DE2514783A1 - METAL ROLLING METHOD AND DEVICE - Google Patents

Description

25H783

Dr. V / errer Haßler Lüdenscheid, April 3, 1975

PATENT ADVOCATE

588 LÜDENSCHEID ^A

A «nberg 35-Poitiach 1704

Applicant: Nippon Steel Corporation

6-3 »Otemachi 2-chome, Chiyoda-ku Tokyo, Japan

Method and device for rolling metal

The invention relates to a method and a device for rolling metallic workpieces, in particular flats, Rods, rods, double flange beams and the like. In the context of the invention, the relative decrease in the cross section is intended be as large as possible in one stitch.

For forming metal into plates, rods, shaped steel and the like. rolling is widely used. Because this enables mass production in continuous operation. in the With regard to efforts to increase economic productivity in the steel industry and in other branches of industry the improvement of the effectiveness of known processes and the development of new processes are examined.

Conventional rolling processes do not allow a high relative reduction in cross section of the workpieces if one of special processes using a planetary rolling mill or a Fendel rolling mill disregards. This is due to the fact that the workpiece is no longer gripped between the work rolls and from slides off the work rolls if the relative decrease is chosen too large. In the conventional rolling process then occur other difficulties as well. A difficulty that as

25H783

An example for understanding this situation is that the relative cross-section would decrease during V / arm rolling of steel plates by conventional methods is not greater than 30% in one pass when the plate thickness ratio namely the ratio of the roll diameter D to the thickness Hq of the workpiece has a value of 5 before rolling and the The coefficient of friction between the work roller and the workpiece is 0.36.

Because of the small relative reduction in cross-section in one pass, there is an increase in the number of roll stands or an increase the number of stitches required in a roll stand. This causes a greater need for building floor space for the Rolling mill and for the additional equipment such as hall crane and roller table; In addition, a large number of scaffolding changes are required, in particular roll change for the various rolling processes' and additional equipment is required; it is one large numbers of operator and maintenance personnel required. As a result, there are strong efforts to resolve it these problems are necessary so that the usefulness of the capital employed and the work required can be increased. Even With regard to energy consumption, appropriate efforts are essential, because the increased number of stitches when rolling requires an increased expenditure of energy and a longer processing time.

In the following, some other difficulties of the conventional rolling method with a small decrease in one Stitch explained. According to this, the width of the rolled product when rolling in one direction is only a factor of 1.1 up to 1.2 compared to the width before rolling. If, therefore, a wider spreading of rolling stock of greater thickness is required is, you have the workpieces in question, such as slabs after rolling or as part of a stitch within of the rolling program within the workpiece plane by 90

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and then another rolling process to achieve widening carry out. This mode of operation is known as cross rolling.

When producing strip steel of great length and width, however, the starting material must be of sufficient size to give the tape material of the appropriate size. As a result, the ingots, slabs and castings must be large enough Have dimensions. Apart from the required extensive Facilities such as molds for ingot casting, slab rolling mills. Slab handlers and Ro 11 went as well as a crane of sufficient size, you need extensive technical aids that cause ongoing costs.

For the reasons mentioned, the maximum width of tape material when rolling in one direction, it should not be greater than 2134- now.

Even when rolling thick plates, the workpiece must be rotated perpendicular to the rolling direction, so that cross rolling in one further rolling process is possible. As a result, the required Machining time long and leads to a low profitability. The high time requirement makes an additional one Fuel consumption is required to heat the workpieces so that the temperature drop is compensated.

Another difficulty is that you have to manufacture the workpieces in numerous sizes so that you Rolled products of the required dimensions received. When rolling shaped steel, a blank with a square cross-section, about a bloom rolled with groove rollers at least in a few ten passes. Even when rolling blocks, A large number of stitches are necessary for clubs, sticks or the like, about a few tens of stitches. This large number of stitches is necessary on the one hand because the relative decrease is a maximum of 30% if one does not use an additional pulling force

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begins, and on the other hand is based on the fact that the workpiece must be drawn in by the caliber rollers. One difficulty in ^T vValzen of shaped steel is the forming of the flanges. In order to overcome these difficulties, numerous roll gauges have been proposed which are used in the rolling of sectional steel.

The required large number of stitches according to conventional methods leads to a large space requirement for V / arm rolling, to one Increase in the number of required rolling equipment, aids, Plant parts, buildings, hall cranes and operating equipment.

In the production of rolled profiles with a complicated shape for individual rolled products, special process technologies are required and extensive experience is also required. The necessary high number of stitches leads to a disturbed temperature distribution within the workpiece, which not only causes anisotropies in the workpiece, but also residual stresses and irregularities in the deformation resistance have their cause. This enables the design of profile cross-sections difficult.

A reduction can be achieved by conventional rolling methods the flange width of the rolling stock compared to the starting material not prevent. As a result, one must have a variety of dimensions Have the workpieces ready. This means a lot of effort in keeping the raw pieces in stock. When log rolling conventional processes make the difference in size and shape between the ingot and the rough rolled one Block a large number of stitches, each of which has a relative decrease of 20 to less than 30%, so that the size and shape of the workpiece is gradually changed. When rolling a block of 250 mm from a cast block of 610 mm, 19 stitches are required in a duo reversing stand. When rolling large-format sectional steel, a pre-

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rolling the ingot into a shape similar to the final shape necessary, so that a total of 20 to 30 stitches are required. This significantly reduces the economic viability.

You have to use such rolling frames and rolls that the size and shape of the rolling stock are adapted. When rolling billets, the number of rolling stands must be increased. You need Rollers in different shapes. Overall, a high investment requirement and a spaciousness of the production plant are necessary.

Planetary rolling mills or pendulum rolling mills are known, which allow high acceptance. A planetary rolling mill comprises two backup rolls, on the circumference of which a number of thin work rolls are arranged, which are held in cages. Since the Work rolls move in the rolling direction around the backup rolls, they rotate so that the pushed in by feed rolls Workpiece is rolled. In a planetary rolling mill, the decrease caused by a work roll is small; However the total decrease caused by a large number of work rolls is large.

In a pendulum mill, the work rolls sit at the end of a pendulum arm that periodically moves in the direction of the rolling stock movement swings back and forth. The rolling stock is rolled as a result of the movement of the vibrating work rolls, and it is done gradually moved on. The decrease in an oscillating movement of the pendulum rolling mill is only small. However, since the decrease several times is repeated, there is a high overall decrease.

The planetary rolling mill and also the pendulum rolling mill enable a high overall decrease, but have the following disadvantages on. Since the decrease per work roll or per pass is small, the metal only flows in the vicinity of the Work rolls acted upon workpiece areas. This requires

an uneven flow distribution in the thickness direction. Consequently Edge cracks can occur at the ends of the workpiece where high stresses are present. This will make the Reduced quality of rolled products. The rolling processes with a large number of work rolls or with multiple repetitions lead to a wavy, uneven surface of the rolling stock. Since the work rolls move in the rolling direction, its diameter cannot be chosen larger. As a result, its strength in the width direction is poor. Man therefore cannot roll wide steel plates using this method. The maximum plate width that can be used in a planetary rolling mill can be machined is 1.2 m. These rolling mills are also very intricate in structure and produce strong noises. When operating a planetary rolling mill, the upper and lower planetary rollers must be driven synchronously which makes extensive control equipment necessary. These rolling mills can only be used to roll plates, but not be used for rolling bars or shaped steel.

The object of the invention is to provide a rolling process, which allows a high relative reduction in cross section, so that a shape in one or a few stitches of the rolling stock is possible. This can increase profitability, save work, the necessary Investments are reduced, energy requirements are reduced and the quality of the rolled products is improved.

With a further objective, the invention provides a method ready, after which the expansion of plates or flanges in the case of structural steel by adjusting the continuous impact force precisely regulated on the workpiece between the rollers and / or the continuous tensile force on the workpiece from the rollers can be.

Another object of the invention is to provide a method for rolling H-shaped steel with high relative

5-

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- 7 acceptance and great economic efficiency.

Furthermore, the invention aims to provide a method for rolling continuous castings into semi-finished or finished products.

The invention seeks to provide a method for folding workpieces with a high decrease and at the same time Joining the abutting edges of two consecutive workpieces with one another, thus enabling continuous rolling during hot rolling of 7, 'is possible.

Finally, the invention seeks to provide a rolling train with rolling stands of high relative decrease to the Rolling of strip material, bars, rods, pre-profiles and other semi-finished products in high quality and with high economic efficiency.

These tasks are in a rolling process according to the invention solved in that in a roll stand with rolls mounted in stationary bearings, a roll gap corresponding to a high relative reduction in cross section is set so that the pressure angle -0 has a value tan / u (, u as the coefficient of friction between roller and workpiece), and the workpiece continuously into the gap with such an impact force is pushed in, which ensures a flow sheath in the area of engagement between the work roll and the workpiece.

Further features of the invention are specified in the subclaims.

Embodiments of the invention are explained below with reference to the accompanying drawings, in which represent:

1 shows a diagram of the range of possible pressure angles for carrying out the rolling operation,

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Fig. 2 - 8th -
a diagram of the possible pressure angles depending on the impact force, Fig. 3 and 4- schematic individual representations of Push-in devices, Fig. LTN a schematic representation of an electro magnetic pusher, Fig. 6th a graph showing the relationship between Ab taking and spreading a steel plate, Fig. 7th a schematic representation of the broadening on flanges of an H-profile, Fig. 8th and 9 cross-sections of Η-profiles according to a conventional method and according to the Invention are rolled, Fig. 10 and 11 graphs showing the relationship between the Impact force and the flange width of H-Pro filen, Fig. 12th a graph of the relationship between the train tension and rolling force, Fig. 13th a schematic picture of a rolling mill with high decline and with pusher and with pull-out device, Fig. 14th a graph of the relationship between train tension and expansion of a steel plate, Fig. 15th a graph of the relationship between train tension and spread of the flanges of H-shaped steel, Fig. 16 a schematic representation of a rolling mill with regulation of the spread, Fig. 17th and FIG. 18 are schematic representations of rolling mills with high decrease and with pusher device and pull-out device, Fig. 19th a pass schedule for rolling H-shape steel in a universal roll stand, Fig. 20th a section through deformed flange parts of an H-shaped steel, Fig. 21 and 22 schematic views of a universal

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scaffolding with push-in device and pull-out device,

Figures 23 and 24 are schematic representations of the front end of H-shaped steel made according to a conventional method and according to the invention is rolled,

Fig. 25 is a graph showing the relationship between decrease and strength of the joint area between two steel plates joined together,

26 is a graph showing the relationship between the impact force and the strength of the joint area of two steel members joined together;

27 to 31 are block diagrams of a hot rolling mill for

Strip steel, a cold rolling mill for strip steel, a block rolling mill, a bar rolling mill and a section steel roughing mill within the scope of the invention.

In the context of conventional rolling technology, the driven work rolls grip the workpiece. These rollers move it Workpiece with simultaneous decrease in the rolling direction according to the rotation of the rollers, whereby the frictional force takes the workpiece between the surface of the workpiece and the rolling surface. So that the rolling process is carried out the workpiece must be completely gripped by the rotating rollers. After grasping is allowed to do not change the speed of movement of the workpiece abruptly. In order for these conditions to be met, the horizontal component must the frictional force between the workpiece and the work roll acting on the workpiece in the exit direction of the The roll gap acts to be greater than the horizontal component of the frictional force acting on the workpiece in recoil Affects the senses. If this condition is not met, the workpiece slides back on the work rolls so that there is no movement takes place in rolling direction and rolling is not possible

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The subject of the valid rolling theory is reproducible rolling only possible if the pressure angle -0 and the coefficient of friction / U between work roll and workpiece of the relationship enough

e <tan ~ ^Λ αϊ (1)

1 shows in a diagram the relation of the formula (1), where the plotted curve divides the plane of the sheet into a lower possible rolling area and an upper impossible rolling area where rolling is not possible. Since the pressure angle θ is determined geometrically by the radius of the work rolls and the size of the decrease, it follows that if the pressure angle Q is reduced below a certain value, the decrease cannot be made larger than a value determined thereby. As a result of this limitation, rolling with a high reduction is not possible according to the conventional rolling technique.

Thorough and extensive research and attempts to increase the relative decrease in a stitch have led to the Recognition led that a continuous pushing of the workpiece between the work rolls a greater engagement angle and thus allows a greater decrease.

In this case, the range of allowable rolling conditions can be set using the pressure angle Θ, the coefficient of friction / U and the compressive stress created by the impact force on the workpiece can be represented as follows:

where ι ,, is a function and K is the yield stress at the rolling temperature of the workpiece. Fig. 2 shows in a diagram the relation of the formula (2) for different curves with the impact force as a parameter. These curves each divide the plane of the drawing into a possible rolling area and an upper, impossible rolling area. One recognizes from this

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Diagram that with increasing impact force the pressure angle 0 and thus the possible decrease will be greater.

The application of a nudging force to the workpiece prevents and allows it to slide back from the work rolls a continuous rolling operation under working conditions, where the flow divide, in whose area the peripheral speed of the work roll is equal to the movement speed of the workpiece, within the range of engagement remains between the work roll and the workpiece. So that this is secured, the pusher must always be equipped with a Working speed are driven synchronously with the movement speed of the workpiece. As a known way of working To apply a pushing force to the workpiece, pushing rollers of a planetary rolling mill are available.

According to the invention, however, the work rolls of the rolling stand, each acting on a surface of the workpiece in a decreasing sense, with their axes fixedly mounted, so that the rollers are not in the direction of the workpiece move. As a result, the operation of the work rolls according to the invention differs significantly from the rollers of a planetary rolling mill. There is also an important difference in the application of the impact force between the Rolling mill according to the invention and a planetary rolling mill available. The application of an impact force to the Workpiece at the beginning of the rolling process so that the work rolls easily grip the front end of the workpiece. This way of working differs from the invention in that, within the scope of the invention, the impact force is continuously applied to the workpiece is also applied after grasping.

Among the known methods for pushing in the workpiece, the working method of pushing in the workpiece is known ' the rear between the work rolls. A hydraulic cylinder or a combination is available to apply the push-in force

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an electric motor and a coupling arrangement or the arrangement of a rack with a pinion available.

FIGS. 3 and M each show a push-in device where a piston rod 3 of a hydraulic cylinder 2 itself is designed as a hydraulic cylinder which contains a further piston rod 4. This arrangement according to FIG. 3 works up to a direct approach of the outer piston rod 3 to the work rolls 1, the outer piston rod 3 together with the inner piston rod 4 exerting an impact force on the workpiece. Then, the outer piston rod 3 is stopped, whereas the inner piston rod 4 continuously exerts a pushing force on the workpiece W until the workpiece W emerges from the roll gap. Then this piston rod is also stopped. The entire hydraulic device is returned to its starting position for the next operation. "The hydraulic cylinders 2 and 3 are controlled with regard to the pressure and flow rate of the fluid and other influencing variables by using known control loops, valves and the like.

In addition, there are working methods for pushing in workpieces available between the work rolls where the workpiece passes on the surface and the sub-surface or on both surfaces Pinch rollers, pull chains or the like. Is detected.

Fig. 5 shows a method for pushing the workpiece under Application of an electromagnetic force where a linear motor 6 is placed immediately above the workpiece W, the is on a roller table 5. The core 7 of the linear motor 6 is aligned in the direction of movement of the workpiece. If from a supply device 9, a three-phase alternating current is fed into the winding 8 of the core 7, becomes an electromagnetic Moving field generated that moves linearly to the direction of movement of the workpiece. The ones from the moving field in that Electromagnetic force generated by the workpiece acts as an impact

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- 13 force for the workpiece W.

As a further push-in technique, a rolling mill can be used, where there is another rolling stand in front of the rolling stand with high acceptance is arranged that enters the workpiece directly into the second roll stand with a high decrease Circumferential speed of the work rolls of the two roll stands controlled so that the workpiece speed at the exit of the first roll stand is higher than the entry speed of the second roll stand, so that within the workpiece a compressive stress is built up. This creates a continuous pushing force for the workpiece into the rollers of the second roll stand applied with high decrease. The first roll stand can be a conventional roll stand, a roll stand with high reduction or use an edging framework.

Another push-in technique uses the pusher that pushes the respective workpiece out of the heating furnace, the is arranged in front of the roll stand with high decrease. This pusher doubles as a push-in device for the workpiece exploited.

When continuously rolling a number of workpieces one after the other you can make the interpretation so that the back of a previous workpiece on the face of the next Workpiece. The push-in force is then applied by this subsequent workpiece, so that each leading workpiece is pushed between the work rolls. This increases the economy and the output significantly increased.

As will be explained in detail, the impact force must have such a size that the in the workpiece through the impact force generated compressive stress is smaller than the yield stress of the workpiece at the rolling temperature. Then can buckling or bulging of the workpiece before gripping

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_ 14 can be switched off by the work rolls.

When rolling metal that does not have a clear yield point, yield stress can also be used instead of yield stress will. Retaining guides and pressure rollers can also be used effectively to suppress bulging. So that one receives a constant impact force under constant control conditions, the compressive stress should expediently 0.01 times the yield stress. Then the workpiece can be pushed in between the work rolls with high Approval to be rolled. Rolling with a high relative decrease is the rolling of the workpiece that is between the driven Rolling is engaged and its cross-section or thickness to the same size as the setting of the roll gap is reduced between the rollers. The pressure angle has a value

Q ^ tan ~ ¹ Ai (3).

The high reduction rolling means a large reduction in area that can be achieved with a conventional rolling process can not be achieved, since then the workpiece is not gripped and easily slides back from the work rolls.

When hot rolling steel plates with a D / EU ratio of 5 (D as the diameter of the work rolls and Hq as the plate thickness) and a coefficient of friction, u = 0.36, the decrease that can be achieved using a conventional method is less than 30 %. The high decrease rolling according to the invention allows a decrease of more than 30 %.

The method of the invention is applicable to a variety of metals at any rolling temperature, independently of differences in the cross-sectional shape and size of the Work pieces. In the following, the method is explained using individual examples of the rolling of steel products.

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The interest impulse force applied to a steel workpiece must be determined so that the value of the compressive stress 6l generated in the workpiece by the impact force is as follows Relationship fulfilled:

ce - C ₁ ) - ι> ο

with K as the flow stress (kp / mm) within the workpiece

the rolling temperature,
0 as pressure angle (rad)
a as a constant = 1-8
b as a constant = 1.5 - 0.5
C ₁ as a constant = -0.2 - +0.2.

The coefficient of friction / U appearing in the above formula is converted to the formula by Ekelund and A. Geleji for the compensation of roller lubrication as follows / U = -f C ₂ (1.05 - 0.0005 · T) - 0.056 - V ₁ Jc ₃ (5)

with Cp as a constant depending on the roll material (1.0 for rolls made of forged steel, 0.8 for rolls made of cast steel)

C, as a constant depending on the lubricant for the reels = 1 to 0.1

V as rolling speed (m / sec)

T as the rolling temperature (C).

The formula (4) indicates the impact force as it is by far Scope can be used for steel products.

The following explains in detail the high-decrease rolling of steel plates and flange sections made of steel.

Due to numerous attempts with a wide variety of working conditions and different workpieces could be shown that the spreading of a steel plate during rolling with high decrease is much greater than can be achieved otherwise

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leaves. The width B / B _Q (B as the width of the steel plate after rolling, B _Q as the width of the steel plate before rolling) depends on the relative decrease ^, the plate thickness ratio ^ = D / H _o (D as the diameter of the work roll, Hq as Thickness of the steel plate before rolling), the plate ^{width ratio C 1} = B ₀ / Hq (B ₀ as above, H _Q as above), the impact force and the coefficient of friction. The relative spread becomes greater with an increase in the relative decrease and the impact force up to a value of 3 as the maximum. 6 shows the change in the relative spread as a function of the relative decrease with the impact force as a parameter, from which one can clearly see the increase in the spread.

When rolling steel plates, the impact force acting on the workpiece must be so great that the value of the compressive stress fr within the workpiece satisfies the following relationship:

with a = d W + f,

b as a constant = 0.1 - 2.5

c as a constant = 0.5 - 1.5

d as a constant = 0.9 -1.2

f as a constant = 0.2 - 0.4-

n as a constant = 1.5 - 2.5.

The rolling of shaped steel flange profiles also results in a large widening of the flange area due to the high relative decrease, which can also be achieved as with steel plates. If the relative width H / H _Q (H is the mean flange width, Hq is the thickness of the workpiece before rolling, see FIG. 7) as a function of the relative reduction in cross-section, the size of the workpiece before rolling, the coefficient of friction and the impact force changes, the relative spread becomes greater, in particular with increasing impact force. Fig. 7 gives the relationship between the various dimensions for the relative

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- 17 -
Spreading when rolling H-shaped steel.

A larger relative broadening of the molding steel means that the workpiece fills the roll caliber better, so that you get a better cross-sectional shape of the rolled product receives.

Fig. 8 shows the section through a Η-profile, which according to a conventional rolling process without the application of an impact force is made. This rolled product is in one pass from a workpiece with a square cross-section in a universal rolling stand manufactured. The relative decrease was obtained without applying a pushing force as the workpiece made of a malleable 7 / material with a high coefficient of friction / U existed. It can be seen from the drawing that the filling of the roll caliber in the area of the flange edges apparently insufficient is. So the flange parts are rolled into a deformed shape.

Fig. 9 shows a cross section through a Η-profile, which after the method according to the invention is rolled. The rolling of this profile is done in one piece from a 'workpiece with a square Cross-section under application of an impact force. It can be seen from this drawing that the workpiece is rolling with continuous application of an impact force between the rollers for the filling of the roller caliber is very significant is, so that the flange in the area a has a good shape.

Figs. 10 and 11 show the relationship between the compressive stress, generated by the impact force in the workpiece and the flange width of the Η-profile. For the trials a universal roll stand is used for plastic deformation. The workpiece used in each case is 55 mm thick and 50 mm wide. The bridge is 8 mm wide and 61 mm wide. The measured values 0 show the maximum flange width, the measured values

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show the minimum flange width. The workpieces used for the experiments in Fig. 11 are 55 mm thick and 50 mm wide, the bridge is 11 mm thick and 61 mm high. In the drawings, the maximum width is the distance between the caliber walls of the rollers.

In order to obtain good gauge filling, the preferred conditions are such that the relative cross-section decrease is more than 30 % . The impact force must be such that the value of the compressive stress <5l caused in the workpiece by the impact force satisfies the following equation:

C ™ = a ^ + b (ib / K) + d (7)

with C- as the coefficient of the flange width ^c f = iq ° B ° - b _w ^ww

H _n as 7 / workpiece thickness before rolling B ₀ as 7 / workpiece width before rolling IL nominal flange width

B web width

T web thickness

B inner web width

as a relative web reduction

M- ^(H 0 - ^T w)
(H ₀

a as a constant = 0.5-6.0
b as a constant = -0.1 - -6.0
d as a constant = 1-4.

The rolling of workpieces with high cross-section decreases can be achieved by continuously pushing the workpiece between the work rolls. However, the rolling with high relative decrease does not lead to an increase in the rolling force. Therefore, studies were made to determine the influence the rolling force carried out to find a solution. It has

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has been shown that an increase in the rolling force by continuous Pulling out the workpiece on the exit side of the 7 'alzgerüsts can be avoided. Fig. 12 shows in one Diagram showing the decrease in the rolling force as a function of the increase in the tensile force. The applied tensile force is only allowed in this way be large that the tensile stress generated in the 7 / piece <? ^ _ less than the yield stress of the workpiece at the rolling temperature is.

Fig. 13 shows an apparatus for rolling with high relative Decrease where the workpiece V / pushed continuously between the work rolls 1 and by the hydraulic cylinder 10 grasped at the front end on the exit side of the roll stand by a gripping device 11 and by means of a hydraulic cylinder 12 is continuously pulled out. The invention is not limited to details of the push-in device and pull-out " device limited. One can use other devices such as pinch rollers, pull chains, a combination of sprockets and Use rack and linear motors, which are used depending on the respective working conditions can.

In the continuous rolling operation, the peripheral speed of the work rolls of each roll stand must be adjusted so that both a push-in force and a pull-out force act continuously on the workpiece. Accordingly, the peripheral speed of the work rolls of the two roll stands in front of and behind the roll stand with a high decrease higher than the peripheral speed of the rolls of this roll stand so that the workpiece on the entry side is continuous Push-in force and a continuous pull-out force acts on the exit side.

In this case, it works with a high decrease in front of the roll stand arranged roll stand without impact force. As a result, the decrease size of this roll stand is essentially the same

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as with a conventional roll stand. However, one can of course also use a push-in device.

The width of the block is somewhat reduced by the continuous pulling out on the exit side of the roll stand. When rolling steel plates, the relative width B / Bq (B workpiece width after rolling, B _Q workpiece width before rolling) changes depending on the relative decrease W , the plate thickness ratio>, the plate width ratio, the push-in force, the pull-out force, the coefficient of friction and other factors. Fig. 14- shows the reduction in spread as a function of the pull-out force.

When rolling shaped steel flange profiles, the changes relative width H / Hq (H mean flange width of the rolled product, Hq workpiece thickness before rolling, see. Fig. 15) depending on the cross-section, the workpiece size, the size of the rolled product, the coefficient of friction, the push-in force, the pull-out force and other factors. Fig. 15 shows the reduction in flange width in Dependence on the extraction force for an H-shaped steel.

In rolling steel products with a high relative decrease with continuous application of a pushing-in force and a pulling-out force one must ensure that the compressive stress 6 "! caused by the impact force satisfies equation (4) and that the tensile stress 67 caused by the pull-out force is within of the workpiece satisfies the following equation:

with K as the flow stress of the workpiece at the rolling temperature (kp / mm)

Q as pressure angle (rad)
Sq as the cross-sectional area of the workpiece before rolling

-I as the cross-sectional area of the workpiece after rolling

(mm) '

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- 21 as rolling force (kp).

When rolling steel plates, the width of the plate must be controlled by the pushing force, which is caused by the pushing force Compressive stress 0 must satisfy the equation (9), and by the pull-out force, where the tensile stress caused by the pull-out force O ^ must satisfy the following equation (10):

0 "

B as the workpiece width before rolling B as the workpiece width after rolling K as the flow stress of the workpiece at the rolling temperature a = d-rj + f

d as a constant - 0.9 - 1.2 f as a constant = 0.2 - 0.4 b as a constant = 0.1 - 2.5 c as a constant = 0.5 - 1.5

η as a constant = 1.5 - 2.5

(b / B _o ) / _q - '^ ₀ V as the relative spread in tension

g as a constant = -0.05 - -0.8.

When rolling shaped steel flange workpieces, the desired rolling condition to ensure good filling of the roll caliber by the rolling stock is that the relative cross-sectional decrease is greater than 30 % . In addition, with regard to the width constriction of the workpiece, the impact force must be so

Be sure that the resulting compressive stress corresponds to the following Formula (11) is sufficient, and the pull-out force is so great that the tensile stress caused thereby (51 of the following formula (12)

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enough.

(5
^ a ₁ η + Ta ₁ (- ^p ) + d (11)

H, Ο ". H ₁

- ¹ = a ₂ (- *) + (J) (12)

H ₀ κ H ₀ «r _t = o)

^c f-

H as the workpiece thickness before rolling

B as the workpiece width before rolling

H as the nominal flange width

B as the web width

t as the web thickness

B as the inner flange width

H-T

^ as relative web reduction -

^H o

a ^ as a constant = 0.5-6, ο
b. as a constant = -0.1-6.0
d as a constant = 1-4
a ₂ as a constant = -0.1 - -0.9

ο) as a relative flange width for tensile stress Ö. = o

Do the previous one by rolling plates or flange profiles with a high decrease with simultaneous thrusting of the workpiece between the work rolls to a large widening of the Workpiece. This spread increases as the decrease or the impact force increases. In view of this is the rolling process designed according to the invention so that the relative decrease in one stitch and / or the size of the impact force

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in order to regulate the width of the workpiece. This gives a rough regulation of the lateral spread, by reducing the cross-section and the size of the impact force

be ordered. Fine control is obtained by setting the size of the impact force. In addition, the pull-out force can be set in addition to the push-in force and the decrease, so that the most precise control possible is obtained. When rolling of plates and right-edged workpieces according to the invention, the width of the rolling stock can be in a ratio between 1.1 and 3.0 can be freely adjusted based on the initial size of the workpiece.

In particular, to regulate the finished width of steel plates, the pushing force is adjusted to such an extent that the Compressive stress 0 ~, which is caused by the impact force, satisfies the formula (6). If in addition to the impact force too the pull-out force is adjusted, the pull-out force is adjusted to such a level that the tension 6, the formula (10) is sufficient.

For regulating the flange width of structural steel flange workpieces

just by adjusting the force of the push, it is adjusted in such a way that that the resulting compressive stress 6 "of the

Formula (7) is sufficient. In addition, if the pull-out force is also divided, the tensile stress 61 satisfy the formula (12).

16 shows a rolling mill according to the invention with control the spread of the workpiece. In this case, the workpiece W is continuously fed into the roll stand 14 by means of pressure rollers 13 Acceptance pushed in and also continuously removed by pressure rollers on the exit side of the roll stand 14. Direct in connection with the roll stand 14, a width measuring device is arranged which contains a photoelectric receiver and the width of the rolled product is recorded. The relative decrease

B09850 / 0276

by the rolls of the roll stand 14 and / or the peripheral speed of the work rolls and the peripheral speed of the pressure rolls 13 and 15 are controlled by a control circuit 17 regulated, which acts as a feedback signal as the detection signal of the Width measuring device 16 used, so that one obtains the desired nominal width of the rolled product.

In the case of continuous rolling using a roll stand in front of the roll stand with bdber.A decrease can be the size of the impact force of the workpiece can be controlled by setting the corresponding peripheral speeds of the two roll stands. As a result, the width of the workpiece can also be regulated by adjusting the peripheral speed of the work rolls. will. Accordingly, by arranging roll stands in front of and behind the roll stand with a high decrease Control of the width of the workpiece by adjusting the respective peripheral speeds of the work rolls of the three Roll stands received.

With regard to the deformations during rolling with a high decrease, it must be taken into account that the material flow is in the direction of the thickness of the workpiece is large and comparatively uniform because a high relative decrease occurs in one pass and that Workpiece is continuously pushed so that no edge cracks occur. As a result, the surface will be damaged of the workpiece largely reduced within the scope of the invention. Because the shape of the workpiece in the core area is large, you can cast ingots within the scope of the invention

Roll continuously in a wider range of different shapes and sizes. The surface of the rolling stock is free of waves and thus results in a very good surface design. The widening of the rolling stock can be adjusted by adjusting the push-in force and / or the extraction force can be regulated. The deformation of the front area and the rear of the workpiece is sufficient ut, so that a high output of Walζer certificates can be achieved.

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holds. Workpieces of great width can be rolled. No excessive noise is generated during operation. The scheme of the form of rolled plates is done in the same way as in conventional rolling processes.

Taking into account a high degree of utilization, the desired shape can be created in one stitch or in a small number of stitches so that the rolling time is reduced. Because of the reduced number of stitches, you get a smaller one Number of roll stands.

The high-volume rolling mill, the push-in device, the pull-out device and the other auxiliary devices within the scope of the invention can largely consist of conventional devices be constructed so that the inventive method does not require any new devices.

The power requirement for rolling is due to the power requirement for rolling the end part due to the high decrease the impact force is not influenced. On the contrary, decreased

I all the power needs. The rolling force can be applied by a tensile force can be reduced in the manner described. The roll stand according to the invention must be dimensioned so large be that high-decrease rolling is possible. The effort required by this larger dimensioning becomes largely compensated for by the advantages of the invention.

Embodiments of rolling processes with a high decrease in the For the purposes of the invention are explained in the following individual examples:

example 1

The rolling mill of Fig. 13 has work rolls with a diameter of 1000mm, which are driven at 9.6 rpm. Cast ingots are used whose cross-sectional dimensions ? 00 χ 900mm and which are 1000mm long. The ingots

B09 & 50/0276

be rolled in one pass, so as to obtain a rolled product having a thickness of 40mm and a width of 1090mm at a roll temperature of 1200 ⁰ C. The roll surfaces are cooled with water. The compressive stress within the workpiece caused by the impact force is 1.5 kp / mm at the moment of gripping and during the rolling process. The impact force is 270 tons. The relative decrease is 80 %. The power consumption is 13000 kW. Useful rolled products are obtained.

Under the same rolling conditions as before, a pull-out force is applied, which generates a tensile stress of 1.4 kp / mm in the workpiece. This reduces the power requirement by 13 % . A satisfactory decrease is obtained.

Example 2

There is a continuous rolling mill with roll stands 18 and 19 for high acceptance, which are arranged one behind the other as shown in FIG. The blank W is a steel slab with transverse dimensions and 100 χ 500mm ynd a length of 5000mm. The preheating temperature of the blank is 1280 ⁰ C. The blank is rolled in one pass of the first stand 18 on cross-sectional dimensions 85 x 505mm and a length of 5800mm. Then it is rolled in one pass within the second roll stand 19 to transverse dimensions of 17 × 611 mm and a length of 24000 mm. The decrease in the first roll stand is 15 %, the decrease in the second roll stand is 19 80 %. The circumferential speed of the work roll ies first roll stand 18 is 2 % greater compared to the tension-free operation. The impact force consequently leads to a compressive stress of 0.5 kp / mm ² on the rolling stock W in the area between the two roll stands 18 and 19. A satisfactory rolling result is obtained under these conditions. The power requirement

Around 6% less than a conventional rolling process and the rolling time is shortened by around 62 % .

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9KU783

Example 3

In Fig. 18, an additional roll stand 20 is used for high removal. The blank has the same dimensions as in Example 2. The dimensions of the rolling stock W on the exit side of each roll stand have cross-sectional dimensions at the exit of the first roll stand 18 of 72 χ 505mm and a length dimension of 5800mm, cross-sectional dimensions at the exit of the second roll stand of 17 x 611mm and a Length dimension of 24000mm and cross-sectional dimensions at the exit of the third roll stand 20 of 13.6 χ 586mm and a length dimension of 31400mm. The decrease in each roll stand is 15 %, 80% and 20 %. The compressive stress of 0.5 kgf / mm transmitted to the rolling stock W between the first roll stand 18 and the second roll stand 19 is similar to that in Example 2. Between the second roll stand 19 and the third roll stand 20, the rolling stock is applied. W transmit a tensile force such that the tensile stress becomes 1.5 kgf / mm ^c . The peripheral speed of the work roll of the third roll stand 20 is 7 % greater compared to one

voltage-free operation. This gives a satisfactory rolling result. The power requirement of the motor of the roll stand 19 for high decrease can be compared to a conventional rolling process can be reduced by 13%.

Example 4

The rolling mill used had a pusher in addition to the high-demand rolling mill. Steel billets with transverse dimensions of 55 x 50mm are used. The preheating temperature is 1200 ^° C. The respective billet is rolled in one pass with a high decrease in an H flange steel with a flange width of 55 mm, a web thickness of 8 mm, a web height of 60 mm and a flange thickness of 7 mm. The reduction in cross-section is 53.5 %, the impact force for the rolling stock is 5.8 tons, which causes a compressive stress of 25 % of the flow stress of the material. With these rolling conditions, good rolling

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- 28 results.

In the following, further rolling processes are described using a rolling stand with high acceptance »

First, the rolling of H-flange profiles in a universal rolling stand treated. The formation of the flange part of an H-shaped steel by conventional methods is carried out in the manner that the material flow from the web into the flange occurs when the web part is rolled out between the horizontal rollers. Accordingly, when rolling H-shaped steel in a universal mill According to FIG. 19, the flange width is increased solely by rolling the web part. If the bridge part is alone under the Effect of the horizontal rollers is rolled out, the rolling force of the horizontal rollers is not effective in the flange part. Consequently According to FIG. 20, a deformation occurs as a result of the frictional force, which occurs in the areas N on the vertical end faces the horizontal rolling occurs. Satisfactory shaping of the flange parts is not possible. In these circumstances it turns one assumes some shaping of the flange part in a conventional rolling process. This will decrease the flange part greater. One can also use a caliber that is deformed by the frictional force on the end faces of the horizontal rollers excludes. But then the flange width becomes smaller contrary to the expectation. As a result, problems arise in maintaining the shape and dimensions of the flange part.

Tests carried out have shown the importance of deformation due to frictional forces on the inside of the flange. Because according to the conventional process, the 3-web part is first rolled out by the horizontal rollers, which are compulsorily

are driven and whose diameter is larger than that of the vertical rollers. Then the respective flange part is through iie vertical rollers rolled out, which are designed as drag rollers. So when the web part begins to decrease, it acts on ien flange part no limitation in the horizontal direction, so that

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the deformation becomes effective due to the frictional forces effective in the area N according to FIG. Based on these findings, using the invention, the following procedure can be developed. This is characterized by the fact that the rolling of the web part is carried out by the vertical rollers designed as drag rollers without a driving force acting on the same. The rolling out and elongation of the flange parts is achieved by the horizontal surfaces on the end faces of the vertical rollers and caused by the driven horizontal rollers. As a result, the flange part starts to decrease first under the action the horizontal rollers, the diameter of which is comparatively large; he removal of the web part is carried out by the vertical roller underneath conditions where the flange part is held between the upper and lower orizontal rollers. This prevents any deformation o occur due to the frictional force on the inside of the flange part.

If, when rolling H-shaped steel in a universal stand, the upper and lower horizontal rollers are driven and the vertical rollers work as slack rollers, this means a Rolling of I-shaped steel instead of H-shaped steel. In this case one works, however, with a strong decrease in the web part of the rolling stock due to the dragged vertical rolls and causes the small decrease of the flange part by the driven horizontal rollers, so that a sliding of the roller surface Rolled stock can occur and special precautions must be taken to ensure the function.

As a rolling process according to the invention intended for a high decrease brings a solution to this problem. This is because the workpiece is rolled with a high reduction in cross-section, with the rolling stock l is pushed in between the work rolls of the universal roll stand by a push-in device. The application of the impact force on the workpiece eliminates sliding between the surfaces of the work rolls and the workpiece. Simultaneously the width of the flange part is increased, so that a

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25H783

good shaping of the flange part is ensured. At the same time as the impact force is applied to the workpiece, this becomes Workpiece pulled out on the exit side of the universal roll stand, whereby the increase in rolling force caused by the impact force can be compensated.

The application of the push-in force and / or the pull-out force on the workpiece can be achieved by supporting the rear of the workpiece according to FIGS. 3 and 4, by gripping the workpiece as shown in FIG. 16, by exerting an electromagnetic force ier Fig. 5 or by setting the peripheral speeds of the work rolls in a continuous rolling mill according to the figures 7 and 18 take place.

Figures 21 and 22 show an embodiment of a rolling mill for rolling H-shaped steel. A workpiece W supported by inten on the roller conveyor 5 is in the roll gap between len horizontal rollers 24 and the vertical rollers 25 of the universal folding stand 23 is pushed in by the pushing device 21 with the hydraulic cylinder 22. The horizontal rollers 24 are driven The vertical rollers 25 are not driven, but can be dragged along by being rotated by the frictional force on the workpiece W side. The diameter of the vertical

The roller 25 is smaller than that of the horizontal rollers 24. The land part of the workpiece W is formed by the vertical rollers 25 lusrolled, the flange portion by the upper and lower surfaces of the horizontal rollers 24 and through the end faces of the / "ertikalwalzen 25. The workpiece W is on its front side is grasped by the gripping device 26 and pulled out under the action of the hydraulic cylinder 27. This takes place in detail folding H-shaped steel in the following way.

Example 5

! The starting material is steel billets with a thickness of ? 5mm and a width of 50mm. The universal rolling mill ■ used 22 has horizontal rollers with a diameter of

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480mm and vertical rollers with a diameter of 300mm. The teg part of the workpiece W is by the vertical rollers 25 in the Reduced cross-section. The flange part is reduced in cross section by the horizontal rollers 24. The rolled product has a flange width of 60mm, a flange thickness of 1.5mm, a web thickness of 10mm and is rolled out in one pass. The rolling conditions are the following ι

relative reduction in cross-section 25 % Power requirement 45 kW Speed of the rollers 10 rpm Impact force 5.8 tons (0.25 times the flow tension) WalztemOeratur 1200 ⁰ C

In this embodiment, a blank with a rectangular cross-section is used rolled into an H-shaped steel in one pass. This way of working is not limited to one stitch. The goal the invention can also be achieved with the provision of several stitches.

Example 6

On the entry side of the universal rolling frame, which in the example 1 is described, a duo stand with smooth rolls and

arranged in a roller diameter of 200mm. In this embodiment becomes a blank with a rectangular cross-section 69mm thick and 49mm wide with the same material composition as rolled out in example 1. The speed of the rollers of the duo stand is adjusted so that the workpiece is removed from the duo stand is pushed into the universal roll stand. The work rolls of the duo stand are in engagement with the upper and lower one Surface of the workpiece. In this way, impairments and deformations of the rolled product can be avoided. The rolling conditions are the following:

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25H783

Rolling mill Two-high rolling mill Universal mill stand acceptance 20 % Cross-section decrease
35 % Roller turning
number 25 rpm 10.0 rpm Performance
allowed
—— ι 10.3 kW 43 kW

During rolling, the circumferential speed of the work rolls of the two-high rolling stand is around 4 % greater than what corresponds to a stress-free rolling condition. The compressive stress is about 1.0 kp /

mm, so that the workpiece is pushed between the work rolls will.

The end part of the H-shaped steel product pointing in the direction of rolling is shown in Fig. 24 ^. The yield is improved, because the length of the front tongue-shaped area is noticeable is shortened in comparison to the end region in the rolling direction according to the prior art according to FIG. 23.

The invention is with reference to a conventional universal mill explains where the arrangement of the H-shaped steel on the exit side of the universal frame is an I-shaped steel corresponds, so that the flange area through the driven horizontal rollers and the web area through the dragged Vertical rolling is rolled out. However, if the rolling in H-arrangement with horizontal rolling comparatively small diameter

r follows that are driven, this arrangement is also in Scope of the invention.

The rolling method is applicable to the rolling of H-shaped steel. However, the invention can also be used on structural steel with other cross-sections, for example when rolling rails.

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25Ί4783

In the following the rolling process according to the invention is applied on the rolling of continuously cast metalworking materials explained using the casting heat. In this case, the rolling with a high decrease with nudging takes place in a continuous manner Rolling mill.

In continuous casting, the casting speed should increase productivity can be increased. However, the increased casting speed can be due to the static pressure of the Molten metal cause bulging by the surface area the casting bulges. When such a bulging occurs, that part of the solid phase causes the temperature of which is immediately below the melting point and which is more closely approximated in its properties to the liquid phase, a disturbance of the tensile stress distribution due to the bending deformation due to bulging, which may cause internal cracks. The molten metal, in which sulfur and other trace elements accumulate, enters these cavities or blowholes

in and becomes solid. The segregation effects caused by this deteriorate the quality of the product. As a result, the Jieβ speed cannot be increased above a limit value. As a result, countermeasures are taken by using support rollers as close as possible to each other.

The technique of rolling immediately after continuous casting has advantages in that the casting heat can be exploited. The dimensions of the raw material can be adjusted by setting Slightly change the decrease. When examining this technique, two rolling processes are important. After a procedure takes place rolling after complete solidification of the metal, flat another method, rolling if not yet solidified There are areas in the middle part, so it is a rolling with a liquid core. When rolling with Liquid core can cause additional internal cracks due to the rolling process occur, which depends on the rolling conditions. These internal cracks can occur even if there are no internal ones

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due to bulges. As the decrease is increased, internal cracks are more likely to occur. However, if the decrease exceeds a limit of about 30% , internal cracks no longer occur. In order to eliminate internal cracks, this direct rolling technique uses rolling after consolidation in many cases.

In the context of the invention, one or more rolling mills that contain rolling stands with a high decrease in connection with the Arranged outlet of a continuous casting plant. A compressive stress is generated in the casting between the roll stands, so that the liquid core can be rolled with a high decrease. The occurrence of cracks due to bulging is thereby prevented prevented. As a result, according to this technique, the casting speed increase. The quality of the product is very good.

Individual examples of the invention are explained on the basis of a rolling train with three rolling stands, where the peripheral speed of the work rolls of each rolling stand is set and a compressive stress is generated within the casting between the rolling stands. When rolling the casting, the decrease in the first and third roll stands is comparatively small and in the second roll stand it is comparatively large, where the cross-sectional reduction exceeds a value of 30% , the first and / or third roll stand can be omitted, and additional rolling stands can also be provided. The first roll stand is used to push the casting into the second. Roll stand with high acceptance. The casting can also be pushed in by the support rollers of the continuous casting plant, so that the first roll stand can then be omitted. In the second roll stand with a high reduction in size, the reduction in cross section is greater than 30 %, so that the formation of internal cracks is suppressed. Even if internal cracks should occur, the molten metal containing impurities and penetrating into the cracks becomes due to the large decrease

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- 35 squeezed out and tied to the cracks.

The compressive stress in the rolling direction is generated within the casting. As a result of this compressive stress occurs in the internal parts his casting has only a low tensile stress. As a result, the occurrence of internal cracks can be prevented not only during rolling, but also the formation of internal cracks due to bulging can be eliminated. As a result of this compressive stress the pushing into the second roll stand is supported, so that a high decrease is possible. The power requirement can be reduce.

The process of rolling immediately following the casting will now be explained for steel slabs with cross-sectional dimensions of 200 1000mm, which are produced in a continuous casting plant with vertical deflection in a radius of curvature of 10.5m. The first roll stand is arranged in the area where the slabs are each leveled and causes a cross-section reduction of 5% · The cross-section decrease in the second rolling mill is 66.7%. During the rolling process, the speed of movement of the casting at the exit of the first roll stand is set 2 % greater than the speed at which it enters the second roll stand, so that compressive stress is generated in the casting. The diameter of the work rolls of both roll stands is 1000mm.

When producing slabs without rolling, internal cracks occur at a casting speed of 1.2 m / min. In the same casting process no internal cracks occur at the same casting speed when the rolling process described is carried out. The casting can immediately follow the rolling with a high level of waste be cooled, whereby the quality is improved.

The continuous hot rolling of steel workpieces is now being used (Slabs, billets, billets and semi-finished products) using a rolling stand with a high decrease in the following. At the

5- ^ 6

In conventional hot rolling of steel workpieces, a workpiece of a conventional length is fed into the rolling mill. The operation (is intermittent, with one workpiece being machined at a time, Disturbances can easily occur if the front part of the workpiece enters the entry side of the roll stand or the guide device enters on the entry side of the reel. To suppress this interference, sometimes the Rolling speed reduced. If such a failure occurs, it will take a long time to correct the consequences necessary. This means not only a deterioration in productivity but also a loss of energy and a degradation the yield.

In the context of the invention was an elimination of the mentioned Difficulties possible. Productivity can be increased by continuing to join the steel workpieces introduction of the same into the roll stand, continuous hot rolling is carried out. This leads to an improvement in quality of rolling mill products. The productivity of the rolling mill is also improved. One distinguishes irregularities the thickness due to an imbalance in the rolling speed of the various rolling stands at the front and rear ends of the Work pieces.

5098 5 0/0276

On the basis of numerous tests it could be confirmed that the end face at the front end of a subsequent steel plate could be pressed under pressure against the end face at the rear end of the preceding steel plate. The scopes the abutting end faces could be locally attached and connected to one another, for example by welding. Then it is rolled with a high decrease, whereby the pressure remains. This allows the end faces of steel plates be completely and cohesively connected to one another.

In order for two steel plates to be materially connected to one another in this way, the steel plates have to be rolled with a comparatively high decrease, the steel plates having to be introduced into the respective roll stand with a corresponding impact force. The strength of the joint between the two steel plates becomes greater as the decrease or the pushing force becomes greater, as shown in FIGS. 25 and 26. One must choose the compressive stress "5 _D (kp / mm) due to the impact force and the cross-section reduction according to the following equation:

+ C (13)

with a as a constant = 0.2 - 2.0
b as a constant = 0.5 - 3> 5
c as a constant = -1.5 - +1 »5
n ^ as a constant = 0.2 - 1.5

n ^ as a constant = 0.5 - 1.5

2 6 "as the desired strength of the connection (kp / mm) 6l as the deformation resistance of the base metal (kp / mm) η> 0.3

* 0.02.

This modification of the method according to the invention is in

25H783

the following is explained in detail. The steel product from a continuous casting plant or from the blooming mill or the steel product obtained by rough rolling is cut by a shearing device at the exit side of the plant concerned. The shearing device can also be arranged in the central area of the ϊ / Alzenstraße. Preferably, the scale is removed from the cut surface before the connection is made, and the surface is smoothed. The surfaces to be joined are preferably at a high temperature. Cleaning or smoothing or scaling or setting a high temperature is carried out with the help of an oxygen jet, another gas jet or a fluid. These treatments can be carried out simultaneously for the rear end face of the preceding workpiece and for the front end face of the following workpiece. The facing end faces are welded to one another at their edges, pressure being additionally applied by the push-in device or the push-in roll stand, an edging stand or pressure rollers. The required pressure is then generated and rolling is carried out. By this treatment, a preceding steel plate and a subsequent steel plate are welded together under pressure. A high decrease is preferable during the creation of the connection. The decrease should preferably be about 30 ° / o. The compressive force generated in the workpiece due to the pusher

ο
should be more than 0.05 kp / mm.

Individual examples of this embodiment of the invention will now be explained. In a hot rolling mill, the Steel slabs coming from the heating furnace are descaled in a scale crusher with pressurized water. Then a spot weld takes place with welds of 20 mm j3 on each side of the slab, placing the face of the subsequent slab against the back the preceding slab is pressed. Afterward

B09Ö5Ü / Ü2 7B

25H783

-? 9

is rolled with a decrease of 50% in a roughing stand, whereby the pressure applied by the pusher

2
tension is 1.0 kp / mm. The subsequent slab is completely connected to the preceding slab during rolling. The subsequent hot rolling can be carried out continuously without interruption.

Fig. 27 shows the overall structure of a hot strip plant. A hot cleaning machine 29 for removing scale from the slabs is located on the exit side of a slab manufacturing device 28, which is a continuous caster or a block rolling mill. Following the hot cleaning machine 29 there is a heating furnace 30 and a scale breaker 31 · After that the slabs pass into a pusher device 32 for applying a pushing force to the slabs, a buckling suppressor device 33 »a connecting device 34 and a roll stand 35 with high decrease. These assemblies are arranged directly one behind the other. The buckling suppressing device 33 prevents the slabs from buckling under the action of the impact force. You can use pressure rollers, lateral guide rollers or guide shoes. The connecting device 34 · joins the abutting front and rear surfaces by welding, thus making one Pre-connection of the slabs is given. A normal roll stand or an edging stand can be used as the push-in device 32 use to roll the side surfaces. The edger can have smooth rollers or smooth rollers. The roll stand 35 with high decrease is designed as a reversing mill stand. This is followed by an edging frame 36 for shaping the workpiece provided and finally a finishing stand 37 · Subsequently A hot roller table 38, a strip store 39, a pair of scissors 40 and a reel 41 are located on the finishing roll stand 37

In this system you can use the scale breaker 31, the bulging " suppression device 33 »the edging frame 36, the strip store 39 and leave out the scissors 40. You can have a plurality

509850 / 027b

of 7 / roll frames 35 with high decrease and a plurality of Provide finishing stands. The scale breaker 31 can also be used as a push-in device. Furthermore, you can immediately following the roll stand 35 with a high decrease arrange an extractor. These and other modifications of a hot rolling train according to FIG. 27 are within the scope of FIG Invention.

28 shows a cold strip line. They are a pickling machine 42 for removing scale from a slab, a connecting device 43 and a cold rolling stand 44 are provided. Behind the cold rolling stand 44 there is a dent suppressing device 45 and a roll stand 46 with a high decrease. The peripheral speed of the work rolls of the cold rolling stand 44 is adjusted for the purpose of generating a push-in force for the plates. Following the 'roll stand 46 with a high decrease, a middle stand 47, a finishing stand 48 and a reel 49 are provided. All Roll stands 44, 46, 47, 48 can be present several times. The middle frame 47 can be omitted. Behind the cold rolling mill 44 a pushing device can be arranged by which the slab is pushed into the roll stand 46 with a high reduction will.

A modified cold strip line according to FIG. 29 comprises a Descaling device 50 for descaling hot strip, a Connection device 51 »a tape store 52 and a Usual cold rolling stand 53. Following the cold rolling stand 53 are a buckling suppressor 54 and a cold rolling mill 55 provided with high decrease. The tape is in the roll stand 55 with high decrease by adjusting the peripheral speed of the work roll of the cold rolling stand pushed in. Following the rolling stand 55 with a high decrease there is a finishing stand 56 and a reel Each of the roll stands 53, 55, 56 can optionally have multiple to be available. The cold rolling stand can be omitted. Instead of

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25U783

the tape storage 52 can be provided with a reel. The wound up Strip can then be rolled in the cold rolling stand 55.

A block line is shown in FIG. There is a Block rolling mill 60 following a heating furnace 58 for heating of the blocks set up at rolling temperature and following a descaling device. The block rolling mill 60 is a conventional duo stand or trio stand or a universal roll stand. Following the block rolling mill 60 are a Punching device 61 and a roll stand 62 with a high decrease are provided. This is followed by a hot cleaning machine 65 and one Scissors 64. A vertical roll stand can be arranged in front of the roll stand 62 with a high reduction. This vertical roll stand can replace the pusher 61. The roll stand 62 can be designed as a reversing roll stand. In this case you can use smooth rolls or grooved rolls for the vertical roll stand. The block rolling mill 60 can also be omitted. The hot cleaning machine can also be installed elsewhere, for example in front of the pusher device 61.

Fig. 51 shows a bar mill. Following a heating furnace 65 for heating the blocks to rolling temperature and a descaling device 66 are a pusher 67, a buckling suppressor 68 and a roll stand 69 with high purchase planned. In the high-decrease rolling mill, the bars are fixed in cross-sectional shape and size obtained directly by rolling the blocks. Following the roll stand 69 with a high decrease is a descaling device 70, a roughing mill 71, an intermediate rolling mill 72 and / or an edging stand 75 and a finishing mill 74. The roughing mill 71 can be one or more roll stands high decrease. The roughing mill, the intermediate rolling mill and / or the edging stand 75 can be omitted. Behind the scale breaker 66, a roll stand can be used to

509850/0276

arrange the shape of the blocks.

32 shows a rolling mill for carrier pre-profiles. A heating furnace 76 for heating the castings to rolling temperature and a hot plastering machine 77 are on the outlet side of a continuous Casting plant, for example a continuous casting machine 75, is arranged. Following this, pressure rollers 78 are used for production an impact force for the castings, a buckling suppressor 79 and a roll stand 80 with high acceptance is provided. Instead of the pressure rollers 78 one can use a Use a vertical roll stand, a universal roll stand or an edging stand. -The roll stand 80 rolls with a high decrease the castings to the desired cross-sectional shape and dimensions in one go.

The roll stand described with a high decrease sets the number of the necessary devices and shortens the rolling train. Productivity can be increased. Energy can be saved because the number of stitches required is reduced, because the casting, the block rolling and the Hot rolling can take place immediately after one another. Products with different cross-sectional shapes and dimensions can be rolled from a blank. This versatile possibility of forming the blanks is very advantageous. Because this simplifies the storage of blanks. The heat economy is improved, because the rolling takes place using the residual heat of the casting or the block. Righs just improving the Productivity, but also the improvement of the quality of the products and the output can be within the scope of the invention realize. Especially when rolling the side surfaces of the workpiece, for example in an edging stand and at the adjustment of the width of the workpiece by adjusting the pushing force and the decrease in the roll stand with high Delicate erofiles with tail-shaped

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and tongue-shaped parts. This will make the application improved.

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Claims (45)

25H783 patent claims: 1.! Process for hot rolling metal workpieces, thereby characterized in that in a roll stand with rollers mounted in stationary bearings, which are in the direction of movement of the Do not move the workpiece, a roll gap is set according to a high relative reduction in cross section so that the pressure angle θ has a value 0 ^ tan / u (/ u. as a coefficient of friction between roller and 'workpiece) and that the workpiece continuously in the nip with such Impact force is pushed in, which ensures a flow gap in the area of engagement between the work roll and the workpiece. 2. The method according to claim 1, characterized in that the impact force is set to such a value that the Compressive stress generated in the component is less than the yield point of the workpiece is at the rolling temperature. 3. The method according to claim 1 or 2, characterized in that the workpiece is continuously between the work rolls is pushed in by pushing in the end part. 4. The method according to any one of claims Λ to J, characterized in that the Y / piece is pushed continuously between the work rolls and that the workpiece is gripped. 5. The method according to claim 3 or 4, characterized in that that the workpiece is pushed in by an electromagnetic force generated due to a magnetic field. 6. The method according to any one of claims 1 to 5 *, characterized in that that the same is carried out in a rolling mill with a first roll stand and a second roll stand, wherein the second roll stand enables a high reduction in cross-section, that the roll stands are arranged one behind the other, so that S098B0 / 0276 . - 45 - the first roll stand the workpieces "directly into the second Enters roll stand and generates the push-in force for the workpieces in the second roll stand. 7. The method according to claim 6, characterized in that the impact force by adjusting the peripheral speed of the Work rolls of the first roll stand to a value greater than the peripheral speed of the work rolls of the second Roll stand is applied. 8. The method according to any one of claims 1 to 7, characterized in that that the rolling program without pushing into a first group of more than one roll stand and then pushing in carried out between the work rolls of each roll stand of a second group of more than one roll stand so that there is a high reduction in cross-section within the rolling train. 9. The method according to any one of claims 1 to 8, characterized in that that the front face of a subsequent workpiece on the back of a previous workpiece is pending and that this subsequent workpiece thereby supplies the push-in force for the preceding workpiece. 10. The method according to any one of claims 1 to 9> characterized in that when rolling steel plates, bars, rods or wire, the impact force has a value (kp / mm) after has the following formula: with K as the yield point (kp / mm) of the workpiece at the rolling temperature -θ as the pressure angle of the work roll (rad) a as a constant
b as a constant
Cy, as a constant 509850 / 02TB / U as the coefficient of friction between the work rolls and the workpiece _{/ U} = {c ₂ (1.05 - 0.005 · τ) - 0.056 - v _r Jg ₃ Cp as the material constant of the work rolls (1.0 for Rolls made of forged steel, 0.8 for rolls made of cast steel) CT as a constant determined by roller lubrication = 1-0.1 V _R as roller speed (m / sec) T as roller temperature ( ⁰ G). 11. The method according to claim 10, characterized in that the decrease in cross section is more than 30 % . 12. Rolling process according to one of claims 1 to 5 »thereby characterized in that the workpiece is continuously drawn out on the exit side of the roll stand with a high decrease and that the pull-out force produces a tensile stress less than the yield point of the workpiece at the rolling temperature. 13 · Rolling method according to claim 12, characterized in that the pull-out force is applied by pushing the workpiece on the back using the push-in device as a gripping device, applied using an electromagnetic force to produce linear movement of the workpiece and that the pull-out force is applied continuously by either one. Extraction device for the male part, using a gripping device or an electromagnetic pulling device. 14. The method according to claim 6 and 12, characterized in that the rolling program is also in a third roll stand is carried out, which is arranged in series with the first two roll stands, during a period of the rolling process all work rolls of the roll stands grasp the workpiece, and that the workpiece in addition to being pushed into the second roll stand is also continuously pulled out of the second roll stand by the peripheral speed of the 509850/0276 25U783 third roll stand is set so that the workpiece speed when entering the third roll stand is greater than when exiting the second roll stand, so that a tensile stress is generated within the workpiece. 15. The method according to claim 12, characterized in that the workpiece without being pushed into the first group of rolls of a rolling train and then with being pushed into the work rolls of one each roll stand of the second group of rolling lines is rolled so that the roll stands of the second group have a high Cause cross-section decrease. 16. The method according to claim 12, characterized in that the respective preceding workpiece between the work rolls is pushed in by the pushing action of the following workpiece, the end faces of successive workpieces butt against each other. 17 · Method according to one of claims 12 to 16, characterized in that The compressive stress to a value (rl (kp / mm after the relationship: indicates that the compressive stress is reduced to a value (rl (kp / mm) and the tensile stress to a value ^ L according to the relationship: with K as the yield point (kp / mm) of the workpiece at the rolling temperature θ as pressure angle (rad)
a as a constant = 1-8
b as a constant = 1.5 - 0.5
C ₁ as a constant = -0.2 - +0.2 Sq cross-sectional area of the workpiece before rolling (mm) Sy, cross-sectional area of the workpiece after rolling (mm) 509850 / 0Γ7Τ - 48 I _t rolling force (kp) _{/ U} = G ₂ (I, 05 - 0.005 · τ) - 0.056 · v _r C ₃ Cp as the material constant of the rollers (1.0 for rollers from Forged steel; 0.8 for cast steel rollers). C ₅ , as a constant corresponding to the roller lubrication = 1-0.1 V rolling speed (m / sec) T as the rolling temperature (° C). 809350/0276 25H783 18. The method according to claim 17, characterized in that the decrease in cross-section in steel bars or rods is more than 30 % . 19. The method according to any one of claims 1 to 18, characterized in, that the reduction in cross-section and the impact force are set to determine the lateral width of the workpiece so that a certain width and the other desired dimensions can be obtained when rolling. 20. The method according to claim 19, characterized in that the impact force in the sense of achieving a compressive stress of CT and the relative decrease I ^ are set according to the following equation: + a (7 ^ -) f (b> 7 ⁿ + c) with: a = d / £ + f b as a constant = 0.1 - 2.5 c as a constant = 0.5 - 1.5 d as a constant = 0.9 - 1.2 f as a constant = 0.2 - 0.4 η as a constant = 1.5 - 2.5 so that the spread of the plate is controlled. 21. The method according to claim 19, characterized in that the impact force in the sense of the rolling of shaped steel flange parts Achieving compressive stress (T according to the following relationship is set: bb _w 509850/0276 25H783 with: H as the thickness of the workpiece before rolling B as the workpiece width before rolling EL as the nominal flange width B as the web width t as the web thickness B as the inner web width a as a constant = 0.5 - 6.0
b as a constant = -0.1 - -6.0 d as a constant = 1-4 as web decrease = -% —— so that the width of the flange is adjusted. 22. The method according to any one of claims 19 to 21, characterized in that that in the operation of the rolling mill with a first and a second roll stand with a high decrease the same so can be controlled that the workpiece from the first roll stand directly into the second roll stand under continuous Pushing is delivered that the peripheral speeds of the work rolls of the two roll stands are controlled so that the workpiece speed at the exit of the first roll stand is greater than at the entry of the second roll stand, so that a compressive stress is generated within the workpiece, the workpiece by adjusting the cross-section decrease and the piercing force is spread in the width direction, and wherein the workpiece width is determined by the magnitude of the piercing force will. 23. The method according to any one of claims 19 to 22, characterized in that that the workpiece is drawn out on the exit side of the roll stand with high decrease, the size the extraction force is controlled in terms of a definition of the width of the workpiece. S09850 / 0276 24. The method according to claim 23, characterized in that the push-in force and the pull-out force when rolling steel plates in the sense of achieving a compressive force 0 according to the relationship B. B ~ with: a = d ^ + f b as a constant = 0.1 - 2.5 c as a constant = 0.5 - 1.5 d as a constant = 0.9 - 1.2 f as a constant = 0.2 - 0.4 H t i £ as web reduction = ο η as a constant = 1.5 - 2.5 and a tensile stress oil can be set with: B as the workpiece width before rolling B as the workpiece width after rolling (B / B) / £ <_qn: relative spread for the tensile stress g as a constant = -0.05 - -0.8 so that the relative width of the plate is controlled. 25. The method according to claim 23, characterized in that the impact force and the rolling of shaped steel flange profiles Extraction force in the sense of achieving compressive stress oil according to the formula 1 ^H o ^B o " ^T w ^B w B09850 / 0276 - 52 61 with: Cp = a ^ + b a ^ as a constant = 0.5 - 6.0 b ^ as a constant = -0.1 - -6.0 d as a constant = 1-4 ", η - T η as relative web reduction = - ^ r—- H as workpiece thickness before rolling ο B _Q as the workpiece thickness after rolling EL as the nominal flange width B as the web width t as the web thickness B _T , as the inner web width and a tensile stress (51 can be set according to the formula: ^H 1 oil " with: K as the flow stress at the rolling temperature H as the workpiece thickness before rolling EL as the nominal flange width H ₁
(g -) / q ~ _q \: relative width of the flange at the ⁰ tensile stress oil = 0 so that the flange width is regulated. 26. The method according to claim 23, characterized in that the rolling operation in a first roll stand, a second roll stand is carried out with a high reduction in cross-section and a third roll stand, with all roll stands arranged in series and the workpiece is detected by all the work rolls of the roll stands for a period of time that the workpiece by controlling the peripheral speed of the work rolls of the first roll stand continuously between the work rolls of the second roll stand is pushed in by the workpiece speed at the exit of the first roll stand greater than is at the entry of the second roll stand and thus a pressure 609850/0276 tension within the workpiece between the first and the second roll stand is generated, and that the workpiece continuously from the second roll stand by controlling the peripheral speed of the work rolls of the second roll stand and the third roll stand is drawn out such that the Working speed at the entrance of the third roll stand is greater than at the exit of the second roll stand, whereby a Tensile stress is generated within the workpiece between the second and third roll stands, thereby increasing the workpiece width is regulated by adjusting the size of the push-in force and the pull-out force. 27. The method according to any one of claims Ί to 26, characterized in that that when rolling H-shaped steel in a universal roll stand, the flanges of the workpiece are driven between two Work rolls and the web of the workpiece are rolled between two drag rolls. 28. The method according to claim 27, characterized in that the diameter of the driven work rolls is smaller than that of the towed work rolls. 29. The method according to claim 27 and 28, characterized in that a conventional roll stand in front of the universal roll stand is arranged that the workpiece is continuously between the work rolls of the universal roll stand by controlling the peripheral speed of the work rolls of the roughing stand is pushed in, the workpiece speed at the exit of the Pre-rolling stand larger than when entering the universal rolling stand in the sense of generating a compressive stress within of the workpiece. 509850/0276 30. The method according to any one of claims 12, 27 "to 29, characterized characterized in that when rolling H-shaped steel, the flanges between two driven work rolls of a universal roll stand and the web is formed between two dragged rolls of the universal rolling stand. 31. The method according to claim 20, characterized in that the diameter of the driven work rolls is somewhat smaller than the diameter of the dragged work rolls. 32. The method according to claim 30, characterized in that a roughing stand in front of the universal rolling stand and a second normal stand be arranged behind the universal roll stand that the workpiece through the roughing stand continuously between the work rolls of the universal rolling stand is pushed in by the peripheral speed of the work rolls of the roughing stand and of the universal roll stand can be set so that the workpiece speed at the exit of the roughing stand is greater than at the entry of the universal rolling stand, so that there is a compressive stress is generated in the workpiece between the two roll stands, and that the workpiece through the second normal stand from the Universal roll stand is extended by the peripheral speed of the work rolls of the universal roll stand and of the second normal stand can be set so that the workpiece speed is faster at the entry into the second normal stand than at the exit of the universal rolling stand, so that a tensile stress is generated in the workpiece between the two roll stands. 509850/0276 33. The method according to claim 1, characterized in that a casting produced in a continuous casting process is rolled using the internal casting heat in a roll stand with a high decrease after it has been rolled with a cross-sectional decrease of more than 3 % . 34. The method according to claim 1, characterized in that the continuous hot rolling of steel workpieces the same one after the other are moved with their front surfaces and rear surfaces aligned perpendicular to the direction of movement of the workpiece, daf the same are descaled or descaled and heated and then a previous workpiece fixed to the subsequent workpiece is connected by the front face of the workpiece against the rear face of the front workpiece is pressed, that a rolling process is then carried out with a high reduction in cross-section, with an impact force on said Workpieces acts and that each workpiece is rolled together in conjunction with the following workpiece. 35. The method according to claim 34, characterized in that the connection between two successive workpieces prepared by welding part of the periphery of the interface. 36. The method according to claim 35, characterized in that when rolling steel workpieces, the compressive stress 0 ~ and the cross-sectional decrease ν satisfy the following relationship: j ^ (f) ² ₊ C a as a constant = 0.2 - 2.0 b as a constant = 0.5 - 3.5 c as a constant = -1.5 - +1.5 n ^ as a constant = 0.2 - 1.5 n _? as a constant = 0.5 - 1.5 <£> as the nominal strength of the connection (kp / mm) <ol as deformation resistance of the base metal (kp / mm) 509850/0276 25H783 Ά. > 0.3 1> 0 / K = 0.02 37. Hot strip mill for carrying out the method according to one of claims 1 to 36, characterized by a heating furnace for heating the slabs to rolling temperature, a pushing device for generating an impact force acting in the rolling direction on a slab, a rolling stand with a high decrease in which the respective Slab is pushed in and that has such a large reduction in cross-section that the pressure angle θ between the work roll and workpiece has a value θ * tan ~ μ (μ as the coefficient of friction between work roll and workpiece), through a finishing stand to finish rolling the one rolled in the stand with a high reduction Tape and through a reel for winding the tape 38. Cold rolling mill for carrying out the method according to one of the Claims 1 to 36, characterized by a roughing train, by a push-in device for producing one in the rolling direction acting impact force on a pre-rolled workpiece in the roll stand high reduction for rolling the inserted workpieces and with a cross-sectional reduction corresponding to a pressure angle θ between work roll and workpiece θ = tan ~ ¹ / u (/ u as the coefficient of friction between work roll and workpiece) through a finishing train for finishing the strip and through a strip reel. 39. Cold strip mill for carrying out the method according to one of claims 1 to 36, characterized by a descaling device for removing scale from the hot strip and through in cold rolling mill high reduction for rolling the descaled strip with such a large reduction in cross section that the engagement angle θ between workpiece and belt has a value θ = tan "V (/ u has as the coefficient of friction between the workpiece and the belt). 509850/0276 25H783 40. Block rolling mill for carrying out the method according to any one of claims 1 to 36, characterized by a heating furnace for heating an cast ingot to rolling temperature, by a pushing device for generating an impact force acting in the rolling direction on the heated ingot, by a rolling stand with a high decrease for rolling the by the impact device and with such a high cross-section decrease that the pressure angle θ between the work roll and the workpiece has a value θ = tan yu ( fixed as the coefficient of friction between the work roll and workpiece), by a hot cleaning machine to remove surface defects on the workpiece and by a pair of scissors to cut the workpiece in the desired length. 41 ν block rolling mill according to claim 40, characterized by a Ingot mill for rolling the hot ingots, which is arranged between the heating furnace and the pusher. 42. Bar rolling mill for carrying out the method according to any one of claims 1 to 36, characterized by a heating furnace for heating the workpieces to rolling temperature, by a pushing device for generating an impact force acting in the rolling direction on the workpieces by a roll stand with high reduction for rolling the workpieces that are pushed in and with such a high cross-section decrease that the pressure angle between work roll and workpiece has a value θ ^ tan ~] / u (yes as the coefficient of friction between workpiece and work roll), and through a finishing stand for finishing the workpieces rolled in a center stand. 43. Bar rolling mill according to claim 42, characterized by a roughing stand for roughing the workpieces which are in the rolling stand high decrease are rolled, the roughing stand between the high decrease rolling stand and the finishing stand 'arranged is. S098BO / 0276 44. Bar mill according to claim 43, characterized by a Central stand for rolling the roughed workpieces, which is arranged between the roughing stand and the finishing stand. 45. Plant for the continuous production of profile semi-finished products for performing the method according to one of claims 1 to 36, characterized by a continuous metal casting plant, a furnace on the outlet side of the casting plant for heating the continuously cast workpieces to the required temperature, pressure rollers to generate an impact force in the rolling direction on the casting emerging from the furnace, through a high-decrease rolling mill for rolling the castings entering the furnace with one like that. high cross-sectional decrease that the pressure angle ν. - 1 between work roll and workpiece has a value θ = tan / a (/ u as the coefficient of friction between work roll and workpiece), so that a workpiece of the desired cross-sectional shape is obtained. 509850/0276 Blank page