120103i Flashcards by Megan Read

Up to what length of contact tip is best suited for GMAW with aluminum filler wires?
a) 25.4mm / 1”
b) 50.8 mm / 2”
c) 76.2 mm / 3”
d) 101.6 mm /4”

d) 101.6 mm /4”

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List 3 advantages of using GMAW on Al

Any of the following 3 are correct
- High deposition rates compared to GTAW
- can be used long distances from the power source
- no flux or slag; no inclusions in the weld
- clean up time is reduced or eliminated
- may be used in all positions
- works well on materials 3.2mm (1/8”)
works well for spot welding operations

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Which Al filler metal is not recommended for sustained high temp service
a) 2319
b) 4145
c) 4043
d) 5356

d) 5356
because of its high Mg content it is prone to stress corosion cracking

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What 3 factors should you consider when setting GMAW welding parameters?

Material thickness
alloy type
available equipment

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What effect does stick out have on arc length with GMAW on Al

Very little change in arc length is noticed with various stick out distances.
This is due to the high electrical conductivity of Al, the ESO is not as critical as that required for steel

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After pre-cleaning Al, you should weld the joint:
a) with copper backing bar to prevent oxide contamination
b) before it dries to prevent cracking
c) after age hardening has occurred
d) as soon as all liquids have evaporated from the area

d) as soon as all liquids have evaporated from the area

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What precaution must you take when using heavy wire brushing or an abrasive grinding disk to remove a heavy oxide layer from Al

Heavy brushing or abrasive disks tend to drive Al oxides into the surface and entrap them.
The result is possible contamination of the weld

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What are the 2 most commonly used filler metals for GMAW on Al
a) 2319 & 4145
b) 4145 & 5356
c) 4043 & 4047
d) 4043 & 5356

d) 4043 & 5356

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What is the purpose of a light preheat on Al alloys
a) to remove moisture
b) to reduce residual stresses after welding
c) easier arc starting
d) to remove surface oxides

a) to remove moisture

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What type of current do you use with GMAW for welding Al
a) AC
b) DCEP
c) DCEN
d) AC with continuous high frequency

b) DCEP

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What methods can you use to fill a crater?

-reverse travel direction for a short distance
- use run-off tabs
- breaking and restarting the arc
- the use of special current controls on the power source

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What electrode inclination is recommended for welding Al?
a) forehand
b) backhand
c) forehand at all times
d) backhand at all times

c) forehand at all times

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Most shielding gasses for GMAW on Al are:
a) inert gases
b) oxidizing gases
c) nitriding gases
d) ionized gases

a) inert gases

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The shielding gas most commonly used with GMAW on non-ferrous metals is
a) carbon dioxide
b) nitrogen
c) helium
d) argon

d) argon

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List 4 causes of burn back

Any of the following 4 are correct:
wire feed to slow
worn or dirty tip, or liner
wrong polarity
kinked electrode wire
liner to long
arcing inside the contact tube

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What happens when you use a backhand inclination when using GMAW on Al?
a) lack of fusion
b) the wire tends to burn back into the contact tube
c) a black soot oxide appears on the surface
d) excessive bead convexity

c) a black soot oxide appears on the surface

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Preheat applied to Al components is:
a) done using inductance heating methods only
b) seldom required to exceed 149°C (300°F)
c) not applied unless the ambient temp is below -18°C (0°F)
d) done only prior to solution heat treating

b) seldom required to exceed 149°C (300°F)

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The recommended technique and metal transfer for GMAW on Al is:
a) pulsed spray transfer with a long stickout
b) forehand (pushing) inclination with short circuit or spray transfer
c) backhand ( pulling) inclination with spray transfer
d) fast travel speed with continuous high frequency current transfer

b) forehand (pushing) inclination with short circuit or spray transfer

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What element causes porosity in an Al weld
a) O2
b) N2
c) CO2
d) hydrogen

d) hydrogen

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What can happen if you leave a crater at the end of an Al weld?
a) porosity
b) oxidization
c) cracking
d) lack of fusion

c) cracking

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T / F
By using GMAW mode of metal transfer, Al can be welded using both manual and semi-automatic welding methods

True

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Are each of the following statements T / F?
1. You can achieve high deposition rates on Al with GMAW compared to GTAW _________
2. Welding long distances from the power source is possible using a push-pull gun __________
3. Flux and slag are common inclusions ________
4. You can weld in all positions __________
5. The GMAW process is not adaptable on thin materials ______

T
T
F - there is no flux or slag to become entrapped
T
F - GMAW is readily adaptable on materials as thin as 1/8”

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Using GMAW on Al which technique is preferred?
Stringer beads or weave bead technique

Stringer beads

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What type of liner must you use?

nylon or teflon liners
- they help min the drag on the wire

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Is a longer or shorter contact tip preferred when welding Al with GMAW?

The longer the better as it is easier to feed the wire as the current transfer is more efficient. some are 4" long

What are the 2 most common shielding gasses when welding Al? a) Helium & CO2 b) Helium & Argon c) Argon & O2 d) Argon & CO2

b) Helium & Argon Helium - greater penetration, broader root with less cleaning & poor arc initiation. - higher flow rates & therefore higher $ Argon - more effective, good cleaning action, stable & easy to start arc - lower $ - usually preferred for the non ferrous metals - used extensively on semi-automatic processes

What is necessary for oxide removal? a) heavily abrasive wire brushes, power brush, stainless wire wool b) alkaline solution and tools such as SS wire brush, SS power brush, SS wire wool with light pressure c) alkaline solution and tools such as heavily abrasive wire brushes, power brush, stainless wire wool d) once Al has oxidized there is no way to clean it off

b) alkaline solution and tools such as SS wire brush, SS power brush, SS wire wool with light pressure

What are the 2 most common filler metals when welding Al? a) 4043 & 5355 b) 4043 & 5356 c) 4053 & 5356 d) 4053 & 5535

b) 4043 & 5356

Which filler wire is suitable for high temp service? a) 5535 b) 4043 c) 5554 d) 5535

c) 5554 it has a low Mg content and is not prone to stress cracking

How would you remove traces of moisture before welding Al? a) heavy preheat b) light preheat c) allow to air dry d) use chemicals which evaporate quickly to dry the surface

b) light preheat

What current type is used for welding Al with GMAW a) DCEP b) DCEN c) AC d) current type depends on the thickness of the plate

a) DCEP

Alloy groups require different ESO and have different sounds with each, describe the sound each type would have 1. 5XXX - low voltage - high amperage - aprox 1/4" ESO 2. 4XXX - High voltage - low amperage - aprox 3/8" - 1/2" ESO

1. 5XXX has a crackling sound 2. 4XXX has a hum

When welding using the 5000 series electrodes which statement is correct? a) use lower currents and higher voltages b) use high currents and low voltages c) both use lower currents and higher voltages d) both use higher currents and higher voltages

b) use high currents and low voltages

When welding using the 1000, 2000, 4000 series electrodes which statement is correct? a) use lower currents and higher voltages b) use high currents and low voltages c) both use lower currents and higher voltages d) both use higher currents and higher voltages

a) use lower currents and higher voltages

Does Al have high or low electrical conductivity?

High electrical conductivity

With Al having much higher travel speeds what change to your equipment would you need to make? a) change current type b) use heavy preheat c) use a larger nozzle d) no changes are needed due to travel speed

c) use a larger nozzle

What room temperature or preheat is generally adequate a) up to 149°C (300°F) b) 0°C 32°F c) 66°C 150°F d) Al doesn't require preheat

c) 66°C 150-°F

When welding Al why is it necessary to remove all water?

As H2O breaks down during welding the hydrogen enters the Al and causes porosity

What electrode angle is used with GMAW on Al. a) 1/4 the included angle b) 1/2 the included angle c) 3/4 the included angle d) electrode angle is not as important as it is with steels

b) 1/2 the included angle

What inclination is used with Al welding a) 10-20° back hand b) 10-20° forehand c) 0-30° back hand d) 0-30° forehand

d) 0-30° forehand

T / F If using 0°-30° forehand the resulting weld bead is clean with good appearance

True

Are the following true or false? The use of a back hand technique _____ deeper penetration _____ soot oxide appears on the surface

Both are true

How do you fill a crater to prevent cracking? a) reverse direction for a short distance b) use run off tabs c) breaking and restarting the arc d) using special current controls on the power source e) all of the above

e) all of the above

What electrodes are these welding parameters for a) ER4043 b) ER5356 c) ER 5653 d) both 4043 & 5356

d) both 4043 & 5356

For a 1F weld on Al using Short circuit or spray transfer what should your eso be? a) as short as possible b) as long as possible and still maintain the arc c) 3/8" d) 1/4"

a) as short as possible to supply adequate shielding gas coverage

Maintain room temp up to a preheat of : a) 25°F b) 50°F c) 100°F d) 150°F

d) 150°F

Which weld position are these parameters for? - 1/2 the included joint angle - 0° to 30° forehand - stringer beads recommended - maintain wire at leading edge of puddle

Fill in the blank of this specific phrase. Welds should have penetration , fusion and tie-ins with no ______ or excessive build up a) high-low b) spatter c) crater d) both a & b

c) crater

What position has the plate surfaces to the horizontal plane? a) 1F b) 2F c) 1G d) 2G

b) 2F or d) 2G

What weld position are the plate surfaces in the vertical plane? a) 2F b) 3F c) 2G d) 3G

b) 3F or d) 3G The vertical position may have both the parent metal and the weld axis placed in the vertical plane. UPHILL OR DOWNHILL ALLOWED - USE UPHAND ANYWAYS - less oxide build up

Is uphill or down hill better with GMAW on Al? Why?

GMAW on Al should be done uphill for best results, without the heavy and hard to remove oxide that comes with going downhand

GMAW is a a) manual process b) automatic process c) semi automatic d) semi automatic process

d) semi automatic process

Final oxide removal of the weld area takes place by: a) using a file b) using solvents c) using a wire brush d) the welding arc

d) the welding arc

When using GMAW to weld Al, arc starting can be affected by: a) wrong polarity b) no shielding gas c) improper grounding d) all of the above

d) all of the above

Wire brushes used for cleaning Al, prior to welding should be a) SS b) low carbon steel c) high carbon steel d) all of the above

a) SS

Electrode angle for GMAW on Al. a) 1/4 the included angle b) 1/2 the included angle c) 0° to 30° forehand d) 0° to 30° backhand

b) 1/2 the included angle

Electrode inclination for GMAW on Al a) 0° to 30° forehand b) 10° to 30° backhand c) 10° to 45° forehand d) 0° to 30° backhand

a) 0° to 30° forehand

A weld performed in the 1F position is described as a) 1" flat weld b) flat fillet weld c) horizontal fillet weld d) overhead fillet weld

b) flat fillet weld

GMAW of Al is recommended on material a) less than 3.2 mm (1/8") b) 3.2 mm (1/8") or thicker c) only 12.7mm (1/2") or thicker d) all of the above

b) 3.2 mm (1/8") or thicker

The 1F position places the joint surfaces a) in the vertical plane b) in the horizontal plane c) in the 6G position d) aprox 45° to the horizontal

d) aprox 45° to the horizontal

Due to higher travel speeds when welding Al you may require a) a smaller nozzle compared to steel b) a larger nozzle compared to steel c) the same size nozzle as steel d) special nozzles made for Al

b) a larger nozzle compared to steel

When welding with GMAW, use a travel speed that will maintain the wire a) at the back of the puddle b) at the middle of the puddle c) at the leading edge of the puddle d) at a min of 1/4" in front of puddle

c) at the leading edge of the puddle

Which of the following GMAW Al filler metals are most common a) 4043 b) 5156 c) 4047 d) 5056

a) 4043

A 3 F weld is described as: a) plates and weld axis placed in flat position b) plates and weld axis placed in horizontal position c) plates and weld axis placed in vertical position d) plates and weld axis placed in overhead position

c) plates and weld axis placed in vertical position

Which current setting is most suitable to weld with the 5000 series GMAW wire? a) high current/ high voltage b) high current/ low voltage c) low current/ high voltage d) low current/ low voltage

b) high current/ low voltage

The shielding gas most commonly used for GMAW on Al? a) Ar b) N2 c) hydrogen d) CO2

a) Ar

Which of the following Al filler metals is most common? a) 4047 b) 5256 c) 5356 d) 5053

c) 5356

Short circuit or spray transfer may be used when welding Al with the GMAW process T / F

True

Final oxide removal of the weld area takes place by: a) using a file b) using solvents c) using a wire brush d) the welding arc

d) the welding arc

Room temp or preheat of up to ___ is generally adequate and safe for Al alloys. a) 66°C / 150°F b) 177°C / 350°F c) 232°C / 450°F d) 260°C / 500°F

a) 66°C / 150°F

When using GMAW on Al, a longer contact tip produces: a) poor wire feed ability b) less efficient current transfer c) an increased chance of burn back d) more efficient current transfer

d) more efficient current transfer

Which of the following could cause burn back when performing maw on Al. a) worn or dirty liner b) worn or dirty contact tip c) insufficient wire feed speed for voltage selected d) all of the above

d) all of the above

A general rule of thumb is that all GMAW on Al should be done with the uphill progression for best overall results T/F

True

A light preheat is beneficial prior to welding Al a) to ensure a hard HAZ b) to endure a ductile HAZ c) to ensure moisture is eliminated d) to speed up the quench

c) to ensure moisture is eliminated

The nozzle to work distance when welding Al should be a) 1/4" b) 3/8" c) 1/2" d) as short as possible

d) as short as possible

When using GMAW to weld Al, arc starting can be affected by: a) wrong polarity b) no shielding gas c) improper grounding d) all of the above

d) all of the above

When performing surface welds in the flat position with GMAW on Al, a weave technique is preferred to stringer beads T /F

False stringer beads are preferred

Which current setting is most suitable to weld with the 4000 series GMAW wire a) high current/ high voltage b) high current/ low voltage c) low current/ high voltage d) low current/ low voltage

c) low current/ high voltage

What is a disadvantage of using helium over argon shielding gas for GMAW on Al a) narrow root width b) poor arc initiation c) decreased penetration d) all of the above

b) poor arc initiation

The nozzle to work distance when welding Al should be a) 8 times the wire diameter b) as long as possible to reduce turbulence c) as short as possible to supply adequate shielding gas coverage d) you cant change nozzle to work distance, its set by voltage

c) as short as possible to supply adequate shielding gas coverage

A vertical weld on Al with the GMAW process may be performed in either downhill or uphill progression T/F

True

Which of the following is an advantage of using the GMAW process for Al a) no flux or slag b) welds can be completed in all positions c)produces higher deposition rates compared to GTAW d) all of the above

d) all of the above

A weld in the 2F position arranges the adjoining plates in the a) in the vertical plane b) in the horizontal plane c) in the form of a horizontal groove d) with the plate surfaces at 45° to the horizontal plane

b) in the horizontal plane

When welding the root pass in the 1GR position work in a downhill progression at : a) 12 - 1 o'clock position b) 1-2 o'clock position c) 2-3 o'clock position d) 3 - 4 o'clock position

b) 1-2 o'clock position

For steel pipe ranging in size from ____ the nominal size is the aprox inside diameter of standard was thickness pipe a) 1/8" - 10" b) 1/8" to 12" c) 1/8" - 24" d) 1/8" - 36"

b) 1/8" to 12"

What are the most common tools for preparing a uniform, accurate land on a piece of pipe? a) buffers and files b) grinders and files c) cone stone and files d) grinder and hacksaw

b) grinders and files

The terms tube and pipe are not interchangeable because tubing is generally sized to the OD and the wall thickness is lighter in weight True or False

True

Bridge tacks remain in the joint and become part of the root pass. True or False

False

NPS of 14" and larger pipe is identified by the: a) ID b) OD c) OD divided by 2 d) ID divided by 2

b) OD

A useful tool for tacking pipe is a: a) drill b) wedge c) hacksaw d) trammel

b) wedge

When tacking pipe coupons, align the: a) ends of the pipe b) inside surfaces of pipe c) outside surfaces of pipe d) any of the above will work

b) inside surfaces of pipe

Which filler metal designation would be used for the root when welding pipe a) E492T-1 B) E491T-6 C) E70T-1 D) B-G 49A 5 C G6

D) B-G 49A 5 C G6

The wall thickness of standard- weight pipe is equal to : a) schedule 20 from 1/2" to 10" NPS b) schedule 30 from 1/2" to 10" NPS c) schedule 40 from 1/2" to 10" NPS d) schedule 80 from 1/2" to 8" NPS

c) schedule 40 from 1/2" to 10" NPS

When welding pipe in the 5G position, the pipe is positioned with the pipe axis a) vertical b) horizontal c) 45° to horizontal plane d) horizontal and rotated while welding

b) horizontal

Bridge tacks are: a) left in the root to ensure full fusion b) permanent and integrated as part of the weld c) inserted and penetrate the full thickness of the pipe d) placed so as not to contact the root edge or land

d) placed so as not to contact the root edge or land

When performing a 2GR pipe weld with flux core using stringer beads you may need to : a) decrease travel speed to reduce excessive reinforcement b) increase electrode stickout to prevent porosity c) decrease voltage to promote blend d) change the electrode angle to reduce undercut

d) change the electrode angle to reduce undercut

When feathering a tack, it is important to also remove metal from the root face? True or False

False

Root tacks must be feathered so: a) slag will not be trapped in subsequent passes b) you ensure full fusion when welding the rood bead c) they are not to large and promote excessive build up d) they can be fully removed when welding the root bead

b) you ensure full fusion when welding the rood bead

When GMAW is performed for the root pass on pipe, the land prep is: a) 0" - 1/16" b) 0" - 1/8" c) 0" - 5/32" d) 0" - 1/4"

a) 0" - 1/16"

Wall thickness on pipe may vary as much as ______ and still be within pipe manufacturers allowance. a) 6% b) 8% c) 10% d) 12%

d) 12%

The term schedule of pipe is used to reference: a) the % of carbon in the pipe b) the recommended service intended for the pipe c) the length of pipe with reference to its wall thickness d) the weight of pipe with reference to its wall thickness

d) the weight of pipe with reference to its wall thickness

When tacking pipe coupons, you can utilize weld metal shrinkage to : a) weld in longer tacks b) put in stronger tacks c) overcome cracking of root bead d) equalize the gap

d) equalize the gap

Which 3 dimensions are significant to pipe size a) length, weight, ID b) length, wall thickness, schedule c) nominal size, length, schedule d) schedule, OD, ID

d) schedule, OD, ID

Pipe size is referred to by the term a) numerical pipe size (NPS) b) normal pipe size (NPS) c) national pipe size (NPS) d) nominal pipe size (NPS)

d) nominal pipe size (NPS)

A record of a test specimen using variables listed in a WPS that has been thoroughly tested to ensure welders consistently yield good welds is referred to as: a) PQR b) AWS c) CWB d) MSDS

a) PQR

Converting pipe sizes from imperial to metric requires a factor of: a) 2.54mm/inch b) 25.4mm/inch c) 254 mm/inch d) 2450mm/inch

b) 25.4mm/inch

When using FCAW for fill and cap passes, what mode of metal transfer is used a) spray b) globular c) pulse spray d) short circuiting

b) globular

Which of the following are variables, listed on a welding procedure specification? a) base metals and filler metals b) preheat and post heat requirements c) voltage, amperage, travel speed d) all of the above

d) all of the above

When welding the root pass in the 1GR position, what could likely occur in the 12 o'clock position. a) concave root b) root suck back c) excessive penetration d) incomplete penetration

c) excessive penetration

When completing the root pass using GMAW, what mode of metal transfer is used? a) spray b) globular c) pulse spray d) short circuiting

d) short circuiting

GMAW with a downhill progression on the root bead is faster and more controllable and heat adjustments are not as critical as the needed for uphill progression True or False

True

Root spacing for the 1GR pip project is recommended at: a) 1/16" - 1/8" b) 1/8" - 5/32" c) 5/32" - 1/4" d) 3/16" - 1/4"

b) 1/8" - 5/32"

When welding pipe in the 2G position, the pipe is rotated. True or False

False

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120103i Flashcards

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