DE1934302B2 - Method and device for hot rolling metal slabs - Google Patents

Description

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Length of the roughing train and thus the cooling times to be solved so that the metal slab during roughing or reduce, is to increase the coil weight intermediate rollers under compressive tension in the longitudinal direction it has been proposed that the last 2 to 3 steps be reduced in thickness, with more advantageous scaffolding the roughing train to a group to assign the size of the longitudinal compressive force by changing. The cooling of the bandage per unit of time through the roll gap is particularly strong, in particular the rear end of the strip, on which the volume of the rolled material resulted in the change The roller table section between the last stand is set to the front of the roller speed or the roller gap road and the finishing mill, because that's already wasted here.

relatively thin strip only very slowly into the die to carry out the rolling process

Finishing mill can run in. To reduce the rolling mill provided by the invention is thereby Heat loss has already been proposed, which is characterized, as is known, between the To increase the thickness of the sliver, d. H. the length of the roller table revolving support rollers and above To shorten the pre-strip, and this pre-strip in the rolling stock has a lifting leg running on the rolling stock To roll the finishing train with an increased number of stands. and lowerable roller are provided between However, the increase in the sliver thickness is due to the rolling stands of the roughing train and / or the rolling mills Rolling in the finishing train has its limits, the intermediate train is set up as a hold-down device the width deviations are formed at the beginnings of the tape, the liftable and lowerable and strip ends that roll in the finishing train without the pull on a roll holder running in guides Loop regulators are rolled, arranged with a thicker ring and by means of an adjustable end Prelaps become impermissibly large. 20 adjusting cylinder is adjustable in height. To

F-S is also a device for regulating the thickness of a preferred embodiment of the thickness of the rolled stock according to the invention in a rolling device according to known rolling mill are below the rolling stock (See German Auslegeschrift 1 018 019), in which the roller tables are arranged. It is also expedient Belts or profiles both by rolling force and the upper edge of the support rollers above the upper diameter in front of and / or behind the roll gap in the roll edge of the lower work rolls. In Longitudinal pulls exerted in the direction are deformed, further training of the new rolling mill is included in the case of a thickness regulator, depending on the one on the roll holder, a stop for actuation Deviation of the rolling stock thickness from a given one arranged by the control lever of a potentiometer, Setpoint one or both longitudinal trains for the purpose of upright over the the speed of the drive motor obtained the target thickness can be controlled. Can be regulated by means of the 30 work rolls. In an expedient manner This device should be the thickness of strips or pro - is also between the work rolls of the Walzgefilen, their deformation by rolling pressure and equipping the roughing train and / or the rolling stands at the same time applied tension in the rolling direction - intermediate train below the rolling stock followed by a roller, Infinitely variable and sensitive within a large table with rotating rollers and above the rolling area automatically controlled or regulated and thereby 35 good ones on each roll stand one around a fulcrum always optimal use of the rolling machine rotatable roll holder with rolls arranged, the by distributing the deformation work to the arms by means of a hydraulic cylinder against the rolling work the rolling force and the work of the longitudinal pull is easy to adjust, with advantage by means of guaranteed. This known device is hydraulic cylinder or roller mount limited to those rolling machines where the 40 has a contact pressure gauge or a limit switch Deformation due to roller pressure as well as the drive of the work rollers can be switched off in emergencies in front of and / or behind the roll gap in rollable and the speed of the work rolls by means of direction on the material exerted tension takes place. a Potentio-Um coupled to the roll holder a lateral deflection of the rolling stock can be regulated between two meters.

To prevent seeing the work rolls, it is 45 The advantages of the rolling process according to the invention known (see. German patent rens or rolling mill are in a continuous 538 630), a guide device for the individual roughing train can initially be seen in the fact that this upright stand can be shortened vorzu- borrowed by continuous rolling mills. In addition, it occurs seen In the case of the concave guide rollers, there is less temperature drop in the rolling stock that is there arranged in a zigzag shape like bending rollers 5 °, on the one hand the temperature of the slab are allowed and the upper guide roller by means of a heating furnace, which is connected upstream of the roller train, Lever linkage can be swiveled out and in. Lower them by about 100 ° C and in this operating lever linkage there is an arm that saves fuel and repair costs, the working position of the swing-out guide and, on the other hand, the specific coil weights roll enables the formation of a belt loop. 55 increase, resulting in acquisition and operating costs

The invention is based on the object of providing advantages in the area of the hot strip mill and in the Process for hot rolling of metal slabs leads downstream processing plants, and a suitable for performing this method. In addition, the width deviations of the To create a great rolling mill, by means of which increased strips through the interaction of longitudinal pressure specific coil weights by increasing the single and longitudinal tension in the individual scaffolding groups Preliminary strips made, the length of the reduced. The result will be one over the whole drive system of a hot strip mill produces a considerable length of strip of uniform width because shortened, the drive power to be installed is reduced by unavoidable belt pulls in the finish ringert and the heat losses of the line to be rolled caused by constrictions in width des can be lowered. At the same time, a 65 should cover most of the tape length with additional Uniform spreading of the bands over the entire length of the band in a framework group in which Width can be achieved. with compressive forces in the longitudinal direction of the belt

According to the invention, this object is compensated for by rolling.

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The method for hot rolling according to the invention rolling pressure gauges in the vertical upsetting is in the schematic drawing on hand 111, 112, 113 the speed of the motor 91 and hot rolling mills designed according to the invention with the longitudinal forces in the rolling stock. Explained in more detail in the roll stands. It show 104,105 with longitudinal compressive forces in the rolling stock to

F i g. 1 to 3 exemplary embodiments of rolling mills worked 5 enlargement of the bandwidth. The size

in the schematic structure, the longitudinal compressive forces are advantageously

F i g. 4 a plan view of a roughing train, tion of the roll speed in the roll stands 104,

F i g. 5 is a plan view of a set for roughing train 105 via the speed of motor 92. the

according to FIG. 4 belonging finishing train, engine speed and / or the roll gap is in

F i g. 6 a plan view of a further roughing train, 10 expediently adjusted so that the spread

F i g. 7 is a plan view of the so different to the roughing train in the middle of the strip compared to the strip ends

F i g. 6 belonging intermediate and finishing mills, that the different constriction between

F i g. 8 a longitudinal section through two frames of the tape ends and the middle of the tape, which are later replaced by the

Pre-road or intermediate road according to FIGS. 4 and 6 different train of the sling lifter IS in the

or 7, 15 finishing train 13 is being compensated.

F i g. 9 shows a longitudinal section of two stands of the pre-strip exiting from roughing train 2

Finishing train, and runs over the roller table 7 to the crop shear 5, where it

F i g. 10 to 14 diagrams of the balance of power is drawn, and occurs after in the tinder-

in the rolling stock during rolling. scrubber 6 the secondary scale was removed into the

F i g. 1 shows the schematic structure of a fully ao roll stand of the finishing train 3, where the strip in

continuous hot strip rolling mill, which is reduced to the finished strip thickness in the known manner

Heating furnace group 1, a roughing train 2, a finishing line.

street 3 and a reel group 4. The pre-should from one pre-slab width in one

road 2 is a scale washer 6, the finishing line 3 produces a wide area of strips of different widths

If a crop shear 5 and a scale washer 6 25 are provided, a group is expediently

upstream. The individual machine groups of the pierung of the roll stands according to FIG. 2 are used.

The rolling train are connected to one another by the roller tables 7 This rolling train, which is also a fully continuous

tied together. works, consists of the heating furnace

As can be seen from Fig. 4, the rolling group 1, the roughing train 16, the intermediate train 17, stands 101 to 105 of the roughing train 2 by a synchronizer 30 of the finishing train 3 and the coiler group 4. The single-chron motor 8 and two DC motors 91, 92 individual machine groups are driven by 7 roller tables. By changing the speed of the interconnected. The roughing train 16, the intermediate direct current motor 91 is a change in the rolling train 17 and the finishing train 3 is preceded by a scale scrubber 6 , each with a speed of rotation of the rolling stands 101, 102. Between the intermediate, while by a change in the speed 35 between the line 17 and the scale washer 6, one of the motor 92, the roller speeds of the stands 104 crop shear 5 is arranged. Before the roll stands and 105 are changed. However, 101 to 105 of roughing train 16 are all vertical stands of roughing train 2 can be driven individually by controllable upsetting stands 113 to 115 and also the low motors. holding devices 12 installed. Between the

The stands 101, 102, 103 of the roughing train 2 are 40 set up 171, 172 (FIG. 7), strip guides 13 and the vertical stands 111, 112, 113 are connected upstream. Between the stands 173 and the cropping scissors 5 see the stands 101, 102 and 102, 103, as well as between the stands 14 of the hold-down devices 12, and between the stands of the finishing train 3, a loop lifter 15 is arranged. 103, 104 and 104, 105 are strip guides 13 arranged. The rolling stands 101 to 105 of roughing train 16 are arranged, the structure and function of which is explained below (FIG. 6) are driven by an identical. The finishing train 3 (Fig. 1), which in its slrommotor 91 and a three-phase motor 19 and details in F i g. 5 is shown, a common transmission 20 is known in the art. The frames 171 to are formed; the stands 14 are individually 173 of the intermediate train 17 (FIG. 7) are driven by the controllable direct current motors 141 via the direct current motor 91 also via a common gear 142 and pinion rollers 143. 50 sames, e.g. B. hydraulic gear 20, or between the scaffolding looper 15 are seen in front of three individual, not shown direct current, motors driven. The roll stands 14 of the prefabricated

A slab is in the fully continuous line 3 are according to the embodiment

Bucket rolling mill according to FIG. 1 with the roughing train F i g. 5 powered. A slab is in the full

according to FIG. 4 and the finishing train according to FIG. 5 in 55 continuous hot rolling mill according to F i g. 2 mil

rolled into strip in the following way: the roughing train according to FIG. 6 and the intermediate road

The hot-rolled slab is from one of the and the finishing train according to FIG. 7 in the following way zi

Heating furnaces of heating furnace group 1 rolled onto roller table 7 strip:

and runs on this to roughing train 2. Before In roughing train 16, the slab is in the Dicki

the entry into the roughing train 2, the slab 60 of z. B. 300 mm continuously to 80 mm and ii

when passing the scale washer 6 from the furnace - the width e.g. from 1050 to 970mm by 80mm right

detonator exempt. The slab is now reduced to what the speeds of the motors 91,19 ii

Roughing train 2 simultaneously set in the horizontal stands in the manner explained below

101 to 103 in the thickness without longitudinal tensile stress in the that the rolls of the roll stands 101 to 105 mi

Rolled stock and in the vertical upsetting stands 111, 112, 65 slight longitudinal pressure act on the rolled stock

113 reduced in width. The hold-down device certainly does not restrict the width in de

lines 12 between the roll stands 101, 102 and the middle of the pre-strip occurs. Behind the last one

102, 103 control together with roll stand 105, not shown, of roughing train 16, from which the V01

tape exits at a speed of about 1.5 m / sec, it runs freely onto the roller table 7, on which it is transported to the scale washer 6 and enters the intermediate line 17. In stands 171 to 173 of intermediate train 17 , the thickness of the pre-strip is reduced from 80 mm to 15 mm under longitudinal pressure. As a result of the compressive stresses exerted on the rolling stock in the longitudinal direction by the rolls of stands 171 to 173 of roughing train 17, the strip is spread more strongly in the middle of the strip than at the beginning or end of the strip. In order to prevent the band, which is under longitudinal compressive stresses, from giving way up or down in the intermediate train 17, it is expediently supported by band guides 13 between the frames 171 to 173.

After the strip emerges from the last stand 173 of the intermediate train 17 , it is scooped with the help of the Schopischere 5, freed from the secondary scale in the scale washer 6 and then finished in the roll stands 14 of the finishing train 3 in a known manner, with the one produced in the intermediate train 17 additional widening in the middle of the belt serves to compensate for the constriction of the belt produced by the loop lifter IS in the finishing train 3.

The method for rolling hot strip can also be carried out with advantage in a semicontinuous rolling mill according to FIG. 3 perform. The rolling mill according to FIG. 3 consists of the Wärmofengruppe 1, a reverse frame 21 and the corresponding Fig. 7 formed intermediate and finishing train 17 and 3. In the reverse frame 21 be z. B. the slabs are rolled down in five passes of 300 mm thickness. Since the pre-strip can freely run out of the reversing stand 21 after each rolling table, uneven spreading of the rolling stock does not occur.

The semi-continuous, according to FIG. 3 working roller train offers the same advantages as the fully continuous roller train according to FIG. 2 in terms of space requirements, small width deviations and large specific coil weights. 3 larger than in the fully continuous roller train according to FIGS. 1 and 2. so that the pusher furnace in semi-continuous lines according to F i g. 3 have to work with higher temperatures. When converting existing semi-continuous hot strip rolling mills, the arrangement according to FIG. 3, however, very significant advantages because the existing reversing stand 21 can then continue to be used.

Around the rolling without longitudinal tension only with compressive stress in the longitudinal direction in the rolling stands 101 to 103 of the roughing train 2 and in the rolling stands 101 to 105 of the roughing train to roll 16, is advantageously between these stands in each case a hold-down device 12 to F i g. 8 provided. Here are below the rolling stock 801 at the exit or entrance between the stands , z. B. 101 and 102, the roller tables 802, 803 and a rotating support roller 804 arranged between the roller tables, the upper edge of which is above the work rolls 805 of the roll stands 101, 102. Above the rolling stock 801, the hold-down device 12 is provided, which consists of the adjustable adjusting cylinder 121 and the guides 122 for the roller holder 123, in which the pressure roller 124 is rotatably mounted. A stop 126 is arranged on the roller holder 123, by means of which the control lever 127 of a potentiometer 128 can be actuated. The introduction 125 is movably attached to the roll stand 102.

The hold-down device 12 shown in Fig. 8 operates as follows:

The front end of the rolling stock 801 emerging from the roll stand 101 runs at the speed of the work rolls 805 of the roll stand 101 over the roll table 802 and the support roller 804 until it runs against it

ίο the entry bar 125 hits. The tip of the rolling stock 801 is bent downward around the support roller 804 by the infeed bar 125 and runs between the work rolls 805 of the roll stand 102 . The speed of the work rolls 805 in the roll stand 102 is set so that the volume of strip running through the roll stand 102 per unit of time is somewhat smaller than the volume of strip running out of the stand 101 per unit of time. In this way, the rolling stock 801 lifts the roller 124 together with the roller holder 123 against the pressure of the adjusting cylinder 121 . The roll holder 123 pushes up the control lever 127 of the potentiometer 128 with the stop 126 , which lowers the speed of the drive motor of the work rolls 805 of the roll stand 101 via suitable switching devices or the roll gap is reduced until the strip volume running into this stand is equal to that is the volume of strip running through the roll stand 102.

Both the rolling stock located between the roll stands 101, 102 and the rolling stock in the roll gaps is under pressure force in the longitudinal direction, which is determined by the pressure in the adjusting cylinder 121 , for the time of the rolling process during which it is lifted from the support roller 804 . By changing this pressure, the compressive force in the rolling stock can be varied if necessary. However, it must always be set so low or high that the tape does not buckle upwards in front of or behind the roller.

So that the rolling stock 801 or strip under compressive stress cannot buckle up or down between the rolling stands 103 to 105 (Fig. A) or 171 to 173 (Fig. 7), it is guided up and down by a strip guide 13, as shown in FIG. 9 is shown supported. The strip guide, generally designated 13 , is provided between the roll stands 103, 104 shown schematically. It consists of a roller table 131 with the rotatable rollers 132, which is fastened between the roll stands 103, 104 below the rolling stock 801 in the roll stands.

Above the rolling stock 801 are the two roller holders 133 with the rollers 134, which can be rotated about the pivot points 135 and are pressed against the rolling stock 801 passing through with the aid of the cylinders 136. The hydraulic pressure in the cylinders 136 is advantageously set so high that the roll holders 133 are not raised when the degree of compression of the rolling stock 801 is provided.

In the event of malfunctions in the rolling train, belt loops form upwards, which lift the roller holders 133, as a result of which the pressure in the cylinder 136 increases is caused, the roller train is switched off via contact pressure gauges or limit switches (not shown) switched. In an expedient manner, the Roll holder 133 can also be coupled with potentiometers, via which the motor speeds of the work rolls of the roll stands 103, 104 are influenced.

309539/24 «

Viewed from the distribution of forces in the rolling stock (closed arrow), the rolling process according to the invention runs counter to and intensifies the rolling process as follows. The transverse component G (double open arrow) ab: acts in the same direction as the transverse component C.

The tape beginnings and ends are in both (triple open arrow) and increases the width.

Scaffolding groups, d. H. in the roughing train 2 or in the 5 The strip beginning and the strip end are thus behind

Preliminary and intermediate trains 16, 17 and in the finishing section the exit from the first stand group is narrower

line 3, rolled in the rolling direction without any forces. Here as the middle of the tape.

generates the rolling force P during the deformation in the second stand group, ie in the final roll gap if the friction between road 3 is neglected, is in a known manner with Schlingens rolls and rolling stock in this, as in FIG. 10 io lifters 15 rolled. As soon as the strip is shown in two or more frames in the direction of the thickness of the rolled material, the loop tension A. The compressive tension A is set against the strip from below by means of its jack 15 and transverse components in the longitudinal direction of the rolling generate in this a tensile force that is shown in FIG. 13 is denoted with good the tensile stress B and in the transverse direction H , the tensile stress C emerges in the longitudinal direction of the strip of the rolling stock. The tensile stress / with the transverse components K, L shaping of the rolled stock in the direction of its thickness, in the directions of strip thickness and strip width, length and width is in these strip areas, as.

besides the rolling force? no other external forces The stresses from the forces P, H (Fig. 10,

act on the rolling stock, only determined by the 13) overlap according to Fig. 14. The transverse

Magnitude of the stresses A, B and C. ao component K (open arrow) in the same direction

In the first stand group, ie in the roughing train 2 tion like voltage A (closed arrow). In order to

or in the roughing and intermediate train 16, 17, the longitudinal force / the rolling force P is supported

The band as soon as it is in two or more scaffolds - transverse component L (double open arrow) acts

is rolled early, counter by setting suitable transverse component C (triple open arrow)

Speed differences between the individual stands 25 and reduces the spread.

generating the designated in FIG. 11 D upsetting force, therefore more generated in the second stand group the Banddie in rolling wide beginning the Druckspan- in the longitudinal direction and the tape end when the band busbars E with their transverse components F, G. center. There is thus a balance of the

The tensions from the forces P, D (Fig. 10 strip length of unequal widths in the roughing train 2

and 11) are superimposed according to FIG. 12. The 30 and in the finishing train3 or in the preliminary and

Transverse component F (open arrow) of the tension A between the intermediate train 16, 17 and in the finishing train 3 instead.

For this purpose 3 sheets of drawings

Claims (9)

Lischen cylinder (136) or the roll holder Patent claims: (133) the operation of the work rolls via a contact manometer or a limit switch 1. Process for continuous or semi-switchable is continuous hot rolling of metal slab 5 9. Rolling mill according to claim 3, 7 or 8, men to metal strip with a high specific characterized in that the speed of the coil weight, in particular with 30 to 40 kg / mm work rolls (805) by means of one with the rollers - Strip width at which the rolling stock is heated, the holder (133) of the coupled potentiometer is regulated, pre-rolled, if necessary, is interposed.
rolls and during the finish rolling under tension io Tension in the longitudinal direction reduced in thickness is characterized in that the
Metal slab during rough rolling or intermediate rolling under compressive stress in the longitudinal direction. The invention relates to a method for reducing the continuous thickness. 15 continuous or semi-continuous hot rolling 2. The method according to claim 1, characterized ge from metal slabs to metal strip with a high indicates that the size of the longitudinal compressive force has a specific bottom weight, in particular 30 to 40 kg / by changing the de-roll gap per unit of time through the mm strip width at which the rolling stock is heated guided volume of the rolling stock is scaled, pre-rolled, optionally rolled between about the change in the roll speed or the 20 and during the finish rolling under tension Roll gap is set. is reduced in thickness in the longitudinal direction, as well 3. Rolling mill with one behind the other in a line a rolling mill with one behind the other in a line Roll stands, the roll stands arranged in stand groups, those in stand groups to one roughing and finishing train each and, if applicable, one roughing and finishing train each and, if applicable if an intermediate road are divided, as well as 25 an intermediate road are divided, as well as with one with a heating and descaling device, heating and descaling device for the rolling for the rolling stock, for carrying out the process, for carrying out the process. rens according to claim 1 or 2, characterized in that in the hot strip mills, in which strips are characterized by rolling between the rolled steel or non-ferrous metals, tables are revolving support rollers (804) and above are the rolling stands, the as continuous stands from outside the rolling stock (801) are formed on the rolling stock, in a line one behind the other and to the (801) running liftable and lowerable roller (124) part are provided to form groups of stands, which are arranged between the rolling stands (cf. German patent specification 837 085). Sometimes (101 to 105) of the roughing train (2, 16) and / or the individual roll stands are also designed as so-called roll stands (171 to 173) of the intermediate train 35 reversing stands or reversing stands. In (17) these known rolling mills are designed as hold-down devices (12) and in the as vorind, the liftable and lowerable roll (124) on roads designated first 4 to 6 stands after a roll holding possibility running in guides (122) rolled so that the rolling stock is not arranged by tion (123) , and is stressed by means of a regular longitudinal forces in order to avoid constrictions ble adjusting cylinder (121) in its height position 40 in the bandwidth. To achieve that, it is adjustable. the first 4 to 6 stands in which the WaIz- 4. Rolling mill according to claim 3, characterized ge well of z. B. 250 mm to about 30 mm thickness that is adorned below the rolling stock (801) , set up at such a distance that rolling tables (802, 803) are arranged. the tape can run freely between them, so that 5. Rolling mill according to claim 3 or 4, characterized 45 the roughing train in particular when the strip is characterized in that the upper edge of the supporting roll a collar with high specific gravity rolled (804) above the upper edge of the lower one is very long . Work rolls (805) is arranged. After the pre-rolled strip has passed the roughing train 6. Rolling mill according to one of claims 3 to 5, has left another free outlet because of the characterized in that on the roller holding 50 large length of the rolling stock is no longer possible, se tion (123) a stop (126) for actuation that the last 5 to 7 stands of the roller train are brought together to the control lever (127) of a potentiometer (128) on the so-called finishing train, via which the speed of the drive must. In the stands of the finishing train, which can be regulated according to the motors of the work rolls (805) . the bandwidth to be generated at intervals between 7. Rolling mill according to claim 3, characterized see 55 2 and 5 m are set up, the Banc indicates that rolling between the work rolls at the same time. It is not possible, like (805) the rolling stands (103 to 105) of the roughing train in the roughing train, to be free of tension in the finishing train (2) and / or the rolling stands (171 to zen. The strip tension between the stands werder 173) of the intermediate road (17) below the rolling but z. B. with the help of loop regulators possible good (801) a roller table (131) with rotatable 60 kept small. Rolls (132) and above the rolling stock (801) As a result of the length of the roughing train in which the Banc at each roll stand one to be transported around a pivot point only at a limited speed (135) rotatable roller holder (133) with rollers that can be used for the passage of the belt (134) is arranged, which by means of a hydraulic the roughing train requires a relatively long time be see cylinder (136) against the rolling stock (801) 65, the strip cooling down impermissibly. Tue < is employable. Cooling is here because of the increasing decrease 8. Rolling mill according to one of claims 3 to 7, stand of the stands from each other the stronger, ji characterized in that the specific bundle weights are greater by means of the hydraulic. To di <