Level 3 Review Gmaw

Front 1

Uses any type of extinguisher.

Wood, paper, rubber fires

Back 1

Class A

Front 2

CO2 or dry chemical extinguisher.

Oil and gas fires.

Back 2

Class B

Front 3

Dry chemical extinguisher.

Electrical fires.

Back 3

Class C

Front 4

A gas shielded arc welding process, uses consumable electrode wire that is continuously fed in the arc.

Back 4

GMAW

gas metal arc welding

Front 5

Heat input per linear foot compared to SMAW is....

Back 5

Less

Front 6

Good ventilation is needed for GMAW as shielding gases can displace....

Back 6

Oxygen

Front 7

GMAW power source is....

Back 7

CV or CP

Front 8

GMAW CV or CP current is usually...

Back 8

DCEP, DCRP, DC+

Front 9

Protects the molten puddle from atmospheric contamination ( oxygen, nitrogen, hydrogen)

Back 9

Shielding gases

Front 10

Shielding Gas..

>heavier than air

>good on alumin., copper, nickel, and titanium.

>lower heat and narrower penetration

>inert gas

Back 10

Argon

Front 11

Shielding Gas...

>lighter than air

>used on non-ferrous metals (alumn., copper, magnesium)

>inert gas

>high heat in arc

Back 11

Helium

Front 12

Shielding Gas..

>man-made gas, cheap to use

>mainly used on mild steel, must be moisture free!

>added to mixed gases to reduce undercutting

>greatest cooling effect ongun

Back 12

CO2

Front 13

Shielding gas mixtures, _______ is limited to 5% because additional ________ will cause porosity.

Back 13

Oxygen

Front 14

Shielding gases are regulated by these.

Measured in CFH (cubic ft per hour)

inlet pressure should be 50PSI

Back 14

Flow Meter

Front 15

Solid or cored, base metal composition (mild steels, stainless, alumin., ect. )

Provides quality an strengths, shielding gas and current used.

Back 15

Filler Wire

Front 16

O2 and CO2 are ______ gases.

Back 16

reactive gases

Front 17

Helium and Argon are ________ gases.

Back 17

Inert gases

Front 18

Type of metal transfer most frequently used, in all positions. Less than 23 volts and 200 amps. Inductance improves penetration an bead profile

Back 18

Short-circuit Transfer (Dip Transfer)

Front 19

Type of metal transfer not used often due to poor arc stability, poor penetration and excessive spatter.

Back 19

Globular Transfer

Front 20

Type of metal transfer best on thicker material and non-ferrous metals. Over 24Volts used. Must have mix gas of min. 80% Argon. Highest deposition rate.

Back 20

Spray Transfer

Front 21

Squeezing force on an electrode..

Back 21

Inductance.

Front 22

Transfer may cause fusion problems on thicker material...

Back 22

Short-circuit Transfer

Front 23

Pieces of wire from sticking to the weld puddle when trigger is released.

Back 23

Whiskers. =^.^=

Front 24

Prevents wire from sticking to the weld puddle when trigger is released.

Back 24

Burnback

Front 25

When _________ is increased too much stubbing occurs.

Back 25

Wire feed speed ( WFS )

Front 26

Small pinholes in the weld (contamination from atmosphere cause by): excessive gas flow, too little gas flow, dirty ol nozzle, excessive wind or draft.

Back 26

Porosity

Front 27

Removal of gun before letting crater solidify

Back 27

Crater Cracks

Front 28

Weld doesn't fuse to parent metal

Back 28

Lack of Fusion (Cold Lap)

Front 29

Standard sizes of GMAW wire?

Back 29

.023", .030", .035", .045"

Front 30

Drive rolls best for GMAW hard wire

Back 30

V-Grooved

Front 31

Drive rolls best for GMAW aluminum

Back 31

U-Groove

Front 32

Full GMAW gas cylinder pressure

Back 32

2200 PSI

Front 33

To prevent dry ice from forming within the flow controls.

Back 33

Line Heater

Front 34

Electrode extension for Spray Transfer

Back 34

1/2" - 1"

Front 35

A slope of 3-4V per 100 amps is recommended for __________ Transfer.

Back 35

Short-circuit

Front 36

90% Helium, 7.5% Argon, 2.5% Oxygen

Best shielding gas for welding ....

Back 36

Stainless Steel GMAW

Front 37

GMAW wire may need assistance on current in contact tube; prevent corrosion of wire when stored. What coating is applied?

Back 37

Copper Coating