Transcript FERROUS MATERIALS AND ALLOYS I

Production Technology
(IND 006)
Lecture No. 3
Preparatory Year,
Faculty of Engineering,
Fayoum University
Dr. Ahmed Salah Abou Taleb
Lecturer, Industrial Engineering Dept.,
Faculty of Engineering, Fayoum University
Introduction
Introduction
 What are the common characteristics of
engineering materials such as physical,
chemical, mechanical, thermal, optical, and
electrical?
 How they can be processed economically to get
the desired product?
Materials
Materials Integration
Metals
Why metals are considered as the most important
materials?
 They have properties that satisfy a wide variety of
design requirements.
 The metal manufacturing processes have been
developed and refined over many years.
 Engineers understand metals.
 High stiffness and strength - can be alloyed for
high rigidity, strength and hardness.
 Toughness - capacity to absorb energy.
 Good electricity and thermal conductivity.
 Cost.
Metals
Metals
Pure elements
Gold
Silver
Copper
Alloying
is a mixture of two
or more elements, at
least one of which is
metallic
through alloying, it is possible to increase strength,
hardness, and other properties compared to pure metals.
Phase Diagram
Phase Diagram
Ferrous Metals
Ferrous metals and alloys are defined as the materials that
contain a large amount of iron. They are used in the
majority of metallic applications in current eng. design,
Ferrous Metals
1. FERROUS MATERIALS AND ALLOYS
Ferrous Materials
Steel
Steel is an alloy of iron
and carbon up to 2.11 %
in addition to various
elements (or Alloying
Elements) in order to
improve properties .
Cast Iron
Cast Iron (C.I.) is an alloys
of iron, carbon (1.7% 6.67%), and silicon (3.5%).
FERROUS MATERIALS AND ALLOYS
I- Cast Iron (CI):
 Low cost,
 Good casting characteristics,
 High compressive strength,
 High wear resistance and
 Excellent machinability,
 Tensile strength from 100 to 200 MPa,
 Compressive strength from 400 to 1000 MPa and,
 Shear strength is 120 MPa.
FERROUS MATERIALS AND ALLOYS
I- Cast Iron (CI):
Gray Cast Iron
Ductile (Nodular)Cast Iron
Cast Iron
Categories
White Cast Iron
Malleable Cast Iron
FERROUS MATERIALS AND ALLOYS
I- Cast Iron:
A- Gray Cast Iron:
• Carbon is free in the form
of graphite, which exists in
the form of flakes.
• Good compressive &
tensile strength,
machinability, and
vibration-damping ability
• Uses: machine bases,
crankshafts, furnace
doors, Engine Blocks
FERROUS MATERIALS AND ALLOYS
I- Cast Iron:
B- Ductile (Nodular) Cast Iron:
• Carbon is free in the form of
graphite but it takes nodular or
spheroid form.
• High fluidity, excellent castability,
strength, high toughness,
excellent wear resistance,
pressure tightness, weldability and
higher machinability
• Use in gears, cam shaft, crank
shaft.
FERROUS MATERIALS AND ALLOYS
I- Cast Iron:
C- White Cast Iron:
• Carbon exists in the combined
form (Cementite).
• Very hard; wear resistant,
brittle , very difficult to
machine, high tensile strength
and low compressive strength.
• Use in bearing surface, rim of
car, and Railway brake blocks.
FERROUS MATERIALS AND ALLOYS
I- Cast Iron:
D- Malleable Cast Iron:
• It has structure similar to
nodular C.I.
• It has ductility, strength
and shock resistance.
• Use in axle bearing, tracks
wheels
FERROUS MATERIALS AND ALLOYS
II- Steel:
Plain Carbon Steel
Low Alloy Steel
Steel
Categories
Stainless Steel
Tool & Die Steels
FERROUS MATERIALS AND ALLOYS
II- Steel:
A- Plain Carbon Steels:
• So-called plain-carbon steel contains up to 0.5%
manganese,
• Strength increase and ductility reduced with carbon
increase.
Alloy
Composition
Application
Low Carbon Steel
(Mild Steel)
has 0.05% up to
0.20% carbon
Automobile sheet
metal & railroad rails
Medium Carbon Steel has 0.20% up to
0.50% carbon
M/C component &
engine parts
High Carbon Steel
Springs, cutting tool
& blades
Greater than 0.50%
carbon
FERROUS MATERIALS AND ALLOYS
II- Steel:
B- Low Alloy Steels (Constructional Steel):
• Contains additional alloying elements in amount
less than 5% by weight,
• Mechanical properties superior than plain carbon
steel.
• Higher strength, hardness, wear resistance, and
toughness.
• Used for machine parts highly stressed in tension
or compression.
FERROUS MATERIALS AND ALLOYS
II- Steel:
C- Stainless Steels (Special Steel) (SS):
•
•
•
•
High alloyed steel design for corrosion resistant.
Principle alloying element is chromium (> 15%).
Nickel is used to improve corrosion protection.
Is more strength and ductile steel.
• Austenitic stainless - typical composition 18% Cr
and 8% Ni
• Ferritic stainless - about 15% to 20% Cr, low C,
and no Ni
• Martensitic stainless - as much as 18% Cr but no
Ni, higher C content than ferritic stainless
FERROUS MATERIALS AND ALLOYS
II- Steel:
D- Tool & Die Steels :
• High alloy steel.
• have great strength, hardness and wear resistance.
• High strength, hardness, wear resistance, and
toughness under impact
• Used to fabricate cutting tool, moulds and dies.
Effect of carbon content on mechanical properties