Ferrous metals

FERROUS METALS, STEEL & STEEL
ALLOY.
PRESENTED BY :
1]ANIKET LATE.
2]DHANANJAY MARDA.
3]VIJAY SONUNE.
GUIDED BY :
LAXMIKANT
DAHIBHATE SIR.

Ferrous Materials
 Such as steel and cast Iron have been and are being widely used
for a variety of structural purposes.
 Building Frames, Beams, Columns, Reinforcements, bars, etc.
and heavy Gates and Roofing’s sheets are made almost entirely
of ferrous metals.
Non-Ferrous Metals
 Like aluminum and its alloys are fast becoming engineering
materials of great importance ranking next to steel.
 Aluminum sheets, Rods, bars and frames are finding extensive
application in non- load and light loading bearing situations in a
building construction.
 Among the other metals and alloys that are valuable as
engineering applications may be mentioned copper, brass,
bronze, Zinc, Lead, and Nickel.

•Metals and their alloys have been a class of
indispensable engineering materials.
•In facts in all types of ‘Heavy’ Engineering
construction.
•Use of metallic is taken for granted. These
materials also find extensive application in
engineering Industry.
•As such any description of engineering materials
without metallic materials without metallic
materials will be a practically incomplete effort.
We may give a few example before entering into
detailed discussion of these materials.

 The ferrous group of metals include all types of Iron,
Steel, and their alloys.
 It is typical of this group that Iron (Fe) in one form
or another, is the principle component of all ferrous
materials. At present, the role of ferrous metals in
the engineering Industries can be easily described as
most dominating.
 In all jobs ranging from manufacturing of Primitive
type of agricultural implements to advance types of
air crafts, ferrous metals and their alloys occupy a
prominent position. In the automotive, buildings and
bridge construction, railways light and heavy
machinery, shipping and transportation and in many
other fields of engineering activities ferrous metal
and alloys are always there in or form or another.

This is explained by number of reasons.
 The wide abundance of Iron ore in almost all
parts of the world.
 The economic extraction of Iron from its
ores.
 The flexibility that can be induced in the
mechanical properties of Iron by combining it
with other metals and by heat treatment and
such other methods.

 The annual global production of ferrous
metals has been and remain far in excess than
the combined production of all non- ferrous
metals has been and remain far in excess than
the combined production of all non-ferrous
metal produced in all the countries of the
world.

 It is the first or basic form in which Iron is
prepared as a metal from its ores.
 It is therefore, impure and crude and requires
subsequent processing to develop cast Iron,
wrought Iron and steel which are common
ferrous metals used in Industry and
Construction.

Pig Iron is Manufactured in the following
Stages:
Selection of Ore
Dressing of Ore
Calcinations, Roasting, and Smelting

 Iron Occurs in nature in Combined form as Oxide,
Sulphates, Carbonates, and Silicates, etc. Such natural
raw sources from which iron can be extracted
economically are called iron ores. Following are common
Iron Ore:
• Hematite (Fe2O3) It is rich ore containing 70% Iron.
It has a dark brown to red color and is the most
common iron ore of our country. It is also called Red
Iron Ore.
• Magnetite (Fe3O4) It is the black iron ore and has the
richest Percentage(72.4%) of Iron. This is the main
Iron ore in Many other Countries but not in India.

• Siderite (FeCO3) It is also called the spastic iron
ore. It contains 48.2% Iron.
• Siderite is only rarely used as Iron ore in countries
where it occurs in abundance. Primarily, most of
the Iron is produced in the world either from
Hematite or from Magnetite.
• The selection of Suitable Ore is Controlled by two
major factors: Its occurrence in abundance at a
suitable place and its Quality (Purity).

 The Ore, as it is extracted from the earth, is in big
lumps containing many other useless or gangue
minerals.
 The Size of the ore must be reduced to that within
required limits and also the useless association must
be separated.
 The combined Process of reduction in size and
removal of impurities is called ore dressing. This is
achieved by passing the ore through a series of
crushers and washing mills. The latter wash away clay
and other impurities from the crushed ore.

 The blast furnace is a cylindrical Shell like vessel
made of Steel. It is 15-30m high and 6-8m in
diameter.
 It tappers towards the top. The lower part appears
as an inverted cone. The Interior of the furnace is
lined with refractory bricks, the furnace is provided
with
• Hopper for loading at the top;
• The gas outlet again at the top;
• The tuyers for injecting hot gases, near the base:
• Cooling Pipes just around the tuyers.

 Besides the main furnace, a blast furnace plant
requires following additional equipments:
• Engine: for creating and supplying the air blast for
the furnace.
• Stoves, for pre-heating the blast of air before it
blows into the furnace;
• Coke Ovens for converting coal to coke by heating
the same at 1050C or more.
 Equipments for clearing the blast furnace gas, for
storage of raw materials and for receiving the molten
iron from the blast furnace.

 The blast furnace operation is a continuous
process after it is started in the following
manner.
• A Blast of air is first created by blowing the
engines. This blast passes through stoves at
500C-600C and then is made to enter the
furnace through the tuyers in the lower region.
• Meanwhile, a charge is kept ready at the top in
the hopper. The charge consists of alternate
layers of coke, Ore and fluxes (Limestone etc) in
pre-determined proportions.

• When the hot blast has heated the furnace to a
desired extent, the charges is introduced into the
furnace by operating the hopper.
• The hot gases burn the fuel part of the charge
thereby creating still higher temperature.
• The hot molten ore gets reduced by reacting with
carbon monoxide from the coke; Iron (Fe) is
produced in the molten form.
• The molten iron and impurities (as slag) collect in
the lowermost region of the furnace where from
they are removed periodically.
• New batches of charge are introduced at the top.

 After the first charge and removal of the
first melt of Iron, Slag, the operation
becomes continuous; charges is introduced at
regular Intervals at the top through the
hopper and the molten products are drawn of
from the lower zone.

 Following three working zones may be distinguished in a
blast furnace:
• Stack Zone: It is the largest zone and extends from the
top to the middle of the furnace. The charge coming
from above and the hot gasses rising from below interact
resulting in the dehydration of ore temperature range
from 400C to 600C in this Zone.
• The Bosch Zone: It forms an inverted cone and is the
hottest Zone. It receives the hot air from the blower
through the tuyers, and the dehydrated charge from the
stack zone.
• The Hearth Zone: It forms the lowermost part of the
furnace. It serves as a receiving pot for the molten iron
and slag. Since the iron and slag have different densities,
they form layer, slag floating above the iron melt. These
are drawn out from separate holes provided within the
blast furnace corresponding the hearth zones.

 Following are a few type of pig iron
distinguished on the basis of the properties:
• Grey Pig Iron
 It is distinguished by a typical grey
colored surface of Iron when broken
fresh. It is soft in character and rich in
Carbon. It is produced when the raw
material are burnt at a very high
temperature.

• White Pig Iron
 The broken surface shows dull white appearance.
This type contains sulphur, as the main impurity and
hence is considered as inferior in Grade. It is also
called forge Pig Iron, as it is hard and brittle and
can be converted only by using pressure.
• Bessemer Pig Iron
 This type is practically free from sulphur and
phosphorous. Therefore, it is used for the
manufacturing of steel in the Bessemer Process.

 Cast Iron consists of essentially of remolded pig
Iron. It contains carbon from 2-4% and small
properties of manganese, Silicon, and Sulphur.
 The remelting of pig Iron is done in a special furnace
called Cupola. A Cupola is in essence a small sized
blast furnace.
 It is about 5m in height, about 1m in dia and
cylindrical in shape. The cylinder has an inner lining of
refractory bricks and is provided with tuyers near
the bottom for injecting the supply of air blast.

 The role of various impurities that are deliberately
kept in the cast iron is as follows:
• Phosphorous:
 It increases the fluidity of the cast iron which is an
important property. Its % varies between 1-1.5.
• Sulphur:
 Its presence causes rapid solidification. Its content
is generally maintained below 0.1% to get the best
result.
• Manganese:
 Gives the cast iron its hardness. But its percentage
should be below 0.7% otherwise the metal will be
very brittle.

 Following are the common types of cast Iron :
Grey cast Iron :
 In this type, carbon is present in the flacky,
graphite form. It has a typically grayish color. The
usual composition of grey cast Iron is :
 Iron 92%.
 Carbon 0.5%.
 Silicon 2-3%.
 Grey cast Iron is soft and ductile. It finds
application in making casting, dies, moulds, machine
frames and pipes.

White Cast Iron :
 It is the variety of cast Iron in which carbon is
present in the combined form as Iron Carbide(FeC)
and not graphite. It has a shining white color and
metallic lustier. The metal is very strong, hard and
resistance to wear and tear and heat. It is quite
brittle as well.
 The usual composition of white Cast Iron is as
follows:
 Iron 94%.
 Carbon 2.5-3.0%.
 Silicon 0.5-1.0%.
 White Iron is difficult to machine.

Malleable Cast Iron
 It is actually “white cast Iron” in which
property of malleability has been
developed by the process of heat
treatment.
 The white cast Iron is subjected to the
process of annealing. After that, it is
cooled gradually to room temperature.
 The malleable cast Iron find extensive
application in automobile industry for
making real axel housing, stearing, hubs

 This group includes those types of cast iron in
which one or more allowing element has been
incorporated with a view of increasing the
utility of the metal. The usual alloying
material are nickel and chromium.

The composition of cast Iron depends on three
factors :
 The composition of cast Iron.
 The rate of cooling.
 The nature of heat treatment.

 Following are general account of the properties
Carbon:
 The amount of carbon and the nature in which
carbon is present in the cast iron effects the
property of cast Iron. When the carbon is present
as graphite cast Iron is soft and weak.
 But when carbon is present as cementite, the metal
is hard and strong.

Alloying Element
 Nickel: It may be added in amount varying from 0.5-
20%.
 Chromium: It is also added in small proportion to
cast Iron.
 Molybdenum: This alloying element is added to
increase hardness of cast Iron.
 Heat treatment: This type of treatment changes
the properties of cast Iron to a great Extent
Impurities.
 The influence of certain common Impurities like
Phosphorus, Sulphur, Silicon, and Manganese is
quite pronounced.

 It is purest form of Iron containing all impurities
below a limit of 0.5%.
 Carbon is included in these impurities, its proportion
begin generally less than 0.12%. Besides, Wrought
Iron always contain a small proportion of slag as a
silicate compound.
 The source material for the manufacturing of
Wrought iron pubbling process and aston process.

 This consists of heating the pig iron in a small
reveberatory furnace called Puddling Furnace. The
furnace has lining of Iron Oxide Bricks. The charge is
Heated to 1200C.
 At this temperature, melt is oxidized on coming in
contact with iron oxide lining, to ensure that more
and more fused metal comes in contact with iron
oxide lining the molten charge is regularly stirred or
puddled through puddling holes. Hence the name of
the process.

 In this process, pig Iron is first refined by heating in
a Bessemer Convertor.
 All the impurities get removed by directing a strong
current of air over the molten material. The molten
pig Iron is Cast into moulds.
 A mixture of Iron Oxide is put into the mixing
machine where it is first granulated. When still hot
slag is poured on to it from the slag ladles.
 The Slag is essentially at a lower temperature than
pig Iron. The pouring results in abrupt solidification
of good amount of slag. This step is called shooting
the iron slag balls so formed are subjected to
pressing machine where the extra quality of slag is
squeezed out of them. The resulting material is
Wrought Iron.

In this process,
pig Iron is first
refined by heating
in a Bessemer
Convertor.
All the impurities get
removed by directing
a strong current of air
over the molten
material. The molten
pig Iron is Cast into
moulds
A mixture of Iron
Oxide is put into the
mixing machine where
it is first granulated.
When still hot slag is
poured on to it from
the slag ladles.
The Slag is essentially at a lower temperature
than pig Iron. The pouring results in abrupt
solidification of good amount of slag. This
step is called shooting the iron slag balls so
formed are subjected to pressing machine
where the extra quality of slag is squeezed
out of them. The resulting material is
Wrought Iron.
Aston Process

 Following are the most Important Properties of
Wrought Iron:
• Strength: It has a tensile strength varying
between 2500 to 4000 kg/cm3
• Physical: Wrought Iron is bluish in color, has a silky
lustre and fibrous structure. It is malleable,
ductile and tough.
• Density: The metal has density of 7.8 gm/cc3 and a
melting point of 1500C.
• Wrought Iron shows good resistance to fatigue
and sudden shock.

 Steel is essentially a variety of Iron containing 0.1 to
1.5% carbon in the form of Cementite (Iron Carbide,
Fe3C). Besides Carbon, many other metals may also be
present in addition to Iron, giving rise to a great
varieties of steel.
 If the percentage of carbon exceeds 1.5, the
material will become more like cast Iron because the
carbon will then tend to occur as Graphite (free
Carbon). On the other hand, with decrease in the
carbon content the material would resemble more to
wrought iron or the pure Iron.

 The best thing about steel is that it has very high
compressive strength of Cast Iron and very high
tensile strength of Wrought Iron. As such it is suited
for all types of situation as a structural material.
 Steel is a versatile material of modern age. Its
properties can be varied over a wide range by varying
its composition and by subjecting it to various
mechanical and heat treatment process.

 Steel is at present manufactured by many processes
that fall under three board heading namely bessemer
process, the open hearth process and the electric
process.

 This method takes its names after Bessemer
Converter which is used for steel making.
 The convertor is an egg or pear shaped vessel
supported on trunions in such a way that it can be
tilted and even rotated about its horizontal axis. The
inner walls of the converter are lined with a
refractory material.
 When the refractory bricks are made up of clay or
silica, the lining is acidic in character.

 The process is then called acidic Bessemer Process,
but when the lining is made up of lime of magnesium
bricks, it is basic in character. The process is then
called Bessemer Process.
 The Raw material for making steel in the Bessemer
Process is Pig Iron. In the acid process, the pig iron
must be free from phosphorous and sulphur.
 In the basic process, however, these impurities are
tolerated, and removed by the addition of lime.

 Following are the main stages in manufacturing of
steel:
• Stage 1 :
 The Bessemer converter is first tilted to a
horizontal position. Molten pig Iron is then fed
directly from the furnace. Air is also
simultaneously blown into the converter through
the tuyers and the converter is straightened up.
• Stage 2 :
 Air is kept blowing continuously through the
charge. During this process, most of the
impurities of the pig iron like silicon, carbon,
manganese, sulphur and phosphorous get oxidized
on reacting with iron oxide formed as a result of
reaction of Iron and air.
2Fe + Si = 2Fe + SiO2

• Stage 3:
 When Oxidation Process has progressed
sufficiently, predetermined quantities of
ferrmanganese or spiegleisen are added. This
material serves two purposes:
 It supplies carbon content for the steel
 It deoxidized any iron oxide left during
oxidation of other impurities.
• Stage 4:
 Converter is then tilted into the discharge
position and molten metal poured into moulds of
special rectangular shapes. The solidified steel
known as ingot, which is the starting material for
preparing other steel shapes.

 This is one of the most common processes of steel
making. It consists of an elaborate assembly of
mechanical and metallurgical devices.
 The main part of the plant is known as Hearth which
consists of steel pan lined with a thick layer of
refractory material. The refractory lining may be either
acidic or basic in character. The hearth has varying
dimensions and may accommodate steel up to 3000 tons
in one charge. The plant is provided with various
openings such as charge door stapping holes and entry
ports for gases.
 The raw material or the charge consists of:
• Molten or Cold pig Iron
• Scrap of Iron or Steel
• Limestone

Manufacture for steel in this process:
 Stage I
• The molten charge of the raw material is loaded into the
hearth.
 Stage II
• A mixture of Hot air and coal Gas is blown in and made to
pass over the charge. The gas mixture starts burning and
raises the temperature of the molten charge further is
boiling. The charge is allowed to remain in this boiling period
for some time it is during this period impurities get removed
from the charge by oxidation.
 Stage III
• This is the finished stage or the final stage during which
predetermined quantities of ferro-manganese are added to
accelerate the process of deoxidization.
 Stage IV
• Molten steel is drained into special rectangular moulds to
give the cold steel the typical shape of ingots.

 Steels have been classified in many ways such as on
the basis of method used in their manufacturing.
 It is however, the classification on the basis of their
chemical composition that is very commonly adopted.
 Two major group of steel are:
• The Plain Carbon Steels
• The Alloy Steels

The Plain Carbon Steels
 This is the first major group of steel. In them carbon
is the only controlling component besides Iron, they
are further sub-divided into three sub types:
• Low Carbon Steel
• Medium Carbon Steel
• High Carbon Steel
 Function of Carbon in Steels:
• Carbon in steel plays very vital role in controlling
their properties.

Alloy Steel
 These are steel made with the addition of a definite
proportion of a selected element in addition to
carbon at the manufacturing stage. The alloy steel
show some specific properties that are related to
alloying elements.

 All those types of steels that may be used in civil
engineering are sometimes classified as structural
steels.
 Concrete is the most common material of
construction. Plain Concrete has very high
compressive strength but very low resistance against
bending and tensile forces. This shortcoming of
concrete is overcome by incorporation in it steel
reinforcement.

Prestressing Steel
 This is another use of structural steel, in this
process the steel reinforcement is tensioned at the
time of placement of concrete.
 After this, when the equipment for creating tension
in the steel member is removed, the steel tends to
come to its original shape.
 But being enclosed within the set concrete it fails to
do so. The result is that compressive strength of the
concrete and the tensile strength of the steel come
to establish a useful balance. The most important
useful property is their high yield strength in tension.

Bridge Wire Steel
 In the Construction of suspension bridges use of
steel cables of proper qualities is a very important
consideration such steel should posses following set
of properties:
• High strength
• High toughness
• High resistance to fatigue
• High resistance to corrosion

Cladding Sheets
 These are thin sheets of proper quality of steel that
are used to cover the walls and columns and other
structure in a building. The cladding steels are
generally from the category of stainless steel with a
composition having chromium and nickel they may be
given attractive finish by coating with vitereous
enamel or polyvinyl chloride.

Railway Steel
 Steels find extensive application in railways; from
rails, for construction of bridges, for erecting signal
gentries, etc., the steel for making rail must be:
• Very strong in Compression and bending
• Very resistance against wear
• Very stable against fatigue
• Very stable against shock and impact.

 Iron and steel are made available to the industry in
specified shapes like ingots, sheets, plates, wires,
pipes, rods sections and so on.
 Casting: It is defined as a method by which specified
shapes, are produced by pouring molten, metal into
specially prepared moulds, where it is allowed to cool
the shapes so obtained are designated as casting.
 In fact, in steel casting forms the first step in the
process of giving shapes.

 These are the basic casting of the metal and are
made by the melt pouring from the furnace into
rectangular moulds.
 A single ingot is a rectangular block with a length of
2-3 m and cross section between 40-100 cm
 Following defects may develop into casting if proper
care is not taken at the time of making ingots.

 Blow holes:
• These are small like openings, continuously or
discontinuous that may develop on the ingots.
These are produced when the gases escape from
the metal at the time of cooling in the mould.
 Segregation:
• These are concentration or localized accumulations
of impurities in the interior of ingots. During the
cooling process, impurities are rejected by the
primary metal from the surface. The cooling
proceed from the surface to the interior.

 Ingotism
• It signifies the development of a very coarse
crystalline structure in the ingot. This structure
develop because of slow rate of cooling.
 Pipe
• It is defined as a central continuous cavity
developing within an ingot. It is considered as a
major defect in the ingots.

Control of Defects
 Blowholes and ingotism are cured by mechanical
working, it can be prevented by adopting such
methods of cooling in which the top portion remain
hot till end so that the pipe is formed in the exterior
region of the ingot. It can be removed by cutting off
a thickness of external length of the ingot.

 All those method in which desired shape of iron or
steel are produced by applying pressure in one way or
another are grouped under mechanical working.
 Three main processes included under this head are:
• Rolling,
• Forging, and
• Pressing.

Rolling:
 By rolling is understood reduction of iron or steel
blocks to the desired dimension and shapes by
passing them through a set of rolls in motion.
 The plant where this operation is performed is called
a Rolling Mill.
 A Rolling Mill may have numerous set of rolls. These
rolls are made of Cast Iron, High Carbon Steel or
Special Alloy Steel in a great variety of shapes and
sizes depending upon the nature of the shape to be
produced.
 The process of rolling is further divided into hot
rolling and cold rolling depending on whether the
metal to be rolled is in hot condition or in a cold
condition.

 Hot Rolling:
• It is a very common process for obtaining shapes
from metals, it involves subjecting a preheated
metal to series of rolls.
 Cold Rolling:
• It is invariable a finishing process aimed at
obtaining shapes of very accurate dimensions that
are not possible with hot rolling.

 Forging
• It is a mechanical process for obtaining the
desired shapes of a metal by giving blows to the
metal held within dies.
• This is generally achieved by first heating the
metal to a specified temperature and then giving
blows of definite pressure.
• Blows are given by hand hammers if the part to be
forged are of small size, for bigger product steam
hammers are used.

 Pressing
• It is method of mechanically working the shape of
a metal and involves application of heavy load on
the metal placed on anvil through a hydraulic press.
• During the application of pressure, many original
defects of the metal get removed.
• The method is used for making armor plates. Heavy
shafts and other such thick parts.

 This is a method of shaping metals into wires of
various cross-sections.
 It involves stretching the metal through a series of
tapered dies, each die having a hole slightly smaller
than the preceding one.

REFRENCE :
http://www.slideshare.net/gauravhtandon1/
ferrous-metals-
83079913?from_m_app=android.
THANK
YOU……

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