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Part2 Heat Treatment of Steel

The document discusses various heat treatment processes for steel including full annealing, process annealing, spheroidizing, normalizing, and hardening. It defines terms like recrystallization temperature, hot working, cold working, temper martensite, and retained austenite. The document compares martempering and austempering and discusses TTT diagrams, CCT diagrams, and the microstructures of pearlite, bainite, and martensite. It includes multiple choice questions about TTT diagrams, CCT diagrams, heat treatments, and microstructure formation.

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Ahmed awwad
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171 views57 pages

Part2 Heat Treatment of Steel

The document discusses various heat treatment processes for steel including full annealing, process annealing, spheroidizing, normalizing, and hardening. It defines terms like recrystallization temperature, hot working, cold working, temper martensite, and retained austenite. The document compares martempering and austempering and discusses TTT diagrams, CCT diagrams, and the microstructures of pearlite, bainite, and martensite. It includes multiple choice questions about TTT diagrams, CCT diagrams, heat treatments, and microstructure formation.

Uploaded by

Ahmed awwad
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
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Engineering Materials

ENG 241 & ENG 224

(2)
Heat treatment of steel

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2
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30 oC

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11
12
(A1)

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about 55 oC

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not

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1

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2

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4

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Hardness

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Sheet 3

1-Define heat treatment and its purpose?


2- Describe briefly the following heat treatment process: Full annealing, Process annealing,
Spheroidizing, Normalizing and Hardening?
3- Define the following: Recrystallization temperature, hot working , cold working,
temper martensite and Retained austenite

4- Compare between Martempering and Austempering?

5- Define the following: Recrystallization temperature, hot working , cold working,


temper martensite and Retained austenite ?

6- Cite the limitations of equilibrium phase diagram?

7- Show the difference between TTT diagram and CCT diagram?

8- Describe briefly Pearlite, Bainite and Martensite formation?


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10-

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11-

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MCQ

1. Non-equilibrium phases are shown for their time and transformation using _________
a) Fe-Fe3C diagram
b) TTT diagram
c) CCT diagram
d) TTT and CCT diagram

2. The CCT or the TTT diagrams are used for _________


a) One steel of specific composition
b) A family of various steels
c) Alloy system of various compositions
d) Combination of all alloys and steels with various compositions

3. What does CCT diagram stand for?


a) Constant-critical-temperature
b) Constant-cooling-temperature
c) Continuous-cooling-transformation
d) Continuous-creep-transformation

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4. The first step in constructing a TTT diagram involves _________ the sample.
a) Annealing
b) Normalising
c) Quenching
d) Austenising

5. Austenising of samples for TTT diagram is done __________ temperature.


a) At room temperature
b) Below melting point
c) Above eutectoid temperature
d) Above boiling temperature

6. Isothermal transformations of eutectoid steel between 723oC and 550oC produces


__________ microstructure.
a) Pearlite
b) Bainite
c) Ferrite
d) Cementite

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7. Transformation in eutectoid steels is named as _________
a) Austenitizing
b) Carburizing
c) Decarburizing
d) Nitriding

8. Cooling of hypoeutectoid steel post heating forms __________ ferrite.


a) Proeutectoid
b) Posteutectoid
c) Hypereutectoid 2.08%
d) Mild eutectoid
9. Cooling of austenite of eutectoid composition at 723oC results in formation of ________
a) Ledeburite
b) Sphereoidite
c) Pearlite
d) Bainite

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10. Normalising is best used for is which kind of materials?
a) Steel castings
b) Steel wires
c) High carbon steels
d) Low and medium carbon steels

11. The structure obtained by normalising depends on __________


a) Stresses induced
b) Toughness of material
c) Thickness of cross section
d) Strength of weld

12. Isothermal transformations of eutectoid steel between 723oC and 550oC produces
__________ microstructure.
a) Pearlite
b) Bainite
c) Ferrite
d) Cementite

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