weld?

The lowest bead in each layer should be welded first to provide a base for the next weld bead to build on

Which of the cables on a water-cooled torch serves two purposes? What are those two purposes?

The power cable is responsible for carrying an electric current to the torch and also carries water away from the torch

In a water-cooled welding gun, what do the two hoses carry? What does the cable assembly carry?

The red hose carries water from the gun and the blue hose carries water to the gun. The cable assembly carries the electricity, electrode, and shielding gas

In globular transfer, what forces the molten metal to leave the electrode?

The weight of the globule (ball)

What work angle is used when making a horizontal butt weld?

The work angle used is a 10-20 degree angle.

Metallic salts in the electrode covering may cause the weld metal to become stronger, more corrosion resistant or more ductile

True

True or False? If metal explodes from the end of the electrode, the inductance should be increased

True

True or False? The volt-amp curve for a constant potential machine is a flat curve

True

What voltage, wire feed speed, shielding gas, and flow rate should be used to FCAW 1/4″ (6 mm) mild steel using an E71T-1 1/16″ (1.6 mm) electrode?

Voltage: _25-35v_________ Wire feed: __160-340 in/min or 410-860 cm/min________ Shielding gas: __CO2_______ Flow rate: __35 cmf or 15L/min________

What voltage, wire feed speed, shielding gas, and flow rate should be used to weld 1/8″ (3 mm) aluminum using 3/64″ (1.2 mm) diameter electrode wire and spray transfer?

Voltage: __22-28v_______ Wire feed: _235-375 in/min or 6.0-9.5 M/min_________ Shielding gas: ___Argon_______ Flow rate: ___35 cfm or 15L/min_______

What type of weld bead is formed by moving the torch or electrode from side to side as the welding progresses?

Weave bead

The molten metal under the welding arc is called the

Weld Pool

What does B2 represent in an AWS E8016-B2 electrode designation?

When a suffix is used, it indicates that the alloy has been added to the electrode

In short circuiting transfer, when does the metal from the electrode enter the weld?

When the electrode touches the base metal

Which type of welding current applies most of the heat to the base metal and gives the best penetration?

direct current electrode negative (DCEN)

Name three methods of preparing the edges of metal for welding

flame cutting, plasma cutting and gouging

Name 4 welding positions and state the condition of the AWS 2G position.

flat, horizontal, vertical or overhead. AWS 2G referred to a welder position and the 2G is a vertical groove joint weld.