GB1571623A - Operation of hot strip mills - Google Patents

Operation of hot strip mills Download PDF

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Publication number
GB1571623A
GB1571623A GB563/77A GB56377A GB1571623A GB 1571623 A GB1571623 A GB 1571623A GB 563/77 A GB563/77 A GB 563/77A GB 56377 A GB56377 A GB 56377A GB 1571623 A GB1571623 A GB 1571623A
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United Kingdom
Prior art keywords
furnace
rolling mill
strip
roughing
train
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Expired
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GB563/77A
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Hoesch Werke AG
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Hoesch Werke AG
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Publication of GB1571623A publication Critical patent/GB1571623A/en
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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
    • B21B1/22—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length
    • B21B1/24—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length in a continuous or semi-continuous process
    • B21B1/26—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length in a continuous or semi-continuous process by hot-rolling, e.g. Steckel hot mill
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
    • C21D9/54—Furnaces for treating strips or wire
    • C21D9/68—Furnace coilers; Hot coilers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
    • F27B9/06—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity heated without contact between combustion gases and charge; electrically heated
    • F27B9/062—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity heated without contact between combustion gases and charge; electrically heated electrically heated
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
    • F27B9/14—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment
    • F27B9/20—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path tunnel furnace
    • F27B9/24—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path tunnel furnace being carried by a conveyor
    • F27B9/2407—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path tunnel furnace being carried by a conveyor the conveyor being constituted by rollers (roller hearth furnace)
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B15/00—Arrangements for performing additional metal-working operations specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
    • B21B2015/0057—Coiling the rolled product
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B33/00—Safety devices not otherwise provided for; Breaker blocks; Devices for freeing jammed rolls for handling cobbles; Overload safety devices
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B45/00—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
    • B21B45/004—Heating the product
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B9/00—Measures for carrying out rolling operations under special conditions, e.g. in vacuum or inert atmosphere to prevent oxidation of work; Special measures for removing fumes from rolling mills
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/20—Recycling
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/10—Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Thermal Sciences (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Combustion & Propulsion (AREA)
  • Metal Rolling (AREA)
  • Winding, Rewinding, Material Storage Devices (AREA)

Description

(54) IMPROVEMENTS IN OR RELATING TO THE OPERATION OF HOT STEP ROLLING MILLS (71) We, HOESCH WERKE AKTIENGESELL- SCHAFT, of Eberhardstrasse 12, 4600 Dortmund, Germany, a German Company do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates to the preservation of material in a hot strip rolling mill during a disruption of operation of the mill.
The invention is particularly applicable to continuous hot strip rolling mills, in which the material in slab or strip form is subjected in a roughing train to preliminary rolling down to the entry thickness for a subsequent finishing train. Such a continuous hot strip rolling mill may comprise a pusher type furnace and an arrangement in series in the rolling direction, of a roughing train with scale washing means and roughing stands, and a finishing train with scale washing means, cropping shears and finishing stands, as well as coilers and the roll tables interconnecting the various components of the system, whilst between the roughing train and the finishing train a strip withdrawing device is arranged adjacent the roll table.
In continuous hot strip rolling mills disturbances occur more or less frequently, in the course of which the rolling operations must be interrupted. The material which has been wholly or partly rolled at the time when the disturbance occurs, must then be removed from the train without there being any possibility of treating it as useful material, a substantial part thereof only having waste value. If the disturbance is in the nature of a fault at the coilers, being due for example to a seizing up at the entry end of a strip, then if the mill has a continuous hot strip train, there will be a total of three slabs in the process of being rolled, so that a substantial loss is suffered through only a single disturbance.
Apart from this, when it is considered that between the roughing train and the finishing train in hot strip rolling mills a strip with- drawing device is arranged adjacent the rolling mill table for rapid removal of a portion of the rough rolled strip out of the rolling line, and that otherwise no devices other than indoor cranes are provided for removing the further portions of rolled material out of the rolling train, then it is evident that a considerable period of time must pass before the rolling train can be restored to full operation after a disturbance has taken place.
The present invention accordingly provides a method of preserving material in a hot strip rolling mill during a disruption in operation of the mill, the method comprising the steps of reversing the direction of movement of rough rolled material through a roughing stand or a roughing train, coiling up the rough rolled material and maintaining the material at least approximately at rolling temperature by application of heat both externally and internally of the coiled rough rolled material.
The invention also provides a hot strip rolling mill comprising a roughing stand or train for rolling material down to the entry thickness for a subsequent finishing train, rolling mill roll tables for conveying the material in the mill, and a holding furnace with a coiling device located upstream of the roughing stand or the last roughing stand of the roughing train, the furnace being arranged to receive rough rolled material in coiled form and having heater elements arranged to apply heat externally and internally to the coiled material to maintain at least approximately the temperature of the rough rolled material during a disruption of the operation the mill.
The invention also provides a hot strip rolling mill comprising a pusher type furnace and, arranged in series in the rolling direction, a roughing train having a scale washer and a plurality of roughing stands, and a finishing train with a scale washer, cropping shears and finishing stands, as well as coilers and rolling mill roll tables connecting the individual components of the mill, a material withdrawing device adjacent the rolling mill table between the roughing train and the finishing train, a holding furnace having a coiling device within the roughing train for receiving rough rolled material during disruption of operation of the mill in coiled form and heater elements for heating the coiled material internally and externally, and a roller hearth furnace for accommodating rough rolled material which has already been rolled through at least one reduction stage, the lower working roll and the lower support roll of the downstream roughing stand in the roughing train being capable of being lowered. Preferably, the coiled rough material and the rough rolled material are moved during the time they are maintained in the hot condition so that a uniform distribution of heat through the rolled material is ensured.
In a preferred arrangement, the holding furnace comprises a removable hood provided with a fireproof heat insulating lining which hood lies upon a frame provided above the roll table and provided with a strip receiving opening.
The roller hearth furnace can be arranged within the roughing train in a position between the first roughing stand and the second roughing stand and adjacent that section of the roll table situated between said roughing stands. If such an arrangement is not possible within the available space, then preferably the roller hearth furnace is arranged at the end of the roll table before the first pusher furnace.
Furthermore in order to make it possible to hold the rolled material, that is to say, the coiled roughing strip and the slab which has already been worked through at least one reduction stage, for a protracted period in the furnace, all of the rolls in the holding furnace and the roller hearth furnace are made of heat resistant material and the shafts thereof are cooled, preferably water cooled.
By the adoption of simple means, the invention permits the waste of material resulting from disturbances in hot strip rolling mills, the duration of the disturbance periods, and the production losses, to be reduced.
A method and rolling mills embodying the invention are more particularly described below by way of illustration with reference to the accompanying drawing, in which: Fig. 1 is a schematic diagram of a first embodiment comprising a fully continuous hot strip train; Fig. 2 is a schematic diagram of a second embodiment comprising a 3/4 continuous hot strip train; Fig. 3 is a schematic diagram of a third embodiment comprising a semi-continuous hot strip train; Fig. 4 is a side elevation patly in section for a holding furnace with a coiling device included in the first, second and third embodiments; Fig 5 shows a roller hearth furnace, included in the first and second embodiments, in sectional side view and Fig. 6 shows the roller hearth furnace together with a rolling mill table in plan view.
As shown in fig. 1, a fully continuous hot strip train, preferably a wide hot strip train, comprises a pusher type furnace 1, of which only one is shown in the drawing, and the following components arranged in series in the rolling line:- a scale washer 2, the roughing stands 3 to 7 of the roughing train, a further scale washer 8, a cropping shears 9, finishing stands 10 to 15 of the finishing train, coilers 16 to 18 and sections of roller table 19 connecting the individual components. Adjacent that section of the roller table 19 which is situated between the last roughing stand 7 of the roughing train and the scale washer arranged in front of the cropping shears 9, there is provided a strip withdrawing device 20, by means of which, when a disturbance occurs, for example a disturbance at the winches 16-18, that portion of a rough strip which is still lying outside the first finishing stand 10 and has been parted by the cropping shears 9, can be withdrawn laterally from the roller table 19.
The 3/4 continuous hot strip train according to fig. 2 differs in its construction from the fully continuous train according to fig. 1 solely in the fact that only three roughing stands 3, 4 and 7 are provided, of which the middle roughing stand 4 is designed as a reversing stand.
The last roughing stands in the trains of Figs. 1 and 2 are provided with a so-called "back pass" device by means of which the lower working roll and the lower support roll can be dropped down.
In a corresponding manner, in a semicontinuous hot strip train according to Fig. 3 the single roughing stand is designed as a reversing stand 21.
In each of the hot strip trains shown in Figs. 1, 2 and 3, a holding furnace 22 with a coiling device as shown in Fig. 4 is located within the roughing train, which begins with the scale washer 2 and ends with the last roughing stand 7 in the trains of Figs. 1 and 2 and the stand 21 of Fig. 3, the holding furnace being placed upstream in the rolling direction with respect to the last roughing stand 7 or the roughing stand 21.
The holding furnace 22 as will appear from Fig. 4 comprises a removable hood 23, which is provided with a fireproof heat insulating lining 24 and is supported upon a frame 25, which is mounted above the roll table 19 and is provided with a receiving opening. In a bearing block 26 arranged upon the frame 25 there is mounted the coiling device comprising a pair of driving rolls 27, a triple roll bending set 28, a rotatable mandrel 29 and a driven pair of support rolls 30. The mandrel 29 serves only for centering the coil in the furnace 22 and takes no part in the coiling operation. A side wall of the hood 23 is preferably designed as a door, through which a coil may if necessary be removed.
If a disturbance occurs in the hot strip train, then the strip which is situated in the finishing train is removed in a known manner by means of the strip withdrawing device 20 and a crane, whilst the rough slab which is situated in the roughing train is rolled in the usual manner down to the final rough strip thickness necessary for the finishing train.
After leaving the last roughing stand 7 or 21 respectively, in the rolling direction the rough strip is drawn back in opposition to the rolling direction through the roughing stand 7 or 21 respectively. Advantageously for this purpose the rolls of the roller table section l9c situated between the cropping shears 9 and the holding furnace 22 have their direction of rotation reversible. The rough strip passes over a roller table section 19a, which has been inclined from its normal position by means of a piston and cylinder arrangement 31 so that the rough strip then passes through the pair of guide rolls 27 into the triple roll bending set 28, whereby it is upwardly bent around the mandrel 29 and then formed into a coil. The finished coiled rough strip is supported by the pair of support rolls 30 and during its holding period in the holding furnace is slowly rotated, for example at 0 5 rpm.
Heater elements 32 are arranged in cavities, which are uniformly distributed about the axis of the mandrel, these cavities being provided not only in the fireproof lining 24 of the hood 23 but also in the rotatable mandrel 29. Further heater elements 33 are arranged in the side walls of the furnace facing both end surfaces of the coiled rough strip. Immediately a disturbance occurs in the rolling mill, the heater elements 32, 33, which can be radiation or induction heater elements, are switched into circuit and the strip is maintained at rolling temperature.
In order to prevent the formation of scale on the surface of the rough strip in the holding furnace 22, the interior of the furnace is charged with an inert protective gas, for example nitrogen, for the period of retention of the strip. For this purpose filling unions 34 are provided in the hood 23, and a closure device, not shown in the drawing, is provided for the reception opening in the frame 25.
For uncoiling the rough strip to deliver it from the holding furnace 22, a pivotable wedge 26a and a guide rail 26b are secured to the bearing block 26. By means of the wedge 26a the starting end of the strip is lifted from the coil and is introduced by the guide rail 26b into the triple roll bending set 28.
In a fully continuous and a 3/4 continuous hot strip train, upon the appearance of a disturbance in the region of the coilers 16 to 18, a slab will be receiving the first reduction pass in the roughing stand 3. For the purpose of conserving this slab for the period during which the operation of the rolling mill is interrupted, a roller hearth furnace 35 shown in figs 5 and 6 is arranged adjacent the roll table section 19b in a position between the first roughing stand 3 and the second roughing stand 4.
As is clear from fig. 5, the roller hearth furnace 35 comprises essentially cooled rolls 36 arranged in the furnace bed and driven by means of motors 36a, together with a removable furnace roof 37 and oscillating pusher devices arranged at the sides. Heater elements 39 are arranged in cavities both in the furnace roof 37 as well as in the furnace bed. Between the rolls 36 there are arranged guides 40 of a drag hook appliance 41, these guides being introduced between each two rolls of the roll table section 19b. By means of the drag hook appliance 41 the slab, which has received the first reduction pass in the roughing stand 3, is drawn from the roll table section 19b into the roller hearth furnace 35.
The drag hook appliance 41 (fig. 6) comprises a motor 42 and a reduction gear 43 with a shaft 44, by means of which the drag hooks, not shown in the drawing, are synchronously moved, for example by means of chains or cables.
During the period of time in which the slab is retained in the roller hearth furnace 35, the furnace being at that time charged with a protective gas, the heater elements 39 are switched into circuit, these being likewise designed as radiation or induction heater elements. During this time the slab is reciprocated within the furnace 35 by means of the suspended rolls 36.
After the disturbance in the rolling mill has been removed, first of all the rough rolled strip which has been held at rolling temperature is removed from the holding furnace 22 by unwinding it in the rolling direction, and is delivered through the last roughing stand 7 or 21 to the finishing stands 10-15 for further rolling. During this time the slab which has been retained in the hot condition in the roller hearth furnace 35 is restored to the roll table section 19b by means of the drag hook appliance 41 and is immediately further rolled in the roughing train.
WHAT WE CLAIM IS: 1. A method of preserving material in a hot strip rolling mill during a disruption in
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (1)

  1. **WARNING** start of CLMS field may overlap end of DESC **.
    coiling device comprising a pair of driving rolls 27, a triple roll bending set 28, a rotatable mandrel 29 and a driven pair of support rolls 30. The mandrel 29 serves only for centering the coil in the furnace 22 and takes no part in the coiling operation. A side wall of the hood 23 is preferably designed as a door, through which a coil may if necessary be removed.
    If a disturbance occurs in the hot strip train, then the strip which is situated in the finishing train is removed in a known manner by means of the strip withdrawing device 20 and a crane, whilst the rough slab which is situated in the roughing train is rolled in the usual manner down to the final rough strip thickness necessary for the finishing train.
    After leaving the last roughing stand 7 or 21 respectively, in the rolling direction the rough strip is drawn back in opposition to the rolling direction through the roughing stand 7 or 21 respectively. Advantageously for this purpose the rolls of the roller table section l9c situated between the cropping shears 9 and the holding furnace 22 have their direction of rotation reversible. The rough strip passes over a roller table section 19a, which has been inclined from its normal position by means of a piston and cylinder arrangement 31 so that the rough strip then passes through the pair of guide rolls 27 into the triple roll bending set 28, whereby it is upwardly bent around the mandrel 29 and then formed into a coil. The finished coiled rough strip is supported by the pair of support rolls 30 and during its holding period in the holding furnace is slowly rotated, for example at 0 5 rpm.
    Heater elements 32 are arranged in cavities, which are uniformly distributed about the axis of the mandrel, these cavities being provided not only in the fireproof lining 24 of the hood 23 but also in the rotatable mandrel 29. Further heater elements 33 are arranged in the side walls of the furnace facing both end surfaces of the coiled rough strip. Immediately a disturbance occurs in the rolling mill, the heater elements 32, 33, which can be radiation or induction heater elements, are switched into circuit and the strip is maintained at rolling temperature.
    In order to prevent the formation of scale on the surface of the rough strip in the holding furnace 22, the interior of the furnace is charged with an inert protective gas, for example nitrogen, for the period of retention of the strip. For this purpose filling unions 34 are provided in the hood 23, and a closure device, not shown in the drawing, is provided for the reception opening in the frame 25.
    For uncoiling the rough strip to deliver it from the holding furnace 22, a pivotable wedge 26a and a guide rail 26b are secured to the bearing block 26. By means of the wedge 26a the starting end of the strip is lifted from the coil and is introduced by the guide rail 26b into the triple roll bending set 28.
    In a fully continuous and a 3/4 continuous hot strip train, upon the appearance of a disturbance in the region of the coilers 16 to 18, a slab will be receiving the first reduction pass in the roughing stand 3. For the purpose of conserving this slab for the period during which the operation of the rolling mill is interrupted, a roller hearth furnace 35 shown in figs 5 and 6 is arranged adjacent the roll table section 19b in a position between the first roughing stand 3 and the second roughing stand 4.
    As is clear from fig. 5, the roller hearth furnace 35 comprises essentially cooled rolls 36 arranged in the furnace bed and driven by means of motors 36a, together with a removable furnace roof 37 and oscillating pusher devices arranged at the sides. Heater elements 39 are arranged in cavities both in the furnace roof 37 as well as in the furnace bed. Between the rolls 36 there are arranged guides 40 of a drag hook appliance 41, these guides being introduced between each two rolls of the roll table section 19b. By means of the drag hook appliance 41 the slab, which has received the first reduction pass in the roughing stand 3, is drawn from the roll table section 19b into the roller hearth furnace 35.
    The drag hook appliance 41 (fig. 6) comprises a motor 42 and a reduction gear 43 with a shaft 44, by means of which the drag hooks, not shown in the drawing, are synchronously moved, for example by means of chains or cables.
    During the period of time in which the slab is retained in the roller hearth furnace 35, the furnace being at that time charged with a protective gas, the heater elements 39 are switched into circuit, these being likewise designed as radiation or induction heater elements. During this time the slab is reciprocated within the furnace 35 by means of the suspended rolls 36.
    After the disturbance in the rolling mill has been removed, first of all the rough rolled strip which has been held at rolling temperature is removed from the holding furnace 22 by unwinding it in the rolling direction, and is delivered through the last roughing stand 7 or 21 to the finishing stands 10-15 for further rolling. During this time the slab which has been retained in the hot condition in the roller hearth furnace 35 is restored to the roll table section 19b by means of the drag hook appliance 41 and is immediately further rolled in the roughing train.
    WHAT WE CLAIM IS:
    1. A method of preserving material in a hot strip rolling mill during a disruption in
    operation of the mill, the method comprising the steps of reversing the direction of movement of rough rolled material through a roughing stand or a roughing train, coiling up the rough rolled material and maintaining the material at least approximately at rolling temperature by application of heat both externally and internally of the coiled rough rolled material.
    2. A method as claimed in claim 1 comprising the step of maintaining material already rolled through at least one reduction stage in the roughing train at least approximately at rolling temperature.
    3. A method as claimed in claim 1 or 2 in which the coiled rough rolled material and/ or the material rolled through at least one reduction stage are moved whilst being maintained at the rolling temperature.
    4. A hot strip rolling mill comprising a roughing stand or train for rolling material down to the entry thickness for a subsequent finishing train, rolling mill roll tables for conveying the material in the mill, and a holding furnace with a coiling device located upstream of the roughing stand or the last roughing stand of the roughing train, the furnace being arranged to receive rough rolled material in coiled form and having heater elements arranged to apply heat externally and internally to the coiled material to maintain at least approximately the temperature of the rough rolled material during a disruption of the operation of the mill.
    5. A rolling mill as claimed in claim 4 having a roughing train and a roller hearth furnace for accommodating, during a disruption of the operation of the mill, material which has already been rolled through at least one reduction stage in the roughing train.
    6. A hot strip rolling mill comprising a pusher type furnace, and arranged in series in the rolling direction, a roughing train having a scale washer and a plurality of roughing stands, and a finishing train with a scale washer, cropping shears and finishing stands, as well as coilers and rolling mill roll tables connecting the individual components of the mill, a material withdrawing device adjacent the rolling mill table between the roughing train and the finishing train, a holding furnace having a coiling device within the roughing train for receiving rough rolled material during disruption of operation of the mill in coiled form and heater elements for heating the coiled material internally and externally, and a roller hearth furnace for accommodating rough rolled material which has already been rolled through at least one reduction stage, the lower working roll and the lower support roll of the downstream roughing stand in the roughing train being tapabie of being lowered.
    7. A rolling mill as claimed in claim 6 in which the roller hearth furnace is arranged at the end of the roller table before the first pusher type furnace.
    9. A rolling mill as claimed in any one of claims 5, 6, 7 or 8 in which the roller hearth furnace comprises cooled rolls arranged in the furnace bed, motors for driving the cooled rolls, and a removable hearth roof and oscillating pusher devices arranged at the sides of the furnace.
    10. A rolling mill as claimed in claim 5, 6, 7, 8 or 9 having means for providing the roller hearth furnace with a protective gas filling.
    11. A rolling mill as claimed in any one of claims 5 to 10 in which heaters are provided in cavities in the roof and in the bed of the roller hearth furnace.
    12. A rolling mill as claimed in claim 11 in which the roller hearth furnace heaters are radiation or induction heaters.
    13. A rolling mill as claimed in any one of claims 5 to 12 having guides of a drag hook device between the rolls in the furnace bed, the guides being continued into the roll table section and being interspersed between each adjacent pair of rolls of the roll table.
    14. A rolling mill as claimed in claim 13 having a motor and reduction gearing for driving the drag hook device, a shaft being connected to the gearing by means of which draft hooks are movable in synchronism in the guides.
    15. A rolling mill as claimed in any one of claims 5 to 14 in which the rolls in the roller hearth furnace are made of fireproof material, the shafts thereof being provided with cooling means.
    16. A rolling mill as claimed in any one of claims 4 to 15 in which the holding furnace comprises a removable hood provided with a fireproof heat insulating lining and supported above the roll table upon a frame provided with a strip receiving opening.
    17. A rolling mill as claimed in claim 16 in which the frame supports a bearing block mounting the coiling device, the device comprising a drivable pair of drive rolls, a drivable triple roll bending set, a drivable rotatable mandrel and a drivable pair of support rolls, a pivoted wedge and a guide rail being secured to the bearing block.
    18. A rolling mill as claimed in claim 17 in which the rolls in the holding furnace are made of fireproof material, the shafts thereof being provided with cooling means.
    19. A rolling mill as claimed in claim 17 or 18 having cavities distributed uniformly about the axis of the mandrel and provided in the fireproof lining of the hood and in the rotatable mandrel, the heater elements being received in the cavities and located in positions to face both end surfaces of the coiled material.
    20. A rolling mill as claimed in claim 16, 17 or 18 having filling connections for the hood and a closure device for the strip reception opening in the frame.
    21. A rolling mill as claimed in any one of claims 16 to 20 in which one side wall of the hood is arranged to function as a door.
    22. A rolling mill as claimed in any one of claims 4 to 21 in which the holding furnace heater elements are radiation or induction heater elements.
    23. A method of preserving material in a hot strip rolling mill during a disruption in operation of the mill, substantially as herein described with reference to the accompanying drawings.
    24. A hot strip rolling mill substantially as herein described with reference to Figures 1, 4, 5 and 6 or Figures 3 and 4 of the accompanying drawings.
GB563/77A 1976-01-10 1977-01-07 Operation of hot strip mills Expired GB1571623A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2600784A DE2600784C3 (en) 1976-01-10 1976-01-10 Process for rolling hot strip and hot strip mill for carrying out the process

Publications (1)

Publication Number Publication Date
GB1571623A true GB1571623A (en) 1980-07-16

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Family Applications (1)

Application Number Title Priority Date Filing Date
GB563/77A Expired GB1571623A (en) 1976-01-10 1977-01-07 Operation of hot strip mills

Country Status (4)

Country Link
JP (1) JPS5285956A (en)
DE (1) DE2600784C3 (en)
FR (1) FR2337594A1 (en)
GB (1) GB1571623A (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
LU80840A1 (en) * 1979-01-29 1980-08-08 Mecanarbed Sa IMPROVEMENTS ON REVERSIBLE HOT ROLLING PLANTS
US6134934A (en) * 1996-01-31 2000-10-24 Voest-Alpine Industrieanlagenbau Gmbh Process and device for reverse rolling metal strips
DE102018122047A1 (en) 2018-09-10 2020-03-12 voestalpine Automotive Components Dettingen GmbH & Co. KG METHOD AND DEVICE FOR CONNECTING SHEET PARTS TO SHEET PACKAGES

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2658741A (en) * 1949-04-11 1953-11-10 Westfalenhutte Dortmund Ag Rolling mill for rolling strips or bands and sheets of steel and nonferrous metals
DE1158024B (en) * 1960-03-24 1963-11-28 Verwaltungsgesellschaft Moelle Hot plate rolling mill
AT286915B (en) * 1969-04-01 1970-12-28 Voest Ag Method and device for preventing damage to hot strip finishing lines
GB1373375A (en) * 1971-11-15 1974-11-13 Canada Steel Co Method for rolling hot metal workpieces

Also Published As

Publication number Publication date
DE2600784C3 (en) 1978-11-09
FR2337594A1 (en) 1977-08-05
DE2600784A1 (en) 1977-07-21
DE2600784B2 (en) 1978-04-06
FR2337594B1 (en) 1982-08-27
JPS5285956A (en) 1977-07-16

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