CWB Level 2 exam with correct answers ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What is the description of damage of a brittle fracture? - correct ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
answers✔✔Sudden rapid fracture under stress (residual or
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
applied) where material exhibits little or no evidence of ductility ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
or plastic deformation
||\\||\\ ||\\||\\ ||\\||\\
What type of Steel are of primary concern with brittle fractures? ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
- correct answers✔✔Carbon and low alloy steels. 400 series SS
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
are also susceptible ||\\||\\ ||\\||\\
What has a significant influence on toughness and resistance to ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
brittle fractures? - correct answers✔✔Steel cleanliness and ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
grain size ||\\||\\
In most cases brittle fractures occur only at what temperature? -
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
correct answers✔✔Below the charpy impact transition
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
temperature.(or ductile-to-brittle transition temperature) ||\\||\\ ||\\||\\ ||\\||\\
The point at which the toughness of the material drops off
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
sharply
,What kind of equipment or units can be affected for brittle
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
fractures? - correct answers✔✔*Can occur during ambient ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
temperature hydro testing due to high stresses and low ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
toughness at the testing temperature ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
*Most processes run at elevated temperature so the main
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
concern is during startup, shutdown, or hydro/tightening ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
testing.
What is the appearance of a brittle fracture? - correct
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
answers✔✔Typically appear straight, non branching, and largely ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
devoid of any associated plastic deformation. (Although fine
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
shear lips may be found along free adge of the fracture or
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
localized necking around neck of crack. ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What is thermal fatigue a result of ? - correct answers✔✔Cyclic
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
Stress caused by variations in temperature.
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
In thermal fatigue damage occurs as cracking, where may this
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
occur? - correct answers✔✔Can occur anywhere in a metallic
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
component where relative movement or differential expansion ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
is constrained. Particularly under repeated thermal cycling.
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
, What type of material can thermal fatigue happen on? - correct
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
answers✔✔All material of construction. ||\\||\\ ||\\||\\ ||\\||\\
What are a couple but not all critical factors for thermal fatigue?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
- correct answers✔✔*Key factors affecting thermal fatigue are
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
the magnitude of the temperature swing and the frequency
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
(number of cycles) ||\\||\\ ||\\||\\
*Damage is also prompted by rapid changes in surface ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
temperature that results in thermal gradient through the ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
thickness or along the length of a component. ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What are some affected units or equipment of thermal fatigue?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
- correct answers✔✔*Major problem in coke drum shells
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
*another example is the mix point of hot/cold streams such as ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
hydrogen mix points in hydroprocessing units. ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
*locations where condensate comes in contact with steam ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
systems such as de-superheating or attemporating equipment ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What is the appearance of a thermal fatigue crack? - correct
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
answers✔✔*Usually initiates on the surface. Generally wide ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
and often filled with oxides due to elevated temperature
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
exposure. *May occur as single or multiple cracks ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What is the description of damage of a brittle fracture? - correct ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
answers✔✔Sudden rapid fracture under stress (residual or
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
applied) where material exhibits little or no evidence of ductility ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
or plastic deformation
||\\||\\ ||\\||\\ ||\\||\\
What type of Steel are of primary concern with brittle fractures? ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
- correct answers✔✔Carbon and low alloy steels. 400 series SS
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
are also susceptible ||\\||\\ ||\\||\\
What has a significant influence on toughness and resistance to ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
brittle fractures? - correct answers✔✔Steel cleanliness and ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
grain size ||\\||\\
In most cases brittle fractures occur only at what temperature? -
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
correct answers✔✔Below the charpy impact transition
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
temperature.(or ductile-to-brittle transition temperature) ||\\||\\ ||\\||\\ ||\\||\\
The point at which the toughness of the material drops off
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
sharply
,What kind of equipment or units can be affected for brittle
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
fractures? - correct answers✔✔*Can occur during ambient ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
temperature hydro testing due to high stresses and low ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
toughness at the testing temperature ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
*Most processes run at elevated temperature so the main
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
concern is during startup, shutdown, or hydro/tightening ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
testing.
What is the appearance of a brittle fracture? - correct
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
answers✔✔Typically appear straight, non branching, and largely ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
devoid of any associated plastic deformation. (Although fine
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
shear lips may be found along free adge of the fracture or
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
localized necking around neck of crack. ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What is thermal fatigue a result of ? - correct answers✔✔Cyclic
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
Stress caused by variations in temperature.
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
In thermal fatigue damage occurs as cracking, where may this
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
occur? - correct answers✔✔Can occur anywhere in a metallic
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
component where relative movement or differential expansion ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
is constrained. Particularly under repeated thermal cycling.
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
, What type of material can thermal fatigue happen on? - correct
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
answers✔✔All material of construction. ||\\||\\ ||\\||\\ ||\\||\\
What are a couple but not all critical factors for thermal fatigue?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
- correct answers✔✔*Key factors affecting thermal fatigue are
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
the magnitude of the temperature swing and the frequency
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
(number of cycles) ||\\||\\ ||\\||\\
*Damage is also prompted by rapid changes in surface ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
temperature that results in thermal gradient through the ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
thickness or along the length of a component. ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What are some affected units or equipment of thermal fatigue?
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
- correct answers✔✔*Major problem in coke drum shells
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
*another example is the mix point of hot/cold streams such as ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
hydrogen mix points in hydroprocessing units. ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
*locations where condensate comes in contact with steam ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
systems such as de-superheating or attemporating equipment ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
What is the appearance of a thermal fatigue crack? - correct
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
answers✔✔*Usually initiates on the surface. Generally wide ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
and often filled with oxides due to elevated temperature
||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
exposure. *May occur as single or multiple cracks ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\ ||\\||\\
