EP3016762A1

EP3016762A1 - Cast-rolling installation and method for producing metallic rolled stock

Info

Publication number: EP3016762A1
Application number: EP14736733.8A
Authority: EP
Inventors: Olaf Norman Jepsen; Guido Kleinschmidt; Markus Reifferscheid; Dieter Rosenthal; Christian SPRUNG
Original assignee: SMS Group GmbH
Current assignee: SMS Group GmbH
Priority date: 2013-07-03
Filing date: 2014-07-02
Publication date: 2016-05-11
Anticipated expiration: 2034-07-02
Also published as: CN105492140A; EP3016762B1; WO2015000968A1; DE102013212951A1

Abstract

The invention relates to a cast-rolling installation and to a method for producing metallic rolled stock. Known cast-rolling installations (100) of this type comprise a casting line and a rolling line, arranged offset parallel to the casting line. Slabs are transported from the casting line to the rolling line transversely in relation to the casting direction with the aid of a transverse transporting device. In order to minimize furnace heat losses and to optimize the heat transfer from heating gas in the furnace to the slabs, it is provided according to the invention that the furnace (150) encloses the complete transverse transporting device (130) as well as at least part of the delivery roller table (128) of the strand guide (120) and at least part of the feeding roller table (140) for the slabs into the rolling line. In addition, the feed of the furnace for the slabs is arranged in the casting line and the delivery of the furnace for the slabs is arranged in the rolling line, and so it is possible for the slabs to be fed in at one end face of the furnace and the slabs to be delivered at the other, rear end face of the furnace.

Description

Casting rolling mill and method for producing metallic rolling stock

The invention relates to a casting and rolling plant and a method for producing metallic rolling of carbon steel.

Such casting machines and methods are basically known in the prior art; see, for. For example, the documents DE 196 81 466, EP 1 1 12 128, DE 693 16 703, EP 1 833 623 and EP 1 940 566.

Specifically, European Patent Specification EP 1 833 623 B1 discloses a cast roll mill for producing slabs with a mold, a mold guide downstream of the mold for deflecting the cast strand from the vertical to the horizontal, a heating furnace, a descaling device, a roughing stand, a Steckel mill Scissors, a cooler and a reel. After passing through the heating furnace, the cast strand or slabs first pass through the roughing stand before they enter the Steckel mill. All components of the system are in one line.

European Patent EP 1 940 566 B1 discloses a thin slab caster with a tandem rolling device. Already in the strand guide a reduction in thickness of the cast strand is provided; a so-called Liquid Core Reduction LCR area. The radius for the deflection of the casting strand in the horizontal is less than 2 m, the casting thickness is 25 - 32 mm and the casting speed is 6 to 16 m / sec.

German publication DE 196 81 466 T1 discloses a casting and rolling plant for producing metallic rolling stock, comprising a casting line with a mold for vertical casting of a cast strand and with a strand guide, which has a carpet for deflecting the casting strand from the vertical to the horizontal, a straightening device, a pair of scissors for distributing the casting strand in slabs and an outlet roller conveyor. Parallel to the casting line, the casting rolling mill comprises a rolling line with an inlet roller table and a Steckel rolling mill for rolling the slabs of rolling stock, a Steckel rolling mill downstream cooling device and a cooling device downstream winding device. Between the casting line and the rolling line a transverse displacement device is arranged for transversely transporting the slabs from the outlet roller conveyor of the strand guide to the inlet roller conveyor of the rolling line. An oven is provided for heating the slabs during transverse transport.

The invention has the object of developing a casting and a method for producing metallic rolling material according to the type described in the last paragraph to the effect that the heat losses during transporting the slabs from the casting line are further reduced in the rolling line.

This object is achieved by the claimed in claim 1 casting rolling. This casting and rolling plant is characterized in that the furnace includes the complete transverse displacement device and at least part of the outlet roller table of the strand guide and at least part of the inlet roller table of the rolling line and that the inlet of the furnace for the slabs in the casting line and the outlet of the furnace for the slabs is arranged in the rolling line.

The claimed embodiment of the furnace has the advantage that the slabs are not only secured during their transverse transport, but already on the outlet roller conveyor of the strand guide and on the inlet roller table of Steckel rolling against unwanted cooling, because the furnace extends over these areas. By the arrangement of the openings the furnace for the entry of the Brannnnen in the casting line and the analogous arrangement of the opening for the outlet of the Brannnnen in the rolling line in the rolling direction, the widths of the openings or the doors in these openings can be substantially limited to the width of the Brannnnen. This is particularly advantageous in view of the energy losses or the energy balance of the furnace compared to the design of furnace doors in the prior art, where the furnace doors extend over the entire length of a slab, because the slab is retracted transversely into the furnace. Thus, both claimed measures serve to reduce the temperature losses of the slab and to increase the efficiency of the furnace.

The claimed cast-rolling mill is used to produce rolling stock in the form of flat steel with an annual production of less than 700,000 t per year of carbon steel. The system is characterized by a compact system layout and z. B. due to the lack of a Vorgerüstes and the high efficiency of the furnace by low investment and production costs. It is therefore particularly suitable for (new) steel producers in regions without their own flat steel production. It is used for casting slabs with widths between 700 and 1, 700 mm.

According to a first embodiment of the invention it is provided that the heating gas is conducted in the oven in a flow direction which runs counter to the direction of movement of the slabs in the oven. This countercurrent principle also leads to a significant increase in efficiency of the furnace, because the slabs are kept better warm in this way.

According to a further preferred embodiment, the furnace has a further opening, which either serves as an outlet for slabs, which are not to be introduced into the rolling line or acts as an inlet for slabs, which should not be supplied via the casting line of the rolling line. For this purpose, the run-out roller conveyor of the strand guide is extended beyond the transverse displacement region of the furnace through the said further opening to the outside of the furnace in the casting line.

According to a further embodiment, the roller carpet of the strand guide is formed from a plurality of segments, which are arranged one behind the other in the casting direction. In a first, downstream of the mold segment three to seven pairs of rollers are initially arranged vertically one above the other to form a vertical guide region for the cast strand. In the casting direction, five to eleven further pairs of rollers within the first segment, which are arranged in an arc shape to form a bending region for bending the casting strand out of the vertical into a casting radius between 3.5 and 6.5 m, are arranged downstream of this vertical guide region. After the bending area, which is still attributed to the first segment, followed by two to four other arc segments for further guidance of the casting strand.

The said compact design of the system is particularly evident in its supported length of <12 m and in a low overall height of the casting rolling mill between 5 and 8 m.

The above object is further achieved by a method for producing metallic rolling stock according to claim 15. This method is characterized in that the slabs enter the front side in the casting direction in the oven and backward end face in the rolling direction from the oven. The advantages of this solution correspond to the advantages mentioned above with reference to the claimed cast rolling mill. The casting rolling mill is planned for casting speeds between 1 and 3.5 m / min. After leaving the furnace, the slabs run directly into the rolling stand of the Steckel mill, are thinness reduced there in a first pass and are subsequently wound downstream of the rolling stand on a Steckel located there, ie a winding furnace located there Steckelwalzwerks. To increase the production efficiency of the slab is not first wound in a winding furnace located upstream of the rolling mill of the Steckel mill and cached before it enters the rolling mill of the Steckel mill.

Further advantageous embodiments of the claimed casting and the claimed method are the subject of the dependent claims.

The invention is accompanied by three figures, wherein

FIG. 1 shows the claimed cast roll plant in a longitudinal section;

Figure 2 shows the oven with associated inlet roller table and associated

Outlet roller table in a plan view; and

Figure 3 shows the essential components of the casting line of the claimed

Casting mill shows.

The invention will be described in detail below with reference to the said figures in the form of embodiments. In all figures, the same technical elements are designated by the same reference numerals. Explanation of terms used: The term "rolling direction" corresponds to the term "casting direction"; both terms mean the same direction. However, the rolling direction is offset parallel to the casting direction. The terms "Steckel" and "winding furnace" are synonymous.

The length of the furnace means the length in the casting or rolling direction. The width of the furnace means the extent of the furnace transverse to the casting or rolling direction. The outlet roller table of the strand guide is basically synonymous with the inlet roller table of the furnace. Both run in the casting direction. An extension of the outlet roller conveyor of the strand guide, which extends through the oven and to the outside of the oven, also runs in the casting direction. The outlet roller table of the furnace extends in the rolling direction and is basically synonymous with the inlet roller table of the Steckel mill.

FIG. 1 shows the claimed cast roll plant in a side view. The casting rolling mill 100 comprises a casting line and a rolling line, which are connected to one another via a transverse displacement device 130. The casting line comprises a casting platform 105, a mold 1 10, a strand guide 120, a pair of scissors 127 and a run-out roller table of the strand guide 128. All the components of the casting line are arranged one behind the other in the casting direction in the stated order.

The casting platform typically includes a turret or ladle for handling the pans for sequence casting. It is a covert casting with ceramic components between pan and distributor (shadow tube) or between distributor and mold (dip tube) provided. The distributor is typically covered with cover powder and the mold with casting powder. The mold 1 10 may be formed either of four parts, two broad sides and two narrow sides or as a frame mold. It preferably has an integrated level measurement, which for example works radiometrically or with eddy current. Advantageously, the mold, in particular if it has two narrow sides, preferably has a narrow side adjustment for format adjustment during the casting operation. The mold is positioned vertically below the casting platform. It can be formed with or without funnel on the upper Kokillenkopf. When forming a funnel mold, the crown is 10 to 60 mm at the top mold head. The exit of the mold preferably runs parallel, but in the case of a funnel mold it can also have a residual embedment <10 mm. The mold walls or mold plates are preferably formed from copper or a copper alloy with or without full or partial wear-reducing coating. The alternative to using a funnel mold is the use of a plane parallel mold. The mold is equipped with an eccentric or hydraulic oscillation drive for oscillation strokes up to 360 strokes per minute and amplitudes <± 5 mm. The mold is water-cooled with water volumes of 1 .000 to 3,000 l / min / meter casting width. The strand guide 120 consists essentially of a roll carpet with divided or undivided rolls with diameters <250 mm. The rollers may be designed as axle rollers or as pin rollers, preferably with internal cooling. A bearing cooling is intended above all for center bearings. The rollers of the roller carpet are preferably grouped into segments 121, 122, 123, 124, as shown in FIG. The segments typically each consist of an upper frame and a lower frame, on each of which a plurality of rollers is rotatably mounted. The cast strand is, as shown in Figure 2, guided between the opposite roles of a segment. The upper frame and the subframe with the respective rotatably mounted rollers are relative by means of hydraulic cylinders 129 mutually adjustable or adjustable. This hydraulic segment adjustment is carried out as a black / white circuit on spacers or position-controlled with a monitoring of the forces occurring with respect to a minimum and maximum permissible force value.

In a first segment 121, which immediately follows the mold 1 10 in the casting direction R, as shown in FIG. 2, initially three to seven pairs of rolls are arranged vertically one above the other. The predetermined by the mold vertical orientation of the casting strand is initially extended in this way a bit far. The said rollers are followed within the first segment 121 by a bending region which extends over 5 to 1 1 further pairs of rolls and continuously flexes the cast strand into a casting radius between 3.5 and 6.5 m. In Figure 2, this bending region can be seen on the horizontal lines, which extend from the pairs of rollers to the right; These lines represent the change in the bending radius, which results successively at the individual roller pairs of the bending area. The said preconnection of three to seven pairs of rollers in a vertical arrangement in front of the bending area has the advantage that forces occurring in the bending area are not transmitted to the mold 110, but are absorbed by said pairs of rollers in a vertical arrangement.

Two to four further floor segments 122, 123, 124 adjoin the first segment 121 in the casting direction. The supported length of the casting machine is less than 12 m. Within the strand guide no appreciable thickness reduction of the casting strand is provided by means of Liquid Core Reduction LCR. Changes in the thickness of the cast strand arise only from conventional Tapereinstellungen in parts or over the entire roll carpet in the casting direction, ie due to usual wedge settings of the segments in the casting direction to compensate for naturally occurring shrinkage of the cast strand in the casting direction due to its cooling. In addition, thickness reduction can at best occur through the use of soft reduction. Soft reduction means the active squeezing of the upper and lower strand shell in the area before the solidification of the casting strand to z. B. to avoid segregation. Within the strand guide 120, in the region of the segments, a regulated secondary cooling is preferably provided for cooling the strand after its exit from the mold. The cooling is typically done via spray plans or preferably via a process model. In the transition region from the circular arc guide to the horizontal, the strand guide 120 has a straightening device 126, which consists of individual controllable and at least partially driven roller pairs. The controllable pairs of rollers preferably have a position and force monitoring. The straightening device 126 can be designed as three or four roller pair unit or alternatively in segmental construction. The casting thickness of the casting strand at the exit of the straightening device 126 is between 90 mm and 120 mm. The height of the plant is between 5 and 8 m.

As shown in Figure 1, the strand guide 120 is a pair of scissors 127 downstream of dividing the cast strand in slabs of predetermined length. The width of the slabs is between 700 and 1, 700 mm in the claimed casting rolling mill.

The scissors 127 is downstream in the casting direction an exit roller conveyor 128 of the strand guide.

From the pouring line just described, the slabs are transported by means of a furnace 150, for example a Hubherdofens, in a parallel to the casting line arranged offset rolling line. As such, the scissors 127 and the oven 125 with a transverse shifting device 130 therein serve for the final coupling of the casting and rolling processes. The rolling line comprises an outfeed roller conveyor of the oven 150, which is equivalent to an infeed roller conveyor 140 in a Steckel mill 160. In the rolling line, a descaling device 158 is preferably arranged between the oven 150 and the Steckel mill 160. The Steckel mill 160 includes upstream and downstream each a Steckel, ie a winding furnace for temporarily storing the rolling stock between the individual stitches. A predetermined odd number of passes is made to reduce the thickness of the slabs to a desired final thickness. The thus produced rolling stock in the form of flat steel is cooled after passing through the Steckel mill 160 in a cooling device 170, before it either deposited as a plate or, as shown in Figure 1, wound by means of a winding device 180 to form a coil.

In the following, the furnace according to the invention will be described in detail with reference to FIG.

As can be seen in FIG. 3, the furnace 150 according to the invention comprises not only the actual area of the transverse pushing device 130, which serves to transversely transport the slabs from the casting line into the rolling line, but also the upstream exit roll course 128 of the strand guide 120 and the downstream Einlaufrollgang 140 of the rolling line in the Steckelwalzwerk 160. Heated or exposed to the furnace atmosphere is that part of the outlet roller table 128 of the strand guide 120, which is surrounded by the furnace 150, also called the inlet region of the furnace, as well as the said region of the transverse displacement device 130 (Hubherdbereich called) , The heating gas for the interior of the furnace provided by a heater, not shown in FIG. 3, is directed into the interior of the furnace via an inlet in the stroke hearth area. From there it flows against the transport direction of the slabs to an outlet, which is preferably arranged at the beginning of the kiln inlet region transversely from the inlet for the slabs in the oven, as shown in Figure 3. In this way, a countercurrent principle arises Slab running and heating gas, which is advantageous for the heat transfer to the slabs.

The length X2 of the transverse displacement device 130 in the casting direction, d. H. Correspondingly, the length of the part of the inlet roller conveyor 140 enclosed by the oven for the Steckel mill 160 is between 15 and 35 m, corresponding to the maximum length of the slabs. The length of the inlet zone into the oven, d. H. the portion of the outfeed roller table 128 of the strand guide 120 encompassed by the furnace is in relation to the length X2, the ratio X1 / X2 being <1.5, preferably approximately 1. The width Y1 of the furnace 150 transverse to the casting direction is also in relation to the length X2 of the furnace 150. Preferably, the ratio Y1 to X2 is 0.2 to 0.8, preferably about 0.5.

Said data for the length X2 and the ratios X1 to X2 and Y1 to X2 are chosen so as to be able to realize a roll change without casting sequence interruption.

The furnace 150 according to the invention is constructed so that, as shown in Figure 3, the slab frontally in the casting direction frontally over the outlet roller conveyor 128 with its narrow side can advance into the oven. Also, the leading out of the slabs takes place the front side, ie, with its narrow side forward backwards over the roller table 140 in the direction Steckel mill. The outfeed roller table 128 of the strand guide 120 may be extended through and beyond the oven 150 in the form of a slab run-out roller 190, as shown in FIG. In this case, another door should be provided in the furnace wall in transition to the said pullout roller 190. Due to the frontal and non-transverse inlet of the slabs in the oven, all the doors of the furnace at the outlets and inlets for the slabs in width to substantially the max. Width of the slabs are limited. In particular, no doors or openings must be provided in the furnace, which allow insertion and execution of the slabs transverse to the casting line. In this way, the temperature and energy losses of the furnace can be significantly reduced.

All roller conveyors in the oven 150 can be designed with single-sided or double-sided rollers with or without roller cooling.

LIST OF REFERENCE NUMBERS

100 cast rolling mill

105 Casting platform

1 10 mold

120 strand guide

121 first segment

122 second segment

123 third segment

124 fourth segment

125 roll carpet

126 straightening device

127 scissors

128 outlet roller table of the strand guide

29 hydraulic cylinders

130 transverse displacement device

140 Entry roller table into the Steckel rolling mill in the rolling line

150 oven

156 opening in the oven

158 descaling device

160 Steckel mill

162 winding furnace

164 winding furnace

170 cooling device

180 take-up device

190 Removable roller table for slabs 210 cast strand

R casting direction

X1 Length of furnace in the casting direction

X2 Length of the transverse displacement area in the casting direction

Y1 Width of the transverse displacement area

Claims

claims

1 . Cast rolling mill (100) for producing metallic rolling stock,

comprising: a casting line with a mold (1 10) for vertical casting of a

Casting strand (210) and with a strand guide (120), which a

Roller carpet (125) for deflecting the casting strand from the vertical to the horizontal, a straightening device (126), a pair of scissors (127) for

Cutting the cast strand into slabs and

a discharge roller table (128), a rolling line parallel to the casting line arranged with a Einlaufrollgang (140) and with a Steckel rolling mill (160) for rolling the slabs to the rolling stock; a transverse displacement device (130) for transversely transporting the

Slabs from the outlet roller table (128) of the strand guide to the

Inlet roller table (140) of the rolling line; and a furnace (150) for heating the slabs during

Quertransportes characterized in that the furnace (150) the complete transverse displacement device (130) and at least a portion of the outlet roller table (128) of the strand guide and at least a portion of the inlet roller table (140) of the rolling line includes; and the inlet of the furnace for the Brannnnen in the casting line and the outlet of the furnace for the Brannnnen in the rolling line is arranged.

2. Cast rolling mill (100) according to claim 1,

characterized in that

the furnace (150) has heating means for providing heating gas for the interior of the furnace, an inlet for supplying the heating gas into the interior of the furnace opposite to the conveying direction of the slab, the inlet preferably being arranged at the end of a transverse displacement area of the furnace, and Outlet for discharging the heating gas from the furnace, wherein the outlet preferably at the beginning of the

Auslaufrollgangs the strand guide querab the inlet for the slabs in the oven is arranged.

3. Cast rolling mill (100) according to one of the preceding claims,

characterized in that

the length (X2) of the part of the furnace enclosed by the furnace

Infeed roller table (140) for the Steckel mill is between 15m and 35m.

4. Cast rolling mill (100) according to claim 3,

characterized in that

the ratio of the length (X1) of the portion of the outlet guide of the strand guide enclosed by the furnace to the length (X2) of the strand guide

Querverschiebebereiches smaller than 1, 5, preferably about 1.

5. Cast rolling mill (100) according to one of the preceding claims,

characterized in that

the ratio of width (Y1) of the furnace to the length of the furnace Transverse shift range (X2) between 0.2 and 0.8; preferably at about 0.5.

6. Cast rolling mill (100) according to one of the preceding claims,

characterized in that

the furnace (150) has a further opening (156) which either serves as an outlet for slabs which are not to be introduced into the rolling line or acts as an inlet for slabs which are not to be fed via the casting line to the rolling line; and

the outlet roller table (128) of the strand guide over the

Querverschiebebereich is extended through the further opening (156) therethrough outside of the furnace in the casting line.

7. Cast rolling mill (100) according to one of the preceding claims,

characterized in that

the oven (150) is designed as Hubherdofen.

8. Cast rolling mill (100) according to one of the preceding claims,

characterized in that

the broad side walls of the mold (1 10) are formed to extend parallel to the output of the mold.

9. Cast rolling mill (100) according to one of the preceding claims,

characterized in that

the roll carpet (125) of the strand guide of a plurality of

Segments is formed, which are arranged in the casting direction (R) in succession;

wherein in one of the mold (1 10) immediately following first

Segment (121) initially 3 to 7 pairs of rollers are vertically stacked to form a vertical guide portion for the casting strand, and subsequently another 5 to 1 1 pairs of rollers within the first segment are arcuately arranged to form a bending region for bending the casting strand from the vertical into a casting radius between 3.5 to 6.5 m; and

wherein the first segment 2 to 4 arc segments (122, 123, 124) are arranged downstream for guiding the casting strand in the casting radius between 3.5 and 6.5 m.

10. Cast rolling mill (100) according to one of the preceding claims, characterized in that

the supported length of the casting mill, measured from the pouring level until the beginning of the outlet of the strand guide, is less than or equal to 12 m.

1 1 .Gießwalzanlage (100) according to any one of the preceding claims, characterized in that

the thickness of the casting strand (210) at the end of the strand guide is between 90mm and 120mm.

12. Casting rolling mill (100) according to one of the preceding claims, characterized in that

the height of the casting rolling mill is between 5 and 8 m.

13. Casting rolling mill (100) according to one of the preceding claims, characterized in that

the strand guide (120) has a soft reduction region in front of the solidification area of the casting strand.

14. Cast rolling mill (100) according to one of the preceding claims, characterized by

a the Steckel rolling mill (160) in the casting direction (R) downstream

Cooling device (170) for cooling the rolling stock; and

for example, one of the cooling device downstream in the casting direction Winding device (180) for winding up the cooled rolling stock.

15. A method for producing metallic rolling, comprising the following steps:

In a pouring line:

Vertical casting of a cast strand (210);

Diverting the casting strand from the vertical to the horizontal;

Cutting the cast strand into slabs;

Transversely transporting the slabs from the casting line into a parallel offset rolling line, wherein the slabs are heated in an oven or at least kept warm; in the rolling line:

Rolling and reducing the thickness of the slabs in a Steckel mill to rolling stock; characterized in that the slabs enter the front side in the casting direction in the oven and backward end face in the rolling direction of the oven.

16. The method according to claim 15,

characterized in that

the casting speed is between 1 and 3.5 m / min.

17. The method according to claim 15 or 16,

characterized in that

the slabs in the interior of the furnace (150) immediately after their entry into the furnace, during their transverse transport and preferably also during their subsequent transport in the rolling direction with a Heating gas are applied, which opposes the respective

Transport direction of the slabs flows.

18. The method according to any one of claims 15 to 17,

characterized in that

After leaving the furnace, the slabs enter directly into the rolling stand of the Steckel mill, are thinness reduced there in a first pass and are subsequently wound up on the Steckel of the Steckel mill located downstream of the rolling stand.

19. The method according to claim 18,

characterized in that

the slabs are rolled in the Steckel rolling mill with at least 3 stitches to their predetermined final thickness, before being cooled as rolling stock in the form of flat steel and, for example, wound up.

20. The method according to any one of claims 15 to 19,

characterized in that

the material from which the cast strand, slabs and rolling stock are made is carbon steel.