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TURBULENCE PICKLING LINESFOR CARBON STEELTURBULENCE PICKLING LINESFOR CARBON STEELTechnology and references

METALLURGICAL PLANTS and ROLLING MILLS

Strip Processing Lines

SMS SIEMAG

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TURBULENCE PICKLING LINESFOR CARBON STEELTURBULENCE PICKLING LINES FOR CARBON STEEL

Optimal descaling

without over-pickling

Essential for the production of high-quality steel stripwith pure, scale-free surfaces is cleaning the stripwith acid – technically termed pickling. Newly devel-oped and patented by SMS Siemag, our turbulencepickling process for descaling steel strip withhydrochloric acid has not only proved its worth inmany plants, but we also improve the system con-stantly.

Using our pickling lines, you benefit from high-qualitycleaning without over-pickling your steel strip. Fur-thermore, the process stands out for its low energyand acid consumption as well as low maintenanceand operating costs over a long service life.

This turbulence pickling process can be integratedinto all lines designed for pickling carbon steel: pick-ling line/tandem cold mills, continuous, semi-continu-ous, and push-pull-pickling lines. It is also ideal in stripprocessing lines for stainless steel and electrical steelstrip (silicon steel).

Yet there is more, because apart from turbulencepickling plants, SMS Siemag supplies otheradvanced components. Just one example is the X-Pact® laser welding machine that joins even hard-to-weld materials.

Turbulence pickling linesSMS SIEMAG

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The mechanical equipment used here, such as ten-sion levelers, loopers, entry and exit sections, isspecifically tailored to the conditions in pickling lines.

Our cold rolling mills come in a modular design, com-plete with high-tech elements such as CVC® plustechnology.

Effective and eco-friendly, acid regeneration plantsfrom SMS Siemag Process Technologies recoverspent pickling acid and feed it back into the process.

This means SMS Siemag is your one-stop-shop forcomplete pickling lines including coil logistics, bindingstrip treatment, laser welding machines, all themechanical components, as well as drive and controltechnology.

That ensures you can cut your operating expenses foryour overall plant because both your maintenance andspare parts costs are minimized due to perfectlymatched components. You also save on customercoordination and training costs.

Read on to learn about the various line types availableas well as the key components and technology forpickling lines from SMS Siemag. Then, starting onpage 18, you will find a list of some of our referenceplants.

Contents

Introduction and contents 2-3

Line types 4-5

Entry area, loopers, scale breakers 6-7

SMS Siemag laser welding machine 8-9

Turbulence pickling –

optimal descaling without over-pickling 10-11

Acid regeneration plants

from SMS Siemag Process Technologies 12-13

Side trimmer, Duma-Bandzink oiling machine,

inspection line, exit area 14-15

High-tech tandem cold rolling mills 16-17

Global references 18-19

Baoshan Iron & Steel – pickling line/tandem cold mill 20-21

China Shougang Corporation –

pickling line/tandem cold mill 22-23

Tianjin Tiantie – pickling line/tandem cold mill 24-25

Salzgitter Flachstahl –

continuous pickling line with acid regeneration 26-27

Tokyo Steel –

continuous pickling line with acid regeneration 28-29

Gazi Metals Mamülleri –

semi-continuous pickling line 30-31

Severstal Columbus – push-pull-pickling line 32-33

References since 2000 at a glance 34-35

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LINE TYPESLINE TYPES

Off-the-peg is not our style. SMS Siemag tailors your pickling line to your specific requirements. Dependingon the capacity, the steel grades and qualities as well as the strip dimensions you want to produce, yourplant comes equipped with the right technologies and components. Generally speaking, pickling lines areavailable in four types.

Push-pull-pickling lines (PPPL)

This is where strips are threaded into the pickling millindividually and pushed or pulled through the processsection. The advantages of this discontinuous productionmethod are its great flexibility in terms of productionplanning and materials that can be processed as well aseasy manufacturing of thick strip.

Semi-continuous pickling lines (S-CPL)

Stand-out features of semi-continuous pickling lines are thesmall loopers that ensure the strip in the process section doesnot have to come to a complete halt while the strips are joinedby a stitcher in the entry area. As a result, it is not necessaryto re-thread every length of strip. These plants are suitable forsmall to medium capacities. It’s an added advantage that theycan be subsequently upgraded to continuous models.

Continuous pickling lines (CPL)

A welding machine at the entry of the continuous picklingline joins individual strips into endless strip, then horizontalloopers ensure continuously high speed in the processingsection. That means you achieve top quality standards atvery high capacities. Continuous pickling lines can also becoupled to cold rolling mills.

Pickling line/tandem cold mills (PLTCM)

What happens here is that these mills continuouslypickle and cold roll hot strip in one go. They come withthree loopers to ensure a continuous process. Both theentry and exit areas are designed so that the plant canoperate continuously at high speed.


Typical plant parameters:Strip thickness: 1.2 – 16 mmStrip width: 600 – 2,080 mmCapacity: 300,000 – 600,000 t/a

Typical plant parameters:Strip thickness: 1.2 – 6.5 mmStrip width: 600 – 2,080 mmCapacity: 350,000 – 700,000 t/a

Typical plant parameters:Strip thickness: 1.2 – 6.5 mmStrip width: 600 – 2,080 mmCapacity: 1,500,000 – 2,700,000 t/a

Typical plant parameters:Strip thicknessEntry: 1.2 – 6.5 mmExit: 0.3 – 3.5 mmStrip width: 600 – 2,080 mmCapacity: 1,500,000 – 2,500,000 t/a

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Turbulence pickling lines

ENTRY AREA

SMS SIEMAG

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ENTRY AREA

HORIZONTAL STRIP LOOPERSHORIZONTAL STRIP LOOPERS

Easy threading in

with short downtimes

SMS Siemag supplies high-qualitymechanical equipment for the entryarea of hot strip mills that can beequipped with one or two payoffreels or with one payoff reel andone support reel for coil preparation.Included here are:

Coil lifter in an extremely flat,robust designCoil preparation station forremoving faulty or difficult stripends (e.g. fishtails) and for bend-ing a slight lift that makes thread-ing in easier

Anti-Coil-Break systemStrip center control systemsHydraulic pre-leveler to flattenthe strip end with precise, highly

Keeping the process

moving

Vital here are the horizontal loopers.They ensure a constant strip speedin the process section of the plants.Depending on the plant type, two orthree loopers are installed that areoften more than 100 m long andcollect over 500 m of strip in up tosix layers.

The loopers fill up and empty due tothe action of looper cars that travelat speeds of up to 150 m/min. Thestrip in the carriages is guided by asmany as three rolls. After passage of the loop carriage, swivel

gates that support the strip in the loopersclose.

Built in to this system are swivelgates to support the loops of strip inthe loopers. Whenever the loop car-riages travel over switching curves,the gates open and close mechani-

cally. To regulate the strip position in and after the horizontal loopers,separate strip centering devices areinstalled.

dynamic control of the sevenguide rollers and scale suctiondevice.

Double entry of a pickling line with coilpreparation station.

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SCALE BREAKERSCALE BREAKER

INTEGRATED SCALE SUCTION CONCEPTINTEGRATED SCALE SUCTION CONCEPT

Descaling and improving

strip geometry

Next in line is the scale breaker(also called tension leveler). Itbreaks up and removes some of thescale from the strip and preparesthe surface for the pickling process.Moreover, it increases strip flatnessand removes any sabers. Then thestrip can travel through the narrowturbulence pickling tank – smoothlyand without catenary.

S-roll units are installed bothupstream and downstream of thescale breaker to stretch the strip tothe necessary tension of up to 600kN. To save energy, the rolls of thetwo units are coupled by a mechani-cal tensioning system. Bending rollsbend the strip in both directions

A newly developed, integrated suc-tion concept minimizes scale dustproblems in the entry area of pick-ling plants, while simultaneouslyreducing the suction power. Yourbottom line: Low exposure ofemployees to dust, less susceptibil-ity of the plant to disruption andwear, and reduced dust emissions.

All that makes your plant simultane-ously safer, more effective, andgreener. Optimized after extensiveprocess and flow studies, this devel-opment improves suction or collec-tion features at all the critical points.These devices operate with power-ful fans linked to a central system.

several times at a relatively highstrip tension. This breaks up thescale and improves strip geometry.

Also important at this stage is thecorrection roll unit in the bending roll

stand that eliminates any crosscambers resulting from longitudinalstretching of the strip grain. Thebroken scale is blown off andextracted using compressed air.

In the scale breaker the strip is first bent under hightension (yellow rolls), then it travels through a cor-rection roll unit (green rolls).

Key features:

Reduction of volume flows of theindividual suction hoods withsimultaneous improvement ofscale removalOptimized distance betweensuction hoods and stripSuction hoods with active blow-off system that picks up the dustand transports it to the hoods

SMS SIEMAG LASER WELDING MACHINE

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SMS SIEMAG LASER WELDING MACHINE

Precise, fast welding

The innovative laser weldingmachine has been up and runningsince 2008. It has proved invaluablefor precise, rapid joining of hard-to-weld thin and high-alloy strip –which is then perfectly prepared totravel smoothly through the process.As a result, even high-carbon stripsuch as C 67 can be treated in acontinuous line.

Two further laser welding machineshave been successfully in operationat ThyssenKrupp Steel USA andTokyo Steel, Japan since 2011.

Moreover, there were two neworders for SMS Siemag to supplylaser welding machines for picklingtandem lines to JSW, India, andHyundai Hysco, Korea.

Welding head and inductors for heat treatment before andafter welding.

Precise, fast, and reliable weldingof hard-to-weld steel grades.

Cutting strip ends.


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Automatic adjustment

of welding parameters

and inductive pre and

post-heating of seams

The compact welding machinecomes with many innovative fea-tures. Take for instance the auto-matic adjustment of the weldingparameters to new material pairings,controlled by an analysis of themelting characteristics.

Even difficult material combinationsare possible with our patented induc-tive pre and post-heating of the weld seam. That’s how an excellentmicrostructure develops in the heat-treated zone with a homogeneousweld seam quality. An integratedweld seam analysis system fullyautomatically checks the seambefore, during, and after welding.

Reliable welding process

Crucial here is that the individualstrips are positioned in relation toeach other without any offsetting or angles. This is where a shiftingfunction comes in. It aligns the headend of the new strip with the end of the previous strip.

The integrated shear is a cross-cut-ting shear. To take account of differ-ent strip thicknesses, the stroke canbe adjusted between center, top,and bottom.

The welding process takes placeusing a sliding carriage fitted withthe laser head and pre-heatinginductor. The inductor for post-heat-ing is mounted on a separate under-carriage, which means that thedelay between welding time andpost-treatment can be set variably.

Laser welding machinefrom SMS Siemag.

To ensure the vibrations of the car-bon dioxide laser resonator do notimpair its welding accuracy, it restson its own foundations.

Simpler commissioning

The laser welding machine is com-pletely assembled and commis-sioned in the SMS Siemag work-shop. Here is where we test all thefunctions of the main machine.

We also use this opportunity to train the maintenance and operatingpersonnel who will work on themachine in the future while it is fullyoperational. This makes commis-sioning simpler.

THE TURBULENCE PICKLINGPROCESS FROM SMS SIEMAG

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THE TURBULENCE PICKLINGPROCESS FROM SMS SIEMAG

Efficient descaling

without over-pickling

The turbulence pickling processfrom SMS Siemag stands out for its high pickling performance, lowenergy and acid consumption, aswell as low maintenance and oper-ating costs over a long service life.

All the key pickling process parame-ters can be actively controlled andperfectly adjusted to currentrequirements. This is how theprocess achieves optimum picklingresults at low energy consumption.Due to the constant analysis of thepickling process, expensive chemi-cals are not needed to prevent dam-age to the base material.

Plastic pickling tanks,

cascade rinsing unit,

air drying

As a rule, high-performance SMSSiemag pickling lines consist ofthree to four pickling tanks. Theyeach feature their own circular system, are made of plastic or rub-ber-backed steel, and come in amodern, lightweight design. Thecascade rinsing unit cleans the stripsurface and removes residual acid,followed by hot air drying.

Shallow pickling channel

and patented immersion

covers

The extremely shallow design ofthe pickling channel and the hori-zontal position of the strip explainwhy the tank volumes are verysmall. There is a patented immer-sion cover above the pickling chan-nel that closes off the acid bath surface. This is how we minimizeevaporation and associated energylosses.

Minimized acid evaporation and energylosses - the patented immersion cover.

A hydrodynamic sealing separates the acid cascadesand ensures exact gradation with a minimum ofmechanical components.

High turbulence

Racks of nozzles in the shallowchannel constantly spray heatedhydrochloric acid, generatingextremely high turbulence. Thatensures maximum contact betweenthe pickling acid and the entire stripsurface by continually forcing freshacid into the cracks in the scalelayer. It only takes a very short timeto create the electrochemical poten-tial required for the pickling process.Furthermore, the destruction of thelaminar top layer on the strip sur-face greatly improves not only thematerial exchange, but also the heattransfer. Both of these processesincrease the effective pickling time.That means increased strip speed atthe same tank length.


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SMS Siemag turbulence

pickling technology

Fast pickling due to high turbu-lence and kinetic energy

Low acid consumption frommaximum utilization of acid andavoidance of over-pickling

Fast strip heating

Horizontal strip positioning forhigh strip tension and excellentstrip guidance

No moving parts in the acid bath

Low acid volume for fast temperature changes

Low exhaust air volume and low acid and heat losses due topatented tank cover

Excellent controllability of turbu-lence and temperature

Optimal preparation of the steelstrip as it enters and use ofspent pickling acid in patentedrecuperation tank

Turbulence control and

hydrodynamic sealing

Frequency-controlled centrifugalpumps generate the turbulence.That makes it possible to adjust theturbulence independently of the stripspeed, actively influencing the pick-ling process. There are hydrody-namic seals separating the individualacid cascades, providing for exactadjustment of the acid concentrationand optimal acid utilization. The acidruns through the cascade counter tothe strip direction so that the clean-est acid is in the last pickling tank.

Recuperator tank

The acid can also be utilized in thepatented recuperator tank arrangedupstream of the first pickling tank.Here, used pickling acid is sprayed

onto the strip as it enters. Thisremoves loose scale particles andheats the strip. What’s more, theprocess chemically activates thesurface, speeding up the subse-quent pickling stage. Not only doesthis optimize the pickling result andsave thermal energy, it also cutsacid consumption because no loosescale particles go into the acid cas-cade.

Process model

The pickling process in a turbulencepickling plant can be optimizedusing a process model. Such amodel keeps the acid temperatureas low as possible and avoids dis-ruptions to the process caused bychanging production speeds. To dothis, the model determines the opti-mal pickling parameters 10 to 20

coils in advance and controls thetransitions between coils for therequired pickling result every time.This is how the model reduces acidand energy consumption while alsoincreasing the service life of thecomponents exposed to acid.

High turbulence nozzle racks sprayheated acid into the pickling channel(here with opened lid).

ACID REGENERATION PLANTS

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ACID REGENERATION PLANTSfrom SMS Siemag Process Technologies

The waste gas from the fluidizedbed furnace is cooled in a Venturievaporator. Next in line are processstages in which the hydrogen chlo-ride gas is washed out with rinsingwater.

Spray-roasting process

The spray-roasting process consistsof three main steps: pre-concentra-tion, roasting, and absorption. This isanother pyrohydrolytic process, buthere the acid is roasted and brokendown at a temperature of some 650 °C. The treatment, which takesplace under the influence of heatand gases, generates re-usable acidand iron oxide dust.

Fluidized bed acid

regeneration plant

The first stage in this pyrohydrolyticprocess is breaking down the spentacid into its chemical components in a heavy fluidized bed furnace ataround 850 °C. One component isiron oxide granulate which is contin-ually removed from the furnacefloor. Because the iron oxide granu-late from a fluidized bed regenera-tion plant is ideally suited to in-house smelting, this process isfrequently used by customers whooperate their own blast furnace.

An increasingly important factor forany new pickling plant is compliancewith environment protection regula-tions, plus high energy efficiency.Plants for spent acid regenerationare an outstanding example of greenand efficient technology. It’s not justthe regenerated acid they put backinto the steel strip pickling process.These systems also produce valu-able by-products that can be mar-keted separately. That creates aclosed material cycle. Furthermore,what makes regeneration plantsstand out is their excellent energyefficiency. SMS Siemag ProcessTechnologies of Vienna, Austria, supplies acid regeneration plantsdeveloped specifically for picklingtechnology.

The iron oxide recovered in a fluidized bed acidregeneration plant can be smelted in-house.

Spray-roaster acidregeneration plant.


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Future technology:

Hydrothermal acid

regeneration

Focusing on hydrothermal acidregeneration, SMS Siemag is devel-oping a new acid treatment processthat promises significant economicand ecological advantages.

Take for instance energy consump-tion. The closed process that takesplace at temperatures of between70 and 170 °C uses up to 50 per-cent less energy than conventionalsolutions. Furthermore, it generatesvery high-quality recovered prod-ucts.

The treatment consists of threemain stages: First, the spent acid isconcentrated at low temperaturesunder vacuum, during which freehydrogen chloride (HCl) and waterevaporate from it. The second stepis oxidation of the iron (II) chlorideunder high pressure with pure oxygen to make iron (III) chloride.The third step is low-temperaturehydrolysis. Here, the concentratediron (III) chloride solution is con-verted into iron oxide and hydrogenchloride.

While special filters remove the ironoxide from the solution, the restevaporates. Finally, the evaporatedacid condenses into regeneratedacid together with the distillate fromthe concentration stage. In a hydrothermal acid regeneration plant, the

acid is recovered in three process steps.

Diagram of a hydrothermal acidregeneration plant.

In a fluidized bed furnace, thespent acid is broken down at 900 °C.

ASC SIDE TRIMMER

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ASC SIDE TRIMMER

High cutting perform-

ance and permanent

availability

It is the job of the ASC (AutomaticSetting Control) side trimmer tostraighten the edges and trim thestrip precisely to the required width.There is a major advantage of the double-headed side trimmer,because the trimming blades in the maintenance position can bechanged during ongoing production.

The trimming blades in maintenance position can bechanged during ongoing production.

The circular blade units are equippedwith a combined blade gap settingfor the blade cover and gap. As it isbeing trimmed off, the edge is con-tinually chopped into small pieces bya cutter and removed by a conveyorbelt.


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DUMA-BANDZINKOILING MACHINEDUMA-BANDZINKOILING MACHINE

EXIT AREAEXIT AREA

Electrostatic coating

To protect the strip surfaces, theelectrostatic Duma-Bandzink oilingmachine applies a film of oil cleanlyand evenly to both sides. Becausethe oil droplets are applied electro-statically – therefore contact-free –the machine does not affect thestrip transport or damage the strip.Using servo-controlled meteringpumps, the oiling machine guaran-tees unvarying oil application evenwhen process speeds change.

Reliable coiling with

short downtimes

The exit area of the pickling line fea-tures one or two coilers that ensureperfect coiling with short downtimes.

First, a cross-cutting shear cuts thestrip to length in the exit area. This iswhere the weld seams can be cut outand samples taken. Next, after theshear, comes a strip centering devicethat ensures the start of the new stripis placed in the center of the reel man-drel. A deflecting plate helps threadthe strip into the clamping slot of thereel mandrel.

The coiler is mounted on a slide, and ithas a mandrel with a center spreadingclamping slot.

Alternatively, the plants by SMSSiemag feature a belt wrapper, wichsupports the first windings of the striparound the mandrel. In this way thestrip can be wrapped withaout anyclamping.

While a counterbearing supports thereel mandrel, the strip is coiledaligned either in the middle or at theedge. Finally, the coils are placed ona coil transporter, tied with strapsand transported away.

Duma-Bandzink oiling machines are designed tocustomer specifications – already more than 270machines have been fitted.

Single exit area in a continuouspickling line with strap winderand coil transport system.

Turbulenzbeizlinien

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HIGH-TECH TANDEM COLD MILLSHIGH-TECH TANDEM COLD MILLS

SMS Siemag launched its first pick-ling line/tandem cold mill (PLTCM) in1979. So far, we have erected andsuccessfully commissioned 30plants of this type worldwide.

Cost-effective plant oper-

ation for high production

performance

Coupling a pickling line with a tan-dem cold mill (TCM) to achieve con-tinuous production opens up scopefor an annual production capacity ofup to 2.5 million t of cold strip. Theeconomic advantages of the PLTCMdesign result from a smooth produc-tion flow, lower roll wear, higheryields, and consistent product qual-ity.

Wide product range for

soft and high-strength

grades

Tandem cold mills process strips inwidths from 700 to 2,100 mm withan initial thickness of up to 6.5 mm,rolling them to a minimum finalthickness of 0.1 mm. There is awide spectrum of suitable materials– from soft IF steels to high-strength grades.

Usually, the modern coupled TCMsfrom SMS Siemag consist of fiveconsecutive mill stands in four orsix-high design. We also supply spe-cial constructions for specific appli-cations. Included here is our CVC®

plus M18/4 multifunction rolling millfor processing soft to high-strengthgrades as well as stainless steels ina single plant.

This type of stand ensures flexible,cost-effective production of evensmall batches.

Advanced mechanical

and electronic systems

for excellent strip quality

and efficient plant opera-

tion

Practice-proven and innovative tech-nological control elements in the millstands reliably produce the requiredcold strip properties such as stripthickness, flatness, and surfacepurity. Standard features of SMSSiemag mill stands are CVC® plus,roll bending and EDC®, which guar-antees a constant strip thicknessright to the edges. Installed in thefinal mill stand, a multi-zone coolingfeature optimizes flatness, while theT-Clean Dry-Strip System efficientlydries the strip surface.

Fully automatic work roll change inthe four-high type.

The carousel reel in the exit area of the TCMcontinuously coils the finished strip.


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Depending on the plant design,either a double reel unit or acarousel reel for continuous coilingof the finished strip are available.There is also the option of an inlineor offline inspection station for pro-duction-near quality control. RotaryInspect, the latest inspection sys-tem from SMS Siemag, is ideal forchecking both strip sides easily andthoroughly during ongoing opera-tion.

The perfect performance of theTCM is the result of the smoothinteraction between mechanicalequipment, electronics, andautomation. X-Pact® Level 1 to 3 forSMS Siemag tandem cold mills isperfectly geared to the specific

process technology applied here. Allcontrol and regulation functions areintegrated on the X-Pact® Embed-ded hardware platform with thecommon logi.CAD programmingenvironment. Level 1 contains thetechnological regulation systems forthickness and flatness as well asthe especially user-friendly HMI.Then there is Level 2 with the tech-

nological process models for reliablesetting of the rolling mill and record-ing the production data, as well asfor reporting. Level 3 provides theplant operator with all the necessarytools for planning and control of theproduction processes.

Five-stand coupled tandem cold mill,MMK, Russia.

Rotary Inspect inline strip inspection.

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GLOBAL REFERENCESGLOBAL REFERENCES

175 pickling lines from SMS Siemag worldwide

SMS Siemag has supplied and erected 175 pickling lines for carbon steel for many of the world’s leading steelmanufacturers. So far that includes a total of 125 continuous pickling lines and pickling line/tandem cold mills.We have also supplied 50 push-pull-pickling lines for our customers on all continents. First installed in 1985, asmany as 55 of our turbulence pickling systems were implemented in continuous pickling lines or push-picklinglines for carbon steel, electric strip, and stainless steel. Each of these plants was designed, erected, and com-missioned according to our customers’ wishes. Read on for some examples of plants with details of their specialfeatures plus technical facts and figures.

The process iscontinually monitored.

The continuous pickling line at Jinan in Chinaproduces more than one million t of pickledand oiled hot strip per year.

In 2008, Shougang Jingtang ordered a pickling line/tandem cold mill for more than 2 million t of coldstrip per year. It went online as early as 2010.


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More than one million t of cold strip per year: the pickling line/tandemcold mill at Severstal Columbus, USA.

For the new ThyssenKrupp Steel USA complex in Calvert, Ala-bama, SMS Siemag installed a pickling line/ tandem cold mill(2.5 million t/a) and a continuous pickling line (1.1 million t/a).

Pickling line/tandem cold mill for MMK,Russia with an annual capacity of morethan 2 million t of cold strip.

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PICKLING LINE/TANDEM COLD MILL PICKLING LINE/TANDEM COLD MILL at Baosteel

Pickling line/tandem cold mill for cold rolling complex No. 5

It started up ahead of schedule and passed the acceptance tests with flying colors. That was why Baoshan Iron &Steel Company issued SMS Siemag with the approval certificate for the pickling line/tandem cold mill at an early date,in April 2009. Ever since, the plant has been producing materials including high-quality, high-strength cold strip forautomotive panels. The strip is also used in the construction industry or for electro-technical applications. Commission-ing and start-up went like a dream. Not only was the production line put into operation two months before the sched-uled deadline, but the optimization phase was also short and wrapped up successfully with the final approval tests.

Third pickling line/tandem

cold mill for Baosteel

The five-stand pickling line/tandemcold mill is the fifth plant SMSSiemag has supplied for the Baosteelcold rolling complex in Shanghai.Also included in the package were acontinuous annealing line and severalstrip processing plants. This was thethird pickling plant from SMS Siemagfor the Baosteel group.

Highlights of the

pickling line

A double payoff group optimizes thecoil infeed times in the entry area,increasing the plant flexibility. Thenthe integrated scale breaker breaksup the scale and shortens the pick-ling process. That improves strip flat-ness so that the strip runs smoothlyinto the pickling channel. Equippedwith turbulence technology, the pick-ling section stands out for excellenteffectiveness at minimized operatingcosts. It is important to keep thegeneration of acid vapor as low aspossible. This is where the patentedimmersion cover comes in, because

it seals off the acid bath in the pick-ling channel. Right in the exit area,there is an automatic ASC side trim-mer with a time-saving rapidchangeover system for the blades.

High-tech components in

the tandem rolling mill

All five six-high stands in the picklingtandem mill feature our CVC® plustechnology. They are built in our prac-tice-proven modular design. A multi-zone cooling system in the final millstand ensures the ultimate strip flat-ness. Next in line, the Dry-Strip-Sys-tem produces a dry strip surface free

of emulsion marks. That happensentirely contact-free, while the strip is protected from the emulsion by aprecisely controlled air flow. Thecarousel coiler in the exit area of thetandem mill effects fast coil changes.Finally, the strip inspection linemakes quality control easy and reli-able. This ensures the strip qualitymeets high customer requirements.

A finished coil is transported awaywhile the carousel coiler is alreadywinding the next coil.


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BaosteelCommissioning 2008Material CQ, DQ, DDQ, EDDQ,

SEDDQ, HSS, BH, DP, TRIPStrip width 700 to 1,630 mmStrip thickness (entry) 1.6 to 6.0 mmStrip thickness (exit) 0.25 to 2.3 mmCapacity 1,740,000 t/a

Speed:Entry 700 m/minProcess 270 m/minExit 1,400 m/min

The strip enters the pickling tank.

The scale breaker breaks up thescale for better strip geometry.

Inspection of the pickledstrip.

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PICKLING LINE/TANDEM COLD MILLPICKLING LINE/TANDEM COLD MILL for China Shougang Corporation

Green technology for high-quality cold strip

The China Shougang Corporation is setting new standards in Beijing with its clean plants from SMS Siemag,not least when it comes to green technology. Shougang has decided not to extend its old works complex in thewest of Beijing and has relocated to the east of the city. This is where a consortium headed by SMS Siemagerected a state-of-the-art pickling line/tandem cold mill and a continuous annealing line for high-quality cold stripwith excellent deep-drawing properties. Now Shougang can produce some 1.8 million t of deep-drawing coldstrip on its new production plants.

Turbulence pickling

section

The line starts with a payoff groupconsisting of two coilers. Next, the laser welding machine createsthe endless strip that is fed into the entry looper at speeds of up to700 m/min. A scale breaker breaksup the scale ready for the picklingprocess. Then the strip enters theturbulence pickling section at a rateof 230 m/min. The triple benefits:low acid consumption, low acidtemperature, and high picklingeffectiveness. What makes this possible is the turbulence picklingprocess with its shallow pickling

tanks and patented immersion cov-ers. Downstream, the rinsing anddrying units remove residual acidand dry the strip. Next in line areanother horizontal looper, a sidetrimmer, and an inspection station.

Tandem mill

Another looper after the inspectionsection stores strip between theplant parts. Leaving the looper, thestrip travels through the five-standrolling mill. There it is rolled to itsfinal thickness under a maximumrolling force of 33 MN. The millstands are of a six-high constructiontype – featuring work, intermediate

and backup rolls. Each stand isequipped with the very latest rollingtechnologies.

Included here are CVC® plus com-ponents as well as interim and work roll bending devices. Theresult: a flat strip surface and stripthicknesses within narrow toler-ances. The plant’s green credentialsare underlined by the rolling emul-sion removal and regeneration sys-tems. Next, the rotary shear cutsthe strip into lengths at high speed.These are then coiled on a compactcarousel coiler.

Double-headed side trimmer. Turbulence pickling tankswith circulation system.


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China Shougang Corporation PLTCMCommissioning 2008Material CQ, DQ, DDQ, EDDQ,

SEDDQ, HSS, BH, DP, TRIPStrip width 800 to 2,080 mmStrip thickness (entry) 1.6 to 6.0 mmStrip thickness (exit) 0.2 to 2.5Capacity 1,870,000 t/aSpeed:Entry 700 m/minProcess 230 m/minExit 1,400 m/min

Double entry area and stripflattener with scale extractor.

Five-stand CVC® plus tandem mill.

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COUPLED PICKLING LINE/TANDEM COLD MILLCOUPLED PICKLING LINE/TANDEM COLD MILLat Tianjin Tiantie

More than 1.6 million t of cold strip per year

Following successful approval tests, in September 2008 Tianjin Tiantie Metallurgical Group Steel Plate Company inTianjin, north-eastern China, put its first coupled pickling line/tandem cold mill into continuous production. The coldstrip manufactured here is mainly used in the automotive and white goods industries. Previously, in March 2006, Minmetals International Tendering Co. awarded the contract for construction of the plant to a consortium led bySMS Siemag.

Approval four months

after commissioning

The first strip rolled off the plant inMay 2008. During this first cam-paign, 660 t of strip was pickled androlled. That is equivalent to a produc-tion rate of approx. 290 t/h, signifi-cantly higher than the specified tar-get figure of 274.5 t/h. According to the availability of the strip types to be processed, almost 90 % of allthe approval tests were successfullycompleted by the end of July 2008.Finally, in September, just fourmonths after commissioning, theplant was fully optimized, theapproval tests passed, and the cus-tomer approval granted. The plantalso fully met the required parame-ters such as gage performance, off-gage-length, and flatness perform-ance.

Scope of supply

and services

Included in the supply scope of SMSSiemag were the design and supplyof mechanical equipment for theentire plant, as well as supervision of installation and commissioning.Equally crucially, we were responsi-

ble for coordinating all deliveriesand work by the consortium mem-bers.

Continuous process

To guarantee the continuous processthat significantly increases the prod-uct quality while slashing energyconsumption, the plant features alaser welding machine and three hor-izontal loopers. Among the compo-nents SMS Siemag supplied for thepickling section were a scale breakerwith clamped drive system, a turbu-lence pickling plant with pickling

model, and a side trimmer. The tur-bulence pickling plant features ourpatented energy-saving immersioncovers. They ensure compliancewith tough environment regulations.Also part of our supply scope werethe mill stands with CVC® plus tech-nology, Dry Strip System, and modu-lar stand piping, as well as a rotaryshear and carousel coiler.

Pickling plant immersioncover.


25

Tianjin Tiantie PLTCMCommissioning 2008Material CQ, DQ, DDQ,

EDDQ, HSS, IFStrip width 730 to 1,600 mmStrip thickness (entry) 1.5 to 6.0 mmStrip thickness (exit) 0.25 to 2.0 mmCapacity 1,640,000 t/a

Speed:Entry 650 m/minProcess 220 m/minExit 1,250 m/min

Entry section.Scale breaker.

The strip travels through the process section at a continuous speed of 220 m/min.

Side trimmer with bladechanging device.

26

CONTINUOUS PICKLING LINE WITH ACID REGENERATION CONTINUOUS PICKLING LINE WITH ACID REGENERATION at Salzgitter steel production location

Top productivity and flexibility

Salzgitter Flachstahl GmbH is the largest subsidiary of Salzgitter AG. It manufactures a wide range of conven-tional and innovative flat products geared to customer requirements. This explains why Salzgitter Flachstahlinsists on top plant technology. SMS Siemag installed a new continuous pickling plant that provides the stripwith flawless surfaces in preparation for the downstream processes.

Technological highlights

Salzgitter defined very specialrequirements of the technology andcapabilities of the plant. Includedamong the highlights is the highcapacity of 2.5 million t per year.The plant can handle a huge prod-uct range, also covering innovative,high-strength and high-yield-strength steel grades.

Developed by SMS Siemag, thelaser welding machine easily dealswith this extremely challengingproduct mix. It produces gradessuch as C60 and C67. To cope withthe high speed of 650 m/min in theentry area, the plant features loopcarriages that can move at rates ofup to 145 m/min.

Plant components

Essentially, the plant consists oftwo payoff reels, an SMS Siemagwelding machine, a horizontal entrylooper, a tension leveler, a turbu-lence pickling section with fourpickling tanks followed by a cas-cade rinsing unit and dryer, an exitlooper, a side trimmer, an inspec-tion station, an oiling machine, and a coiler. It also comes with awhole raft of measuring, control,and surface inspection systems, aswell as equipment for labeling andpackaging.

Fluidized bed acid

regeneration

You can imagine that, in a picklingline of this capacity, large quantitiesof used hydrochloric acid and rins-ing water are generated. That’s whySMS Process Technologies addedan acid regeneration plant.

It uses the fluidized bed process toregenerate up to 12 cubic meters ofspent acid per hour with a recoveryrate of almost 100 percent.

Without this plant, the pickling linewould need to be refilled every daywith many truckloads of acid. Yetit’s not only about the acid. Theregeneration plant also recovers theiron removed from the strip. Thiscan then be recycled in the form ofiron oxide granulate in further steelproduction.


Coil preparation inthe entry section.

27

Salzgitter CPLCommissioning 2008Material CQ, DQ, DDQ, EDDQ,

SEDDQ, HSS, DPStrip width 800 to 1,900 mmStrip thickness 1.5 to 6.0 mmCapacity 2,500,000 t/a

Speed:Entry 650 m/minProcess 250 m/minExit 500 m/min

Circulation tank.View of the plant from the entry side.Exit section.

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CONTINUOUS PICKLING LINE WITH ACID REGENERATIONPLANT

CONTINUOUS PICKLING LINE WITH ACID REGENERATIONPLANT for Tokyo Steel

August 2011 saw the first strip processed on the continuous turbulence pickling line SMS Siemag had erected forTokyo Steel in Japan. Operating in continuous production, the pickling line achieves an annual capacity of 1.8 million t.Right from the start, the plant foundations were designed to allow for a possible future coupling with a tandem mill.Furthermore, SMS Siemag Process Technologies installed an acid regeneration plant that uses the spray-roastingprocess to regenerate 10,000 liters of acid per hour from the pickling plant and to feed it back into the process.

SMS Siemag laser weld-

ing machine

A highlight of the line is the newlydeveloped laser welding machine.During commissioning, all the con-tractually specified material combina-tions were successfully joined. Evenstrips with thickness differences ofup to 1.5 mm were perfectly weldedtogether. The new machine featuresvarious innovative extras, for exam-ple determination of the weldingparameters based on a smelt analy-sis, inductive heat treatment of theseam, or an integrated weld seamevaluation system.

Hydraulic scale breaker

Here, before infeed into the turbu-lence pickling section, a scalebreaker breaks up the scale on thestrip surface and improves the strip

flatness. Incidentally, the scalebreaker at Tokyo Steel is the first ofits type to feature completelyhydraulic regulation. That means itcan be adjusted very flexibly.

Recuperator tank

Now, before it enters the turbulencepickling tanks, the strip runs throughthe patented recuperator tank whereit is sprayed with used acid from thepickling process. This pre-cleaningremoves above all large pieces ofscale so that they do not go into thepickling tank and contaminate thepickling acid. Moreover, this stagepre-heats and activates the strip.

Turbulence pickling

section

Each of the three turbulence pickling tanks is 35 m long andequipped with racks of nozzles thatspray acid heated to 80 - 85 °C intothe shallow pickling channel. Thissection is followed by a 20-metercascade rinsing unit. Then the stripis dried with hot air.

SMS Siemag laser weldingmachine at Tokyo Steel.

Plant components

Two entry coilers, a laser weldingmachine, horizontal entry looper,scale breaker, turbulence picklingsection, horizontal exit looper, sidetrimmer, Duma-Bandzink oilingmachine, flying crank shear, and twocoilers.

Tokyo Steel in Tahara

The new Tokyo Steel complex inAichi Prefecture on the Atsumipeninsula mainly produces flat prod-ucts. These materials are destinedabove all for the automotive manu-facturing works in the industrialregion around Toyohashi.


29

Tokyo Steel CPLCommissioning 2011 Material Low carbon steelStrip width 780 to 1,630 mmStrip thickness 1.5 to 6.0 mmCapacity 1,800,000 t/a


The hydraulically controlled scalebreaker breaks up the scale on thesurface and increases flatness.

Open turbulence tank withimmersion covers.

Entry area of the continuous pickling line.

View of the scale breakerand entry area in the turbu-lence pickling section.

30

SEMI-CONTINUOUSPICKLING LINESEMI-CONTINUOUS PICKLING LINE for Gazi Metal

New cold rolling complex

for Gazi Metal

Gazi Metal Mamülleri contractedSMS Siemag in April 2011 to supplya new cold strip production plantnear the town of Karazu in Turkey.Starting in 2013, it will produce car-bon and silicon steel strip, achievingan initial total capacity of 350,000 t/a.Gazi Metal Mamülleri is set to supplyfor instance the automotive industryand manufacturers of householdappliances. SMS Siemag will supplyall the core components along withdrive technology and automation.Included in the supply package forthe first stage are a semi-continuouspickling line with integrated acidregeneration plant, a CVC® plus six-high reversing cold rolling mill, and askin-passing mill in four-high con-struction type.

Semi-continuous

pickling line

The entry area of the semi-continu-ous pickling line features two payoffreels and one stitcher that joins theindividual strips. Next in line, theprocess section consists of a 35-ttension leveler and a turbulencepickling section containing three 18-meter plastic pickling tanks, a 5-stage cascade rinsing unit, and astrip dryer. Finally, the pickled stripgoes through a side trimmer, aninspection station, and a Duma-Bandzink oiling machine before it is cut by a cross-cutting shear andcoiled on a coiler using a belt wrapper.

Integrated before and after theprocess section are two horizontalloopers with looper carriages. Dur-ing stoppages in the entry and exit

areas, they can supply strip to theprocess or take up strip from theprocess. These loopers aredesigned to ensure the process canalways run at a speed of at least 30m/min.

Already planned is a second stagewhich will convert the plant fromsemi-continuous to continuousoperation, and all the requirementsfor this were created right from thestart. The upgrade will involveextending the two horizontal loop-ers and integrating a laser weldingmachine into the entry area. Then itwill be possible to transport thestrip through the process at a per-manent speed of 140 m/min, dou-bling the capacity of the plant. Themaximum speed in the entry andexit areas will increase to 220m/min.

Diagram of the semi-continuouspickling line.


31

Gazi Metal Mamülleri S-CPLCommissioning 2013 (planned)Material CQ, DQ, DDQ, EDDQ, HSLA,

low-carbon steel grades,NGO electrical steel strip

Strip width 600 to 1,550 mmStrip thickness 1.5 to 6.0 mmCapacity 350,000 t/a


Fluidized bed acid

regeneration

To recondition the used, iron-enriched hydrochloric acid from thepickling process, SMS SiemagProcess Technologies is supplyingan acid regeneration plant. It isdesigned to regenerate 1,700 l/h,coping with all the acid consumedby the semi-continuous pickling line.Operating according to the fluidizedbed process, the plant is equippedwith the latest technology for emis-sion control and energy consump-tion optimization.

Once the second construction stagehas been completed, a second plantwith the same capacity will beinstalled to regenerate the doubledvolume of acid used in the continu-ous pickling line.

Entry area with two payoffreels and a stitcher.

Exit side of the picklingline.

32

PUSH-PULL-PICKLING LINE PUSH-PULL-PICKLING LINE at Severstal Columbus

Push-pull-pickling line successfully commissioned

In November 2011, the new push-pull-pickling line at Severstal Columbus successfully produced its first coil.Using this plant, the company can now pay off, level, pickle, trim, and re-coil hot strip in widths of up to 1.880mm. The up to 12.7-mm thick strips travel discontinuously through the plant at a rate of as much as 152 m/min.Included in the planned range of materials are soft deep-drawing grades, IF steels, and modern high-strengthsteels. The annual capacity achievable with this material mix is 540,000 t.

Flexible production

There are three main benefits of thediscontinuous production method:great flexibility in production plan-ning, a wide range of materials, andthe easy production of thick strip. It is not necessary during produc-tion planning to take account of thedifferent geometrical dimensionsand qualities of subsequent stripsbecause they are not weldedtogether. That means even steelgrades that are difficult or impossi-ble to weld can be processed.

The strip runs horizontally withoutbending, so even very thick stripcan be treated without the bendinglosses that otherwise occur. Sever-stal Columbus not only increases its pickling capacity with the plant,but it can also expand its productrange and react extremely flexibly to customer wishes.

Plastic tanks

A special feature of the plant arethe pickling tanks made of plastic in the turbulence pickling section.There are granite blocks on thewalls and floor to protect the tanksfrom mechanical wear. The advan-tages of plastic tanks are their lightweight and easy installation. Unlikeconventional solutions with graniteblocks, bricks, cement, acid-resis-tant rubber, and steel, the plastictanks do not require masonry orcementing work.

The new push-pull-pickling line processesstrip up to 12.7 mm thick.


33

Severstal Columbus PPPLCommissioning 2011 Material CQ, DQ, DDQ, EDDQ,

HSLA, IF, HSSStrip width 1,880 mmStrip thickness 1.4 to 12.7 mmCapacity 540,000 t/a

Speed:Process 120 m/min

Turbulence pickling

section

Looked at in terms of the process,turbulence pickling technology inpush-pull-pickling comes with thefollowing advantages:

The strip runs through a com-pletely enclosed, shallow granitechannel. Due to the V-shapedgranite profile, even thin and softsteel strip is safely transportedduring feeding in. The heavygranite covers prevent the stripfrom buckling and support thefeed-in process.

The high turbulence in the narrowpickling channel intensifies thepickling process and shortens thepickling time. Because the turbu-lence pickling channel is com-pletely filled with acid, the steelstrip is covered from the entry tothe exit.

The granite covers are immersedin the acid and seal off the evapo-ration surface, minimizing heatand acid losses caused by evapo-ration.

The hydrodynamic sealing mini-mizes the acid quantities on thesqueezing rolls. This preventsthat acid escapes from thesqueeze rolls out of the tank.

Coiling the first coils pickled on the newpush-pickling line at Severstal Columbus.

SMS Siemag erected the entire works for Severstal Columbus – consisting of not only thepush-pull-pickling line but also a pickling line/tandem cold mill (see box).

34

REFERENCES SINCE 2000REFERENCES SINCE 2000Pickling lines for carbon steel

Date of Customer Products order

2012 HABAS Aliaga Izmir, Turkey Hot-rolled steel strip

2011 Gazi Metal Mamülleri, Turkey CQ, DQ, DDQ, EDDQ, HSLA, low-carbon steel grades, NGO

2011 JSW Steel, India CQ, DQ, DDQ, EDDQ, SEDDQ, IF, HSS, BH, DP, TRIP, CP

2010 Bhushan Steel, India CQ, DQ, DDQ, EDDQ, SEDDQ, IF, HSS, BH, DP, TRIP, NGO-Si-steel

2008 Shougang Jingtang, China CQ, DQ, DDQ, EDDQ, SEDDQ, IF, HSS, BH, DP, TRIP

2008 Severstal Columbus, USA CQ, DQ, DDQ, EDDQ, IF, HSS

2007 Handan Iron & Steel, China CQ, DQ, DDQ, EDDQ, SEDDQ, IF, HSS, BH, DP, TRIP

2007 ThyssenKrupp Steel USA, USA CQ, DQ, DDQ, EDDQ, IF, HSLA, HSS, DP

2007 ThyssenKrupp Steel USA, USA IF, HSLA, HSS, DP

2007 Ilva Cornigliano, Italy Low-carbon steel grades

2007 MMK, Russia CQ, DQ, DDQ, EDDQ, SEDDQ, IF, HSLA, BH, CP, DP, TRIP

2007 Tokyo Steel, Japan Low-carbon steel grades

2007 US Steel Serbia, Serbia Hot-rolled steel strip

2006 Tianjin Tiantie, China CQ, DQ, DDQ, EDDQ, HSS, IF

2006 Salzgitter Flachstahl, Germany CQ, DQ, DDQ, EDDQ, SEDDQ, HSS, BH, DP

2006 CD Wälzholz, Germany Hot-rolled steel strip

2006 CD Wälzholz, Germany Hot-rolled steel strip

2005 Baoshan Iron & Steel, China CQ, DQ, DDQ, EDDQ, SEDDQ, HSS, BH, DP, TRIP

2005 ArcelorMittal Bremen, Germany CQ, DQ, DDQ, EDDQ, IF, HSS

2005 Severstal Columbus, USA CQ, DQ, DDQ, EDDQ, IF, HSS

2005 China Shougang Corporation, China CQ, DQ, DDQ, EDDQ, SEDDQ, HSS, BH, DP, TRIP

2004 Jinan, China CQ, DQ, DDQ, HSS, EDDQ, SEDDQ, TRIP, IF

2004 Nakornthai Strip Mill, Thailand Hot-rolled steel strip

2003 Wuhan Iron & Steel, China CQ, DQ, DDQ, EDDQ, SEDDQ, IF, HSS, BH, DP

2003 Baotou Iron & Steel, China CQ, DQ, DDQ, HSLA, HSS

2003 Sahaviriya Steel Industries, Thailand Low-carbon and medium steel grades

2003 IMSA-MEX SA, Mexico HSLA

2003 Galvasid, Mexico Hot-rolled steel strip

2002 Handan Iron & Steel, China Hot-rolled steel strip

2001 VEGA Do Sul, Brazil Low-carbon steel grades

2001 Mobarakeh Steel, Iran Low-carbon steel grades

2001 Cargill Steel & Wire, USA Low-carbon steel grades

2001 CISA, Brazil Low-carbon and medium steel grades

2000 Nelson Steel, Canada HSLA


35

Strip dimensions [mm] Speed [m/min] Annual Line conceptWidth Thickness Entry Process Exit production [t/a]

700 - 2,100 1.2 - 16.0 / 150 / 500,000 Push-pull-pickling line

600 - 1,550 1.5 - 6.0 120 100 120 350,000 Semi-cont. pickling line

830 - 1,890 1.5 - 6.5 / 0.3 - 2.6 750 300 1,450 2,300,000 Pickling line/tandem cold mill



1,880 1.4 - 12.7 / 152 / 540,000 Push-pull-pickling line



900 - 1,870 1.5 - 6.0 170 110 145 1,100,000 Continuous pickling line

700 - 1,650 1.8 - 5.5 / 0.27 - 2.,5 500 250 1,440 1,300,000 Pickling line/tandem cold mill



710 -1,600 1.5 - 6.0 300 125 175 250,000 Cont. pickling line (mod.)



1,350 up to 12.0 / 120 / 350,000 Push-pull-pickling line (mod.)

650 up to 12.0 / 45 / 150,000 Push-pull-pickling line (mod.)


600 - 2,120 1.5 - 7.0 / 260 / 2,000,000 Cont. pickling line (mod.)





830 - 2,080 1.5 - 6.0 700 270 1,400 2,300,000 Pickling line/tandem cold mill






750 - 1,875 1.2 - 4.8 / 0.4 - 2.0 550 125 850 880,000 Pickling line/tandem cold mill

570 - 1,680 1.2 - 5.3 / 260 / 1,100,000 Continuous pickling line

1,830 1.27 - 12.7 / 152 / 500,000 Push-pull-pickling line (mod.)



W7/31

7E

1500

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rinted in German

y

MEETING your EXPECTATIONS

SMS SIEMAG AG

Strip Processing Lines Division

Walder Strasse 5340724 Hilden, Germany

Phone: +49 211 881-4618Telefax: +49 211 881-4212

E-mail: [email protected]: www.sms-siemag.com

“The information provided in this brochure contains a general description of the performance characteristics of the products concerned. The actual products may not always have thesecharacteristics as described and, in particular, these may change as a result of further developments of the products. The provision of this information is not intended to have and willnot have legal effect. An obligation to deliver products having particular characteristics shall only exist if expressly agreed in the terms of the contract.”

Documents

TURBULENCE PICKLING LINES FOR CARBON STEELsiemag.sms-group.com/...Turbulence_Pickling_Lines_for_Carbon_Ste… · section. The advantages of this discontinuous production method are