ASU MSE 250 Chan Quiz 4 (Lectures
16-19) Spring Exam Questions With
100% Verified Answers
1. What are austenite, ferrite, cementite, pearlite, bainite,
martensite, tempered martensite, and spheroidite?
2. How are they different from each other in terms of composition?
3. How are they different in terms of microstructure?
4. How are they different in terms of mechanical properties? -
correct answer ✅1. Pearlite, bainite, and martensite all develop
from austenite; and tempered martensite comes from martensite.
Pearlite is slow cooled austenite, bainite is moderate cooled
austenite, and bartensite is rapidly quenched austenite. tempered
martensite is from reheating martensite.
What is the difference between
carbon steel,
stainless steel, and
cast iron? -
correct answer ✅Carbon steels (<1 wt% C): as %C increases,
strength increases and ductility decreases.
Stainless steels (<1 wt% C): resistant to corrosion (rust,) at least 11
wt% Cr required. Most common: 316L, 304 (properties vary)
, ASU MSE 250 Chan Quiz 4 (Lectures
16-19) Spring Exam Questions With
100% Verified Answers
Cast Irons (> 2.14 %C): Fe3C decomposes to ferrite and graphite
and is easily cast into molds.
Copper -
correct answer ✅high conductivity, high corrosion resistance,
ductile. Can't be strengthened with heat treatment.
Mechanisms of electrical conduction in metals, intrinsic
semiconductors, extrinsic semiconductors, and insulators -
correct answer ✅In metals, electrons need energy to move from
valence band to the empty states above the band gap for
conduction to occur.
In intrinsic semiconductors, both electrons and holes move and
contribute to conduction. Electric field needs to be large enough to
excite valence electron to conduction band.
Extrinsic semiconductors are doped with impurity atoms to
increase the number of free electrons or holes.
16-19) Spring Exam Questions With
100% Verified Answers
1. What are austenite, ferrite, cementite, pearlite, bainite,
martensite, tempered martensite, and spheroidite?
2. How are they different from each other in terms of composition?
3. How are they different in terms of microstructure?
4. How are they different in terms of mechanical properties? -
correct answer ✅1. Pearlite, bainite, and martensite all develop
from austenite; and tempered martensite comes from martensite.
Pearlite is slow cooled austenite, bainite is moderate cooled
austenite, and bartensite is rapidly quenched austenite. tempered
martensite is from reheating martensite.
What is the difference between
carbon steel,
stainless steel, and
cast iron? -
correct answer ✅Carbon steels (<1 wt% C): as %C increases,
strength increases and ductility decreases.
Stainless steels (<1 wt% C): resistant to corrosion (rust,) at least 11
wt% Cr required. Most common: 316L, 304 (properties vary)
, ASU MSE 250 Chan Quiz 4 (Lectures
16-19) Spring Exam Questions With
100% Verified Answers
Cast Irons (> 2.14 %C): Fe3C decomposes to ferrite and graphite
and is easily cast into molds.
Copper -
correct answer ✅high conductivity, high corrosion resistance,
ductile. Can't be strengthened with heat treatment.
Mechanisms of electrical conduction in metals, intrinsic
semiconductors, extrinsic semiconductors, and insulators -
correct answer ✅In metals, electrons need energy to move from
valence band to the empty states above the band gap for
conduction to occur.
In intrinsic semiconductors, both electrons and holes move and
contribute to conduction. Electric field needs to be large enough to
excite valence electron to conduction band.
Extrinsic semiconductors are doped with impurity atoms to
increase the number of free electrons or holes.
