Tig Flashcards
Aws tig color green
Ewp
Pure tungsten
Aws tig color orange
2% ceriated
Aws tig color black
Lanthanated 1 or 2%
Aws tig color yellow
1% thoriated
Aws tig color red
2% thoriated
Aws tig color brown
Zirconium oxide
Aws tig color grey
Contain unspecified additional rare earth oxides
What is the advantage of ground finish electrodes over chemically cleaned?
Ground finished have better electrical contact with the collet
Cryogenic liquid def
Boiling point below -151.11 degrees c
Dewar def
A vessel containing cryogenic liquid gas
Argon is ________ than air
1.4 x heavier
The reason thoria is added to gtaw electrodes
Increase current carrying capacity and arc stability
What is the gtaw machines volt-amp curve
Steep drooping
What is the purpose of a regulator
To reduce the supply pressure to a safe working pressure
A flow meter is calibrated in
Liters per minute or cubic feet per hour
What is the purpose of a flow meter
To meter the flow of gas
What is the purpose of tailing out at the end of a weld
To prevent cracking in the weld crater
What is likely to happen if s keyhole forms in the 1 g position
Fall through
What is suck back?
And area of the root bead has been drawn into the groove. Usually from overheating the root on the 2nd pass
Dc gtaw
Requires the use of larger electrodes
Wrong combination of filler to base metal
The element in stainless steel that oxidizes readily is:
Chromium
How much distortion due to thermal expansion occurs during welding stainless steel vs mild steel?
Stainless distorts 50% more
What is a common work site method of testing for 300 / 200 series stainless
Use a magnet, its non magnetic
Whats the advantage of using a flux covered rod
Preventing contamination on the root side
ER316L is
E = Electrode
R = rod
316 = chemical composition
L = low carbon content (.03% max)
How are wrought aluminum alloys visually identified?
Rolling marks and smooth finish
It is essential to use plastic hoses fir what gas?
Helium
When ac tig is used the electron and weld metal emit unequal amounts of electrons, causing an unbalanced sine wave. This is called:
Arc rectification
Tig wire ER-70S-4, the 4 indicates?
Chemical analysis of the wire
What is the minimum amount of chromium that must be added to iron to make stainless steel?
10 %
Why can’t stainless be cut with an oxy torch?
Chromium oxides
What types of stainless usually require preheat and post heat?
Ferritic and martensitic
