Welding

Question 1

What does GMAW stand for?

Answer 1

Gas Metal Arc Welding

Question 2

What was the previous term for GMAW?

Answer 2

MIG Welding

Question 3

How does GMAW work?

Answer 3

continuous solid wire along with an external shielding gas that protects the molten weld from contacting surrounding air

Question 4

What is the purpose of shielding gas?

Answer 4

protects arc from surrounding air

Question 5

How much slag is produced from GMAW?

Answer 5

almost none

Question 6

Why was GMAW first developed?

Answer 6

speed up production of heavy aluminum plates

Question 7

When was GMAW first developed?

Answer 7

mid 1940’s

Question 8

What type of shielding gas was used with welding aluminum?

Answer 8

Argon or Helium

Question 9

Why is MIG no longer correct for GMAW?

Answer 9

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Question 10

What maintains the Arc gap with GMAW?

Answer 10

The Machine itself

Question 11

What 3 things does a GMAW machine perform?

Answer 11

maintain arc, feed wire and supply shielding gas

Question 12

What 3 things does a GMAW operator perform?

Answer 12

gun position, direction and travel speed

Question 13

What equipment is part of a GMAW?

Answer 13

power source, wire feed unit, gun assembly, ground connection, high pressure bottle and a flow meter

Question 14

What power source does a GMAW use?

Answer 14

Constant Voltage Direct Current (CV/DC)

Question 15

What polarity is used for welding Carbon Steel?

Answer 15

Direct Current electrode positive (DCEP)

Question 16

What is the power source trying to do while you are welding?

Answer 16

constantly adjusting voltage & amperage to keep Arc going

Question 17

What is the purpose of the Spring-roll nut on the end of the wire spindle?

Answer 17

Stops the wire spool when drive roll stops

Question 18

What are the drive rolls specifically designed for?

Answer 18

specific wire sizes

Question 19

How tight should the drive rolls be tightened?

Answer 19

just enough to keep wire from slipping

Question 20

What parts are located at the end of a GMAW gun?

Answer 20

insulator, adapter, contact tip and nozzle

Question 21

Why do contact tips come in different sizes?

Answer 21

to match wire diameter

Question 22

How far should the contact tip protrude beyond the end of the nozzle?

Answer 22

not at all, nearly flush

Question 23

what should be done to the welding gun parts when feeding the wire through the liner?

Answer 23

remove nozzle and tip

Question 24

What should be done to a gas cylinder when transporting it?

Answer 24

valve cover installed

Question 25

What does a flowmeter do?

Answer 25

regulates gas flow

Question 26

What safety precaution should be performed when opening a gas cylinder?

Answer 26

stand behind the valve

Question 27

How should a Gas Cylinder be opened?

Answer 27

crack slowly first, the open all the way

Question 28

What is an average welding gas flow setting/reading?

Answer 28

20 cubic feet per hour

Question 29

How do you get an accurate reading when setting gas flow?

Answer 29

pull the trigger to allow gas flow

Question 30

What can excessive welding gas flow do to a weld puddle?

Answer 30

cooling effect

Question 31

What can little welding gas flow do to a weld deposit?

Answer 31

cause porosity (gas pockets)

Question 32

What should always be done to the wire before making a new weld?

Answer 32

snip off excess wire

Question 33

What should always be done to the nozzle before making a new weld?

Answer 33

clean out any splatter

Question 34

What can excessive weld splatter build up on the contact tip do?

Answer 34

pinches wire causing erratic feeding

Question 35

What is 'burn back'?

Answer 35

Wire sticking at the tip

Question 36

When does 'burn back' typically occure?

Answer 36

bad angle or dirty metal

Question 37

What is important to consider with the welding nozzle in relation to the end of the gun?

Answer 37

needs to fit snug

Question 38

What is a common filler wire used in GMAW?

Answer 38

ER70S-6

Question 39

What does tensile strength refer to?

Answer 39

force required to pull apart wire

Question 40

What is the purpose of adding deoxidizers to filler wire?

Answer 40

cleans surface oxides and gases from molten welds

Question 41

How are filler wires sized?

Answer 41

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Question 42

What effects do filler wire sizes have on a weld deposit?

Answer 42

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Question 43

What type of shielding gas is used for welding carbon steels?

Answer 43

Carbon Dioxide & Argon

Question 44

While GMAW, what does Carbon Dioxide do to the Arc?

Answer 44

Wider arch stream, good penetration & better fusion

Question 45

While GMAW, what does pure Argon do to the Arc?

Answer 45

Narrow stream with secondary stream.

Question 46

Why is Carbon Dioxide and Argon blended for welding carbon steels?

Answer 46

To create sufficient Arc energy at lower voltages

Question 47

Why is Oxygen sometimes added to Gas blends?

Answer 47

Argon reduces energy, so oxygen is added to increase energy back up

Question 48

What is a common gas blend for welding carbon steels?

Answer 48

75% Argon & 25% Carbon Dioxide

Question 49

What 3 things will occur when the welding trigger is pulled?

Answer 49

current is applied to wire, solenoid opens valve for shielding gas and drive rolls feed wire

Question 50

What is done to welding equipment to produce more weld deposits and/or more heat?

Answer 50

increase machine voltage and wire speed

Question 51

While welding, what type of metal transfer will take place at lower voltages?

Answer 51

filler and base metal melt, fusing them together

Question 52

What position can you weld in with lower voltage settings?

Answer 52

all positions (flat, horizontal, vertical, overhead, etc.)

Question 53

What voltage will change the transfer mode?

Answer 53

22 volts

Question 54

While Gas-Metal Arc Welding, what transfer mode will take place when voltage is increased even higher, and a Argon rich gas blend is used?

Answer 54

Spray Transfer

Question 55

When is Spray Transfer best used in?

Answer 55

high speed production welding

Question 56

What shade should be used when gas-Metal Arch Welding?

Answer 56

Shade 10.0

Question 57

What is important to consider regarding position and condition of welding workpiece connection?

Answer 57

clean metal, on the workpiece itself

Question 58

What can you do if the Welding Arc sputters at the start?

Answer 58

check ground connection

Question 59

What should your hand position look like while making a weld?

Answer 59

both hands on the gun with one arm supported

Question 60

What 4 things is the molten puddle controlled by?

Answer 60

distance between gun and metal, where the Arc hits the puddle, angle of gun and travel speed

Question 61

What term is used to describe how much wire is produced from the end of the tip?

Answer 61

Electrode extension

Question 62

What is the recommended wire protrusion when welding?

Answer 62

1/4" - 3/8'

Question 63

What effect will a longer welding protrusion have on the Arc?

Answer 63

reduces amperage and heat

Question 64

Where should the welding gun be held to provide a good hot start?

Answer 64

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Question 65

Where should the wire be directed when welding?

Answer 65

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Question 66

What will happen if the wire is directed at the back of the puddle?

Answer 66

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Question 67

How much angle should the gun have while welding?

Answer 67

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Question 68

What will happen if the welding gun is angle to much?

Answer 68

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Question 69

What direction should we travel in when Gas-Metal Arc Welding?

Answer 69

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Question 70

What will a 'pull technique' do to a weld?

Answer 70

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Question 71

When Gas-Metal Arch Welding, what gun movements should be made?

Answer 71

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