Cutting Chapter 5 Flashcards
All base materials should be what before welding?
Cleaned
New materials are clean if they look clean
F
The most common defect caused by surface contamination is
Porosity
Porosity occurs when what or what appears in the weld metal.
Pockets or Voids
Used to remove paint and light-to-medium surface corrosion.
Wire brushes
Wire brushes with stainless steel bristles must be used to clean what and what (2things)
Stainless steel
Aluminum
When brushing aluminum , use stainless steel brushes that have been used….
only on aluminum.
If a standard wire brush with steel bristles is used, it will what
contaminate the surface with mild steel, causing welding defects.
Very effective in removing large areas of surface contamination. (2 types of grinders)
Angle Grinders
End Grinders
The only type of weld that is applied to just one base metal surface.
Surfacing
Surface welding is not used to build up a base surface that has become worn below the desired thickness or dimension.
F
Surface welding involves adding material to a base to increase its strength and stability.
T
Used to join metal pieces when the edges cant be welded.
Plug and slot welds.
The plug and slot weld can be applied to what 3 things?
Lap
Corner
T-joints
When possible, a double V-groove weld should be used in place of a what
single V-groove.
The double V-groove requres half the weld metal compared to the what.
single V-groove.
For open root welds on PLATE, the groove angle should be what degrees, and the maximum size of the root opening and root face is what inches?
60 degrees
1/8”
For open root welds on PIPE the groove angle is what 2 degrees.
The maximum size of the root face is how many inches?
60-or 75 degrees depending on the code or specification used.
1/8”
The recommendation for a backing strip for welding mild steel up to 3/4” this is how many inches thick by how many inches wide.
3/8” thick
3” wide
It is easier and faster to weld groove welds in the flat position and fillets in the flat or horizontal position than it is to what?
weld out of position.
Always try to position the weldment so that the what
welding is performed in the flat position.
A detailed listing of the rules and principles that apply to specific welded products.
Welding code
Most often used on alloy steel, stainless steel and nonferrous metal piping or plate.
Mechanical joint preparation
Mechanical joint preparation is faster than thermal methods such as oxyfuel, carbon arc and plasma arc.
F, Slower
Mechanical joint preparation has the advantages of 3 things
high precision
low heat input
the absence of oxides commonly left by thermal methods.
Various models are available to cut and bel…
2” to 60” pipe
For larger pipe (54” or larger)
Special internal equipment is available.
