Historical Review of Continuous Casting
Though the idea of continuous casting (CC) was proposed as
early as mid-1800s, its real industrial application of the technology started
a century later. The extensive industrial application of the continuous casting
started in the late 1960s and early 1970s. Today the continuous casting ratio
of crude steel output has reached about 90%.
Large continuous slab and bloom casting machines have been
widely installed in existing steel plants to replace ingot casting, as well as
in plant expansions and large new integrated facilities. Smaller continuous
billet casters, together with ultra‑high powered electric arc furnaces,
were the critical technology development which created the phenomenon of the
mini‑mill‑a small capacity plant (originally a few hundred thousand
tons per year) serving local markets. In continuous casting the process yield
is more than 95 per cent compared with approximately 80 per cent for the
production of semi‑finished products made by rolling ingots in slabbing or blooming/billet mill facilities. In addition,
significant quality benefits have also been achieved.
If we try to divide the one-and-a-half century of CC
development, we may put them into two periods, before and after 1970. Or we may
also divide it into three major periods, with dividing points of 1940 and 1970.
1840 1940: The Pioneer Development
Started from the grant of the first continuous casting
patent, the first century of the CC development is mainly in the proposal and
pioneer development stage. Various areas, such as twin wheel strip casting
process, tundish, ladle, vertical and banding type
billet casting, mold oscillation, strand inline sizing, and cooling, were
proposed and studied. Real industrial application was still in its very stage
and was limited to some low melting-point metals.
1940 1970: Full
Range Industrial
Development
This period started from the installation of pilot plant for
steel casting. The major feature of this period is the intensive development in
whole industry. While new processes of CC were continuously proposed, this
period mainly pushed the previous proposals to the full range industrial
application. By 1970, about 4% of the steel was continuously casted.
Table 1: CC development before 1970 [1][2]
|
Year
|
Event and Development
|
Inventor/Developer
|
|
1840
|
First patent granted for continuous casting lead tubing
|
G.E. Sellers (U.S.A.)
|
|
1843
|
Patent granted for continuous casting of lead tubing which
recognized the necessity of moving the mandrel to prevent adhesion of the
cast material
|
U. Lang (U.S.A.)
|
|
1846
|
Patent for the production of tin foil and sheet lead, and
experimental production of sheet glass using water‑cooled rotating
rolls
|
H. Bessemer (England)
|
|
1856
|
Continuous casting of malleable iron using rotating rolls
announced and patent granted
|
H. Bessemer (England)
|
|
1872
|
Concept of continuous casting with moving molds
|
W. Wilkinson and E. Taylor (England)
|
|
1886
|
Basic principles of vertical casting of steel Production
unit reported in operation until 1910.
|
B. Athea (U.S.A.)
|
|
1889
|
Vertical‑type casting machine designed similar to
those currently in operation
|
M. Daelen (Germany)
|
|
1912
|
Advantages of mold oscillation in the direction of the
strand recognized with horizontal casting
|
(A. H. Pehrson, Sweden)
|
|
1915
|
Automatic control of metal flow into mold depending on
metal level in mold considered
|
G. Mellan
|
|
1921
|
Continuous relative motion between strand and mold
proposed
|
(C. W. van Ranst)
|
|
1933
|
Nonharmonic mold oscillation
proposed, which would not influence heat transfer between the solidifying
section/mold. First industrial continuous casting plant built for the
production of brass sections. The facility embodied a vertical design with an
open‑ended mold and had a production rate of 1700 metric tons/month.
|
S. Junghans (Germany)
|
|
1935
|
Brass plates continuously cast by using casting rolls
|
Scovill Manufacturing Co. (USA.).
|
|
1938
|
Semi‑horizontal machine built for the casting of
steel based on the Goldobin principle of moving
molds
|
USSR
|
|
1943
|
Early pilot plant for casting steel
|
Junghans (Germany)
|
|
1946/
1947
|
Pilot plants for casting steel installed by various
countries. Melting capacity varied from 200 lb to approximately 7.5 metric
tons.
|
USA,
England, Austria
and Japan
|
|
1951
|
First slab caster for the production of stainless steel
installed with the section sizes up to 800 mm x 180 mm (32 in. x 7 in.) and a
rated capacity of 36 000 metric tons/year
|
Krashy Oktubri
(USSR)
|
|
1952
|
First billet caster for the production of carbon and low
alloy steel brought into operation. Initially a single‑strand machine
for casting 50 to 100‑mm sq. billets. Twin strand operation started in
1958.
|
Barrow (England)
|
|
1952
|
Patent issued describing a curved casting machine
|
(O. Schaeber (Germany)
|
|
1952
|
First electromagnetic stirrer designed for continuous
casting at Mannesmann.
|
Junghans and Schaeber
(Germany)
|
|
1954
|
First slab caster for the production of stainless steel
slabs in North America started upSlabs up to 622 mm
x 165 mm (24 1/2 in. x 6 Y2 in.) were cast from 27.3 and 45.5 metric‑ton
heats (30 and 50 net ton).
|
Atlas Steels (Canada)
|
|
1954
|
First 4‑strand unit installed for casting rounds
(Production status not achieved until 1973).
|
Mannesmann (Germany)
|
|
1956
|
Cutting strands to length in the horizontal position
following bending instead of in the vertical permitted a significant
reduction in the height of the casting machine
|
Barrow (England).
|
|
1956
|
Patent filed for a curved mold
|
E. Schneckenburger and C. Kung (Switzerland)
|
|
1958
|
First 8‑strand billet caster installed
|
Societa per l'Industria
a I'Elettricita (Italy)
|
|
1961
|
Start‑up of first large vertical‑type slab
casting machine with bending of the strand for a horizontal discharge. The
single‑strand machine casts large low carbon steel slabs up to 1520 mm
x 200 mm (60 in. x 8 in.) from 30 metric‑ton (33 net‑ton) hems.
????
|
Dillinger Steelworks (West
Germany)
|
|
1963
|
Start‑up of first curved mold billet caster
|
Von Moos' Eisenwerke (Switzerland)
|
|
1963
|
A world survey indicated a total of 61 machines in
operation with 44 under construction.
|
|
|
1964
|
First new steelworks which depended 100 percent on continuous
casting brought on stream. Casting facilities consisted of four machines (11
strands total) which produced medium to large carbon and low alloy blooms
from 140 mm (.5 '/2 in.) sq. to 622 mm x 432 mm (24 Y2 in. x 17 in.) as well
as slabs from 56 metric‑ton (62 net‑toti)
heat
|
Shelton Iron
and Steel (England)
|
|
1964
|
Start‑up of the first curved mold machine for large
slabs, up to 1600 x 250 mm (63 x 9.8 in.). This design permitted a 50 percent
reduction in machine height in comparison with a vertical‑type machine.
|
Dillinger Steelworks (West
Germany)
|
|
1965
|
Production casting of rounds on a 4‑strand machine
|
Eschweiler
Bergwerks (Germany).
|
|
1967
|
High productivity slab caster with in‑line rolling to
change slab widths at a capacity of 1.5 million metric tons (1.65 million net
tons) per year.
|
U.S.
Steel's Gary Works (USA)
|
|
1968
|
First 4‑strand slab caster with curved mold
installed in North America
|
National Steel's Weirton Division for tinplate
applications
|
|
1968/
1969
|
Four slab casters placed in operation with combined annual
capacity of 2.2 trillion metric tons (2.4 million net tons).
|
McLouth Steel
|
|
1968/
1969
|
First continuous centrifugal caster
|
Vallourec and Creusot‑Loire (France).
|
Since 1970: Extensive Industrial Application
This period has truly witnessed the metal industrial
revolution due to the continuous casting and related technologies (e.g. Near-Net-Shape
casting). Steel continuous casting ratio jumped from 4% in 1970 to todays 90%.
CC ratio now is one of the most important criteria to judge the technical level
of a country or a metal producer.

Fig. 1: Evolution of world steel production and share of
continuous casting [2]
Recent developments adopted:
- Rapid
ladle and tundish changing equipment to improve
productivity and yield through sequence casting.
- Longitudinal
slitting of slabs to minimize mold changing and improve productivity.
- Variable
width adjustable molds to minimize mold changing and improve productivity.
- Multi‑point
bending of strand to improve quality.
- Mist
cooling using air‑atomized water to improve both cooling efficiency
and homogeneity and, consequently, product quality.
- Divided
or split molds to improve productivity.
- Total
shrouding of metal streams from ladle to tundish
and from tundish to mold to improve quality.
- Electromagnetic
stirring in and below the mold to improve quality.
- Inline
strip casting and Near-Net-Ship casting (e.g., for Dog-Bone)
- Integrated
Process Control (Level 1), Supervisory Control (Level 2), etc. with help
of computer
- High
speed casting, while maintaining billet/strip quality (surface, etc.)
- Continuous
casting of strip/billet with liquid core, in order to further reduce
production stages and energy consumption (This technology is still under
development).
References
[1] The making, Shaping and Treating of Steel, 1985, US
Steel.
[2] The making, Shaping and Treating of Steel, 2002, AISE
Steel Foundation.