CWB Level 2 Certification – Complete
Study Guide & Exam Prep REAL EXAM
2025!!
What is the description of damage of a brittle fracture? - ANSWER ✔---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? - ANSWER ✔---Carbon and low
alloy steels. 400 series SS are also susceptible
What has a significant influence on toughness and resistance to brittle fractures? - ANSWER ✔---
Steel cleanliness and grain size
In most cases brittle fractures occur only at what temperature? - ANSWER ✔---Below the charpy
impact trANSWERition temperature.(or ductile-to-brittle trANSWERition 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? - ANSWER ✔---*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? - ANSWER ✔---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 ? - ANSWER ✔---Cyclic Stress caused by variations in
temperature.
In thermal fatigue damage occurs as cracking, where may this occur? - ANSWER ✔---Can occur
anywhere in a metallic component where relative movement or differential expANSWERion is
constrained. Particularly under repeated thermal cycling.
What type of material can thermal fatigue happen on? - ANSWER ✔---All material of construction.
What are a couple but not all critical factors for thermal fatigue? - ANSWER ✔---*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? - ANSWER ✔---*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
Study Guide & Exam Prep REAL EXAM
2025!!
What is the description of damage of a brittle fracture? - ANSWER ✔---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? - ANSWER ✔---Carbon and low
alloy steels. 400 series SS are also susceptible
What has a significant influence on toughness and resistance to brittle fractures? - ANSWER ✔---
Steel cleanliness and grain size
In most cases brittle fractures occur only at what temperature? - ANSWER ✔---Below the charpy
impact trANSWERition temperature.(or ductile-to-brittle trANSWERition 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? - ANSWER ✔---*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? - ANSWER ✔---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 ? - ANSWER ✔---Cyclic Stress caused by variations in
temperature.
In thermal fatigue damage occurs as cracking, where may this occur? - ANSWER ✔---Can occur
anywhere in a metallic component where relative movement or differential expANSWERion is
constrained. Particularly under repeated thermal cycling.
What type of material can thermal fatigue happen on? - ANSWER ✔---All material of construction.
What are a couple but not all critical factors for thermal fatigue? - ANSWER ✔---*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? - ANSWER ✔---*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
