Continuous Casting Theory

8/13/2019 Continuous Casting Theory

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Continuous Casting - Continuous Development

Dieter Senk

RWTH Aachen University, Dept. of Ferrous Metallurgy, Chair of Iron and Steel Metallurgy*

AbstractContinuous casting means continuous development. The coordinated work in designing,

operation, and research led to a fast success of a new technology during 30 years after a 100

years period of basic inventing and testing. Continuous casting of steel is the team play of

metallurgy, mechanical and electrical engineering, and all kinds of information technology.

Common R&D projects generated knowledge and transfer of results to daily operation.

Starting from roots and simple tests CC today is a technology which shows up with high

reliability. More wishes of steel producers, but also improvement ideas from research

institutes, focuses the intention of development on widening the technological windows, on

pushing technical boundaries of productivity, product geometry and quality, on automation of

steelmaking concerning melt preparation, casting, and rolling. Due to the rising complexity ofstrict supply chains and the applied surveillance by computer programs, the fundamental

education as well as continuous training of involved staff becomes more and more important.

In this paper, the way of continuous development shall be assigned and some modern

continuous casting equipment is high lighted.

1. Meeting the continuity

Metal production, particularly steel making, should be done without interruption. Switch-on a

steel plant, let it run, sell the goods, make the money, switch it off if the demand decreases.

That was already the concept of Mr. Henry Ford which came along with his ‘assembly line’ in

1913 when he designed his famous continuous car manufacturing line.

The people operating shaft furnaces for iron making in the first step of steel production

showed up with charging by trolleys, one after the other, while liquid hot metal was tapped in

batches, but continuously charging by conveyer belt was applied first in the 1970th. But today

the flow is interrupted by using torpedo cars for transportation. Further approaches come from

solid sponge iron made by direct reduction processes or addition of scrap with a subsequently

located electrical smelter.

Steel making using batch converters is a business that started from the mid-19th century and

last until now. A few ideas on continuous treatment of hot metal using oxygen and slag have been tested about 1970, e. g. Aachen counter flow runner with steel upward by

electromagnetic linear fields and slag downward by natural gravity [1]. Ladles are used for

metallurgical treatment of the steel melts in precisely working batch process steps,

individually concerned to one of those 3000 different steel grades on demand, ready to cast.

The casting people change between liquid and solid matter, and they looked for machines

with an input funnel on one side and a rolling mill on the exit side to make the steels semis in

one endless step. The way from single ingots to continuous strands was long but without

interruption; the goal was clear, and the commercial savings, too. The way started already in

* Email: [email protected] . Fon: 0049-241-8095792 . Fax : 0049-241-8092368



the middle of 19th century, and the dream of uninterrupted controlled solidification and inline

forming came true about 150 years later.

2. Shy start-up, courageous progress

The strip casting machine of Henry Bessemer from 1846 (resp. 1856) was invented to

produce metal sheet directly from melt using moving mould drums [2,3]. But the thin stripswere not convenient to produce ship vessels, railway components or structural parts for civil

engineering, thicker sheet has been asked for. Automobiles have not been invented at that

time, as well as household goods like washing machines or refrigerators, and roof layers in

Europe were made by wood or bricks, like today.

But in mid-20th century the demand on steel sheet, wire for concrete strengthening, and tubes

increased heavily, so that the world wide steel production increased, too.

Moulds are used since the first steel ingots were to be manufactured. The ingots must be pre-

rolled, re-heated and finally rolled. And due to the long solidification time of ingots the

number of filled moulds was soon fiercely multiplied (Fig. 1). A 10 t ingot of 2.5 m heightand 70 cm in square needs about 3.5 hours to solidify completely before stripping. Convertors

delivered more liquid steel at increased frequency and tonnage. And the yield after cutting

head and tail was about 85 % before hot rolling; the off-cut is scrap.

There were some ideas and technical approaches to strip the ingot with liquid core, and also,

further-on, to pour fresh melt into the new free space. But broken shells, poor surface quality

by sticking of steel to the cast iron mould walls let those trials stop quickly. The way to use an

open vertically tube led to visions of casting machines, e. g. by B. Athena (1886) or M.

Daelen (1889) (Fig. 1) [4,5]. The relative movement and friction had to be controlled to avoid

breakouts of the shell; tube oscillation by the car motor engineer C. W. van Ranst (1921) [6]

with some lubrication worked better, and finally the invention of mould oscillation made the

things fine: Mould speed downward was the same as the strand moved to let a shell stabilize a

moment, and than the mould returned rapidly upward to escort the strand again (Dr. h.c.

Siegfried Junghans, 1933, 1943) [7,5].

The beginning of CC technology was probable the meeting of Irving Rossi, the future founder

of the Concast company, and Siegfried Junghans in Germany in 1936 [5]; Rossi was the

typical enterpriser and businessman, Junghans a man who found technical solutions; in their

contract of co-operation the optional marketing areas have been devided out. Since that

process worked in priciple, pilot plants were installed in many countries, and in the decade of

1951 to 1961 industrial operated casters are reported in Russia, England, Canada, Germany,and Italy.

Early inventions and developments were made for curved moulds (1963) of copper alloys for

bow type casters [5], electromagnetic stirring and bending the strand from vertical to

horizontal position during operation.

The casting machines of Rossi’s Concast company, founded 1954, aimed on the mini steel

mills using an electric arc furnace for scrap melting with an annual capacity of about

40.000 t/y using 20 t EAF, first in 1956 at Barrow, UK [5,8,9] (Fig. 2).

The cross sections in the 1960s were already square or round billets, or slabs with 200 mm

and even 250 mm thickness, in a vertical bending mode (Fig. 3). Number of parallel billetstrands ranged from 1 to 8; and even centrifugal casting has been tested. Eventually, in 1970



the restless development of suppliers, steel producers and research institutes led to the

situation that 4 % of world steel production was continuously solidified.

The furious development in those days came to realization by restless inventions and brave,

courageous tests of ideas directly in steel plants. Trial and error were the daily business of the

well interested engineers and operators of that brand new technology, thirsty of knowledge.They had to learn about heat transfer and cooling intensity, shrouding the steel melt against

air contact, mould lubrication, de-oxidation and killing of the melt, and last but not least about

the specific solidification behaviour of each steel grade.

3. Glorious rise

Latest with appearance of extra large blast furnaces and oxygen blowing converters in big size

revamped steel works and green field installation the change from well established ingot

teeming group cast to the new continuously running process had to be performed. More than

300 t per heat and converter with a sequence rate of 40 minutes made the implementation of

2-strand slab casters necessary; thickness was already more than 250 mm, or 6-strand bloom

casters; for stainless steel slabs thickness was at about 150 mm.

The annual increase rate of CC was about 20 mio t of steel between 1970 and 2000 when the

ingot/CC rate decreased from 24 to 0.1. Some authors even prognosticated that all steel will

be cast on CC machines. While in Europe, USA and USSR the large steel producers had to

change their production plants from group ingot casting to continuous casting, the young and

raising steel industry in Japan, South Korea and Taiwan adapted immediately the new

technology so that new green field installations came up year by year. In 1980, the ratio of CC

in Japan was already 58 %, in Europe at 35 % at the same total steel production amount [10].

In those days the development was turned on more sophisticated basis. In USA research on

CC fundamentals was carried out also at the MIT, and big steel producers like US-Steel

employed numerous scientists in big R&D departments to solve metallurgical problems

instantaneously. In Europe, the famous ECSC fund on research about coal and steel supported

the intensified co-working between caster suppliers, steel producers and research institutes.

The intensive international collaboration of different companies and universities in more and

more European countries made sure that results could be exchanged and discussed freely

between the experts. Transfer of knowledge worked instantaneously.

The collaboration on CC development did not stop at the borders of nations or continents;

workshops, conferences and cooperation agreements between companies spread new findings

from west to east and around the globe. There was strong exchange of new findings inworkshops and conferences between European companies and Japanese, later South Korean

ones; engineers have been exchanged, too. VDEh in Germany and ISIJ in Japan are two

associations collaborating since more than 40 years ago.

Not only the casting process had to be engineered but also the customers had to be convinced

that the semi-products had the same or even a higher quality level as the well known ones

made by ingot hot rolling and forging. E. g. rails for railway construction, pipeline tubes or

camshafts for automobile motors are sensible goods, and the new process was very suspicious

in the eyes of costumers concerning demanded quality. New patents came up daily. Also the

employees and young upcoming engineers had to be instructed and trained in the new field of

CC machine design, operation, and strand quality of steel materials.



4. Infinite wishes

As soon as the CC processes of slab, bloom and billet casting could run at good reliability end

of 1970s and begin of 1980s, new wishes came up immediately. The following frequently

asked questions from steel producers are listed here:

- Can we save or suppress further hot rolling effort?

- Can we cast all steel grades for all purposes continuously?- How can we increase productivity?

- How can we overcome recent limits in width, thickness, and casting velocity?

- Can we cast infinite strands?

- Can we couple casting and subsequent forming processes in one integrated machine?

- Can we run the processes fully automated?

Those questions led immediately to new design of complete casters, caster components like

mould or bending units, or on new processes adapted from old ideas, patents, and processes

from non-ferrous metal industry.

The development took three different ways from now, but in all cases nearer to the final shapeof semi-products: 1) thicker and wider, 2) thinner, 3) pre-shaped.

There was good progress to increase thickness from 200 mm (1962) and 250 mm (1964) to

300 mm after 20 years in the early 1980s to produce heavy plate by CC slabs [11]. Different

solutions are possible (Fig. 4). Of course, there were ideas to increase to thicker slabs, but it

took about another 15 years to meet 400 mm thickness (1998) [12], then 10 more years for

450 mm (2010) [13], at least 5 more years for 500 mm [14]. The base plates of civil

engineering were brought into the ground 10 m in the beginning, later 35 m and at least 50 m.

The other route of development, to cast thinner, started a great number of projects all around

the world. The intensive period of inventions and development lasted from 1980 to 2000. The

driving forces behind that unique power of innovation were

- Casting of steel grades which could not be produced on regular CC machines (i.e.

oscillation mould walls, long liquid crater, secondary strand cooling) and subsequent

rolling steps, e. g. high silicon alloyed grades with also high brittleness.

- Produce thin strip gauges, down to 50-80 µm or 200 µm directly from the steel melt to

suppress cold rolling, grinding and annealing steps. Make metallic glasses.

- Suppress hot rolling steps, produce directly a hot strip of stainless steel with a thickness

of 1-3 mm which should be cold rolled subsequently.

- Suppress slab-to-strip pre-rolling, deliver thin slabs directly to the finishing train of a hot

rolling mill. If possible, combine casting and rolling to one single machine.

One more the development took two branches: on one hand starting from thin gauges with

moveable mould walls like Bessemer already did, on the other hand diminishing slab

thickness as far as possible, using the well known oscillating mould concept. Many

companies and research institutes supported by national foundations all around the globe

invented processes for steel casting in the shape of thin slabs, strips and thin strips, or wire.

The principles of moving walls have been taken from Bessemer’s Twin Roll Caster using one

or two water cooled rollers, from Hazelett’s double belt caster for Zinc or Copper with two or

one belt, and from caterpillar systems. Even a casting machine on the basis of a Dwight-Lloyd

sinter machine has been tested, or the Osprey process using sprayed steel droplets to producea strip was in development, a forerunner of the modern 3D-printing process. Wire has been



produced by thin round moulds in horizontal casters or by squeezing a melt jet into a rotating

water filled ring. There were two decades to test many different principles of direct or so-

called near-net-shape casting [15] (Fig. 5). At least, the thin slab casting process and beam

blank production are now well established. Special solutions are horizontal or rotation casting

to serve only a few single requirements.

The demand on full automation of the casting process led to application of measurement and

acting systems. There are several zones of interest in CC machines:

- Mould with steel level and temperature field, including heat flux from steel strand to

cooling water.

- Mould-strand friction and mould distortion.

- For each case an optimized mould oscillation and casting flux properties

- Mass flow and casting velocity; high productivity; strand length; strand support.

- Superheat of the melt and controlled fluid flow in the mould.

- Surface temperature field, water flow intensity and homogeneity.

- Resulting contractions or expansions of the shell.

- Bending and unbending forces; resulting stress and strain and their rates.- Fraction of solid in the centre area. Position of the crater-end.

- Segregation control.

For all those issues the special knowledge, the measurement techniques and sensors, the

strategic and tactic concepts and the integration into operation systems had to be found.

5. Knowledge generation

The knowledge about steel solidification in ingot moulds was well developed in the 1960s.

The basic fundamentals were phase diagrams describing the concentration differences

between liquid and solid, the formation of nuclei and growth of crystals, all more or less on

the long term of solidification, near to thermodynamic equilibrium.

Continuous casting changed the situation concerning higher solidification and cooling rates, a

steel surface which was not removed be scaling in long pit annealing periods, and the strictly

change from rimmed to killed steel. In spite of some serious approaches to cast semi-rimmed

steel with a compact shell in the cc moulds the total de-oxidation with Aluminium became

rapidly the way of melt treatment instead of Mn-Si steel killing. But immediately new

problems arose from that method: clogging of open pouring nozzles and submerged entry

ones by alumina particles. The cleanliness became a serious problem, too, because alumina

tends to form relatively large clusters of up to 100 µm in diameter. The freshly invented ladle

metallurgy for steel melt preparation had to be developed including consequent vacuumapplication and alumina treatment by starting a Calcium treatment about 1980 [16].

The casting processes for the different shapes need general approaches, but also individual

ones:

Lubrication between mould and strand by oil and casting flux was investigated more and

more on the basis of physical-chemistry; so, special laboratory trials brought numerous data

and systematic understanding about the heat transfer and friction. Heat transfer from strand to

the mould cooling water taking into account copper wall properties and thickness was the key

to estimate the critical shell thickness at the mould exit.

Secondary cooling with spray water and subsequently water-air-mixtures was applied to thehot strand to remove the solidification enthalpy from the strand. Many investigations have



been carried out to understand the heat transfer mechanism and heat flux, the optimum water

nozzle designs and the optimized spray pattern. Optimal strand guiding to prevent bulging and

crack formation by bending and unbending were challenges which could be overcome only by

combined knowledge about mechanical behaviour of steel strand at high temperatures and

stress-strain analysis of the strand guiding process itself [17,18].

The transfer from one plant to others depending on casting velocity, steel grade, curve

geometry and other parameters needed on one hand a lot of trial-and-error development, on

the other hand the tool of modelling and simulation was required intensively. Step by step

since about 1970 mathematical models with numerical simulations of heat transfer, fluid

dynamics or crack sensibility have been developed at universities and in R&D departments of

steel makers or plant suppliers. The use of main frame computers and -a little later- of

personal computers became the essential tool of CC research. In the 20-year period between

1970 and 1990 more than 120 of those interdisciplinary research programs with more than 2

international partners have been sponsored by the European Commission to develop

continuous casting of steel grades; between 1993 and 2013 the number follower projects was

about another 70 projects [19,20]. Concerning very different steel grades like ULC- or high-Si-steels, medium alloyed tool steel, linepipe steel, ball bearing grades, stainless steels,

ferritec, austenic, duplex or peritectic grades the deeper understanding of solidification

behaviour and as-cast structure development was the goal of numerous research projects.

They provided data about the description of micro- and macro-segregation, control of

unwanted precipitation of nano- and micro-particles, crack avoidance, high steel cleanliness

or a smooth surface concerning pin holes or oscillation mark defects. Lots of special detailed

results are collected in the text book about continuous casting steel [21].

In parallel, the development of plant reliability and minimizing of cost in investment and

maintenance, in measurement techniques and automation of the casting process was steadily

ongoing and is recently one of the most important development issues.

6. Continuousness in steel production

The 1990s were impressed by international fusions and mergers between steel companies, and

the same thing happened to the steel plant suppliers like machine builders or refractory

material producers. Former competitors became colleagues in then one concern. The so-called

IT-hype had started, and the economy became clearly global. The recent situation in CC of

steel shows a stabilized technological and well organized field with well established and

experienced suppliers and steel makers, running reliable casters.

Today, the casting machine geometry for slab CC shows a metallurgical length of up to 45 m,slab width of 3225 mm at 150 mm thickness or 3000 mm at 280 mm thickness or 2200 mm at

450 mm respecting weight per meter of 3.5 to 7.1 t [22]. Dillinger Hütte Caster #6 ordered a

new vertical caster with the shape of 300-500 x 2200 mm, resp. 7.9 t/m [23].

In round bloom casting the diameters are up to 800 mm, resp. 3.6 t/m, (Fig. 6) and increasing.

Here, a substitution of ingot casting for forging applications is the goal taking the benefits of a

continuous process again. Beam blanks with beam heights of up to 1150 mm are cast

continuously [24,25]. High speed thin slab casting runs up to 7 m/min with a hot strip

thickness of less than 1 mm, including liquid core reduction for thinner slab gauges and 3

parallel strands working on one hot rolling mill (Fig. 7) [26]. Strip casting on twin roll casting

machines are able to produce directly with one inline hot rolling step a hot rolled strip of 1-1.5 mm in thickness and 1600 mm in width; a casting sequence of 24 heats, each 100 t of



plain carbon steel, has performed at Nucor with good quality results [27]. Also stainless steels

are castable in industrial operation [28,29,30]. As-cast weight is only 30 kg/m, but casting

velocity is 90 m/min.

Many other highlights occurred in CC technology [31], e.g. changing nozzles or tundishes ‘on

the fly’, casting floor operation by robots [32] (Fig. 8), detailed measurement and temperaturefield monitoring of the mould walls, so-called High Definition Mould (Fig. 9) [33]. Latest

commercial model is “Mould Screen®” [34,35], which gives online information about the slag

film between strand and mould by taking into account the casting parameters and data from

the mould cooling system. Crater end position is computed online, and a soft reduction in

exact position prevents of severe centre line segregation during final solidification. Those

models based on numerical simulation with the input of casting speed, cooling data, steel

grade and machine geometry, like “DSC®”[36], “Simetal Dynacs 3D®” or “MAGMAcont®”

[37]. Solidification behaviour of new steel grades is to be predicted by computation from first

physical principles and using models like the Phase Field Method [38,39]. The future

development in CC concerns measurement, modelling, and automation.

New ideas, test machines and pilot plant installations are showing up to increase productivity,

and new steel grades become producible. Those are RTSC [40,41] or BCT (Belt Cast

Technology) [42,43,44]. The coupling of casting and rolling has been carried, not only as

casting and subsequently rolling of cut slabs but also as a fully integrated process where the

hot strip is cut during coiling [45]; Cavalliere Arvedi succeeded at least in making his dream

of continuous steel casting and rolling true, like Eurostrip fulfilled the forecast of Sir Henry

Bessemer on the same issue [46].

References

1 H. Schenk, E. Steinmetz, J. Kuhn; Stahl und Eisen 89(1969), pp. 1185-1190;see also: ECSC-Project, „Verbesserung von Metall-Schlacke-Reaktionen durch Anwendung derGegenstrommetallurgie“, EUR Report 5304d (1976)

2 H. Bessemer;.„On the manufacture of continuous sheets of malleable iron and steel, direct from the fluid

metal“, Journal of Iron and Steel Institute (1891), pp. 23-41; see also Stahl und Eisen 11 (1891), pp. 921-9263 H. Bessemer; „Improvement in the manufacture of iron and steel“, US Patent Office, Patent n° 49,053 (1865)4 R. M. Daelen; „Schalen mit Wasserkühlung und bewegtem Boden für Güsse von Metall“, Kaiserliches

Patentamt Deutschland, Patent 51217 (1889)5 A.H. Tanner; „Revolution der Stahlindustrie: Strangguss“, Printhouse Neue Zürcher Zeitung, (1997)

6 “The Making, Shaping and Treating of Steel”, 10th ed.; edited by W.T. Lankford jr., N.L. Samways, R.F.

Craven, H.E. McGannon, USS, AISE, Printhouse Herbick&Held, Pittsburgh, PA, (1985), p. 742 7 S. Junghans; “Process for continuous casting of metal rods”, US Patent n° 2,135,183 (1938);8 I.M.D. Halliday; “The main issues of continuous casting”, Proc. Gen. Meeting Iron & Steel Inst. Nov. (1964)

9 H. Schrewe; “Stranggießen von Stahl”, Verlag Stahleisen, Düsseldorf (1987)10

See [6], p. 743 11 G. Holleis, K. Schwaha, W. Scheurecker; „Umbau und Modernisierung von Stranggießanlagen“, Proc.

Duisburger Stranggießtage 19./20.3.1987, pp. 35-6312 N. Bannenberg, B. Bergmann, K. Harste, J. Klingbeil, V. Schwinn; „Die neue Stranggießanlage der Dillinger

Hütte als Vorstufe zur Erzeugung von Grobblechen mit höchster Qualität“, Stahl und Eisen 120(2000)2, pp.53-50

13 See [22]

14 See [22]15 J.P. Birat, R. Steffen, S. Wilmotte; “State of the art and developments in near-net-shape casting of flat

products”, ECSC Rep. EUR 16671, Luxemburg (1995)16

G.J. Kor; “Calcium Treatment of steels for castability”, Proc. 1st Intern. Calcium Treatment Symp., Univ.

Strathclyde, Glasgow, UK (1988)17 B.G. Thomas, J.K. Brimacombe, I.V. Samarasakera; “The Formation of Panel Cracks in Steel Ingots: a State-

of-the-Art Review, I. Hot Ductility of Steels”, ISS Transactions 7 (1986), pp. 7-20



18

K. Schwerdtfeger; “Rißanfälligkeit von Stählen beim Stranggießen und Warmumformen”, Verlag Stahleisen,Düsseldorf (1994)

19 Synopsis of ECSC Steel Projects; European Commission DG Research, Europ. Coal and Steel Community,(2005), ftp://ftp.cordis.europa.eu/pub/coal-steel-rtd/docs/synopsis_ecsc_1994-2001_en.pdf

20 European Commission DG Research and Innovation Research Fund for Coal and Steel; Full list of projects co-

Financed by the Research Fund For Coal And Steel Of the EuropeanCommission, Draft version, (2013);ftp://ftp.cordis.europa.eu/pub/coal-steel-rtd/docs/synopsis_ecsc_1994-2001_en.pdf

21 K. Schwerdtfeger (Ed.); “Metallurgie des Stranggießens”, Verlag Stahleisen, Düsseldorf, (1992)22

SMS-Siemag, “Continuous casters for flat products - Reference journal 2009-2014”, http://www.sms-group.com/downloads/S1-304E_Referenzen_Stranggiessanlagen.pdf, (2013), pp. 30-31

23 See [21], p. 8

24 http://www.sms-group.com/downloads/S1-304E_Referenzen_Stranggiessanlagen.pdf25 G. Disaro, M. Meier, S. Feldhaus; “New developments in continuous casting of blooms - aiming for highest

quality and achieving new section sizes”, Proc. 27th Aachener Stahlkolloquium, M. Wolff Aachen, (2012), pp.

233-24426

D. Rosenthal, S. Krämer, C. Klein, C. Geerkens, J. Müller; „20 years of CSP: Success story an extraordinarytechnology“, stahl und eisen 129(2009)11, pp. S73-S89

27 Nucor Comp. Release: “Nucor Shatters Strip-Casting Record with the Castrip® Process”;

http://www.nucor.com/investor/news/releases/print/?rid=1096724, (2007/2013);see also: C. R. Killmore, K. R. Carpenter, H. R. Kaul, J. G. Williams, D. G. Edelman, P. C. Campbell, W. N.

Blejde; “Recent Product Developments with Ultra Thin Cast Strip Products Produced by theCASTRIP

®Process”, Material Science Forum, Vol. 654 656 (2010) pp. 198-201

28 Anon.; ThyssenKrupp Nirosta, Forum Technische Mitteilung ThyssenKrupp, (2000), Dez.

29 W. Klos, C. Höckling, J.-U. Becker, L. Ernenputsch; „Herstellung innovativer Stahlkonzepte über dasBandgießen“, Proc. 28th Aachen Steelcolloquium, 7./8.3.2013, Aachen (2013), pp. 217-227

30 Anon.; „Baosteel Strip Continuous Casting Technology Enters the Stage of Industrialization“, Baosteel News

(2012); http://www.baosteel.com/group_e/01news/ShowArticle.asp?ArticleID=2770 (2012-1-23)31

T. Bolender, R. Fandrich, H.-A. Jungblut, G. Kemper, R. Müller, H.P. Narzt, G. Ney, H. Schnitzer; „State ofthe art in continuous casting technology“, stahl und eisen 129(2009)7, pp. 22-39

32 J. Penn, A. Jungbauer, H. Ebner, N. Hügel, H. Wahl; „Liquirob - a new answer for caster safety“, Proc. 6th ECCC, Riccione, Italy, June 3-6 (2008)

33 SMS-Siemag AG; „HD Mold - High definition-high value“, Düsseldorf (2013)34 Anom., „Online-Prozessmodellierung des Stranggießprozesses“, Metall, 08.07.201335

E.A.T. Wosch, E.H. Hilgenhöner, D. Senk: “Visualization of the Flux Film Thickness in Continuous CastingMoulds and Examples of Applications in Practice”, ICS 2012, 5

thInternational Congress on the Science and

Technology of Steelmaking, 01.-03.10.2012, Dresden. Paper-ID 1123.pdf (CD-ROM).36 M. Reifferscheid, Newsletter SMS group 2/2012, p. 5937 W. Schäfer, G. Hartmann, E. Hepp, D. Senk, S. Stratemeier: “Autonomous mathematical optimization of

continuous casting processes.”6th Europ. Conf. Continuous Casting” , June 2008 , Riccione, Italien. Mailand:

AIM 2008, CD-ROM.38

“Steel - ab initio; quantum mechanics guided design of new Fe based materials”, http://abinitio.iehk.rwth-aachen.de/index.php?id=project4&L=2 (2013)

39 B. Böttger; S. Stratemeier, E. Subasic, K. Göhler, I. Steinbach, D. Senk: “Modelling of Hot Ductility duringSolidification of Steel Grades in Continuous Casting - Part II”, Advanced Engineering Materials 12 (2010) Nr.

3, S. 101-109.40

A.J. Hulek; „Rapid Thick Strip Casting - a new concept for strip casting”, Korean-German New Steel Techn.Symp., Düsseldorf (2009); see also US Patent n° 6,945,311 B2 (2009)

41 Nagy, R.; Senk, D.: “Lab experiments on the innovative rapid thick strip casting process”, Intern. J. Minerals,Metallurgy and Materials 19 (2012) 5, pp. 391-398.

42 SMS Newsletter 2012, Sept.43 http://www.sms-group.com/en/sms_siemag/continuous_casting.html44

See also [25], p. 1345

A. Flick, A. Jungbauer, J. Watzinger, G. Eckersdorfer; „Technology and plant design for Arvedi ESP“, stahlund eisen 129(2009)11, pp. S91-S101; and„Arvedi ESP - Endless Strip Production“,http://www.industry.siemens.com/datapool/industry/industrysolutions/metals/simetal/en/Arvedi-ESP-en.pdf

46 E. Luithen, „Beyond energy effiviency“, Dr.-Thesis Universiteit Utrecht (2001); Posen & Looijen bv,

Wageningen; Chapter 5, pp. 129-16247

Siemens-VAI; “Latest Developments”, siemens-vai.com, (2013)



Figure 1: Left side: ingot casting bay (1955). Right side: Patent of M. Daelen (1889) [4]Figure 1: Left side: ingot casting bay (1955). Right side: Patent of M. Daelen (1889) [4]

Figure 2: CC mould at Barrow plant, 1956 [5]Figure 2: CC mould at Barrow plant, 1956 [5]

Vertical type

Vertical bending type

Bow type

Low head bow type,

multiple bending system

H e i g h t , m

Vertical type


Bow type

Low head bow type,


Vertical type


Bow type

Low head bow type,


H e i g h t , m

Figure 3: Types of CC casters [after 9]

Vertical type


Bow type

Low head bow type,


H e i g h t , m

Vertical type


Bow type

Low head bow type,


Vertical type


Bow type

Low head bow type,


H e i g h t , m

Figure 3: Types of CC casters [after 9]



Figure 4: Different solutions of CC machines for similar slabs, 2013 [after 47]

250-400 x 1100-2200 mm

16 m radius

24 m metallurgical length

2 strands, 300 t heats

250-400 x 1600-2400 mm

11 m radius


1 strand, 100 t heats

250-400 x 1100-2200 mm

16 m radius



250-400 x 1600-2400 mm

11 m radius



Figure 4: Different solutions of CC machines for similar slabs, 2013 [after 47]

250-400 x 1100-2200 mm

16 m radius



250-400 x 1600-2400 mm

11 m radius



250-400 x 1100-2200 mm

16 m radius



250-400 x 1600-2400 mm

11 m radius



Figure 5: Different solutions for near-net-shape casting of steel [after 21]

CC mould

Belt casters

Roll casters

CC mould

Belt casters

Roll casters

Figure 5: Different solutions for near-net-shape casting of steel [after 21]

CC mould

Belt casters

Roll casters

CC mould

Belt casters

Roll casters



Figure 6: 600 mm round blooms

(courtesy: Concast/SMS group)

Figure 6: 600 mm round blooms

(courtesy: Concast/SMS group)

Figure 7: 3-strand thin slab caster at Essar Steel (2011) [22]Figure 7: 3-strand thin slab caster at Essar Steel (2011) [22]

Figure 8: Robot at work, change of shroud tube

(courtesy: Siemens-VAI)

Figure 8: Robot at work, change of shroud tube

(courtesy: Siemens-VAI)



Figure 9: High Definition Mold, equipped with lots of glas fibers for temperature

measurement in the walls [33]

Figure 9: High Definition Mold, equipped with lots of glas fibers for temperature

measurement in the walls [33]

Continuous Casting Theory

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Transcript of Continuous Casting Theory