API 570 - 4.2.7 Brittle Fracture Exam
Questions and Answers (Latest
Update 2026)
What is brittle fracture? -
correct answer ✅The sudden rapid fracture under stress where
the material exhibits little or no evidence of ductility or plastic
deformation.
Where can the stresses that cause brittle fracture come from? -
correct answer ✅They can be either residual or applied stresses
What materials are a concern for brittle fracture? -
correct answer ✅Carbon steels, Low Alloy steels, and 400 Series SS
Brittle Fracture: Can occur at what temperatures? -
correct answer ✅Brittle fracture can occur at below or ambient
temperatures
What is the charpy impact test? -
correct answer ✅The charpy test tells us the energy required to
break a small standard specimen
, API 570 - 4.2.7 Brittle Fracture Exam
Questions and Answers (Latest
Update 2026)
Where does brittle fracture occur? -
correct answer ✅It occurs at low temperatures. When
temperature is low it takes less to break it.
Why is there no plastic deformation in brittle fracture? -
correct answer ✅As temperature increases atoms vibrate with
increased frequency and amplitude. This allows them to slip to new
places in the material (break bonds with atoms and form new
bonds with other atoms) This slippage is seen on the outside of the
material as plastic deformation, a common feature of ductile
fracture. In brittle fracture, when temperature decreased, the
atoms vibrate less and do not want to slip to new locations in the
material, so when the stress on the material becomes high enough
the atoms just break their bonds and do not form new ones. This
decrease in slippage causes little plastic deformation before
fracture. Brittle type fracture
What is the transition region? -
correct answer ✅It is the area where brittle fracture transforms
into ductile fracture. Above the transition region energy is absorbed
and is more ductile. Below the transition region, less energy is
absorbed and it is more brittle.
Questions and Answers (Latest
Update 2026)
What is brittle fracture? -
correct answer ✅The sudden rapid fracture under stress where
the material exhibits little or no evidence of ductility or plastic
deformation.
Where can the stresses that cause brittle fracture come from? -
correct answer ✅They can be either residual or applied stresses
What materials are a concern for brittle fracture? -
correct answer ✅Carbon steels, Low Alloy steels, and 400 Series SS
Brittle Fracture: Can occur at what temperatures? -
correct answer ✅Brittle fracture can occur at below or ambient
temperatures
What is the charpy impact test? -
correct answer ✅The charpy test tells us the energy required to
break a small standard specimen
, API 570 - 4.2.7 Brittle Fracture Exam
Questions and Answers (Latest
Update 2026)
Where does brittle fracture occur? -
correct answer ✅It occurs at low temperatures. When
temperature is low it takes less to break it.
Why is there no plastic deformation in brittle fracture? -
correct answer ✅As temperature increases atoms vibrate with
increased frequency and amplitude. This allows them to slip to new
places in the material (break bonds with atoms and form new
bonds with other atoms) This slippage is seen on the outside of the
material as plastic deformation, a common feature of ductile
fracture. In brittle fracture, when temperature decreased, the
atoms vibrate less and do not want to slip to new locations in the
material, so when the stress on the material becomes high enough
the atoms just break their bonds and do not form new ones. This
decrease in slippage causes little plastic deformation before
fracture. Brittle type fracture
What is the transition region? -
correct answer ✅It is the area where brittle fracture transforms
into ductile fracture. Above the transition region energy is absorbed
and is more ductile. Below the transition region, less energy is
absorbed and it is more brittle.
