DE102015210865A1 - Casting-rolling plant and method for its operation - Google Patents

Abstract

The invention relates to a casting-rolling plant (1) for producing metal strips (2), wherein the metal strip (2) passes through the casting-rolling plant (1) in a conveying direction (F), comprising: a casting machine (3) with a mold with a vertical outlet for producing a cast strand and a mold downstream of the mold in the conveying direction (F) for deflecting the cast strand from the vertical to the horizontal, one of the strand guide (4) in the conveying direction (F) downstream connection system (5 ) comprising at least one straightening driver (6) for drawing the casting strand from the strand guide (4) and a furnace (7) for heating the casting strand and a rolling mill (8) downstream of the joining system (5) in the conveying direction (F) for rolling the casting mill Casting strand to the metal strip (2). In order to be able to produce high-quality metal strip at low investment and operating costs, the invention provides that the strand guide (4) has a single or two roller segments, wherein their rollers provided for strand guide are free of a drive. Furthermore, the invention relates to a method for operating such a casting-rolling plant.

Description

The invention relates to a casting-rolling plant for small-scale annual production of metal strips, wherein the metal strip passes through the casting-rolling plant in a conveying direction, comprising a casting machine with a vertical outlet mold for producing a cast strand and one of the mold in the conveying direction downstream strand guide for deflecting the casting strand from the vertical to the horizontal, one of the strand guide in the conveying direction downstream connection system comprising at least one straightening device for pulling the casting strand from the strand guide and a separator, in particular scissors, and a furnace for heating the casting strand and a downstream of the connection system in the conveying direction rolling mill for rolling the casting strand to the metal strip. Furthermore, the invention relates to a method for operating such a casting-rolling plant.

A casting-rolling plant of the generic type is known from EP 0 535 368 B1 known. Similar and other solutions reveal the EP 0 099 076 B1 , the EP 2 571 640 B1 , the WO 2013/113832 A1 and the DE 10 2010 022 003 A1 ,

So-called CSP plants are built and operated in conventional embodiments as Vertical Solid Bending (VSB) plants or as Vertical Liquid Bending (VLB) plants. Such plant types are designed for productions of more than 1 million tons per year.

Especially for small annual production of less than 800,000 tons, special measures are necessary with a dimension of, for example, 1300 mm × 45 mm in order to produce a high-quality strip with the lowest possible capital expenditure and low operating costs.

The invention is therefore the object of a generic casting-rolling apparatus so educate that the functionality of the system can be increased, and it should be possible in particular to produce high-quality metal strip at low investment and operating costs.

The solution of this object by the invention is characterized in that the strand guide has a single or two roller segments, wherein the rollers provided for strand guidance are free of a drive.

In this case, the connection system between steel mill and rolling mill is designed in particular such that the strand at the kiln inlet has a sufficiently high average temperature for the subsequent rolling operation. As a result, the furnace in normal casting operation no longer needs to heat the strand for the subsequent rolling mill or only in exceptional need.

In the presence of two roller segments in the strand guide these are preferably formed substantially identical.

The strand guide is preferably designed to bend the cast strand so that it has a minimum radius of curvature of 2100 mm.

The strand guide preferably has the shape of a clothoid, at least in sections.

The mold is preferably formed vertically or as a curved mold.

The length of the mold is preferably at most 1100 mm, more preferably between 900 mm and 1000 mm.

The height of the strand guide without mold preferably has a maximum height of 3 m. Thus, the much lower than previously known comparable facilities.

The connection system preferably has a separating device, in particular a pair of scissors, which is arranged between the directional driver and the oven. The straightening unit and the scissors are constructed constructively as "straightening shears".

Since the furnace does not have to heat the strand in the normal casting operation, it can be built very short (less than 100 m). It must be at least as long that a slab fits right in and the Slab can be accelerated from the casting to the rolling speed (furnace length = slab length + acceleration length).

The oven therefore advantageously has a minimized length. The length consists of the slab length, the acceleration length and the additional heating length to compensate for the heat losses.

The connection system furthermore has a cold-string delivery unit, preferably a cold-rod rocker, with integrated insulation.

The strand guide preferably ends before the tangent point; this is preferred for low production to obtain a minimum energy requirement.

The strand guidance can also end in or behind the tangent point. This is advantageous in higher productions.

The straightening and driving unit preferably has driven rollers on the top and bottom of the slab. This is advantageous because of the doubling of the withdrawal forces.

The oven is preferably shorter than 100 m. The furnace has, according to one embodiment, at least one inductive heating element. Furthermore, it can be provided that the furnace at least one heat hood upstream or downstream in the conveying direction.

The heating unit is thus specially adapted to the requirements of the short casting machine. It preferably consists of a short furnace (less than 100 m, for example also 60 m with a band length of 50 m) or, alternatively, an inductive heating with a subsequent passive heat hood.

The cold strand can be carried away between separator and oven upwards. In casting this room is protected by a sliding heat hood against heat loss. For discharging the cold strand this heat hood is pushed over the adjoining oven.

The method for operating such a casting-rolling plant is carried out according to the invention in that the casting strand cast in the casting machine is fed into the rolling mill without further heating in the furnace and rolled therein.

Here, it is preferably provided that the cast casting strand is cooled in the strand guide so that it is completely solidified when reaching the straightening driver.

Preferably, the cast casting strand is cooled in the strand guide so that it is completely solidified 500 mm to 10 mm (target interval) in the conveying direction before the last roll of the strand guide. This approach is particularly advantageous in terms of low investment and operating costs.

The solidification fraction FS (= fraction solid) at the final solidification is preferably in the range of FS = 0.9 to FS = 1.0, preferably exactly at FS = 1.0.

The sump tip is thus selectively placed in the target interval, which is done by controlling the casting speed and / or the cooling volume flows.

The segments of the strand guide can be changed to increase the radius of curvature, which is advantageous for crack-sensitive steels or larger thicknesses. Thus, a simple extension of the Micro-CSP system on higher quality steels or higher production is possible.

The oven inlet temperature is preferably greater than 1050 ° C. Due to the short casting machine and the compact design of the connection system, the strand is optimally prepared at this furnace inlet temperature so that it does not have to be further heated in the furnace for the subsequent rolling mill.

Carbon steels with low and average carbon contents are preferably processed. The dimensions are preferably between 40 and 60 mm, preferably between 45 and 55 mm; but also other steels with comparable dimensions are preferably processed.

The invention thus relates to the linking of a steelworks with a rolling mill by a small casting machine (micro-casting machine) and a connection system.

The compact design of the casting machine with the connection system realizes a low capital expenditure with low operating costs. This is achieved through components of small dimensions and short distances. Additionally, for low cost production conditions, a high exit temperature of the cast strand is required at the end of the caster. Due to the compact design according to the invention, little energy is lost, so that energy must be supplied in the subsequent furnace system only in special production conditions.

Here are mainly carbon steels with low and medium carbon content with outlet thicknesses of the strand guide the casting of 40 to 60 mm, preferably 45 to 55 mm, cast, but also other steels with comparable dimensions.

Accordingly, the invention provides a link between steel mill and rolling mill by the inclusion of a suitable casting machine with connection system as key components. The link provides the essential components ladle turret, distributor, casting machine with mold, straightening unit, shears, Kaltstrangausfördersystem and furnace systems. Key component is a casting machine with short strand guide and a small distance to the furnace.

In particular, in the present case, the components behind the caster - such as straightening unit, scissors, Kaltstrangausfördersystem and furnace systems - are addressed as a connection system.

In the drawings, embodiments of the invention are shown.

1 shows schematically a casting-rolling plant, wherein a casting machine is used without driven segments,

2 shows a tabular list, in which for various materials admissible strains, minimum radii of curvature and maximum strand thicknesses are shown,

3 shows a strand guide with mold and a first Richtteiberrolle before the tangent point T,

4 shows a strand guide with mold and a first Richtteiberrolle in the tangent point,

5 shows a strand guide with mold and a first Richtteiberrolle after the tangent point,

6 shows a strand guide with a segment and with two segments,

7 shows schematically production-dependent designs of the strand guide,

8th shows a connection system as a unit with a compact straightening driver and scissors,

9 shows a cold-strand rocker as passive extension of the furnace in the casting operation,

10 shows a cold-strand rocker as a passive extension during transport of the dummy bar,

11 shows a sliding heat hood in the cold-strand discharge,

12 shows the sliding heat hood during production and

13 shows a flow chart for process control during roll change.

In 1 is a cast-rolling plant 1 for the production of a metal strip 2 to see. The plant has a casting machine 3 on, in the mold 14 liquid metal emerges vertically downwards and along a strand guide 4 is deflected from the vertical towards the horizontal. The material of the belt or the belt itself is in a conveying direction F through the system 1 promoted.

The attachment 1 still has a rolling mill 8th , Between the caster 3 and the rolling mill 8th is a connection system 5 arranged. The connection system 5 has a straightener 6 , one yourself subsequent separating device, preferably a pair of scissors 9 , and a stove 7 on; Furthermore, a cold-strand rocker 10 available.

Registered in 1 nor the tangent point T, at which the cast metal band 2 opens into the horizontal.

It is essential that the strand guide 4 a single roller segment or only two roller segments, wherein the rollers provided for strand guidance are free of a drive. The cast metal band is rather of the Richttreiber 6 from the casting machine 3 pulled out.

Due to the low (year) production aspired, pans with smaller volumes and therefore compact ladle turrets and distributors can be used. Due to the small pan sizes, a rigid ladle turret can be used.

Alternatively, a pan transport via ladle is possible; Another alternative possibility consists of fixed, preferably two, parking spaces for the pans and in a transport by means of a steelwork crane.

Regarding the mold 14 In the standard CSP plants for production quantities of more than one million tonnes per year, a 1,100 mm hopper is usually used for casting speeds up to 8 m / min.

For the casting machine in compact design shortened funnel coasters can be used, whose length is between 900 and 1100 mm, depending on the preferred casting speed. If necessary, the mold can be built even shorter. This saves investment and operating costs at the same time.

Regarding the strand guide 4 the following is of importance: According to the present task of a low production in connection with the compact design of the mold and the strand guide according to the invention advantageously results in a casting machine 3 which is shorter than conventional. The strand guide 4 ends in the bow of the strand guide in front of the straightener 6 , The solidification of the strand occurs before the Richttreiber 6 , ie within the strand guide 4 , This is necessary because otherwise the necessary extraction forces for transporting the strand can not be transferred.

In order to keep capital expenditure and operating costs particularly low, the average temperature of the strand at the end of the strand guide must be as high as possible. This is achieved by the smallest possible distance of Enderstarrungsposition to the last role of the strand guide and by the most balanced temperature profile in the strand.

Due to the dependence on different production campaigns, because of fluctuating process parameters such as casting temperature, cooling flow rates, radial roll distances (= jaw widths) and casting speeds but also due to analysis fluctuations, a consistent position of solidification is prevented. Therefore, a final solidification in the range of 10 mm to 500 mm, the target interval, should be aimed at before the last roll of the strand guide. The area of final solidification is defined with a solidification fraction of FS = 0.9 to 1.0, ideally FS = 1.0.

Since the kiln inlet temperature drops sharply with shorter swamp lengths (see the comments below on the kiln), the swamp tip must be within the specified target interval in order to keep the kiln length short. This is achieved by regulating the casting speed and / or the cooling volume flows.

The design of the hopper mold - vertical or curved - has an influence on the design of the upper part of the strand guide.

Possible designs of the mold are the vertical mold, d. H. the strand guide begins perpendicular or with a large radius of curvature (clothoids). Furthermore possible is a bent mold, d. H. the strand guide has a same radius of curvature or a decreasing radius of curvature.

The radius of curvature of the strand guide, starting from the radius present at the mold outlet, preferably up to the minimum radius of curvature (see 2 ) decreased. Then there is the possibility to increase the radius of curvature to the end of the strand guide again, such. B. in the double clothoid.

The use of the minimum radius of curvature within the strand guide leads to a minimized height. In addition, this results in a short strand guide length and thus a small distance to the straightening drivers.

The minimum radius of curvature in the strand guide depends on the material and the strand thickness. It depends on the maximum allowable elongation of the outer fiber of the curved strand. For this purpose, refer to the illustration in 2 directed.

Similarly, larger strand thicknesses can be cast for larger radii of curvature in the strand guide.

In this case, the design of the strand guide is determined by the production or casting speed, the largest strand thickness to be cast and the material to be cast.

At low production (eg 500,000 tonnes per year), strand management ends 4 before the tangent point T; this situation is in 3 shown.

At higher production (eg 800,000 tonnes per year), strand management ends 4 in or after the tangent point T; this situation is in the 4 and 5 shown. Here can in the strand guide z. B. a curve of the radii of curvature can be used in the form of a double clothoid.

For small designs, it makes sense, the strand guide 4 from just a single segment (plus straightening unit or straightening driver). For larger designs, however, two segments are provided. In 6 these two possibilities are illustrated.

Drives within the strand guide are not essential, as the pulling out of the strand 2 through the end of the strand guide 4 located straightening and driver unit 6 is taken over.

For smaller productions or casting speeds, a lower strand guide length is required.

For medium production or casting speeds, a slightly longer strand guide length is required.

For higher production or casting speeds, a longer strand guide length is required.

In 7 is the respectively preferred arrangement of strand guide 4 and Richttreiber 6 as a function of the production volume and in relation to the tangent point T.

In order to lose as little temperature as possible by radiation, the distance between the last supported roll and the straightening unit must be as small as possible. Cost-cutting is that the strand leadership 4 has no driven rollers. In addition, the structurally required distance between the last role and the straightening unit can be secured by insulation and radiation protection components against energy losses.

To expand the product range and increase production, the following should be noted: If the production range of an existing micro-CSP plant for low and medium carbon is to be easily extended to crack-sensitive steels or larger thicknesses (which corresponds to a larger production), the minimum radius of curvature must be increased be increased by exchanging the segments.

This is illustrated by the following example:
At the maximum possible elongation, a radius of curvature of 2,100 mm is desired for a thickness of 40 mm. It follows: 2,100 mm / 40 mm ≈ 2,400 mm / 45 mm

Accordingly, a minimum radius of curvature of 2400 mm is required for the same elongation for crack-sensitive steels of 45 mm thickness.

The strand guide must be designed with the specified system height and the position of the straightening driver. This can be achieved with the help of an already curved hopper mold and a modified strand guide.

The Richttreiber 6 and the separator (scissors) can be used as a Richttreiber-scissors assembly 11 be designed (see 8th ).

For further general cost reduction and to achieve faster segment switching times, the straightening and driving unit and the segments can preferably be changed separately, so that the straightening and driving unit does not have to be changed with the segment change.

The straightening and driver unit 6 consists of at least two roller pairs with drive for transmitting the forces for strand transport. To double the pull-out forces, the rollers are driven on the top and bottom.

In order to shorten the distance between the straightening unit and the shears, straightening drivers and scissors can be used as a compact unit 11 (as "straightener") to be summarized (s. 8th ). Alternatively, the "straightener" can be performed with a driven straightening roller in front of the scissors and a straightening roller behind the scissors. Due to the then higher strand temperatures, the shear requires a lower shear force. This allows the scissors and their drive to be built smaller and more compact.

Is the cold-rod entry and exit zone between the guideway drivers? 6 and the pair of scissors 9 , this area is again as short as possible to build and provided with insulation and radiation protection components.

In the interstices of the system components, energy losses are reduced through the installation of insulation and radiation protection components. The scissors 9 can be protected against the thermal radiation of the high surface temperatures of the strand by insulation and radiation protection components.

The proposed system furthermore has a cold-extruded discharge unit, preferably a cold-rod rocker 10 , on (see this the 9 and 10 ).

The cold-strand threading unit can be between Richtreibereinheit 6 and scissors 9 or preferably after the scissors 9 are located.

If the cold strand after the scissors 9 separated from the strand head, this area must be as short as possible in order to lose as little energy. All free routes can be covered by insulation and radiation protection components.

In one possible embodiment, the dummy leg can be moved by a rocker 10 above the oven 7 transported and stored there. The seesaw 10 is then built so that they are in normal casting above the furnace 7 lies (see 9 ). Your over the oven 7 in the direction of casting machine 3 exceeding length is protected downwards by insulation and radiation protection components. These insulations serve for one, around the rocker 10 to protect against the high temperature of the strand, and second, to reduce the energy losses of the strand. On the side walls of the rocker 10 There are further insulation and radiation protection components that reach into the vicinity of the hall floor. This will cause the space between scissors 9 and oven 7 formed into a kind of heat hood: this allows a passive extension of the furnace 7 ,

In an alternative embodiment (see 11 and 12 ) becomes the dummy strand 12 between the scissors 9 and the kiln inlet to the hall ceiling carried away. Also in this embodiment, the distance between scissors 9 and kiln inlet after the feeding in and out of the cold strand 12 to protect against energy losses. Here is a heat hood 13 z. B. over the oven 7 moved away or by a tilting device over the oven 7 turned. In addition, protection for adjacent mechanical or electrical equipment, such. As the scissors 9 to install against the high heat radiation of the stove.

For all transport rollers between the casting machine and the kiln inlet, non-cooled rolls can be used, preferably furnace rolls. They remove less energy from the strand underside during roller contact.

The furnace system can be heated with fossil fuels or electrically, in particular inductively. There are also combinations of both variants possible. Alternatively, an inductive heating with subsequent passive heat hood can be used to compensate for the temperature profile, or only a passive heat hood.

The furnace must be at least long enough for a slab to fit all the way in and then be accelerated to the required rolling speed (about 18 m / min) from the incoming casting speed, preferably 4 to 5 m / min. For a slab length of approx. 50 m, a 60 m long stove is sufficient.

The following applies: The acceleration length is the length in order to accelerate the slab from the casting to the rolling speed.

For the furnace length, the following applies: The minimum furnace length is the slab length plus the acceleration length.

To compensate for roll change times, this minimum furnace length may need to be extended (see below for roll change times).

Only if the furnace inlet temperature is below the minimum allowable rolling temperature, the furnace must actively heat the slab to this temperature.

d_Sumpf:

= verkürzte Sumpflänge

d_Abstand:

= nicht isolierte Abstand zwischen Ende Gießmaschine und Ofen

d_AbstandIso:

= isolierte Abstand zwischen Ende Gießmaschine und Ofen

The following example is given:
To heat a 1,050 ° C hot slab at an oven temperature of 1,100 ° C, the following additional oven lengths are required: 1 m shorter swamp length ≈ 28 m additional kiln length 1 m uninsulated distance between casting machine and kiln inlet ≈ 5 m additional kiln length 1 m insulated distance between casting machine and kiln inlet ≈ 2 m additional kiln length With

d _swamp :

= shortened swamp length

d _distance :

= not insulated distance between end of casting machine and oven

d _distanceIso :

= isolated distance between the end of casting machine and oven

This results in the furnace length additionally required for heating: additionally required furnace length ≈ 28 · d _sump + 5 · d _distance + 2 · d _distanceIso

From this approximation formula it becomes apparent:
The distance between the end of the casting machine, in particular the end of the target interval, and the kiln inlet is to be kept as low as possible.

The sump tip should be placed at the end of the casting machine (= in the target interval).

Between the end of the casting machine, in particular the end of the target interval, and the kiln inlet, the strand or the slab is to be protected against energy losses by means of insulation or radiation protection components.

This causes the strand or slab to enter the furnace more hotly.

Thus, the oven can be made shorter (lower investment costs).

In the standard production mode, the strand or the slab does not have to be actively or less heated (lower operating costs).

To determine the exact temperature curve in the furnace, mathematical-physical models can be used.

Regarding the roller change times, the following should be noted:
In the rolling process, the rollers wear and must, depending on productivity and roll material, for. B. be changed every five hours. The aim is to perform this roll change without casting break, since the risk of breakthrough increases when re-casting and units should be replaced prematurely.

In order to perform the roll change without casting break, sufficient time must be created between the end of the previous strip and the rolling of the new slab. For this purpose, on the one hand, the rolling of the previous band can be accelerated and, on the other hand, the casting of the new slab can be slowed down. For this purpose, the casting speed is reduced.

So that the temperature does not drop too much, the cooling in the casting machine is reduced according to the casting speed. If the slab nevertheless becomes so cold that it can no longer be brought to the required rolling temperature in the oven, it must be chopped with scissors. The required roll change times are a criterion for determining the required furnace length.

By knowing the required rolling speed, the casting speed and the temperature control in the casting machine can be optimized so that the maximum possible strand temperatures are achieved. This reduces the energy consumption in the oven and reduces operating costs.

In 13 For this purpose, a flow chart for process control during roll change is shown.

LIST OF REFERENCE NUMBERS

1

 Casting and rolling plant

2

 Metal band / slab

3

 casting machine

4

 strand guide

5

 connection system

6

 Straightening / straightening and driving unit

7

 oven

8th

 rolling mill

9

 Separating device (scissors)

10

 Dummy bar rocker

11

 Straightening scissors assembly

12

 dummy bar

13

 movable heat hood

F

 conveying direction

T

 tangent point

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0535368 B1 [0002]
• EP 0099076 B1 [0002]
• EP 2571640 B1 [0002]
• WO 2013/113832 A1 [0002]
• DE 102010022003 A1 [0002]

Claims (21)

Casting-rolling plant ( 1 ) for producing metal strips ( 2 ), wherein the metal strip ( 2 ) the cast-rolling plant ( 1 ) in a conveying direction (F), comprising: a casting machine ( 3 ) with a mold with a vertical outlet for producing a cast strand and a mold downstream of the mold in the conveying direction (F) ( 4 ) for deflecting the casting strand from the vertical to the horizontal, one of the strand guide ( 4 ) in the conveying direction (F) downstream connection system ( 5 ), which has at least one straightening 6 ) for pulling the casting strand out of the strand guide ( 4 ) and a separating device ( 9 ), in particular a pair of scissors, and a furnace ( 7 ) for heating the casting strand and a connection system ( 5 ) in the conveying direction (F) downstream rolling mill ( 8th ) for rolling the cast strand to the metal strip ( 2 ), characterized in that the strand guide ( 4 ) has a single or two roller segments, wherein the rollers provided for strand guidance are free of a drive. Casting-rolling plant according to claim 1, characterized in that in the presence of two roller segments in the strand guide ( 4 ) These are formed substantially identical. Casting-rolling plant according to claim 1 or 2, characterized in that the strand guide ( 4 ) is adapted to bend the casting strand so that it has a minimum radius of curvature of 2100 mm. Casting-rolling plant according to one of claims 1 to 3, characterized in that the strand guide ( 4 ) at least in sections has the shape of a clothoid. Casting-rolling plant according to one of claims 1 to 4, characterized in that the mold is formed as a curved mold. Casting-rolling plant according to one of claims 1 to 5, characterized in that the length of the mold is at most 1100 mm, preferably between 900 mm and 1000 mm. Casting-rolling plant according to one of claims 1 to 6, characterized in that the height of the strand guide ( 4 ) without mold has a maximum height of 3 m. Casting-rolling plant according to one of claims 1 to 7, characterized in that the connection system ( 5 ) the straightening and driving unit ( 6 ) and the oven ( 7 ), wherein between the straightening and driving unit ( 6 ) and the oven ( 7 ) a separating device ( 9 ), in particular a pair of scissors, is arranged, wherein the straightening and driving unit and the separating device are preferably structurally designed as a structural unit. Casting-rolling plant according to one of claims 1 to 8, characterized in that the connection system ( 5 ) a cold-strand rocker ( 10 ) with integrated insulation. Casting-rolling plant according to one of claims 1 to 9, characterized in that the strand guide ( 4 ) ends before the tangent point (T). Casting-rolling plant according to one of claims 1 to 9, characterized in that the strand guide ( 4 ) ends in or behind the tangent point (T). Casting-rolling plant according to one of claims 1 to 11, characterized in that the straightening and driving unit ( 6 ) driven rollers on the top and bottom of the slab ( 2 ) having. Casting-rolling plant according to one of claims 1 to 12, characterized in that the furnace ( 7 ) is shorter than 100 m. Casting-rolling plant according to one of claims 1 to 13, characterized in that the furnace ( 7 ) has at least one inductive heating element. Casting-rolling plant according to claim 14, characterized in that the furnace ( 7 ) at least one heat hood in the conveying direction (F) upstream or downstream. Method for operating a casting / rolling plant according to one of claims 1 to 15, characterized in that the casting machine ( 3 ) Cast strand without further heating in the furnace ( 7 ) the rolling mill ( 8th ) is fed and rolled in this. A method according to claim 16, characterized in that the cast casting strand in the strand guide is cooled so that it upon reaching the straightening driver ( 6 ) is completely solidified. A method according to claim 15 or 16, characterized in that the cast cast strand is cooled in the strand guide so by controlling the amount of cooling water and / or the casting speed, that it completely solidifies 500 mm to 10 mm in the conveying direction (F) before the last roll of the strand guide is. Method according to one of claims 15 to 18, characterized in that the furnace inlet temperature is greater than 1050 ° C. Method according to one of claims 15 to 19, characterized in that the carbon steels are processed with low and average carbon contents. Method according to one of claims 15 to 20, characterized in that the casting strand with a thickness between 40 mm and 60 mm, preferably 45 mm to 55 mm, from the strand guide of the casting plant expires.

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