Uis Report

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UPPER INDIAN STEEL LTD.

STEEL MAKING PLANT

Submitted to:- Submitted by:-Mechanical Deptt. Mukesh Kumar Yadav Roll No. - 7534

Mech. 7th Sem.

CH. DEVI LAL MEMORIALENGG.COLLEGE PANNIWALA

MOTA, SIRSA

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ACKNOWLEDGEMENT

It would be prudent to commence this report with an expression ofgratitude towards all those who have played an indispensable role in

the accomplishment of this report by providing their valuableguidance. For todays professional student, industrial training is very

essential, I was quite lucky to have some practical training at UPPERINDIAN STEELS.

I sincerely thank Mr. RAJESH YADAV(GM of SMSdepartment) for giving me precious guideline to make this project.

I am very much thankful to Mr.J.P.JOLLY(GM of RollingDepartment)who has given all possible support and guidance for

the completion of this report.

I take this opportunity to express my gratitude to my project guide

Mr.Jagmann (GM of Perssonal Department) and

Mr.Sanjeev Sharma (GM of QAD department) who guidedme time to time to complete my summer training . Their constant

motivation & professional approach towards me was the main drivingforce for me.

Last but not the least I would like to thank our worthy director,

Mr.RAJIV SHARMA for motivating us at each step.

Mukesh Kumar Yadav Mech. 7th Sem.

Roll No. - 7534

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TABLE OF CONTENTS

1. HISTORY

2 .SMS(STEEL MELTING SHOP) SCRAP/RAW MATERIAL

EAF(ELECTRIC ARC FURNACE)

FURANCE FINISHING MELTING REFINING DE-SLAGING TAPPING TEMP. SAMPLING PROCESS

COLLING SYSTEM FURNACE HEAT BALNANCE CARBON INJECTION FURNACE TURN AROUND

LRF(LADLE REFINING FURANCE) VD(VACUUM DEGASSING)

3. CONCAST4. QAD(QUALITY ASSURANCE DEPARTMENT)

5. ROLLINGa. COLD WORKINGb. HOT WORKING

6. FINISHING

SAFETY

DIFFERNCE BETWEEN IRON AND STEEL

REFERENCES

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Company History

YEARS AND EVENTS

1964

- The company was incorporated on 7thJanuary,under the name ofUpper Indian Steel Metal Industries Private Limited for themanufacture ofcold rolled steel strips and steel ingots at Focal Pointin Ludhiana(Punjab).

1989

- The company undertook the setting up of a new plant for themanufacture of wide width Cold Rolled Steel Strips with integratedplant facilities.-The company became a deemed public limited company underSection 43-A(I-A) of the Companies Act, 1956 with effect from 14 th

July.

1993

- The company made its maiden Public Issue of 22 lac equity sharesof Rs.10 each at a premium of Rs.55 share aggregating Rs. 1430 lacsin September/October.

- The shares of the company were listed on the Delhi Stock Exchangeon 22nd December consequent to which the company became awidely held listed public limited company.- The Company allotted 26,43,600 No. of Equity Shares of Rs.10 eachat a premium of Rs.55 per share on 3rd December.

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1994

- The galvanising plant was commissioned in January. Presently thecompany has facilities for the manufacture of 1,20,000 tonnesper'annum ofwide width cold rolledsteel strips.

- The Company proposes to set up a new plant for manufacture of 1.5lac tpa of wide width CRCA Coils with further integration by way of40,000 tpa of Galvanised Sheets at an adjacent/contiguous location tothe existing plant facilities at Sahibabad Industrial Area, Distt.Ghaziabad in Uttar Pradesh.

1995

- The Cold Rolling Expansion the Company is installing state of the art

1600mm width 6HI combination Universal Crown Mill (UCM) of Hitachi,Japan with sophisticated features for shape control and surface finishto cater to the requirements of the automobile and white goodssector.

- The Company offered a Right Issue of 82,50,000 Unsecured Zerolnterest Convertible Debentures aggregating Rs. 5362.50 lacs withDetachable Warrants which was well received by the shareholders

and was over subscribed.- The Company also made a Public Issue of 68,94,800 - 14%Unsecured Fully Convertible Debentures aggregating Rs. 16750 Lacsincluding firm allotment of 20,24,800 Debentures aggregating Rs.5062 Lacs.

- Upper Indian Capital & Credit Services Ltd. and Jawahar Credit &Holdings Ltd. are subsidiaries of the Company.

1996

- The Part B of 68,94,800 14% unsecured fully convertible Debenturesaggregating Rs 8375 Lacs have been converted into Equity Sharesw.e.f. 1st April.

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1998

- With the commissioning of the new plant recently set up atcompany's existing site at Sahibabad (UP), the company is nowexploring furthergrowth possibilities of setting up a modern Cold Rolling cumGalvanizing Unit at West Coast of the Country.

- The Delhi-based Upper Indian Steel and Strips Ltd to setup twosteelcold rolling and galvanising units - one near Haldia and the other atPatalganga, near Mumbai.

- The Rs.800-crore Upper Indian Steel has commissioned a cold rolledsteel plant at Ghaziabad, in collaboration with Sumitomo of Japan,which will cater to the needs of the automotive sector.

1999

- During the year, the company has set up a dedicated service centrefor large OEM customers at Sahibabad so as to ensure supplies to

them on 'just in time'concept.

2000

- The Delhi-based Upper Indian Steel and Strips' to set up a Rs 750crore cold rolled steel plant is likely to hit a road block.- The company has proposed to set up a steel plant with a 2.8 m t p.acapacity on 5,000 acres of land in a two-phase programme.

- Upper Indian Steel & Strips is to set up Rs 4,000 crore, 2.5 milliontonne hot-rolled coil steel plant.

- The company is also exploring possibility of raising funds throughthe GDR and ADR route.- The Board has approved amalgamation of Upper Indian Ltd. With thecompany and setting up project of 2,50,000 tpa Cold Rolled Productsin Maharashtra.

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2002-Strikes an important position in the market for cold rolled steelfor automobiles, feeding over 70% of demand for car bodies.

2003-Enters into a strategic alliance with Sumitomo Metal Industries ofJapan under which, the latter has further extended process know-howfor the manufacture of automotive steel sheets for a period of sixyears

-Board approves the setting up of Hot Rolled Coil Project in Orissa-Sanjay Singal resigns as Managing Director of the company

2004-Upper Indian Steel awards Rs 36 cr order for BHEL

-Delists shares from Ahmedabad and Delhi Stock Exchanges

2006

Upper Indian Steel & Strips Ltd has informed that Sh. Sanjay Singal,has ceased to be a Director of the Company w.e.f. October 18, 2006.

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UPPER INDIAN STEEL uses state-

of-the-art technology to maximize

efficiency...

From the scrap yard through shipping, UPPER INDIAN STEEL usesstate-of-the-art technology to maximize efficiency, quality andsafety.

UPPER INDIAN STEEL uses steel scrap as the main raw material forour Electric Arc Furnace in the melt shop. From there, the liquid steelis refined in the Ladle Refining Furnace (LRF). After refinement, thesteel is transferred to our continuous Caster and molded into billets.

After reheating, the billets are processed into finished hot rolledsections in the in-line Rolling Mill. Finally, the rolled product isconveyed to the Finishing department for any additional processing,storage and shipment.

The UPPER INDIAN STEEL Trucking, Garage, Maintenance andEngineering departments round out the team, providing outstandingsupport for the production areas.

Throughout the process, we place safety first. And we make every effortto keep our equipment current and our staff up-to-date on alladvancements in the steel industry. It's how we grow and succeed.

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Number of stages included:-

1) SMS (Steel Melting Shop)

Scrap EAF(Electric Arc Furnace)

LRF(Laddle Refining Furnace)

VD(Vacuum Degassing)

Injection of the CaSi2) Concast3) QAD (Quality Assurnace Department)4) Rolling5) Finishing

1. SMS (Steel Melting Shop):-

Scrap: A Renewable Resource

UPPER INDIAN Steel Texas is one

of the largest recyclers in thestate of Texas. Steel scraparriving at our plant is subjectedto radiation testing to ensure thatno radioactive material entersinto the manufacturing process.

It is then sorted according to

type and characteristics, andprepared so that it may becharged into the furnace in the mixrequired for the product beingmanufactured.

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Electric Arc Furnace Steel making

FURNACE OPERATIONS

The electric arc furnace operates as a batch melting processproducing batches of molten steel known "heats". The electric arcfurnace operating cycle is called the tap-to-tap cycle and is made upof the following operations:

Furnace charging

Melting Refining De-slagging Tapping

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Furnace Charging

The first step in the production of any heat is to select the grade ofsteel to be made. Usually a schedule is developed prior to eachproduction shift. Thus the melter will know in advance the schedulefor his shift. The scrap yard operator will prepare buckets of scrap

according to the needs of the melter. Preparation of the chargebucket is an important operation, not only to ensure proper melt-inchemistry but also to ensure good melting conditions. The scrapmust be layered in the bucket according to size and density topromote the rapid formation of a liquid pool of steel in the hearthwhile providing protection for the sidewalls and roof from electric arcradiation. Other considerations include minimization of scrap cave-ins which can break electrodes and ensuring that large heavy piecesof scrap do not lie directly in front of burner ports which would result

in blow-back of the flame onto the water cooled panels. The chargecan include lime and carbon or these can be injected into the furnaceduring the heat. Many operations add some lime and carbon in thescrap bucket and supplement this with injection.

The first step in any tap-to-tap cycle is "charging" into the scrap. Theroof and electrodes are raised and are swung to the side of thefurnace to allow the scrap charging crane to move a full bucket ofscrap into place over the furnace. The bucket bottom is usually aclam shell design - i.e. the bucket opens up by retracting two

segments on the bottom of the bucket. The scrap falls into thefurnace and the scrap crane removes the scrap bucket. The roof andelectrodes swing back into place over the furnace. The roof islowered and then the electrodes are lowered to strike an arc on thescrap. This commences the melting portion of the cycle. The numberof charge buckets of scrap required to produce a heat of steel isdependent primarily on the volume of the furnace and the scrapdensity. Most modern furnaces are designed to operate with aminimum of back-charges. This is advantageous because charging is

a dead-time where the furnace does not have power on andtherefore is not melting. Minimizing these dead-times helps tomaximize the productivity of the furnace. In addition, energy is lostevery time the furnace roof is opened. This can amount to 10 - 20kWh/ton for each occurrence. Most operations aim for 2 to 3 bucketsof scrap per heat and will attempt to blend their scrap to meet thisrequirement. Some operations achieve a single bucket charge.Continuous charging operations such as CONSTEEL and the FuchsShaft Furnace eliminate the charging cycle.

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Melting

The melting period is the heart of EAF operations. The EAF hasevolved into a highly efficient melting apparatus and modern designsare focused on maximizing the melting capacity of the EAF. Melting isaccomplished by supplying energy to the furnace interior. This

energy can be electrical or chemical. Electrical energy is supplied viathe graphite electrodes and is usually the largest contributor inmelting operations. Initially, an intermediate voltage tap is selecteduntil the electrodes bore into the scrap. Usually, light scrap is placedon top of the charge to accelerate bore-in. Approximately 15 % of thescrap is melted during the initial bore-in period. After a few minutes,the electrodes will have penetrated the scrap sufficiently so that along arc (high voltage) tap can be used without fear of radiationdamage to the roof. The long arc maximizes the transfer of power to

the scrap and a liquid pool of metal will form in the furnace hearth Atthe start of melting the arc is erratic and unstable. Wide swings incurrent are observed accompanied by rapid movement of theelectrodes. As the furnace atmosphere heats up the arc stabilizesand once the molten pool is formed, the arc becomes quite stableand the average power input increases.

Chemical energy is being supplied via several sources including oxy-fuel burners and oxygen lances. Oxy-fuel burners burn natural gasusing oxygen or a blend of oxygen and air. Heat is transferred to the

scrap by flame radiation and convection by the hot products ofcombustion. Heat is transferred within the scrap by conduction.Large pieces of scrap take longer to melt into the bath than smallerpieces. In some operations, oxygen is injected via a consumable pipelance to "cut" the scrap. The oxygen reacts with the hot scrap andburns iron to produce intense heat for cutting the scrap. Once amolten pool of steel is generated in the furnace, oxygen can belanced directly into the bath. This oxygen will react with severalcomponents in the bath including, aluminum, silicon, manganese,

phosphorus, carbon and iron. All of these reactions are exothermic(i.e. they generate heat) and supply additional energy to aid in themelting of the scrap. The metallic oxides that are formed will end upin the slag. The reaction of oxygen with carbon in the bath producescarbon monoxide, which either burns in the furnace if there issufficient oxygen, and/or is exhausted through the direct evacuationsystem where it is burned and conveyed to the pollution controlsystem. Auxiliary fuel operations are discussed in more detail in thesection on EAF operations.

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Once enough scrap has been melted to accommodate the secondcharge, the charging process is repeated. Once the final scrapcharge is melted, the furnace sidewalls are exposed to intenseradiation from the arc. As a result, the voltage must be reduced.Alternatively, creation of a foamy slag will allow the arc to be buriedand will protect the furnace shell. In addition, a greater amount ofenergy will be retained in the slag and is transferred to the bathresulting in greater energy efficiency.

Once the final scrap charge is fully melted, flat bath conditions arereached. At this point, a bath temperature and sample will be taken.

The analysis of the bath chemistry will allow the melter to determinethe amount of oxygen to be blown during refining. At this point, themelter can also start to arrange for the bulk tap alloy additions to bemade. These quantities are finalized after the refining period.

RefiningRefining operations in the electric arc furnace have traditionallyinvolved the removal of phosphorus, sulfur, aluminum, silicon,manganese and carbon from the steel. In recent times, dissolvedgases, especially hydrogen and nitrogen, been recognized as aconcern. Traditionally, refining operations were carried out followingmeltdown i.e. once a flat bath was achieved. These refining reactionsare all dependent on the availability of oxygen. Oxygen was lanced at

the end of meltdown to lower the bath carbon content to the desiredlevel for tapping. Most of the compounds which are to be removedduring refining have a higher affinity for oxygen that the carbon. Thusthe oxygen will preferentially react with these elements to formoxides which float out of the steel and into the slag.

In modern EAF operations, especially those operating with a "hotheel" of molten steel and slag retained from the prior heat, oxygenmay be blown into the bath throughout most of the heat. As a result,some of the melting and refining operations occur simultaneously.

Phosphorus and sulfur occur normally in the furnace charge in higherconcentrations than are generally permitted in steel and must beremoved. Unfortunately the conditions favorable for removingphosphorus are the opposite of those promoting the removal ofsulfur. Therefore once these materials are pushed into the slagphase they may revert back into the steel. Phosphorus retention inthe slag is a function of the bath temperature, the slag basicity andFeO levels in the slag. At higher temperature or low FeO levels, the

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phosphorus will revert from the slag back into the bath. Phosphorusremoval is usually carried out as early as possible in the heat. Hotheel practice is very beneficial for phosphorus removal becauseoxygen can be lanced into the bath while its temperature is quitelow. Early in the heat the slag will contain high FeO levels carriedover from the previous heat thus aiding in phosphorus removal. Highslag basicity (i.e. high lime content) is also beneficial for phosphorusremoval but care must be taken not to saturate the slag with lime.

This will lead to an increase in slag viscosity, which will make theslag less effective. Sometimes fluorspar is added to help fluidize theslag. Stirring the bath with inert gas is also beneficial because itrenews the slag/metal interface thus improving the reaction kinetics.

In general, if low phosphorus levels are a requirement for a particularsteel grade, the scrap is selected to give a low level at melt-in. Thepartition of phosphorus in the slag to phosphorus in the bath ranges

from 5 to 15. Usually the phosphorus is reduced by 20 to 50 % in theEAF.

Sulfur is removed mainly as a sulfide dissolved in the slag. The sulfurpartition between the slag and metal is dependent on slag chemistryand is favored at low steel oxidation levels. Removal of sulfur in theEAF is difficult especially given modern practices where the oxidationlevel of the bath is quite high. Generally the partition ratio isbetween 3 and 5 for EAF operations. Most operations find it moreeffective to carry out desulfurization during the reducing phase of

steelmaking. This means that desulfurization is performed duringtapping (where a calcium aluminate slag is built) and during ladlefurnace operations. For reducing conditions where the bath has amuch lower oxygen activity, distribution ratios for sulfur of between20 and 100 can be achieved.

Control of the metallic constituents in the bath is important as itdetermines the properties of the final product. Usually, the melter willaim at lower levels in the bath than are specified for the final product.

Oxygen reacts with aluminum, silicon and manganese to formmetallic oxides, which are slag components. These metallics tend toreact with oxygen before the carbon. They will also react with FeOresulting in a recovery of iron units to the bath. For example:

Mn + FeO = MnO + Fe

Manganese will typically be lowered to about 0.06 % in the bath.

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The reaction of carbon with oxygen in the bath to produce CO isimportant as it supplies a less expensive form of energy to the bath,and performs several important refining reactions. In modern EAFoperations, the combination of oxygen with carbon can supplybetween 30 and 40 % of the net heat input to the furnace. Evolutionof carbon monoxide is very important for slag foaming. Coupled witha basic slag, CO bubbles are tapped in the slag causing it to "foam"and helping to bury the arc. This gives greatly improved thermalefficiency and allows the furnace to operate at high arc voltageseven after a flat bath has been achieved. Burying the arc also helpsto prevent nitrogen from being exposed to the arc where it candissociate and enter into the steel.

If the CO is evolved within the steel bath, it helps to strip nitrogenand hydrogen from the steel. Nitrogen levels in steel as low as 50ppm can be achieved in the furnace prior to tap. Bottom tapping is

beneficial for maintaining low nitrogen levels because tapping is fastand a tight tap stream is maintained. A high oxygen potential in thesteel is beneficial for low nitrogen levels and the heat should betapped open as opposed to blocking the heat.

At 1600 C, the maximum solubility of nitrogen in pure iron is 450ppm. Typically, the nitrogen levels in the steel following tapping are80 - 100 ppm.

Decarburization is also beneficial for the removal of hydrogen. It has

been demonstarted that decarburizing at a rate of 1 % per hour canlower hydrogen levels in the steel from 8 ppm down to 2 ppm in 10minutes.

At the end of refining, a bath temperature measurement and a bathsample are taken. If the temperature is too low, power may beapplied to the bath. This is not a big concern in modern melt shopswhere temperature adjustment is carried out in the ladle furnace.

De-Slagging

De-slagging operations are carried out to remove impurities from thefurnace. During melting and refining operations, some of theundesirable materials within the bath are oxidized and enter the slagphase.

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It is advantageous to remove as much phosphorus into the slag asearly in the heat as possible (i.e. while the bath temperature is stilllow). The furnace is tilted backwards and slag is poured out of thefurnace through the slag door. Removal of the slag eliminates thepossibility of phosphorus reversion.

During slag foaming operations, carbon may be injected into the slag

where it will reduce FeO to metallic iron and in the process producecarbon monoxide which helps foam the slag. If the high phosphorusslag has not been removed prior to this operation, phosphorusreversion will occur. During slag foaming, slag may overflow the silllevel in the EAF and flow out of the slag door.

The following table shows the typical constituents of an EAF slag:

Componen

tSource

Composition

RangeCaO Charged 40 - 60 %

SiO2 Oxidation product 5 - 15 %

FeO Oxidation product 10 - 30 %

MgO Charged as dolomite 3 - 8 %

CaF2Charged - slagfluidizer

MnO Oxidation product 2 - 5%S Absorbed from steel

P Oxidation product

Tapping

Once the desired steel composition and temperature are achieved inthe furnace, the tap-hole is opened, the furnace is tilted, and thesteel pours into a ladle for transfer to the next batch operation(usually a ladle furnace or ladle station). During the tapping processbulk alloy additions are made based on the bath analysis and thedesired steel grade. De-oxidizers may be added to the steel to lowerthe oxygen content prior to further processing. This is commonlyreferred to as "blocking the heat" or "killing the steel". Common de-oxidizers are aluminum or silicon in the form of ferrosilicon or

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silicomanganese. Most carbon steel operations aim for minimal slagcarry-over. A new slag cover is "built" during tapping. For ladlefurnace operations, a calcium aluminate slag is a good choice forsulfur control. Slag forming compounds are added in the ladle at tapso that a slag cover is formed prior to transfer to the ladle furnace.Additional slag materials may be added at the ladle furnace if theslag cover is insufficient.

Temperature Sampling Process

The modern disposable thermocouple was introduced to steelmakingalmost 40 years ago and temperature measurement had become anintegral part of tracking progress throughout the tap-to-tap cycle insteelmaking. Expendable probes are also used for tracking bathcarbon content and dissolved oxygen levels in the steel. These toolshave enabled the tap-to-tap cycle to be accelerated by eliminatinglong waiting periods for lab results, thus increasing productivity.Disposable probes are typically mounted in cardboard sleeves thatslide on to a steel probe(pole) which has internal electrical contacts.

The disposable probe transmits an electrical signal to the steel pole,which in turn transmits the signal to an electronic unit forinterpretation. Almost all probes rely on an accurate temperaturemeasurement to precisely calculate carbon or oxygen levels. Mostfacilities keep several spare poles on hand so that they can bequickly replaced if they have reading problems.

Cooling System

Another system that is integral to EAF operation is the cooling watersystem. Typically, there are several cooling systems. Someoperations require extremely clean, high quality cooling water.

Transformer cooling, delta closure cooling, bus tube cooling andelectrode holder cooling are all such applications. Typically, thesesystems will consist of a closed loop circuit, which conducts water

through these sensitive pieces of equipment. The water in the closedloop circuit passes through a heat exchanger to remove heat. Thecircuit on the open loop side of the heat exchanger typically flows toa cooling tower for energy dissipation. Other water cooled elementssuch as furnace side panels, roof panels, offgas system ducting,furnace cage etc. will typically receive cooling water from a coolingtower.

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The cooling circuit typically consists of supply pumps, return pumps,filters, a cooling tower cell or cells and flow monitoringinstrumentation. Sensitive pieces of equipment normally haveinstrumentation installed to monitor the cooling water flow rate andtemperature. For most water-cooled equipment, interruption of theflow or inadequate water quantities can lead to severe thermal overloading and in some cases catastrophic failure.

Furnace Heat Balance

To melt steel scrap, it takes a theoretical minimum of 300 kWh/ton.To provide superheat above the melting point of 2768 F requiresadditional energy and for typical tap temperature requirements, thetotal theoretical energy required usually lies in the range of 350 to370 kWh/ton. However, EAF steelmaking is only 55 to 65 % efficientand as a result the total equivalent energy input is usually in therange of 560 to 680 kWh/ton for most modern operations. Thisenergy can be supplied from a variety of sources as shown in thetable below. The energy distribution is highly dependent on localmaterial and consumable costs and is unique to the specificmeltshop operation. A typical balance for both older and moremodern EAFs is given in the following Table:

UHPFURNACE

Low to Medium PowerFurnace

Electrical Energy 50 - 60 % 75 - 85 %

INPUTS Burners 5 - 10 %

ChemicalReactions

30 - 40 % 15 - 25 %

TOTAL INPUT 100% 100%

OUTPUTS

Steel 55 - 60 % 50 - 55 %

Slag 8 - 10 % 8 - 12 %

Cooling Water 8 - 10 % 5 - 6 %

Miscellaneous 1 - 3 % 17 - 30 %

Offgas 17 - 28 % 7 - 10 %

Of course the above figures are highly dependent on the individualoperation and vary considerably from one facility to another. Factorssuch as raw material composition, power input rates and operating

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practices (e.g. post-combustion, scrap preheating) can greatly alterthe above balance. In operations utilizing a large amount of chargecarbon or high carbon feed materials, up to 60 % of the energycontained in the offgas may be calorific due to large quantities of un-combusted carbon monoxide. Recovery of this energy in the EAFcould increase energy input by 8 to 10 %. Thus it is important toconsider such factors when evaluating the energy balance for agiven furnace operation.

The International Iron and Steel Institue (IISI), classifies EAFs basedon the power supplied per ton of furnace capacity. For most modernoperations, the design would allow for at least 500 kVA per ton ofcapacity. The IISI report " The Electic Furnace - 1990" indicates thatmost new installations allow 900 - 1000 kVA per ton of furnacecapacity. Most furnaces operate at a maximum power factor of about0.85. Thus the above transformer ratings would correspond to a

maximum power input of about 0.75 to 0.85 MW per ton of furnacecapacity.

Carbon Injection

Carbon injection is critical to slag foaming operations, which arenecessary for high power furnace operations. Carbon reacts with FeOto form CO and "foam" the slag.

Furnace Turn-aroundFurnace turn-around is the period following completion of tappinguntil the furnace is recharged for the next heat. During this period,the electrodes and roof are raised and the furnace lining is inspectedfor refractory damage. If necessary, repairs are made to the hearth,slag-line, tap-hole and spout. In the case of a bottom-tappingfurnace, the taphole is filled with sand. Repairs to the furnace aremade using gunned refractories or mud slingers. In most modern

furnaces, the increased use of water-cooled panels has reduced theamount of patching or "fettling" required between heats. Manyoperations now switch out the furnace bottom on a regular basis (2to 6 weeks) and perform the hearth maintenance off-line. Thisreduces the power-off time for the EAF and maximizes furnaceproductivity. Furnace turn-around time is generally the largest deadtime (i.e. power off) period in the tap-to-tap cycle. With advances infurnace practices this has been reduced from 20 minutes to less than5 minutes in somenewer operations.

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EAF Transformer

The power flow from the utility's generators, through their network,arrives at the steel plant at very high voltage and must therefore beconverted to low voltage suitable for the furnace arcs. Transformersperform this task. The EAF transformer receives the primary low

current, high voltage power and transforms this to a high current,low voltage power for use in the EAF. Reliable operation of the EAF istotally dependent on reliable operation of the EAF transformer. Manylarge furnace transformers are rated 100MVA or greater.

Transforming the power from the kV level at the incoming utility lineto the voltage level needed in the EAF is usually done in two stages.A first transformer (occasionally two transformers in parallel) stepsthe voltage down from the high-voltage line to a medium voltagelevel which is generally standardized for each country. In the USAthis medium voltage is usually 34.5 kV, while in Europe, Japan andother areas the voltages are not very different, often 30 to 33 kV.From the 34.5 kV busbar, the arc furnace is powered by a special,heavy-duty furnace transformer. The secondary voltage of thisfurnace transformer is designed to allow operation of the arcs in thedesired range of arc voltages and currents. Since there are varyingrequirements of arc voltage/current combinations through the heat itis necessary to have a choice of secondary voltages. The furnacetransformer is equipped with a tap-changer for this purpose.

LRF (Laddle Refining Furnace):-

This method is also called secondary steel making process. In thisdeoxidation will be done means reduction of the oxygen andincrement in hydrogen.

Following steps are taken in this stage:-

Addition of elements according to there demand for eg: -Carbon(C), Magnesium (Mg), Silicon (Si), and Sulphur (S),Aluminium (Al), Copper (Cu), Tin (Sn), etc.

Addition formula/ Wt. of Additive =LM(Liquid Metal)*Point(Max. pt limit)

Efficiency of the element which is to be added

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Supply of the Argon- to maintain the homogeneity in the laddlebecause it is a noble gas which means that it will not react withany metal.

Addition of fluxes for refining of steel and making of reducingslag they are 2Slag, VD Slag, Lime etc.

LRF(Ladle Refining Furnace)

During refining increasing of element add as

Coke for Carbon

FeMn for Mn FeSi for Si(Silicon)

FeS for S(Sulphur)

FeP for P(Phosphorous)

FeCr for Cr(Chromium)

Vacuum Tank degassing systems(VD)

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Vacuum tank degassing is one of the oldest degassing techniques in

use in the steel industry for improving steel quality. A teeming ladleis placed in a vacuum tank, which is connected to a vacuum pumpsystem. The ladle is equipped with 13 porous plugs through whichinert gas is injected into the melt to promote stirring. Metallurgicalreactions such as degassing, deoxidation, decarburization,desulfurization and alloying take place under vacuum conditions.

The VD Process

During vacuum treatment the carbon, oxygen, nitrogen, hydrogen,and sulfur contents are reduced in different process steps dependingon the melt composition. A vacuum alloy hopper system allows forcompositional adjustments. Good homogenization and high alloyyields are characteristic features of this process. Depending on themetal lurgical reactions in the ladle, a freeboard of 6001,200 mm isrequired. In order to increase productivity, the VD system can also bedesigned (or expanded) to a twin-vessel system.

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Features and benefits

Accelerated reactions undervacuum conditions

Achieving low contents of

carbon, oxygen, hydrogen,nitrogen and sulfur

Improved steel cleanliness,especially with respect to oxidesand sulfides

Low investment and operationalcosts

Vacuum Pumps - The Heart of everyVacuum Degassing Plant

The necessary vacuum pump systems for vacuum degassing unitsare entirely designed and engineered by Siemens VAI processspecialists. This assures that the technical performance of eachsupplied pump system will meet the process and metallurgicalrequirements under all climatic conditions.

A typical pump system consists of an arrangement of steam ejectorswith the necessary condensation stages, often in combination withmechanical pumps. Siemens VAI offers the full range of pumpingsystems, including customized and cost-saving solutions for tail pipeand hot well tank systems.

2.CONCAST:-For this the raw material is the liquid metal which is after the VD(Vaccum Degassing). In which all the unwanted gases from themolten iron are removed under some suitable temperature which isaround 14500C-15500C for the concast.

In the concast, there is making of the billets is to be done according tothe requirement. In this process we also cool down the temperature

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with help of the water because in this we are using water as coolant.Supply of the water on the billets on regular interval, this is to bedone because after this stage metal will go in the other departmentwhere the temperature should be less or we can say that very lesstemperature.Dimensions of the billets are:-

a. 80X80b. 100X100c. 130X130d. 160X160e. 180X180f. 200X200 all are in mm (millimeter).

Suppose if we have to prepare a file of 9mm, then which section ofdimension we will use?

The answer is 130X130mm because all the mechanical property likestrength, hardness, fatigue, creep, brittleness, etc. will increase.

Because if we use 100X100 sections then we have compress of onlyof one mm due to this file will not so hard, due to this time life of theequipment will decrease i.e. we use 130X130.

Types of the Concast:-a) Open type Concast

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b) Closed type Concast

Open type Concast: -

In this type of the concast all the liquid metal will be seen by ournaked eyes but it dangerous to the life because it is manually,therefore chance of the accident will goes on increasing.

Closed type Concast:-In this type of the concast all the liquid metal will not seen by ournaked eyes due to this chance of the accident will be very less,therefore life will be safe. One thing more in this type all theprocedure is automatic.

3.QAD (Quality Assurance

Department):-An independent Quality Assurance department is functioning inEmirates Steel Industries with a strong management commitment toquality. The main objective of the department is to achieve andmaintain high quality finished products with consistent compliance.Finished products will be available for dispatch only after inspection,testing and classification by quality assurance.

DIGITAL HARDNESS TESTINGMACHINE

VACUUM OPTICAL EMISSIONSPECTROMETER

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The department has well equipped laboratory and inspection facilitiesmanned by qualified and trained personnel. All the testing, inspectionand monitoring are carried out as per stipulated standards and testcertificates are provided to customers.

With the operation of the Quality management system as perISO9001-2000 and third party product certification by globallyauthorized agency CARES in United Kingdom, the compliance ofproduct to the required specification and consistency is verified byindependent inspection and testing. Unique CARES logo mark onEmirates Steel Industries finished products assures confidence andsatisfaction to customers.

4.ROLLING:-

Types:-

1. Hot Rolling2. Cold Rolling

HOT ROLLING:-

Hot rolling is a hot working metalworking process where large pieces ofmetal, such as slabs or billets, are heated above their recrystallizationtemperature and then deformed between rollers to form thinnercross sections. Hot rolling produces thinner cross sections than coldrolling processes with the same number of stages. Hot rolling, due torecrystallization, will reduce the average grain size of a metal whilemaintaining an equiaxedmicrostructure whereas cold rolling will produce ahardened microstructure.

COLD ROLLING:-

Cold rolling is a metalworking process in which metal is deformed bypassing it through rollers at a temperature below its recrystallizationtemperature. Cold rolling increases the yield strength and hardnessof a metal by introducing defects into the metal's crystal structure.

These defects prevent further slip and can reduce the grain size ofthe metal, resulting in Hall-Petch hardening.

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Hot Rolling:-

Process

A slab, billet, or ingot is passed or deformed between a set ofworkrolls revolving at the same speed, but in opposite directions. Thedistance between the work rolls is slightly less than that of thepassing metal which allows for thinning. The temperature of themetal is generally above its recrystallization temperature, asopposed to cold rolling, which takes place below this temperature.Hot rolling permits large deformations of the metal to be achievedwith a low number of rolling cycles. As the rolling process breaks up

the grains, they recrystallize maintaining an equiaxed structure andpreventing the metal from hardening. Hot rolled material typicallydoes not require annealing and the high temperature will preventresidual stress from accumulating in the material resulting in betterdimensional stability than cold worked materials.

Hot rolling is primarily concerned with manipulating material shapeand geometry rather than mechanical properties. This is achieved byheating a component or material to its upper critical temperature and thenapplying controlled load which forms the material to a desiredspecification or size. The degree of change to the metal is directlyrelated to the heat of the metal, high heats allowing for greaterthinning.

Applications

Hot rolling is used mainly to produce sheet metal or simple crosssections such as railroad rails from billets.

Mechanical properties of the material in its final 'as-rolled' form are afunction of:

materialchemistry, reheat temperature, rate of temperature decrease during deformation, rate of deformation, heat of deformation, total reduction,

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recovery time, recrystallisation time, and subsequent rate of cooling after deformation.

Types of rolling mills

Prior to continuous casting technology, ingots were rolled toapproximately 200 millimetres (7.9 in) thick in a slab- or bloom- mill.Blooms have a nominally square cross section, whereas slabs arerectangular in cross section.

Slabs are the feed material for hot strip mills or plate mills, andblooms are rolled to billets in a billet mill or large sections in astructural mill.

The output from a strip mill is coiled and, subsequently, used as the

feed for a cold rolling mill or used directly by fabricators. Billets, forre-rolling, are subsequently rolled in either a merchant, bar or rodmill.

Merchant or bar mills produce a variety of shaped products such asangles, channels, beams, rounds (long or coiled) and hexagons.Rounds less than 16 millimetres (0.63 in) in diameter are moreefficiently rolled from billet in a rod mill.

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Rolling MillTypes

History

In 1779 a rolling mill was created in Fontley, Hampshire where Henry Cortdeveloped ideas for rolling processes. In 1783 Cort received a patentfor his groove rolling process and in 1784 a patent for puddingfurnace. Much of Cort's work was based on the previous ideas of

Thomas and George Cranege who developed the process of thereverberatory furnace for the production of wrought iron from castiron in 1784.

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Cold Rolling:-

Physical metallurgy of cold rolling

Cold rolling is a method of cold working a metal. When a metal iscold worked, microscopic defects are nucleated throughout thedeformed area. These defects can be either point defects (a vacancy

on the crystal lattice) or a line defect (an extra half plane of atomsjammed in a crystal). As defects accumulate through deformation, itbecomes increasingly more difficult for slip, or the movement ofdefects, to occur. This results in a hardening of the metal.

If enough grains split apart, a grain may split into two or more grainsin order to minimize the strain energy of the system. When largegrains split into smaller grains, the alloy hardens as a result of theHall-Petch relationship. If cold work is continued, the hardened metal mayfracture.

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During cold rolling, metal absorbs a great deal of energy. Some ofthis energy is used to nucleate and move defects (and subsequentlydeform the metal). The remainder of the energy is released as heat.

While cold rolling increases the hardness and strength of a metal, italso results in a large decrease in ductility. Thus metalsstrengthened by cold rolling are more sensitive to the presence of

cracks and are prone to brittle fracture.

A metal that has been hardened by cold rolling can be softened byannealing. Annealing will relieve stresses, allow grain growth, andrestore the original properties of the alloy. Ductility is also restoredby annealing. Thus, after annealing, the metal may be further coldrolled without fracturing.

Degree of cold work

Cold rolled metal is given a rating based on the degree it was coldworked. "Skin-rolled" metal undergoes the least rolling, beingcompressed only 0.5-1% to harden the surface of the metal andmake it more easily workable for later processes. Higher ratings are"quarter hard," "half hard" and "full hard"; in the last of these, thethickness of the metal is reduced by 50%.

Cold rolling as a manufacturing process

Cold rolling is a common manufacturing process. It is often used toform sheet metal. Beverage cans are closed by rolling, and steelfood cans are strengthened by rolling ribs into their sides. Rollingmills are commonly used to precisely reduce the thickness of stripand sheet metals.

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5.FINISHING:-Pickling

Pickling is an acid treatment to remove high temperature scaleproduced in welding, heat treatment or hot working. It also removesred rust from corrosion of the steel or from corrosion of contaminantiron or steel particles. Note that passivation is not sufficientlyaggressive to remove this corrosion product after the free iron has

begun to rust. High temperature dark scale is not only undesirable foraesthetic reasons - it also results in a reduced corrosion resistance ofthe underlying steel surface layer.

The type of scale and hence the methods to remove it will dependupon the steel grade and the heating conditions involved. Thestraight-chromium grades such as Grades 410, 416 and 430 scalemore readily and unfortunately the resulting scale is also moretenacious.

All pickling operations result in metal removal, and the outcome istherefore to some degree a dulling of the visual brightness andperhaps also a significant reduction in dimensions.

The best solution to the scale problem is not to create it in the firstplace! Heat treatment in a vacuum or a good controlled atmosphere,such as bright annealing, eliminates the need for pickling, andgenerally results in a better final surface finish.

If pickling does need to be carried out the treatments given in Table 2can be used. An initial pickle in sulphuric acid is often beneficial asthis softens the scale so that it can more readily be removed bysubsequent pickling in hydrofluoric and nitric acids.

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Pickling Paste

A very convenient method for pickling is use of "Pickling Paste". Thisis a prepared mix of strong acids in a stiff paste which enables it to beapplied to small areas and to vertical or even overhanging surfaces. Itis especially useful for pickling to remove heat tint following welding.Again precautions for handling acids must be followed and the residueflushed thoroughly to a suitable waste stream after completion. Mostcommercial pickling paste is formulated for the austenitic grades, so ifthese are used to clean lower alloyed grades such as 3CR12 theprocess must be closely monitored to ensure the paste is quicklyremoved and very thoroughly rinsed off afterwards.

Table 2. Pickling procedures. Refer ASTM A380

Grade Treatment Temperature Time

All stainlesssteels exceptfree machininggrades. (Usefulto loosen heavyscale prior to

othertreatments)

8-11% sulphuricacid

65-80C 5-45 minutes

Grades with lessthan 16%Chromium(except freemachininggrades e.g. 416)

15-25% nitricacid + 1-8%hydrofluoricacid

20-60C 5-30 minutes

Free machininggrades andgrades with lessthan 16%Chromium

10-15% nitricacid + 0.5-1.5%hydrofluoricacid

20-60C 5-30 minutes

Notes:

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1. Trial treatments should be carried out first to confirm that dullingis acceptable.

2. Pickling should preferably be carried out on fully annealedstainless steels due to risk of grain boundary attack. This problem isespecially relevant to steels sensitised in welding.

3. All pickling treatments must be followed by thorough rinsing.

4. Observe all precautions for handling acids - sulphuric, nitric andespecially hydrofluoric acid are highly corrosive and dangerous toexposed skin.

Degreasing

Grease, oil, cutting fluids, drawing compounds and other lubricantsmust be removed from the surface of stainless steel componentsbefore heat treatment (to prevent carbon pick-up) or final passivatingtreatments (to enable full access by the treatment). Parts must alsobe degreased prior to further assembly by welding, again to preventpick-up of carbon at high temperature.

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CUTTING OF METAL

Both liquid and vapour degreasers are used. Liquid cleaning is oftenby hot alkaline detergents; proprietary mixes may also containvarious additives. The parts should be thoroughly rinsed afterwards.

Organic solvents can be applied by spraying, swabbing or vapour

degreasing. These treatments should again be followed by thoroughhot water rinsing.

As with cleaning operations on other metals, the rate of cleaning canbe increased by the use of brushing, jetting or stirring etc. during theoperation.

ElectropolishingElectropolishing is an electrochemical process which brightens thesteel surface by selective dissolution of the high points - it is theopposite of electroplating, and is carried out with similar equipment.

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The process is able to produce a very attractive and hygienic finish,but trials should first be conducted to determine the optimum priorsurface condition and polishing parameters. Electropolishing of somesurfaces results in a frosted rather than smooth finish.

Grinding and Polishing

Stainless steels can be readily ground, polished and buffed, butcertain characteristics of these materials require some modification ofstandard techniques for best results. Most notably, the high strength,tendency to "load up" abrasive media, and low thermal conductivityof stainless steels all lead to build-up of surface heat. This in turn canproduce heat tinting (surface oxidation) or surface smearing, and inextreme cases even sensitisation of austenitic stainless steels or

"burning" (re-hardening) of heat treated martensitic grades.Techniques that help prevent build-up of surface heat include (a) useof lower speeds and feeds, and (b) careful selection of lubricants, andof proper grit size and type, so as to minimise loading of the abrasive.

Corrosion resistance of stainless steels may be adversely affected bypolishing with coarse abrasives. Corrosion resistance is oftenadequate following polishing to a No.4 (approx 180-grit) finish.Polishing with fine alumina or chromium oxide to obtain still higherfinishes - such as buffed finishes No.7 and No.8 - removes fine pitsand surface imperfections and generally improves corrosionresistance. Buffing can also be carried out by using a "Scotch-brite"buffing wheel.

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Iron contamination must be avoided or removed if polished stainlesssteel surfaces are to have good corrosion resistance. Abrasives andpolishing compounds must be essentially iron-free (less that 0.01% forbest results), and equipment used for processing stainless steels mustnot be used for other metals. If these conditions cannot be met, acleaning/passivation treatment (after pre-cleaning to removepolishing compounds and lubricants) will be required to restore goodcorrosion resistance.

Mechanical Cleaning

Problems associated with chemical cleaning processes can be avoidedby using mechanical cleaning. With all mechanical cleaning processesgreat care must be taken to prevent the stainless steel surface frombecoming contaminated by iron, steel or iron oxide particles.

Barrel Finishing and Vibratory Finishing

Barrel finishing and vibratory finishing both use abrasive media tomechanically polish small parts and are widely used on fasteners suchas screws and bolts and on pipe fittings.

Mechanically cleaned parts are not quite as corrosion resistant as acidpickled material because mechanical cleaning leaves some scaleresidues and often some residue from cleaning. It can be used as apreparatory step before acid pickling.

Background

To a very large extent stainless steels are used because of thecorrosion resistance of their surfaces. This excellent corrosionresistance can only be achieved if proper cleaning and finishing

operations are carried out after any fabrication process which hasimpaired the surface condition.

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Safety

In every field in the universe we need to follow some types of safetywhether in the field of industy.

If we follow the safety rules while working the chance of accidentswill increase.

We believe...

... that each individual must takecharge of his/her safety at UPPERINDIAN Steel Texas;

... that no amount of productionis worth any amount of risk tothe well being of our people;

... that we can reach ourproduction goals only throughsafe work practices and ongoingsafety training;

... that the safe way is the bestway to do any job in our plant;

... that injuries can be avoided ifwe observe reasonable cautionand use good judgment inperforming our jobs;

... and that individuals will

develop a sixth sense ofsafety awareness if they makesafety the most important partof everything they do.

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The Difference between Iron and

Steel:-

Iron is an element, steel is an alloy. Steel is made from Iron. It is analloy made up of iron and carbon. Other metals can also be added to

steel to produce alloys with different characteristics. For instancesteel with chromium added is stainless steel. Unlike regular steel it

doesnt rust. Steel is used extensively in buildings. Steel beams,studs, nails, bolts, doors, and siding are commonly used in residentialconstruction. I believe rerod and wire mesh used in cement is made

of iron. In larger buildings steel is used even more in the structures ofthe buildings. Iron was used first, then cast iron, then wrought iron,

and now steel. We use steel instead or iron because its stronger thaniron; superior in tension and compression.

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REFERENCES

Books with Author Steel-rolling Technology by Ginzburg Metal Cutting Theory and Practice by David A.

Stephenson Manufacturing Engineering Processes by Leo Alting Flat Rolling Fundamentals by Vladimir B. Ginzburg

Websites

www.jlab.orgwww.azom.comwww.niir.orgwww.blog.lib.umn.edu

Internet sites

google.comyahoo.commsn.comWikipedia.com