Welding Flashcards
How are electrodes stored?
Metal containers (ovens)
Describe the bead weld
They are single pass deposits of weld materials used to build up the surface of metal or to replace metal on worn surfaces
weld build up
What type of weld is common with lap, tee + corner welds?
Fillet welds
They join two pieces of metal that are usually at right angles (90 degrees) to each other
What type of weld are commonly used on butt joints?
Groove welds
Groovy Butt
What does a Groove weld consist of?
1st pass = root pass
2nd = hot pass
3,4,5th passes = fill passes
last pass = cap
What determines the amount of weld material required on the depth of penetration?
Size of the root opening, root face, bevel angle + root radius
Size of groove weld is determined by…?
The throat dimension
(depth of weld penetration in the groove or gap bn two pieces)
What determines the joint to choose?
Strength + loading
What are the 5 basic joints?
Tee, Lap, Corner, Edge and Butt
(BELT - C)
What does Static load mean?
Steady + unchanging
Seen on Tee welds that are welded on only side.
What is one downfall of Tee welds?
Uses lots of weld material.
Weld joints with the least amount of material should be considered as it keeps cost down.
How are Lap joints reinforced?
By placing a plug or slot weld along the joint
Which joint is most commonly used with sheet metal?
Edge (flange) joints.
Which joint is used the most?
Butt joints -→ both pieces are on the same plane
Just gotta have that butt all to yourself…
What does the abbreviation “F” mean?
Fillet weld
What does the abbreviation “G” mean?
Groove weld
What does the number 3 mean?
vertical position
When are edge joints used?
For sheet metal
The flow of electricity is called… and measured in….
Called Current and measured in Amperes
Amps = strength of current
What happens when wires opposes flow of current?
Resistance happens
Electrical utility companies distribute AC at what rate?
60 cycles / second
What is Frequency?
The speed at which AC changes direction
What is the definition of Cycle?
It is one complete revolution of the AC generator
True or False: three-phase power are more compact / produce a smoother arc than single phase power.
True
DC = the electron flow is in one direction only. Depending how the circuit is connected, the current flow can be made to affect the heat of the electrode or workpiece…
DC electrode negative = concentrates heat in the workplace
DC electrode positive = concentrate heat in the electrode
What is Buzz Box
The sound of an AC transformer type weld machine
What type of transformer is the most portable?
AC
What is arc voltage
When voltage drops after the circuit is closed (completed)
Use of conductor to completed a path of an electrical current.
What are the 2 types of electrodes?
Consumable: is consumed during welding
Non-consumable: is not consumed during welding
What should you know before you pick flux?
Know the chemical of coating
Why is it called Shielded Metal Arc Welding? (SMAW)
As the chemical in the electrode coating are vapourized, they provide the shielding required to product the molten metal from contamination by the atmosphere
Why is the connection bn welding cable / holder a vulnerable point?
Because it is constantly being flexed during welding operations.
What happens if the connection bn welding cable and holder is loose?
It will increase electrical resistance and cause additional heat that can wear down insulation.
What is the name of the coating that forms on the top of an arc weld?
Slag
What is the purpose of Slag?
To prevent weld from cooling too quickly
What job does the paper wrapping around the electrode cable provide?
Allows the conductor to move easily inside the insulation when it is bent.
(conductor is covered by insulator)
What impact test does Izod Charpy provide?
A welds impact strength
What does the CSA measure?
Tensile strength in Megapascals
