Materials and Products (5) Flashcards
How do Metallic Products differ from one another?
- Different properties
- Different ways of being shaped
Ingot and Casting Defects
- Evidence of shrinkage (surface deformations) such as tearing or cracking
- Turbulent poring, incorrect temperatures (cold shots, cold shuts, misruns, porosity, unfused chills and chaplets)
Discontinuities in Forming, Forging and Rolling
- Cracks (bursts)
- Flaps of material from damaged rollers
- Voids or inclusions; seams, stringers
- Scale
- Scores created from drawing or extruding
Discontinuities in Welds and other Material Fusing
- Lack of fusion, lack of penetration
- Cracks, transverse or longitudinal
- Fit up issues
- Weld profile and fills that don’t meet criteria
- Undercutting
- Arc strikes
Discontinuities in Composites
Can suffer from
- Lack of bonding (lay up)
- prone to air pockets
- cracks
- disbonding
- water ingress
Refractory materials and Ceramics are…
Used to insulate products;
- coating wear or cracking
- brittle
Discontinuities and defects in Concrete and Structural Materials
- cracks
- staining
- poor design
- inadequate strength
- earthquakes
steel rebar;
- if exposed it may not provide enough strength
- if exposed it may ingress water
Insulation
- minimize heat loss
- can indicate corrosion
- damaged from water and liquids
Wood
- rot
- crack
What do Components do?
Move and compress gases and fluids
- pressure vessels, piping, tanks, pumps
- prone to service-related defects
Defects in Boilers
Often covered in refractory material; can be damaged in use
- scale
- soot
- corrosion
- cracks
- seamed ERW welded pipe that can fail
- clips to reduce movement can crack
- outer jacker/shell is insulated
- steam drums and super heaters
Heat-Exchangers
transfer heat
- operate at high-pressure (pressure vessels)
- expose end chambers to inspect
- leaking tubes
- dented tubes
- corrosion
- pitting
- can be U-Shaped
Pressure Vessels
Can be made of composite, mostly metal (carbon steel)
- extreme amounts of energy
- considered a PV if 15lbs pressure per square inch
- normally have welding defects
- vessel ID tag
- cracking
- leaks
- corrosion found in the “liquid Level” area, low points, stress areas
- Cracks occur in welded areas and change in thermal temperature
- wear from material flow
Plate Steel Pressure Vessel Construction
3 components
- two heads (hemispherical shapes)
- cylindrical shell
- support legs
- reinforcing pads
- if made of multiple plates have welds called “long seams” length wise
- circular/girth welds are called “circ seams”
Area in Pressure Vessels where liquid and gas meet
Called the “Liquid Level”
