Download Tut-06_SME1613

DEPARTMENT OF MATERIALS ENGINEERING
FACULTY OF MECHANICAL ENGINEERING, UTM, SKUDAI
SME 1613 (Materials Science)
TUTORIAL 6 (Additional)
(Fe-C System)
1.
Define allotrope of metals? Write the allotropic changes of iron.
2.
Draw the phase diagram for steel and label all the phases and the critical temperatures? Explain
what is meant by hypoeutectoid steel, eutectoid steel and hypereutectoid steel?
3.
Give definition of the following:
(a) Ferrite
(b) Pearlite
(c) Cementite
(d) Austenite
(e) Lower critical temperature
(f) Upper critical temperature
4.
Explain the changes in the mechanical properties when percentage of carbon increases? Why?
5.
A plain carbon steel containing approximately 0.6%C is heat treated as follows:
(a)
(b)
(c)
(d)
(g)
heated at 800oC and quenched in cold water
heated at 800oC and furnace-cooled
heated at 800oC and quenched in cold water and tempered at 600oC
heated at 900oC and air-cooled
heated at 650oC and furnace-cooled
Describe with the aid of sketches, the structures obtained by these treatments. Indicate the
mechanical properties that you would expect from these different processes. Which process is the
best for cutting tools and which for dynamically stressed engineering parts?
m
by,
Dr. Astuty Amrin