A PROJECT REPORT ON “Eliminating corner gap in sc mould at LD2 SNC”. During the internship the following research is evaluated and being verified by the authorized TATA steel employee.

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A
PROJECT REPORT
ON
“Eliminating corner gap in sc mould at LD2
SNC”
SUBMITTED BY:
Vinay kumar
B.Tech
Machenical Engineering
B.A. College of Engg & Tech.
Jamshedpur.
GUIDED BY:
Mr.Shaswat Anand
Manager-segment shop

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APPROVAL CERTIFICATE
The foregoing project report entitled “Elimnating corner gap in sc
mould at LD2 SNC” submitted by Mr. Vinay kumar (Summer Intern
‘15 )is hereby approved as authentic study of his Project work
during his vocational training at Tata Steel, Jamshedpur.
It is presented in satisfactory manner to warrant its acceptance as a
prerequisite in the completion of his vocational training.
GUIDE
Mr. Shaswat Anand
Manager-Segment Shop

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ACKNOWLEDGEMENT
Any accomplishment, big or small, has a number of persons behind
the scene and I must acknowledge that this project was no
exception.
First of all I would like to convey my gratitude to my guide Mr.
Shaswat Anand (Manager-segment shop) for his continuous
support during my project. He has been a constant source of
encouragement during the entire project. He provided me valuable
information as well as knowledge regarding my project. I
Finally, I would like to convey a word of thanks to “ TATA STEEL”
administration for providing me this great opportunity to undergo
my summer internship under its esteemed banner.

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TATA STEEL
An Introduction
Established in 1907, Tata Steel is the world’s 6th largest steel
company with an
Existing annual crude steel capacity of 28MTPA. Asia’s first
integrated steel plant& India’s largest integrated private sector steel
company is now the world’s second most geographically diversified
steel producer, with operations in 24countries &commercial
presence in over 50 countries .Tata steel completed 100years of
existence on August 26, 2007 following the ideals & philosophy laid
down by its Founder , JAMSETJI NUSSERWANJI TATA. The first
private sector steel plant which started with a production capacity
of 1, 00,000 tones has transformed into a global giant.
J.N.Tata-The Founder An overview of TATA STEEL
Tata Steel plans to grow & globalize through organic & inorganic
routes. Its 6.08MTPA Jamshedpur works plans to 10MTPA capacity
by 2012. The company also has three Greenfield steel projects in
the states of Jharkhand, Orissa &Chhattisgarh and proposed steel
making facilities in Vietnam and Bangladesh.
Through investments in Corus , Millennium Steel { Renamed Tata
Steel Thailand }and NatSteel Asia , Singapore , the Tata steel has
created a manufacturing and marketing network in Europe , South

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East Asia and the Pacific- rim countries. Corus, which
manufactured 18.3 MT of steel in 2006, has operations in the UK,
the Netherlands, Germany, France, Norway &Belgium. Tata Steel
(Thailand) is the largest producer of long steel products in Thailand,
with a manufacturing capacity of 1.7 MT. NatSteel Asia produces
about 2 MT of steel products annually across its regional operations
in seven countries. Tata Steel through its joint venture with Tata
Blue Scope Steel limited has also entered the steel building and
construction applications market.
The iron ore ones & collieries in India give the company a distinct
advantage in raw material sourcing. Tata steel is also striving
towards raw materials security through joint ventures in Thailand,
Australia, Mozambique, Ivory Coast (West Africa) and Oman.
Tata Steel’s vision is to be the global steel industry benchmark for
“Value Creation and Corporate Citizenship”.
Process Flow At Tata Steel

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SNTI (Shavak Nanavati Technical
Institute)
• SNTI (Shavak Nanavati Technical Institute) the erstwhile
Jamshedpur technical institute, was established in the year
1921 to provide the technically qualified human resource for
Tata Steel.
• It was the inspiration of the founder of TISCO, “Let the
Indians learn to do things by themselves” , which came into
reality by the establishment of the institute.
• Today SNTI form an integral part of the HR management
division of TATA STEEL.
• It has rendered commendable service in nation development of
technical manpower not only for Tata Steel, but also for the
steel plants in the public sector and other manufacturing
industries.

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What is steel?
Steel is a compound of iron and carbon. Modern steels also use
traces of magnesium, chromium, tungsten, molybdenum,
manganese, nickel and cobalt. All of these can be used to varying
degrees to help make the steel harder, lighter, more or less resistant
to heat and electrical current, more ductile and corrosion resistant.
Steels are a large family of metals. All of them are alloys in which
iron is mixed with carbon and other elements. Steels are described
as mild, medium- or high-carbon steels according to the percentage
of carbon they contain, although this is never greater than about
1.5%.
Steel is an alloy of iron and other elements, including carbon.
When carbon is the primary alloying element, its content in the steel
is between 0.002% and 2.1% by weight. The following elements are
always present in steel:
carbon, manganese, phosphorus, sulfur, silicon, and traces
of oxygen, nitrogen and aluminum. Alloying elements intentionally
added to modify the characteristics of steel include:
manganese, nickel, chromium, molybdenum, boron, titanium, vana
dium and niobium.[1]
Carbon and other elements act as a hardening agent,
preventing dislocations in the iron atom crystal lattice from sliding
past one another. Varying the amount of alloying elements and the
form of their presence in the steel (solute elements, precipitated
phase) controls qualities such as the hardness, ductility, and tensile
strength of the resulting steel. Steel with increased carbon content
can be made harder and stronger than iron, but such steel is also
less ductile than iron.
Alloys with a higher than 2.1% carbon (depending on other element
content and possibly on processing) are known as cast iron.
Because they are not malleable even when hot, they can be worked
only by casting, and they have lower melting point and
good castability.[1] Steel is also distinguishable from wrought iron,
which can contain a small amount of carbon, but it is included in
the form of slag inclusions.

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Though steel had been produced in a blacksmith's forge for
thousands of years, its use became more extensive after more
efficient production methods were devised in the 17th century. With
the invention of the Bessemer process in the mid-19th century,
steel became an inexpensive mass-produced material. Further
refinements in the process, such as basic oxygen
steelmaking (BOS), lowered the cost of production while increasing
the quality of the metal. Today, steel is one of the most common
materials in the world, with more than 1.3 billion tons produced
annually. It is a major component in buildings, infrastructure, tools,
ships, automobiles, machines, appliances, and weapons. Modern
steel is generally identified by various grades defined by
assorted standards organizations.
What is steel production?
When iron is smelted from its ore by commercial processes, it
contains more carbon than is desirable. To become steel, it must be
melted and reprocessed to reduce the carbon to the correct amount,
at which point other elements can be added. This liquid is
then continuously cast into long slabs or cast into ingots.
Approximately 96% of steel is continuously cast, while only 4% is
produced as ingots.[12]
The ingots are then heated in a soaking pit and hot rolled into
slabs, blooms, or billets. Slabs are hot or cold rolled into sheet
metal or plates. Billets are hot or cold rolled into bars, rods, and
wire. Blooms are hot or cold rolled into structural steel, such as I-
beams and rails. In modern steel mills these processes often occur
in one assembly line, with ore coming in and finished steel coming
out.[13] Sometimes after a steel's final rolling it is heat treated for
strength, however this is relatively rare
Iron ore pellets for the production of steel.

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How a steel plant work ?
A plant has many needs for it to grow. The most important are:
Carbon, hydrogen and oxygen Nitrogen, phosphorus, potassium
Sulfur, calcium, and magnesium
The most important of these
are nitrogen, phosphorus and potassium. Nitrogen, phosphorus
and potassium are important because they are necessary for
these basic building blocks. For example: Every molecule making
up every cell's membrane contains phosphorous. Potassium
makes up 1 percent to 2 percent of the weight of any
plant.Without these tree items, the plant could not grow because
it can't make the pieces it needs. In nature, the nitrogen,
phosphorous and potassium often come from the decay of plants.
Steel is an alloy of iron and carbon. It is produced in a two-stage
process. First, iron
ore is reduced or smelted with coke and limestone in a blast
furnace, producing molten iron which is either cast into pig
iron or carried to the next stage as molten iron. In the second
stage, known as steelmaking, impurities such
as sulfur, phosphorus, and excess carbon are removed
and alloying elements such
asmanganese, nickel, chromium and vanadium are added to
produce the exact steel required. Steel mills then turn molten
steel into blooms, ingots, slabs and sheet through casting, hot
rolling and cold rolling.
How is steel produce?
There are two types of metals, ferrous & non-ferrous. Ferrous comes
from, or contains iron, while Non-Ferrous does not contain iron.
Some examples of ferrous metals would be mild steel, cast iron,
high strength steel, and tool steels.
Examples of non-ferrous metals would be copper, aluminum,
magnesium, titanium, etc.

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To make steel, iron ore is first mined from the ground. It is then
smelted in blast furnaces where the impurities are removed and
carbon is added. In fact, a very simple definition of steel is "iron
alloyed with carbon, usually less than 1%."
The following text is taken from the Structural Manual For
Ironworkers Manual V-Volume I.
Blast furnaces require many auxiliary facilities to support their
operations. However, in simplest terms, the furnace itself is a huge
steel shell almost cylindrical in shape and lined with heat-resistant
brick. Once started, or "blown-in," the furnace operates
continuously until the refractory lining needs renewal or until
demand for iron drops to the point where the furnace is closed
down. The duration of furnace operations from start to finish is
referred to as a "campaign" and may last several years.
Iron ore and other iron bearing materials, coke and limestone are
charged into the furnace from the top and work their way down,
becoming hotter as they sink in the body of the furnace which is
called the stack. In the top half of the furnace, gas from burning
coke removes a great deal of oxygen from the iron ore. About
halfway down, limestone begins to react with impurities in the ore
and the coke to form a slag.
Ash from the coke is absorbed by the slag. Some silica in the ore is
reduced to silicon and dissolves in the iron as does some carbon in
the coke. At the bottom of the furnace where temperatures rise well
over 3000 Fahrenheit, molten slag floats on a pool of molten iron
which is four or five feet deep. Because the slag floats on top of the
iron it is possible to drain it off through a slag notch in the furnace.
The molten iron is released from the hearth of the furnace through a
tap hole. The tapping of iron and slag is the major factor permitting
additional materials to be charged at the furnace top.
This brief summary of the complex operations of a blast furnace is
presented here to provide a point of reference for the actual flow of
operations. Very often, several blast furnaces may be arranged in a
single plant so that the most efficient possible use can be made of
fuels, internal rail facilities, etc

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2.0) MATERIAL HANDLING PROCESS AT TATA
STEEL
Under 3.0MTPA Expansion Projectof Tata Steel the following
facilities have been installed at Jamshedpur works in addition to its
present operations:
1.0) Pellet Plant 6.0MTPA: Produces pellets for Blast Furnace
2.0) Blast Furnace 3.0 MTPA: Produces pig iron from
Ore/Sinter/Pellet,
and Coke & PCI Coal
3.0) Coke Oven Battery: Produces coke from coal for Blast Furnace
4.0) Lime Kilns#8&9: Produces lime from lime stone for LD#3
5.0) LD#3: Produces steel from pig ironand uses lime
The following basic raw materials are required for operation of above
plants.
1. Blast Furnace – Coke, Sinter, Ore/additives, Pellet and PCI
coalCoke Ovens – Coal
2. Lime Calcining Plant – Lime stone,
3. Pellet Plant – Iron ore fines,
4. LD: Lime and additives
In order to handle huge amount of several varieties of raw materials
for above production units, Tata Steel has installed fully automated
bulk material handling system. This document outlines the study of
material handling process and the associated automation systems
for operation of Raw Material Handling systems.
Primarily raw material handling process broadly covers the following
activities:
1. Raw materials receiving from various sources thru rail/road
2. Unloading of incoming raw materials
3. Transfer of raw materials from unloading points to
storage/stock pile yards
4. Stock piling of materials

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5. Reclaiming anddistribution of raw materials from storage/stock
piles
thru conveying system to consuming production plants
The automation system associated with materials handling system
ensures safe and energy efficient handling of materials in desired
quantities as per requirements by the production units without any
losses or with minimum losses.
The Material handling system consists the following major
equipment:
1 Weigh bridges 13 Belt Feeders
2 Track hoppers 14 Weigh Feeders
3 Plough feeders 15 Vibrating Feeders
4 Wagon Tippler 16 Vibrating Screens
5 Apron feeder 17 Surge hoppers
6 Stacker cum
reclaimer
18 Reversible
Conveyors
7 Bucket wheel
stacker cum
reclaimer
19 Reversible shuttle
conveyor
8 Traveling Tipper 20 Reversible hammer
mill
9 Conveyors 21 Double roll coke
crusher
10 Magnetic
separators
22 Twin Boom Stacker
11 Bucket wheel on
boom reclaimer
23 Barrel Reclaimer
12 Bins
The operations of the above equipment are fully controlled by using
PLC’s (Programmable Logic Controllers) and facilitate remote
operations from control rooms.
Apart from PLC automation, there are several other systems
facilitate safe operation of the handling process in auto.
1. Electrical motors/drives
2. Safety switches

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3. Metal detectors
4. Magnetic Separators
5. Belt Scales
6. CCTV monitoring
7. Fire Detection and Alarm systems
8. Communication systems
Among all material handling equipment, the conveying system plays major role to
transfer the bulk raw materials from one place to other. The conveying system
used in Tata Steel is elaborated further
LD SHOP DESCRIPTION
• The LD shop takes in Hot metal from the blast furnace and
refine them so that it can be turned into refined steel before
being cast into billets and slabs depending on the
requirements.
• In Tata Steel there are presently LD#1, LD#2, LD#3 and TSCR
departments for the above mentioned process.
LD#2 Shop
The main units of LD#2 Shop are:-
1). Hot metal receiving and Handling
2). Desulphurization
3). Basic oxygen furnace
4). Online purging
5). Ladle furnace
6).RH degasser
7). Gas cleaning plant
8).Secondary emission plant

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LD#2 Shop Process
 The hot metal is received in the torpedo pits of the LD shop
via torpedo (capacity is 200T to 320T) from the blast
furnace.
 The metal received is crude in terms of the composition
and needed to be further refined.
 The first step in LD#2 shop is DESULPHURIZATION
process, the Sulphur content is controlled in this process.
 The desulphurization process takes place in the D.S unit
where calcium carbide and magnesium are used to and the
sulphur is brought down to the target level depending on
the grade requirements.
 The next step is the BOF process. This is the most widely
used steel refining process and this was first introduced in
the towns of Linz and Donowitz and hence the name LD.
 In the LD converter Oxygen is blown from the top of the
converter to reduce the carbon content also various
additives like fluxes, Ferro alloys and scrap is added to
stabilize the process and to produce the required grade of
Steel. The metal obtained is called “Primary Refined Steel”

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 The steel after refining in the BOF is tapped and is sent to
the Ladle furnace where the trimming additions takes place
to fine tune the steel compositions.
 In the ladle furnace the molten steel is heated by means of
electrode to maintain temperature wire feeding system for
Ferro alloy.
 From the ladle furnace the steel is sent to the caster for
casting into billets or slabs.
 In certain cases where high quality and cleanliness is
required the steel is sent t the RH(Ruhrstahl -Heraeus)
facility which is a vacuum degassing unit to further reduce
carbon, oxygen, nitrogen and hydrogen content.
Overview of LD2 & Slab Caster 1.

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LD-2
Supplied by S.N. Portugal of Portugal LD 2 was commissioned in 1993.
With two BOF vessels from VAI, the plant has a rated capacity of 1.10
million tonnes. Hot metal is supplied in 200 t nominal capacity torpedo
ladles from the blast furnaces. The metal is poured into 150 t transfer
ladles at the hot metal pouring pit .The hot metal in the transfer ladle is
desulphuriser at the desulphurization unit after removing the slags and
thereafter, taken to the converters.
The details of hot metal handling system are:
: The input Hot Metal comes from Furnaces A,
B, C, D, F, G, H & I in torpedo ladles of 220tons.
: Hot Metal from Torpedo is transferred to ordinary
Transfer Ladle of 150tons capacity by tilting the Torpedo. From 2
torpedoes we get metal for three heats.
: Initially BF Slag is raked of with the
help of raking machine. Then desulphurisation starts with the injection
of CaC2 & Mg injection through refractory lance with Nitrogen as the
carrier gas. The lance dips inside the metal and injection starts. Sulphur
of the hot metal removes in the form of CaS & MgS and floats up. This is
raked off. The time of DS depends on the initial ‘S’ content of the hot
metal & the final product specification required.
: The 3 BOF vessels have been supplied by SMS Demag. Pig
iron in the transfer ladle is taken inside the BOF vessels for controlled
oxidation using lance heater. At this stage additives are added to prepare
the required blend of steel. Inert gas, Argon is blown in order to maintain
the uniformity of the hot metal.
Lance heater used for oxidation contains 3 concentric flow paths.
The centre flow path is used for blowing oxygen into the vessel and the
other 2 flow paths are used to water cooling of lance.
At the time of oxidation, the lance goes deep into the vessel so that
uniform oxidation can take place. Slag formation takes place in the upper
part of the vessel whereas molten steel in produced in the lower part.
Slag is removed by tilting the vessel from the top of the vessel into a ladle
transfer car below and the steel is poured into another ladle below it from
the neck opening of the vessel by tilting it in opposite direction.

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Steel in the ladle now is taken for further secondary metallurgical
processing in SMLP (Secondary Metallurgical Ladle Processing) shop
mentioned below.
: Different routes of steel making are mentioned
below:
 Converter-Caster(30-35% Heats)
 Converter-RH-Caster(18-20% Heats)
 Converter-LF-Caster(50-55% Heats)
 Converter-LF-RH-Caster(6-8% Heats)
: The process was developed by Rheinstahl Heinrich in
1957. The process in named after him. In order to produce steel for high-
end applications, liquid steel is routed through. This degassing unit in
which treatment takes place under vacuum.
The degassing chamber is a cylindrical steel shell with two legs called
snorkels and the openings at the top side are provided for exhaust, alloy
additions, observations and control. During degassing metal enters the
cylindrical vacuum chamber through one snorkel and flows back under
gravity through other. The chamber is lifted and lowered to an
appropriate level in the ladle containing molten steel. The chamber is
evacuated and the molten steel just rises in the chamber. The
atmospheric pressure causes the molten steel to rise above the, still bulk
level, in the snorkel, under deep vacuum. Lift gas like argon is then
introduced in the inlet snorkel which expands and rises up thereby
raising the velocity of steel in the inlet snorkel. The net result of this is
that degassing takes place very efficiently. Gravity causes steel to flow
back in the ladle via the other snorkel. Degassed steel is slightly cooler
and denser than in the ladle and hence it forces the lighter undegassed
steel upwards thereby ensuring adequate mixing and homogeneity. At
the end of the process alloy additions may be made depending upon the
superheat available in the steel.
: Liquid steel from the converter is tapped into
preheated ladles and then treated at the ladle furnace for
homogenization, increase of temperature and for trimming additions are
done. It is a simple ladle like furnace provided with bottom plug for argon

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purging and lid with electrodes to become an arc furnace for heating the
bath. Another lid may be provided to connect it to vacuum line, if
required. Chutes are provided for additions and an opening even for
injection. It is capable of carrying out stirring, vacuum treatment,
synthetic slag refining, plunging, injection etc. all in one unit without
restraint of temperature loss, since it is capable of being heated
independently.

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2. Slab Caster
There are three single strands continuous casting machine which have
been specifically designed to cast high quality slabs suitable for hot
charging to the Hot Strip. The main machine at LD#2 and Slab Caster
was modified to include a new vertical mould and Bender/Straightener
Segments, up gradation of ladle turret, modification of the Tundish. Car
and existing segments, augmentation of hydraulic systems including pipe
work, instrumentation & automation system and numerous attendant
changes for the Company to manufacture more demanding grades of
steel.
The slab casting machine has been specifically designed to cast high
quality slabs at higher yield, low cost and high productivity.
The machine is equipped to cast 215mm thick and 800-1550mm wide
slabs. No.1 caster is vertical mould caster and other two are curved
mould caster. Each bender strand has mould and a radius of 10m with a
support length of 29.75m. The vertical caster has a radius of 7.5m over
this length this slab is initially supported by mould followed by cooling
grids and then top and bottom rollers during solidification. The partly or
fully solidified curved slab is removed by continuous straightening
method prior to withdrawal and final solidification. Hot metal for casting
is supplied from converters via secondary steel making facilities. The

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charged ladle with steel in its optimum state is transported to position.
As the turret is rotated, the Tundish is driven over the mould from its
pre-heat station by a Tundish car. Ladle shroud is then fixed for
shrouding of ladle to Tundish stream. Once all “ready to cast” interlocks
are healthy, casting is started.
The mould is mounted on pivot arms supported from mould table
support frame and is water-cooled. This mould support frame also
locates and supports the top-zone. This is an important of machine as it
ensures correct relationship between mould, top-zone and strand guides.
The pivot arms carrying the mould are oscillated to improve surface
finish of slabs by means of oscillation.
As the slab emerges from mould, it is cooled by a mist-spray cooling
system. The cooling strand is guided down by various roller segments
following the caster radius along a curved path. The upper sections of
segments can be raised hydraulically and are held by means of hydraulic
cylinders against packers, which are pre-set to give required slab
thickness. Immediately following the strand guide segments is the
straightener segment. This segment is designed to continuously remove
the curvature of the strand as it passes through the segment.
From the straightener, slab passes into withdrawal unit which has 7
segments arranged horizontally to support the slab as it progresses
towards cut-off machine. As strand emerges from cast withdrawal rollers,
the dummy bar disconnect mechanism is activated. The slabs are cut
into lengths by oxygen/gas machine which is supported on rails. As the
predetermined length is sensed, the machine lowers on to the slabs and
travels with the slabs at casting speed. The twin burners mounted on
cross carriages, cut the slab from either end. The discharge roller table
then transports the slabs to the cross transfer area. The slabs are
marked online by an Al-spray marking machine on their way to the cross
transfer.
Some Benefits:
-low carbon steel
strains
d oscillation parameters by using VAI DYNAFLEX
hydraulic oscillation system.

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Continuous Casting
Continuous Casting is the process whereby molten steel is solidified into
a "semi-finished" billet, bloom, or slab for subsequent rolling in the
finishing mills. Prior to the introduction of Continuous Casting in the
1950s, steel was poured into stationary mould to form "ingots". Since
then, "continuous casting" has evolved to achieve improved yield, quality,
productivity and cost efficiency. It allows lower-cost production of metal
sections with better quality, due to the inherently lower costs of
continuous, standardized production of a product, as well as providing
increased control over the process through automation. Steel is the metal
with the largest tonnage cast by this process, although aluminium and
copper are also continuously cast.
In Continuous Casting molten metal is tapped into the ladle from
furnaces. After undergoing any ladle treatments, such as alloying and
degassing, the ladle is transported to the top of the casting machine.
Usually, the ladle sits in a slot on a rotating turret at the casting
machine; one ladle is 'on cast' while the other is made ready, and is
switched to the casting position once the first ladle is empty.
From the ladle, the hot metal is transferred via a refractory shroud to a
holding bath called a Tundish. The Tundish allows a reservoir of metal to
feed the casting machine while ladles are switched, thus acting as a feed
metal feed to the mould and cleaning the metal buffer of hot metal as
metal is drained from the Tundish through another shroud into the top
of an open-base copper mould. The depth of the mould can range from
0.5 m to 2 m, depending on the casting speed and section size. The
mould is water-cooled and oscillates vertically to prevent the metal
sticking to the mould walls. A lubricant can also be added to the metal in
the mould to prevent sticking, and to trap any slag particles — including
oxide particles or scale — that may still be present in the metal and bring
them to the top of the pool to form a floating layer of slag. Often, the
shroud is set so the hot metal exits it below surface of the slag layer in
the mould and is thus called a submerged entry nozzle (SEN). In the
mould, a thin shell of metal next to the mould walls solidifies before the
metal section, now called a strand, exits the base of the mould into a
spray-chamber; the bulk of metal within the walls of the strand is still
molten. The strand is immediately supported by closely-spaced, water

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cooled rollers; these act to support the walls of the strand against the
Ferro static pressure of the still-solidifying liquid within the strand. To
increase the rate of solidification, the strand is also sprayed with large
amounts of water as it passes through the spray-chamber. Final
solidification of the strand may take place after the strand has exited the
spray-chamber.
Important Components of Continuous Casting:
: Steel from the electric or basic oxygen furnace is tapped into a
ladle and taken to the continuous casting machine. The ladle is raised
onto a turret that rotates the ladle into the casting position above the
Tundish. Liquid steel flows out of the ladle into the Tundish. Ladle slide
gate valves are used for greater pouring accuracy, increased ladle hold
time, and safer and easier ladle preparation.
: The shape of the Tundish is typically rectangular, but delta
and "T" shapes are also common. Nozzles are located along its bottom to
distribute liquid steel to the moulds.
The Tundish also serves several other key functions:
 Enhances oxide inclusion separation
 Provides a continuous flow of liquid steel to the mould during ladle
Exchanges
 Maintains a steady metal height above the nozzles to the moulds,
thereby keeping steel flow constant and hence casting speed constant
as well.
 Provides more stable stream patterns to the mould.

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 Ladle shrouds are used for stream protection and reduction of steel re-
oxidation between ladle and Tundish.
: From the Tundish the molten metal enters
the mould through a shroud. Often, the shroud is set so the hot metal
exits it below surface of the slag layer in the mould and is thus called a
submerged entry nozzle (SEN).Submerged Entry Nozzles are used in the

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steelmaking process to prevent re-oxidation of the molten steel directly
from stream contact with the surrounding environment and from air
entrainment and splashing when the molten stream strikes the liquid
surface in the mould. Elimination of accretion formation and the
associated clogging of SENs will lead to increased strand speed, greater
time between changes of SENs, and reduced strand termination
incidence.
: The main function of the mould is to establish a solid shell
sufficient in strength to contain its liquid core upon entry into the
secondary spray cooling zone. Key product elements are shape, shell
thickness, uniform shell temperature distribution, defect-free internal
and surface quality with minimal porosity, and few non-metallic
inclusions. The mould is basically an open-ended box structure,
containing a water-cooled inner lining fabricated from a high purity
copper alloy. Mould water transfers heat from the solidifying shell. The
working surface of the copper face is often plated with chromium or
nickel to provide a harder working surface, and to avoid copper pickup
on the surface of the cast strand, which can facilitate surface cracks on
the product.
Mould oscillation is necessary to minimize friction and sticking of the
solidifying shell, and avoid shell tearing, and liquid steel breakouts,
which can wreak havoc on equipment and machine downtime due to
clean up and repairs. Friction between the shell and mould is reduced
through the use of mould lubricants such as oils or powdered fluxes.
Oscillation is achieved either hydraulically or via motor-driven cams or
levers which support and reciprocate (or oscillate) the mould.
: Segments are the set of rollers which helps the semi
solidified slabs to move from the mould to the torch cutting machine
through the guide rollers. Generally the rollers of the segments are in
taper form so that compression of the slab up to 3 meters is possible.
: Torch cutting machine is used to cut the
solidified slabs into desired length according to the demand. The torch
cutting machine in Tata Steel is supplied by GEGA.

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Commissioning Milestone of LD2 & Slab Caster
Equipment Month Year
Slab Caster 1 October 1993
Ladle Furnace 1 October 1993
Slab Caster 2 July 1994
LD Convertor 1 and GCP October 1994
LD Convertor 2 and GCP December 1994
DS Plant 1 June 1995
RH Degasser September 1996
Gas Recovery Of Convertor no. 1 March 1996
Gas Recovery Of Convertor no. 2 March 1996
Slab Caster 3 July 1998
DS Plant 2 August 1998
LD Convertor 3 October 1998
Ladle Furnace 2 February 1999
Slab Yard Management System April 1999
Gas Recovery Of Convertor no. 3 July 1999
Up gradation of Caster 1 - 2005
Up gradation of Vessel 1,2,3 - 2006-2007

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Introduction
EMBR Mold: EMBR stands for Electro Magnetic Braking.
It is a special kind of a mold quite similar to the conventional mechanical
(gear) mold in terms of physical appearance but hugely different from it
in the working aspect. A mold is a hollow container used to give shape
to molten or hot liquid material when it cools and hardens.
ELECTROMAGNETIC STIRRING AND
ELECTRO – MAGNETIC BRAKE For
CONTINUOUS CASTING
In order to continuously cast high quality steels for demanding purposes
electromagnetic stirring are a must for billets and blooms. Stirring will
improve strand quality, reproducibility, yield, production flexibility and
productivity. For each application the optimum stirrer choice can be

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made taking into account the steel grades cast, the strand sizes,
reduction ratio, etc. Optimizing the molten steel flow pattern is equally
important for slab casting, and here the electromagnetic brake is a
successful alternative to stirrers. Minimills with thin slab casting have
quickly become real competition to the integrated mills and today very
few integrated mills or conventional slab casters are being built or
planned. One of the remaining issues for the integrated mills has been
the steel quality, especially in terms of cleanliness and mold powder
entrapments. However, this situation has changed with the introduction
of the ElectroMagnetic BRake (EMBR) for thin slab casters.
EMBR MOLD is used for thin slab as well as conventional slab casters.
It is a prerequisite when:-
 Casting thin slabs with higher throughputs
 Aiming at higher quality segment.

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it facilitates nearly complete elimination of mold powder entrapments as
a result of reduced flow speed and turbulence.
It greatly improves coil surface quality and operates at relatively higher
speed than conventional steel casters.
It reduces mold copper wear, especially at higher casting speeds.
It reduces meniscus swelling resulting in a more even mold powder layer.
It increases productivity, product quality and lower operating costs.
 Reduced Mold Powder Entrapments-
Inclusions remain small and relatively harmless because of the Ca-
treatment of the steel. Because of this and the high casting speed
normally used for thin slabs, mold powder entrapments constitutes
the major source of detrimental non-metallic inclusions.
With EMBR, the lower meniscus flow speed and the turbulence results
in that mold powder entrapment will be nearly eliminated.
More than 90% of the non-metallic inclusions are eliminated.
 Improved Core Quality-
Higher speed of casting means low quality. When using an optimized
EMBR, the quality level at higher throughputs is improved.
The quality becomes equal or better to the quality level to that for
significantly lower casting speeds without EMBR.
 Reduced Meniscus Swelling-
The braking reduces the meniscus swelling close to the narrow mold
sides. The resulting flatter meniscus allows for a more even layer of
molten mold powder, thus improving lubrication and reducing the
risks of surface cracks.
 EMBR increases mold lifetime-
EMBR lowers the mold level fluctuation. Temperature cycling and
thermal fatigue of the copper plates are dramatically reduced.
Twice as more mold lifetime from casters using EMBR.
 Increases Steel Temperature at Meniscus-
Heat transfer from the middle of the mold to the solidification front is
reduced.

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Hot steel is not pushed down into the strand but kept up higher in the
mold, resulting in an increase of steel temperature at meniscus.
Components of EMBR Mold:-
 Wide and narrow plates
 Electromagnets
 Primary cooling system
 Lateral roll
 Spreading system
 Narrow plate cylinder
 Secondary cooling system
 Wide and narrow plates- EMBR mold consists of two narrow plates
and two wide plates arranged perpendicular to each other to create
a rectangular opening if seen from top.

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An EMBR mold. The left plate is the movable wide plate.
Wide plate
The distance between the wide plates implies the thickness of the
slab to be cast which is normally about 215 in
LD#2 Slab caster#1.
Narrow plates

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The distance between the narrow plates implies the width of the
slab.
The plates are coated with pure copper of thickness 40 mm on one
side which are further coated with nickel and cobalt for improving
the wear resistance of pure copper as pure copper is costly and
degrades every 450-600 heats (1 heat=160 tonnes). The thickness of
this nickel and cobalt coating increases from 0.5 mm at the top to 2
mm at the bottom of the plates.
The junction of the copper coating and the plates is connected to
thermocouples which indicates the temperature of that point in a
screen. Copper is an excellent conductor of heat and electricity,
hence the heat from the molten steel is transferred is transferred to
the thermocouple via the copper coating so that the temperature
and the flow of the molten steel could be monitored analytically.
The thermocouples are welded to their slots in the plates.
There are 4 rows and 11 columns in each of the wide plates while
the narrow plates have 4 rows and 2 columns each with a total of
104 thermocouples.
The narrow plates are kept inclined at an angle of 1.1-1.28 degrees
towards the lower portion so that the molten steel ,which goes on
solidifying and hence consequently decreasing in dimension upon
solidifying, does not just slip from in between the plates.
The movement of the narrow plates are very slow which is 0.8
m/min. Each narrow plate is connected to two servos, one at the
top and the other at the bottom, which facilitates its movement in or
out. In every round of command given to the servos the narrow
plates move by 12.5 mm. There are two methods of movement of the
narrow plates so that the molten steel which is solidifying remains
in a healthy position. These are:-
 S type
 H type,
Depending on the motion which is used to cause the movement.
The plates contain cut lines (as shown in the figure) to facilitate the
free circulation of water in the plates to keep the temperature
moderate and the plates cool as well as prevent the copper coating
from getting degraded.

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 Electromagnets- When molten steel is poured into the mold there
is a lot of turbulence in it which greatly tend to hamper the
properties of the steel which is being casted. Hence to obtain higher
grade and better quality steel the EMBR mold has electromagnets
which greatly tend to nullify this turbulence by developing a high
current electromagnetic field.
The electromagnets are attached to the wide plates and are totally 4
in number.
The control room screenshot of the electromagnets and its cooling
system/mechanism
There are two sets of coil on each of the wide plate or strand (visible
in the figure). There are two strands, namely:
 Strand 1 upper coil, and
 Strand 1 lower coil.
Each of the strands now further has two coils as we discussed
above.
Strand 1 upper coil has:
 Coil 11A
 Coil 11B

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Strand 1 lower coil has:
 Coil 12A
 Coil 12B
Each of the coils is water cooled continuously to maintain and
regulate the temperature. The water used here is a special kind of
water called “de mineralized water”. The properties of this cooling
system are as follows:
Inlet temperature = 41 °C (according to data)
Outlet temperature = 56, 59, 56, 60 °C (data for 4 coils)
Pressure = 6 bar
Flow rate = 200 l/min
Conductivity = 0.1360-1.418 µs/cm
The EMBR electromagnet will trip under the following conditions:
 When the inlet temperature is 48 °C or more than that, and
 When the conductivity>2 µs/cm. (it has to be less than 2 at all
times).
The current and voltage required to produce the electromagnetic
field is 560 Ampere and 180 volts respectively.
 Primary cooling system- Primary cooling system implies the
cooling of the plates. The wide and narrow plates bear an intense
amount of heat from the molten steel so the need to be cooled down.
This is also done to ensure the safety of the copper plates. The
water used in this system is soft water.
Soft water circulates in
 Wide plate at 4000 Lpm.
 Narrow plate at 550 Lpm
 Lateral roll- These are the rolls attached to the bottom of the mold
just below the plates to direct the solidifying steel towards the
bender and from where it proceeds on to the segments. These are
three in number. The average casting speed is 10218 m/min.
 Spreading system- It consists of 4 hydraulic cylinders. It is used
for increasing the thickness of the slabs as per requirement. One of
the wide plate is kept fixed while the other is movable to adjust the
thickness. These 4 cylinders are fixed at 4 corners of the fixed plate.

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One end of the cylinder is fixed at the fixed end where it is clamped
and declamped (ie. Cylinder movement off and on resp.). Upon
declamping a hydraulic oil of very high viscosity index (around 400)
is made to enter the cylinder at very high pressure. This applies
pressure on the piston and pushes it inwards and this piston
subsequently pushes the movable plate. The amount by which the
movable plate has to be moved depends on the amount of the
hydraulic oil made to enter the cylinder and is measured by a gauge
attached to it. When the appropriate thickness has been achieved
the cylinder is again clamped to make the movable plate static at
this new position.
 Narrow plate cylinder- there are 4 hydraulic cylinders placed in
the mold for the movement of the narrow plates. Each narrow plate
is attached to two cylinders, at the top and at the bottom.
These cylinders are connected to the servo valve and position
transducer. These receive the data from the operator and move the
narrow plates very slowly at the rate of 0.8 m/min.

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As seen in the figure, the servo valve is located in the leftmost box.
Attached to it on its right is the cylinder. The servo facilitates the
cylinder movement which is connected to the the narrow plate with
the help of a thread strand.
The main difference between the EMBR mold and other molds is
that here in EMBR molds the narrow plate’s movement is due to the
valves whereas in the normal molds it is due to the arrangement of
gears.
 Secondary cooling system- This refers to the cooling of the molten
steel to form a slab. The slab of steel that comes out of the mold is
molten from inside and solid from outside due to cooling. Since we
desire completely solid slab hence water is sprayed on to it from the

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moment the slab gets out of the mold till the very last segment
Secondary cooling system
The water used in this system is normal tap water and is sprayed on the
slab directly perpendicular it from a pipe whose ends are made flat in
order to make sure that they come out with force and cover the
maximum surface area.
If this is not present then the heat from the molten steel inside the
solidified shell will cause the shell to melt and ultimately leading to
breakout or bleeding.

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Problems
There are various problems in a steel caster. These are mentioned below
with their frequency of happening in the form of a graph:
Problem wise distribution of unplanned mold change
Mold changes in FY ’12 and FY ‘13
 Above plot shows various problems during operation of mold in a
slab caster.
 3 major problems with mold is Breakout, Ramming problem and
Slab Bulging which share almost 80% of total mold problems.
 Breakout is out of scope as research work is in progress for this
problem but it sure can be brought under control. How? We will
see this further in this project.
 My scope was to work for Corner Gap Elimination as it’s the
major cause for breakouts that take place in casters.
The biggest problem in a steel caster is that of breakout or bleeding.
Bleeding is a term used when the solid shell of the slab ruptures and
the molten metal flows out. This condition will keep out the caster
from running for a considerable amount of time.

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 When bleeding occurs all the steel that is in the mold flows out.
 Steel from the tundish and ladle also drains which amounts to the
spillage of more than 200 tonnes of steel.
 The segments also get damaged upon coming in contact with the
molten steel, thus creating more problems in terms of maintenance,
safety, reinstallation, etc.
 A major hazard could be sensed when the molten metal flows and
occupies positions in the lower areas and solidify there.
 Metal removal is yet another challenge that has to be faced.
In steel industry, ideally the caster is expected to be in the running
condition all the time, never stopping even for a minute until the
shutdown of the caster. Even if the caster stops for a minute it will be
termed as a loss because some amount of steel would have been casted
during that time. So when bleeding or breakout occurs one can very well
imagine the loss that the company faces.
Breakout/bleeding occurs due to the following reasons:
 Corner gap developed between the narrow and wide plates
 Coating problem/level fluctuations
 Improper calibration at various points
 Taper loss due to less or excessive angle of taper.

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Data Table 1

42. 42 | P a g e

43. 43 | P a g e
Data table 2
On analyzing the above data one can easily suggest that corner gap is
to be held accountable for more than half of the times when breakouts
have occurred.
Hence if corner gap issue is brought under control then productivity as
well as income will increase and the amount of loss would go down to
a huge extent.
Corner gap problem: Corner gap is the gap that is developed
between the two adjacent narrow and wide plates upon continuous
casting. Corner gap is essential in molds. It is so because the width
arrangement for the slabs is done by the movement of narrow plates
under the influence of the servo. Now if the adjacent narrow and wide
plates are in contact with each other giving zero corner gap then the
narrow plate, upon movement, would graze the copper coating of the
wide plates which is undesirable. Hence some amount of corner gap

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must be present in the mold but it must not increase so as to create
problems.
Ideally corner gap should be 0.6 mm at the top and 0.9 mm at the
bottom. At the bottom more corner gap is needed because of the
increasing thickness of nickel and cobalt coating as well as considering
the shrinkage of the slab upon its movement downward.
Corner gap
It was observed however that once the mold was put into position, in
caster, corner gap abnormally increased to more than 1 mm, thereby
causing breakouts.
The following fishbone diagram will explain the vaious factors responsible
for a high corner gap. This diagram considers almost every factor
responsible for its cause because in order to remove a problem every
thing must be taken care of.

45. 45 | P a g e

46. 46 | P a g e
Counter Measures

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Solution #1: Stopper modification
Since corner gap was a major issue it was tried to get under control by
adding an external stopnness over and above the four clamping bolts to
check the distance by which the loose plate can move. But it proved to
be ineffective. Increased Corner gap was tried to eliminate using stopper
in three ways:
PDCA 1:
PDCA 1: flexible due to cantilever design support

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Drawback : Not able to stop due to deflection.
PDCA 2:
PDCA 2: shims between two rigid stoppers
Drawback : able to stop but difficult to set 0.4 mm.
Wedge type stoppers with locking facility

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Solution #2: Mold and bender alignment
On the failure of stopper arrangements to control the increase in corner
gap, an alternate and reliable solution was needed.
The force required to compress high tensile Sa3O4 grade steel by 0.8 mm
was calculated. This force was too big for any usual explanation.
After that another aspect was looked upon- alignment of mold and
bender. Upon observation it was found that the foot rolls and the bender
rolls were not aligned properly.
ACTUAL REASON FOR THE OCCURRENCE OF CORNER GAP-
Due to ferrostatic force or misalignment forces, all looseness in entire tie
rod assembly and elongation of rod was responsible for loose plate to be
pushed back and create the gap.
Result
Hence the root cause of the problem was found out and appropriate
measures were adopted to avoid it. The frequency of breakout was greatly
reduced which is implied from the following data:-

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Total number down
The level difference of dark blue bar and the light blue bar indicates the
progress.
Thank You