This documentation deals with the all the processes and sub-processes undergoing in the newly installed department in Tata Steel ,i.e., LD3 & TSCR, mainly focussing on "Bleeding Breakout" problem in TSCR shop.

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VOCATIONAL TRAINING REPORT ON STUDY
OF BLEEDING BREAKOUT IN THIN SLAB
CASTER
19 DEC 2017 – 15 JAN 2018
SUBMITTED
BY
SHUBHAM THAKUR
VT20173125
DEPARTMENT OF METALLURGICAL & MATERIALS
ENGINEERING
NATIONAL INSTITUTE OF TECHNOLOGY, JAMSHEDPUR

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ACKNOWLEDGEMENT
I take this opportunity to express my profound gratitude and deep regards
to my guide Mr. TUSHAR for his exemplary guidance, monitoring and
constant encouragement throughout the course of this training .The help
and guidance given by him time to time shall carry me a long way in the
journey of life on which I am about to embark.
I also take this opportunity to express a deep sense of gratitude to my sub-
guides, Mr. RAVI SAHAY and Mr. RAVI VERMA, for their cordial support,
valuable information and guidance, which helped me in completing this
task.
Lastly, I am thankful to all the employees of LD3 and TSCR department in
TATA STEEL for answering my each query regarding the process of the
department. I am obliged to the staff members for the valuable information
provided by them in their respective fields I am grateful for their
cooperation during the period of my training.
SHUBHAM THAKUR
VT20173125
NIT JAMSHEDPUR

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CONTENTS
TOPICS…………………………………………………….Page Nos.
TATA STEEL An Introduction……………………………………………...4-5
What is steel?.........................................................................................6-7
What is steel production?......................................................................7
How a steel plant works………………………………………………..........8
How is steel produced?..........................................................................8-9
LD SHOP DESCRIPTION……………………………………………………...10
LD#3 and TSCR Shop Process………………………………………………11
Overview of LD#3 & Thin Slab Caster………………………………………12-17
CONTINUOUS CASTING AT LD#3 TSCR…………………………………...18-22
PROBLEMS IN CONTINUOUS CASTING…………………………………...23-24
TATA STEEL INVESTIGATION REPORT ON BLEED BREAKOUT……..25-31
CONCLUSION……………………………………………………………………32
REFERENCES…………………………………………………………………...33

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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 23.88 MTPA (in FY17). 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 million
tonnes has transformed into a global giant, thereby becoming the second largest
steel company in India (measured by domestic production) with an annual
capacity of 13 million tonnes after SAIL.
J.N.Tata - The Founder An overview of TATA STEEL
Tata Steel plans to grow & globalize through organic & inorganic routes. Its 6.08
MTPA Jamshedpur works plans to 10 MTPA 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, Tata Steel has created a manufacturing and

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marketing network in Europe, South 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 has set a target of achieving an annual production capacity of 100
million tons by 2015; it is planning for capacity expansion to be balanced roughly
50:50 between greenfield developments and acquisitions. Overseas acquisitions
have already added an additional 21.4 million tonnes of capacity, including Corus
(18.2 million tonnes), NatSteel (2 million tonnes) and Millennium Steel (1.2 million
tonnes). Tata plans to add another 29 million tonnes of capacity through
acquisitions.
Tata Steel’s vision is to be the global steel industry benchmark for “Value
Creation and Corporate Citizenship”.

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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
aluminium. Alloying elements are intentionally added to modify the characteristics
of steel include : manganese, nickel, chromium, molybdenum, boron, titanium,
vanadium and niobium.
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 casting. 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.
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,

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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.
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.
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 works?
A plant has many needs for it to grow. The most important are : carbon,
hydrogen, 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,
the iron ore is reduced or smelted with coke and limestone in a blast furnace,
producing molten iron which is 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
as manganese, 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 produced?
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.
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%."
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-

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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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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#3 and TSCR Shop :
The main units of LD#3 and TSCR Shop are :
1. Hot metal receiving and handling.
2. Desulphurization.
3. Basic oxygen furnace.
4. Online purging.
5. Ladle furnace.
6. Gas cleaning plant.
7. Secondary emission plant.

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LD#3 and TSCR 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 sulfur 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
Donawitz 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”.
 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 slabs.

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Overview of LD#3 & Thin Slab Caster
1.) LD#3 and TSCR :
LD3 and TSCR is the third steel melting shop at the Jamshedpur works and the
second dedicated to Flat Products. A unique feature of this steel melting shop is
that it integrates a Thin Slab Caster and a Rolling mill (a new energy efficient
'Compact Strip Processing' technology) with the upstream LD3 steel making
facility. The first strand was commissioned in February 2012 and the two strand
operations started working simultaneously from the beginning of December 2012.
In Financial Year 2012-13, the TSCR plant achieved 1 million tonnes of slab
production, registering higher yield and producing higher value products.
The details of hot metal handling system are :
 Hot Metal Receiving : The input Hot Metal comes from Furnaces A, B, C,
D, F, G, H & I in torpedo ladles of 220 tons.
 Torpedo Area : 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.

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 Hot Metal Desulphurization : Initially BF Slag is raked of with the help of
raking machine. Then desulphurization 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. Sulfur 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.
 Converter : 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.
Steel in the ladle now is taken for further secondary metallurgical processing in
SMLP (Secondary Metallurgical Ladle Processing) shop mentioned below.
 Direct Route : Direct route of steel making is mentioned :
 Converter-OLP-LF-Caster (100% Heats)
 Ladle Furnace : 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 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.) Thin Slab Caster :
For the production of flat products, liquid steel is generally cast in form of slabs in
continuous slab casting machines. These slabs are inspected, scarfed and then
reheated in slab reheating furnace to the rolling temperatures before being rolled
to hot rolled coils in a semi continuous or continuous hot strip mill. Development
of thin slab casting and rolling (TSCR) is a step forward to reduce the number of
process steps in the production of hot rolled coils (HRC). Originally TSCR
technology was developed with the primary goal of reducing the production and
investment costs but today it has become one of the most promising production
routes to maintain steel as a leading material in technological application and it is
being considered as the technology which has reached a high degree of maturity.
Casting speed of 6.0 m/min for slab thickness of 50/55 mm is quite common.
Initially, only commercial quality plain carbon steels were being cast through thin
slab caster route. But presently most of the steel grades including low, medium &
high carbon, HSLA line pipe grades and steel grades for automotive application
including IF grades can be cast through thin slab caster route. In fact this
technology has brought paradigm shift in steel technology of casting and rolling.
Scheme of Compact Steel Production process
The thin slab casting and rolling technology was made possible because of the
following improvements in casting and rolling processes.
 Design of mould
 Hydraulic mold oscillations
 Use of electromagnetic brakes (EMBR)
 Use of high pressure descaler and roller side guide (edger) in the mill

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 Dynamic liquid core reduction (LCR)
 Mold powder quality and redesigned SEN
 Water spray cooling
Typical level of temperature evolution during TSCR process
The liquid steel after steel making is teemed into the tundish of the continuous
casting machine. The steel is cast into slab of the desired thickness of 50-70 mm
and width of about 900-1680 mm. The slab is then sheared to the proper length
and transported to the tunnel or equilibrating furnace normally set at a
temperature of 1150 deg C. At this point, the slab exhibits an austenite grain size
of 500-1000 microns. After the 20 minute residency time in the furnace the slab
exits the furnace and is crop sheared. The hot thin slab then enters the finishing
mill at approximately 1000 deg C. The slab is rolled into hot strip as it passes
through the finishing mill of 5, 6 or even 7 stands. The hot strip after rolling enters
the run out table (ROT) where it undergoes cooling to the coiling temperature. It
is then coiled to room temperature.
Metallurgical Features of TSCR Process :
1. Rapid solidification of the thin slab refines the dendritic structure and
contributes to greater homogeneity.
2. Non-metallic inclusions are small and globular, retain their shape during
hot-rolling and contribute to isotropic properties (toughness, bendability).

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3. All added micro-alloying elements remain in solution. Because of the high
temperature of the cast slab prior to hot rolling, premature precipitation is
avoided.
4. To minimize the difficulties of casting in the peritectic region, the carbon
content of many micro-alloyed steels is restricted to between 0.05% and
0.06%. This restriction benefits toughness and weldability.
5. The high temperature of the slab during bending and unbending minimizes
the tendency to form transverse cracks.
6. The temperature in the equilibrating furnace depends on the micro-alloying
element and is designed to keep the micro-alloy in solution.
7. Direct charging is the main factor that reduces energy consumption during
hot rolling.
8. In rolling thin slabs, the deformation in the initial passes often exceeds
50%. Heavy deformation at high temperatures is essential to refine coarse
(over 1000 microns) austenitic grains by re-crystallization.
9. The refinement and uniformity of austenitic grains is a prerequisite for a
fine ferritic structure down to 4 to 5 microns.
Some Benefits :
1.) Reduction in capital cost.
2.) Reduction in manpower.
3.) Reduction in floor space required.
4.) Improvement in the yield of finish product from liquid steel.
5.) Reduction in the specific fuel consumption.
6.) Reduction in the specific power consumption.

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CONTINUOUS CASTING AT LD#3 TSCR
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

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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 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 :
 Ladle
 Tundish
 Submerged Entry Nozzle(SEN)
 Mould
 Segments
 Pendulum Shear
 Ladle : 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 so-called butterfly 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.

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 Tundish : 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.
 Ladle shrouds are used for stream protection and reduction of steel
re-oxidation between ladle and Tundish.
 Submerged Entry Nozzle(SEN) : 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 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.
 Mould : 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.

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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 : 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.
 Pendulum Shear : A pendulum shear for a continuous casting installation
wherein the shear is provided with a mechanical drive for a pulse-like
cutting operation, a knife or cutter rigidly connected with the pendulum and
movable by a driven crank towards a second knife. Further, there is
provided mechanism for accelerating the pendulum out of its rest position
at approximately the maximum knife opening in the direction of travel of
the strand, this mechanism, prior to the cutting operation, accelerating the
pendulum at its cutting region to a speed approximately corresponding to
the speed of travel of the strand. The mechanism for the acceleration of
the pendulum consists of a guide arranged at the stand or housing and
guides the pendulum along its path between the rest position and the start
of the cutting operation, and the cooperation of this guide with the
pendulum moved by the crank controls such acceleration.

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PROBLEMS IN CONTINUOUS CASTING
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 :
1.) Above plot shows various problems during operation of mold in a thin slab
caster. 3 major problems with mold is Breakout, Ramming problem and Slab
Bulging which share almost 80% of total mold problems.
2.) My scope was to give a deep emphasis towards the bleeding breakout
problem in thin slab caster.
3.) Lets understand breakout first :
Breakouts are one of the biggest problems encountered during continuous
casting of steel slabs. Slabs get cracked locally or break completely in two parts
during solidification causing the liquid part of the partially solidified billet to empty
inside the cooling chamber. Proper control of important parameters is necessary
to avoid break outs during continuous casting. In the present work, the nature of
the break outs at LD#3 & TSCR at Tata Steel was studied. Data analysis was
also done for certain casting parameters and the Sulphur tracer test was
conducted to understand solidification in the mould. It was found that to reduce

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the occurrence of breakouts, it was necessary to tune the operations based on
the grade being cast and the design of the mould tube being used.
A break out during the continuous casting process is a rupture of the partially
solidified shell inside the secondary cooling chamber, causing the contained
liquid steel to spill out. In the mid 1970s while continuous casting technology was
still in early stage of development, causes of breakouts was not well understood.
Today, with technological development much has been understood about
breakouts but, most of the understanding has been in the slab casting process
wherein due to the higher level of instrumentation, a lot of information has been
gained. In thin slab casting however, due to the geometry of the mould housing
with the tube mould, multiplied by the complexity of the multiple strands,
instrumentation has not been used and obtaining data for analysis has been
difficult.
In order to understand the phenomenon, data of the types of break outs taking
place was collected accompanied by physical inspection of the break out pieces.
This was done for a five month period. It was found that bleeding breakout has
taken place.

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TATA STEEL INVESTIGATION REPORT ON BLEED BREAKOUT
Caster: 1 Date: 8/1/2017 Shift-B Time of B/O: 16:15 hrs Group: RAVI SAHAY
Machinein charge- RAVI VERMA Controller-P.SURESH
Abnormality:Bleedingbreakout from Loose left
Heat Information: Heat ID: T84977 Grade: SE110 Heat in sequence: L+16 Section: 1155mm.
Sample ID Plant Unit C(%) Mn(%) S(%) P(%) Si(%) Al(%) Alsol(%) N (PPM) Ca (PPM)
BAT1 B1 .063 0.026 0.015 0.020 0.0051 1.27 1.1814 27 5.31
OLP1 A1 0.045 0.41 0.010 0.020 0.0048 0.066 0.062 42
LDF1 L2.1 0.045 0.50 0.004 0.018 0.070 0.055 0.053 47 0.3
LDF2 L2.1 0.050 0.54 0.002 0.018 0.066 0.042 0.040 52 43.0
TND1 0.051 0.55 0.0022 0.018 0.064 0.038 0.036 56 29.0
TND2 0.052 0.54 0.0022 0.018 0.066 0.038 0.036 58 24.0
LF Slag Analysis :
Basicity
2.61
Fe+MnO
1.27
CaO
56.37
SiO2
5.44
P2O5
0.0162
Al2O3
30.77
MgO
4.02
MnO
0.14
S
0.64
TiO2
0.06
Ladle History:
ladle no-14,Tap Temp-1658,Tap time-14:01,LF Treatment time-43.96,Lifting temp-1581
Tundish Information:
Tundish car : 02 SRM no.: 7 Td No.: 08 Td heating
duration : 135
SEN heating
duration :
125mins.
Td wt. : 29
Stopper position : Initial/ final position :
(hot zeroing)-48.7
SEN Type
:R3
Tundish deviation :
1mm.
Ramping Position :
50mm
Mould Information:
Mould no. :
04
Plate
ID
Life Thickness Life after
m/c
Flow
(l/min)
Delta T Heat Flux
(Mw/m^2)
HF (ratio)
BF Fix 7176 44 20.30 5871 8.39 2.8
BF Loose 7173 44 20.00 5873 8.47 2.8
NF Left 7423 44 14.62 9.45 2.1 79
NF Right 7606 44 14.64 10.10 2.1 77
Mould width ( topcold) : 1188mm1182
Taper : 2.9/2.9
MLF: NO Stopper rise : No

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MCW Inlet temp :34.59 BPS Slowdown : YES Mould fillingtime :20.3
Casting Parameter: Casting Powder: BC9GERMANY
Mould level
70
Superheat
23,22
Tundish
weight
29t
Casting
speed
5.85mpm
LD wt
47t
BUA current
27/30/28
WSA
Current
24/21/24
LCR
60MM
Spray water parameter:
Cooling
curve
07
Inlet temp. 34.3 deg C
Zone Set point Actual
flow
Pressure
1 346 345 10.37
2 3144 3144 14.8
3 1602 1530 17.6
3.1 368 369 4.36
3.2 169 165 .81
Observations:
 Superheat -23 C
 Heat flux ratio was in the range of 77 % to 81%.
 Tundish deviation was 1mm and ramping position 50mm.
 No reblow and top lance used in this heat.
 Ladle open at 26t of tundish weight at 3.35pm, and B/O at 4:15pm
 Top row TCs were fluctuating in all 4 corners.
 Slowdown also occurred in previous heat.
Action point:
1. Bleeding breakout logic needs to be implemented.

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Breakout Location:
Loose left side.
Mould level and stopper Position trend
Loose side
R L

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HEAT FLUX & HEAT FLUX RATIO

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No abrupt rise or low observed in heat flux
30mins back

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MMS Observations-
BEFORE BREAKOUT

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MMS OBSERVATION
AFTER BREAKOUT

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CONCLUSION
Engineering students gain mass theoretical knowledge from books. It is volatile
and not much of use without knowing its practical implementation.
Vocational Training is one of the most important aspects for an engineering
student’s career in strengthening his/her practical concepts. It was an really an
awesome experience in training as the things we all learnt in our previous year
was observed in a broader sense and also seen implemented practically. We got
to see live performing machines like LD Converter, Thin Slab Caster and their
main units. We were able to interact with the department’s working environment.
A deep emphasis was given to the concerned matter in LD#3 TSCR, i.e., solution
for problem of frequent breakouts occurring within the continuous casting
process. Though breakout is out of scope as research work is in progress for this
problem but it is sure that it can be brought under control.
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. 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. So our
scope was to provide a good amount of time towards the study of bleeding
breakout, and it was possible only by the assistance of my guide, sub-guides,
and all other employees of LD#3 TSCR. Once again thanks to everyone!!

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REFERENCES
 Mould powders for high speed continuous casting of steel : Jan Kromhout
 Fundamentals of Steelmaking : E. T. Turkdogan
 Secondary Steelmaking by R.K. Jha
 An Introduction to Modern Steel Making by R.H. Tupkary
 https://en.wikipedia.org/wiki/Continuous_casting
 ispatguru.com/thin-slab-casting-and-rolling/
 ispatguru.com/breakouts-during-continuous-casting-of-liquid-steel/