Electric Arc Welding Flashcards Preview

Millwright 2nd Year > Electric Arc Welding > Flashcards

Flashcards in Electric Arc Welding Deck (25)
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0
Q

Is a number 9 welding lens darker or lighter than a number 14

A

Lighter

1
Q

What do welding helmets do

A

Protect your eyes and facial area from light
Heat
spatter
slag

2
Q

What do welding lenses do

A

Protect your eyes from:

ultraviolet infrared and visible light

3
Q

What happens when you get arc flash and what does it feel like

A

Little water blisters form on your eyeballs

Feels like you have sand in your eyes

4
Q

Two welding machine classifications

A

Constant current

constant voltage

5
Q

What does SMAW stand for

A

Shielded metal arc welding

6
Q

What does GMAW stand for

A

Gas metal arc welding

7
Q

What are three welding power sources

A

Transformers
inverters
generators

8
Q

What is a duty cycle

A

A rating expressed as a percentage

9
Q

A welder with a higher duty cycle is better or worse for welding and why

A

Better because you can weld for a longer time

10
Q

What is arc blow

A

It condition encountered where extensive DC welding has been done at high heat’s

11
Q

How many sizes do welding cables come in

A

8

12
Q

What is the smallest and what is the largest welding cable you can get

A

4=smallest

4/0=largest

13
Q

What are the two power sources for arc welding

A

Voltage and amperage

14
Q

Define voltage

A

Causes current to flow in a conductor or to cross a gap as occurs in arc welding

15
Q

Define amperage

A

Component that causes the electrode the parent metal or both to be melted

16
Q

What happens when you have a long arc length

A

Spatter loss is high
penetration is shallow
slag cover can be sloppy or incomplete shielding gases dissipate more quickly

17
Q

What happens if your arc length is too short

A

The beat is narrow and built-up penetration is deep
spatter loss is low
Molten slag covers the weld deposit

18
Q

What is straight polarity

A

Electrode is connected to the negative terminal

19
Q

What is reversed polarity

A

The electrode connected to the positive terminal

Most common

20
Q

What size is the most common arc welding electrode

A

14 inches

21
Q

In a CSA E4918 electrode what does the E stand for

A

A covered arc welding electrode

22
Q

In an AWS E7018 electrode what are the first two digits indicating

A

Minimum tensile strength

In this case 70,000psi

23
Q

What are four basic welding types

A

A groove weld
a fillet weld
a plug weld
a surfacing weld

24
Q

What are some advantages of gas metal arc welding

A

Skill requirements are lower
low current arcs are possible
good arc control makes the manual welding of joints with poor fit up possible