IRON AS A
• Iron(Fe) is the second most common metal on Earth,
and the most widely-used metal.
• It is element26, a transition metal in Group 8.
• Its symbol is Fe, from the Latin word for iron, ferrum.
• Atomic number: 26
• Mass number:55.85
• It is used a lot because it is very strong and cheap.
• Iron is the main ingredient used to make steel.
•Iron is a lustrous, ductile, malleable, silver-gray metal.
•It is known to exist in four distinct crystalline forms.
•Iron rusts in damp air, but not in dry air and dissolves readily in dilute acids.
•It has a very high tensile strength.
•Boiling point : 3000 °C(5,400 °F)
•Melting point : 1,536 °C (2,797 °F)
PHYSICAL PROPERTIES OF IRON
• Iron is the most widely used of all the metals,
accounting for 95%of worldwide metal production.
• Its low cost and high strength make it indispensable in
Engineering applications such as -
• The construction of machinery and machine tools,
automobiles, the hulls of large ships, and
structural components for buildings.
• Since pure iron is quite soft, it is most commonly
Combined with alloying elements to make steel.
• Iron is also used for protection from ionizing radiation
Cast iron has been used for centuries and was used in
architecture in the pre-modern period.
APPLICATION AND USES OF IRON
• The main disadvantage of iron is
that pure iron, and most of its alloys,
suffer badly from rust if not
protected in some way.
• Painting, galvanization, passivation,
plastic coating and bluing are all
used to protect iron from rust by
Excluding water and oxygen or
By cathodic protection.
TYPES OF IRON
IRON IS AN IMPORTANT BUILDING COMPONENT
HAS BEEN USED IN MANY FORMS:
1. WROUGHT IRON
2. CAST IRON
Smelted, Hammered, Re-
Smelted (separate the metallic
Wrought Iron Cast Iron Mild Iron(Steel)
Poured into sand
• Cast iron.: 2.0 – 4.5% Carbon content
• Carbon (C) and silicon (Si) are the main alloying elements.
• Great for the environment. Can be recycled more easily than
• It is strong in compression, but weak in tension and bending.
• Prefabrication enabled portability—entire buildings could be
constructed in one place and shipped all over the world.
• Its strength and stiffness deteriorate when subjected to high
• Its structure is crystalline and relatively brittle.
• They don't echo when water moves through as compared to
PVC, because of dense material.
• It does not rust.
• Its use gradually spread from architectural elements like shutter
and door frames to facades because it is relatively
2. durable &
3. easily cast into a variety of shapes.
• As balusters, columns & Arches
• For transporting water, storm drains and sewage.
• Ornate facades.
Fire proof floor- mid 19th century Cast iron is strong in compression weak in bending.
Wrought iron High in elasticity and tensile strength.
Cast iron beams
Thin webs could easily crack. Sharp
angles where web joins flanges were also
This is slightly thicker web and rounded
internal angles, which is less prone to
cracking during casting.
• Construction of machines and structures
(High Tensile Strength)
For a garbage disposal because it is highly resistant to the
grinding and abrasions. (The process of wearing down away by
means of friction)
Design made on column Gate design Decorative pieces
Arches in bridgeUse of cast iron in facade
Oxidation or rusting occurs rapidly when cast iron is exposed to
moisture or air.
Common problems encountered with cast iron construction include
Badly rusted or missing elements.
Damage to connections
Loss of anchorage in masonry
CLASSIFICATIONS OF CAST IRON
1. WHITE CAST IRON
2. GREY CAST IRON
3. DUCTILE (NODULAR) CAST IRON
4. MALLEABLE CAST IRON
1/04. WHITE CAST IRON
• These are iron-carbon alloys having more than 2.11%
• All the carbon is present in the combined cementite
• Hard and wear resistant.
• Tensile strength 20000 to 70000 psi.(per square inch)
• Compressive strength 200000 to 250000 psi.
Microstructure of White
Because of extreme brittleness and lack of machinability, white irons find limited
• Liners For Cement Mixers,
• Ball Mills,
• Certain Types Of Drawing Dies
• Extrusion Nozzles
Liners For Cement Mixers
2/04. Grey cast iron
Iron-carbon alloys containing flakes of graphite
embedded in steel matrix, which show a grey-blackish
coloured fracture due to graphite’—the free foam of
carbon, are called grey cast irons.
The strength of grey iron depends on the strength of steel
matrix and the size and character of graphite flakes in it.
Microstructure of Gray Cast Iron
Microstructure of Gray Cast Iron
PROPERTIES OF GREY CAST IRON
1. Low cost of production.
2. Low melting point: (1150°—1250°C)
3. Cast irons have excellent fluidity and take good mould-impressions easily.
4. High compressive strength.
5. High thermal conductivity, and have ability to withstand thermal shocks.
6. Good resistance to atmospheric corrosion due to high silicon and perhaps other
factors, than mild steels.
7. High damping capacity -due to the graphite flakes, which breaks the continuity of the
metallic matrix, and thus, vibrations are not allowed to transfer from one side of flake
3/04. Malleable cast iron
Malleable iron is produced by heat treatment of cast iron.
The properties of malleable cast iron are more like mild steel.
Microstructure of Malleable Iron
• Graphite in module(knot/lump) form.
• Produced by heat treatment of white cast iron
• Graphite nodules are irregular clusters
• Similar to ductile iron
• Good shock resistance
• Good ductility
• Malleable iron is better for thinner castings
• Vehicle components
1. Power trains, frames, suspensions and wheels
2. Steering components, transmission and differential parts,
3. connecting rods
• Railway components
• Pipe fittings
• Electrical fittings
Rail tracks Pipe fittings
4/04. Ductile (nodule ) cast iron
In ductile irons, the graphite is in the form
of spherical nodules thus prevent the creation of cracks
and providing ductility.
• Strength higher than grey cast iron.
• Low cost
Microstructure of Ductile Iron
Pipe and pipe fittings
Major industrial applications include
Highway diesel trucks,
Oil well pumps.
– Front wheel spindle supports,
– Steering knuckles,
– Disc brake callipers
used for water and sewer lines. Pipes
oil well pumps
Crankshafts in motor engineDisc brake callipers
Wrought Iron Is A form of Iron With A Very Low Carbon Content (0.25%) In Contrast
To Cast iron (2.1% to 4%).
"Grain" Resembling Wood, Is Visible When It Is Bent To The Point Of Failure.
Wrought Iron Is Tough, Malleable, Ductile And Easily Welded.
Purest form of iron in which the total impurities do not exceed 0.5%.
Wrought iron is much more expensive to produce than cast.
Most wrought iron work are joined by riveting.
MAJOR EXAMPLE ARE-
1. Iron pillar at Delhi, India, containing 98% wrought iron.
2. The Eiffel tower
•It can be used to form temporary magnets but cannot be magnetised permanently.
•It fuses with difficulty.
• high elasticity and tensile strength
•Unaffected by saline water.
• If pulled apart, the fracture shows a fibrous break.
• Capable of bearing 24 tons per square inch ultimate
tensile strain, & 20 tons of compression and shearing.
In fencing In main entrance gates
In railings As balusters
• Used for rivets, chains, ornamental
iron work, railway couplings,
bridges, water and steam pipes.
• Roofing sheets, corrugated sheets.
• It is manufactured for bolts and
nuts, horse shoe bars, handrails,
straps for timer roof trusses, boiler
tubes, roofing sheets, etc.
1. 3 I beams used. The inner beam is
riveted through it flanges to the
webs of the outer beams by four
lines of rivets. (permanent
2. 2.channels are used outside in
place of I beams, the flanges
being turned inward gives the
column a better finished
3. 3. composed of two channels and
plates riveted to the flanges of
channels with four lines of rivets.
4. The rolled segment is composed
of 4 segments riveted together
through the projecting
flanges, and made from 4-18”
outside dia.---3 to 24 inches deep (75mm to 600mm) and
with flanges about 200mm wide
Jubilee Bridge (1887) in Derbyshire.
• It's a good example of a structure made from different wrought iron
sections riveted together.
• The bridge spans 85 feet, about 26 metres.
COMPARISON BETWEEN WROUGHT IRON ,CAST IRON& STEEL
Wrought iron Cast Iron Steel
Composition Purest Contains up to
containing 2-4% C
Melting point 1500 degree Celsius 1200 degree Celsius 1300-1400 degree
Hardness Cannot be hardened or
Hard, hardened by
heating & sudden
Can be hardened &
Strength compressive strength is
2.0 tonnes/sq cm
strength 3.15 tonnes/sq
Comp. strength 6.3-
7.1 tonnes/sq cm
strength 1.26 to
Comp strength 4.75
-25.2 tonnes/ sq cm
strength is 5.51 to
11.02 t /sq m
Wrought iron Cast Iron Steel
ductile & moderately
Brittle & cannot
be welded or
rolled into sheets
Tough, malleable &
Cannot stand heavy
Does not absorb
Welding Easily welded Brittle and cannot
be welded or
rolled into sheets
Can be welded
Different types of iron used for pipes
Galvanized corrodes; produces discolored
water; has a short life;
Ductile deteriorates in some soils
Cast Iron no longer manufactured;
deteriorates in some soils
CAST IRON PIPE
1.Cast iron pipe
Adaptable for use in all types of building
Cast iron soil pipe can be preassembled
Product readily available
11/2” to 12” diameter
5’ AND 10’ length
storm drains and sewage
chosen over options like PVC, especially in high rise projects like draining from the roof
garbage disposal because it is highly resistant to the grinding and abrasions
Cast Iron flanged pipe and fittings are usually cast in the larger diameters. Smaller sizes
have loose flanges screwed on the ends of double spigot spun pipe.
Pipes are supplied in 3.7 m to 5.5 meters lengths and a variety of joints is available
including socket and spigot and flanged joints.
The pipes have been classified as LA,A and B according to their thicknesses. Class LA
pipes have been taken as the basis for evolving the series of pipes.
· Class A allows a 10% increase in thickness over Class LA.
· Class B allows a 20% increase in thickness over Class LA.
they don't echo when water moves through
good lasting qualities..
consequent high transport costs,
short length, leading to higher laying and jointing cost,
low tensile strength,
liability to defect of inner surface
. Nominal pipe sizes vary from 3 inches up to
The ductile iron used to manufacture the pipe is
by the spheroidal or nodular nature of the graphite
within the iron
pipe is manufactured using centrifugal casting in
metal or resin lined molds
Individual lengths of ductile iron pipe are
either by flanges, couplings, or some form of
spigot and socket arrangement
Flanges are flat rings around the end of
pipes which mate with
an equivalent flange from another pipe, the two
together by bolts usually passed through holes
drilled through the flanges.
Spigot and sockets involve a normal pipe
end, the spigot, being inserted
into the socket or bell of another pipe or fitting
with a seal being made
between the two within the socket. Normal
spigot and socket joints do not
allow direct metal to metal contact with all
forces being transmitted
through the elastomeric seal
The most popular, quickest, and easiest-to
assemble joint for Ductile Iron pipe and
fittings in underground applications is
the push-on joint. This joint consists of a
single rubber gasket placed in a groove
inside the socket at the bell end of the pipe.
There are two types of push-on joints: the
FASTITE®1 and TYTON®2 joints,which
are shown in Figure
Ductile iron pipe is made from 100% recycled ferritic scrap—and
is itself a 100% recyclable material.
. Ductile iron saves money.
It requires very little maintenance once it’s installed and
It is resistant to corrosion in most soils, and typically requires only
effective, economical polyethylene
It is strong enough to withstand the most severe conditions,
Ductile iron pipe is rugged and resists damage during handling and installation
Similar rate of corrosion to grey iron and steel
Prone to external and internal corrosion
Internal and external protection systems required
Polyethylene wrappings can be damaged
3. GALVANISED IRON
Physically, galvanized steel pipes are
darker than steel pipes because of zinc's
Economically, galvanized steel pipes
are inexpensive and recyclable.
These pipes are widely used for
conveying raw water & distribution of
water in majority of rural water supply