FR2507929A1 - PROCESS FOR COOLING SHOTS OF STRONG SHEETS IN SCROLL, DURING ROLLING AND MACHINE FOR ITS IMPLEMENTATION - Google Patents

Abstract

THE PRESENT INVENTION RELATES TO A PROCESS FOR COOLING STRONG SCREENING SHEET BLADES, DURING LAMINATION, CHARACTERIZED IN THAT IT CONSISTS OF COOLING ONLY THE CENTRAL PART OF THE SURFACE OF THE BLANKET, EXCLUDING PERIPHERAL PARTS. THIS PROCESS IS IMPLEMENTED BY A MACHINE INCLUDING MEANS 13 FOR SUPPORT AND GUIDING THE BLANKET AND OCCULTABLE COOLING MEANS 14, 15 COMMANDS ACCORDING TO THE PASSAGE OF THE BLANK IN A WAY NOT TO COOL ROUGHING ONLY ON A CENTRAL PART OF ITS SURFACE, EXCLUDING PERIPHERAL PARTS.

Description

1.

  The present invention relates to the cooling

  of sheet metal blanks in the course of

  swimming, as well as a machine for its implementation.

  In order to obtain by rolling a product

  both of the optimum characteristics, it may be interesting to conduct the rolling in several phases using for each one of them ranges of temperatures

  different types that are suitable for specific conditions.

  processing, either to conduct section reduction operations in the most economical way,

  to execute the rolling stages in an inter-

  range of temperatures corresponding to specific conditions

  Metallurgical properties for the structure

internal of the metal itself.

  Lamination will thus be able to trade at a tempera-

  high level, favorable to certain metallurgical

  such as the solution of certain compounds

  is also favorable to rapid and economic transformation by taking advantage of the state of malleability

metal related to its temperature.

  The rolling may continue in one or more

  other successive phases at

  growing each adapted to phenomena such as recrystallization, the transformation of the internal structure (so for the steel we can make a part of the

  at a temperature close to that of the

  austenitic formation) or the precipitation of various compounds.

  The various phases of rolling thus

  at different temperatures, it is necessary to cool the product between these phases. In the current methods of work, this cooling is usually obtained in the open air by

  waiting in an additional post provided for this purpose, the drafts

  during rolling for a time necessary for this cooling or by using a fluid such as water, air, water vapor, or mixtures thereof, this fluid being sprayed at variable pressures on

  the entire surface of the blank to be cooled.

  A disadvantage of these methods usually used, both for cooling in ambient air and for spraying a fluid, is to provoke

  significant differences in temperatures between different

  parts of the product and, in particular; this cooling

  the effect of cooling has further cooled the shorelines

and the ends of the blanks.

  The different cooling of the banks and

  ends of the product presents a number of

  which are in particular the following:

  the parts of the sketch that are transformed

  at different temperatures, not following the same metallurgical cycle as the others, have final mechanical characteristics which are different from those obtained for the rest of the product, thus leading to heterogeneous characteristics within a same laminated sheet It can thus be led to eliminate by falling the end parts,

  which causes appreciable losses.

  cold extremities cause

  torque loads and rolling force at the moment

  the passage of these ends between the cylinders,

  so the average load that it is possible to obtain

  nir and causing harmful shocks to the good performance

  of a rolling stand and motors.

  colder banks cause wear

  stronger cylinders at the shoreline, r 6 dui-

  the duration of the rolling campaigns it has

  possible to do without rectifying the cylinders.

  Finally, it can be noted that cooling 3.

  between two successive phases of trans-

  training requires a time of which it is necessary to

  take into account in the organization of the process of

  mining and slowing down the rate of production.

  The object of the present invention is therefore to

  mediate these disadvantages and allow a cooling

  draft reduction which is: faster and of adjustable duration so as to obtain a more accurate coordination over time rolling periods and waiting periods and optimal use of the cage (or cages)

rolling.

  uniform throughout the surface of the blank to obtain homogeneous mechanical characteristics

  on the entire surface of the product.

  The subject of the invention is thus a method for cooling drafts of rolling plate during rolling, which consists in cooling the central part of the surface of the blank, excluding the

  peripheral parts which are constituted by the former

  tremities front and back of the product, as well as by its banks. The cooling of said scrolling central part is obtained in particular by projection of a cooling fluid using ramps arranged

  parallel to the surface of the blank and perpendicular

  the direction of scrolling of the latter, the projection being triggered, respectively for

  each ramp, after the passage of the front edge of the

  bauche and being stopped before the passage of the rear edge of the blank, in the direction of travel, and the useful projection length of each ramp being set to be smaller than the dimension of the blank in a

  direction perpendicular to the scroll.

  The cooling can be obtained by any suitable fluid such as for example water sprayed with a gas under pressure and delivered in the form of a homogeneous two-dimensional sheet from the ramps Ce

gas may especially be air.

4.

  According to a first embodiment of the invention,

  In this way, the cooling is carried out on the roller line itself of the roller table of a rolling stand. According to a second embodiment, the

  Cooling is carried out laterally at the road line.

  the rolling table of a rolling stand, by

  transfer of the blank out of this line, in a

  perpendicular to the axis of this line.

  To implement the cooling process

  Therefore, it is necessary to place the blank in a position in which it is subjected to the accelerated cooling process, while the rolling is

continues on other products.

  Depending on the type of rolling mill

  available, and depending on the number of cooling stations

  accelerated degradation that can be

  including the following provisions.

  In the case of an installation with a

  only rolling cage, if we want to carry out the cooling

  in the line of the rollers,

  two cooling stations, one upstream and one

  downstream of the cage, to allow a sequence

  operations, or use a device that allows

  to pass a blank over the other, the first being sent on the rolling stand, while

  the second is sent to the cooling station

is lying.

  In the case where two cages of la-

  the cooling station can be placed in the line of the rollers between the rolling stands The first rolling phase is carried out on the first

  cage, the blank then goes to the cooling station.

  accelerated deterioration, then, after the waiting time required

  to sufficiently homogenize the temperature between the surface and the inside of the blank, is sent to

  the second cage for the last rolling phase.

  A cooling station placed laterally at the line 5 of the rolling rollers makes it possible to perform the temperature adjustment operation outside the rolling line and to reintegrate the blank in the line.

  at the time necessary for the sequence of operations

  timal of operations. The use of a cooling station placed laterally at the line of rolling rolls

  reduces the total length of tables

  which are necessary for rolling.

  The invention also relates to a machine for carrying out the above method, this machine being remarkable in particular that it comprises means for supporting and guiding the blank, and

  occultable cooling means controlled according to

  the roughing passage so as to cool the blank only on a central part of its surface,

  the exclusion of the peripheral parts.

  The cooling means are constituted

  of a set of projection ramps of a reaction fluid

  cooling, parallel to each other and to the surface of the blank and arranged perpendicular to the direction of movement of the blank, these ramps being placed above and below the blank and controlled by passage detectors and dimension

of the sketch.

  The projection ramps of the cooling fluid

  are designed to deliver a jet

  in the form of a two-dimensional web that reaches the

  bauche following the normal to its surface This sheet is thus for example consisting of a jet of water spray

  by a pressurized gas such as air.

  An example of such a ramp consists of a hollow body having opposite the surface of the blank

  an elongated slot with parallel edges.

  The invention is described below in more detail with the aid of the accompanying drawings which represent only

a mode of execution.

  In these drawings Fig 1 is a general perspective view 6.

  of a blank cooling machine according to the present invention.

  invention lying laterally to a line of

mining;

  Fig 2 is a perspective view of the machine

  china cooling blanks according to the present invention; and Fig. 3 is a schematic view showing the principle of central cooling on a

  draft during cooling.

  FIG. 1 shows a cooling machine 1 according to the invention arranged laterally on a rolling line 2 comprising a rolling stand

  3 in which is engaged a sketch 4 After his

  in the rolling stand 3, the blank 4 is

  on the roller table 5 to a position

  in 4a where it is then removed from the dining table.

  to be directed in a direction perpendicular to the axis of the roll line and introduced into the

cooling machine 1.

  The transfer means of the blank 4 has

  machine 1 to allow its introduction

  in the latter are constituted in the mode of realization

  represented by a set of finials 6a, 6b, 6c, 6d, etc. embracing respectively two series of chain wheels 7a, 7b, 7c, etc. and 8a, 8b, etc., which are secured to two shafts 9 and 10 mounted on a frame

  unrepresented being able to be animated by a movement of

  vertical section represented by the arrow at 11 The chains 6a, 6b, 6c, etc. are inserted between two rollers

  of the roller table 5 and when the assembly is

  raised, raise the sketch 4a and drag it, as

  indicated by the arrow 12, towards the cooling machine

where it is introduced.

  This chain transfer device comprise

  preferably two-phase operation, the first

  making a rapid movement of translation of the blank 4a to evacuate out of the line 2, then the second making a slow movement compatible with the

  speed of introduction into the machine 1.

  This cooling machine has a

  series of lines of rollers 13 whose length is greater than

  greater than the maximum dimension of the blank that is to be cooled Each line of rollers is spaced, for example, from 650 to 900 mm, so that there is

  and at a lower level, lower ramps 14 of pul-

  cooling fluid, parallel to the

  lines of rollers 13 Upper ramps 15 of sprayers

  cooling fluid parallel to the lines of rollers 13 are arranged in a similar manner but

  above the pebble line so as to be able to

  to check a cooling fluid on the upper part

  Roughing of the blank Additional lines of rollers 16 make it possible to completely clear the blank of the zone of the ramps in order to possibly store them, or to homogenize their temperature before reintroduction on

the rolling line 2.

  In the arrangement of the cooling machine

  placed laterally to the rolling line, the roller lines 13 are perpendicular to the rollers of the

table 5.

  Rough passage detectors, which may for example consist of pairs comprising a light source and a photocell 17

  and 17 a, 18 and 18 a, 19 and 19 a, trigger the functioning

  corresponding ramps 14 and 15 respectively.

  that the front end of the blank, in the direction of its movement, is passed and stop the operation of these ramps before the passage of the rear end of the blank Thus, for the blank shown in phantom at the position 4 b, the pair of detectors 19, 19 a,

  will operate the lower and upper ramps

  correspondingly, as soon as the front end is passed, so that the two-dimensional layers of cooling fluid delivered by the ramps reach the surface of the blank only on a part situated below the zones immediately adjacent to the end. before, while the pair of detectors 17 and 17 has interrupted the operation of the lower spray bars 8.

  corresponding higher levels so that adjacent areas

  at the rear end of the surface of the blank shall not be subjected to cooling by

projected fluid.

  According to one variant, the passage sensors of the blank may be constituted by detectors

  pressure placed on the same lines of pebbles.

  It can also be provided in the control device of the ramps operation a

  delay device in order to control the de-

  shutting off the spraying of the coolant

  that from two pairs of step detectors

  placed at the inlet and outlet respectively of the cooling machine, taking into account the speed

  known displacement of the blank.

  Size sensors of the blank in

  a direction perpendicular to the direction of travel

  of the latter are placed respectively at the front and at the rear of the machine, so as to obscure the total length of spray

  ramps 14 and 15 so as not to send the reaction fluid

  These dimension detectors may for example also consist of light source-photocell pairs 20 and 20a, 21a and 21a, etc., the effective spraying length of the coatings. the ramp being calculated to be less than

  the size of the blank measured by these detectors.

  The pebble lines are animated in rotation

  by unrepresented electric motors which allow

  This roller line can be rotated in both directions so that it is possible to subject the blank to a second pass in the direction of the rolling line 2 to the rollers 16 or vice versa. the cooling machine

  or to animate the sketch 4b while cooling a movement

  oscillation under the spray bars of

cooling fluid.

  9. The cooling operation being completed,

  the blank 4b is returned to the transmission device

  chain which takes it back by a movement of

  In the opposite direction The chain transfer device is then placed in the high position and brings back

  the draft 4b in position 4a, then the chains are redes-

  at a lower level than the upper part of the roller table and the blank is again driven in a translation movement towards the 4c position.

  for subsequent rolling operations.

  It is also possible, by reversing the direction of rotation of the rollers of the roller table, to reduce

  the blank 4 has towards the rolling stand 3.

  It is also possible, with the help of

  chain transfer station to place the blank waiting in a position 4 d on the other side of the line

  of rolling with respect to the machine 1.

  In FIG. 2, there is shown in perspective the machine described above in FIG. 1 with its upper and lower ramps 15 for spraying.

  which are respectively supplied with cooling fluid

  drainage through an upper collector pipe 22 and

a lower pipe 23.

  The lower ramps 14 are arranged between roller lines 13 provided with electric motors

  24 Draft 4b during cooling

  receives a set of cooling fluid curtains

  25 and lower 26 on a central portion which leaves exposed a peripheral portion formed by the front and rear ends, and

  only by the banks of the sketch 4 b.

  10. Only the sprinkling of the central part of the blank is shown schematically in FIG. 3 on which it can be seen that the surface of the blank subjected to spraying having a small dimension (a) and a large dimension (b). , is smaller than the total area of the blank whose small dimension is (A) and

the big dimension (B).

  The sprinkling of the blank according to the dimension (a) is obtained thanks to the starting and stopping of the spray bars via the passage detectors which have been previously described. On the other hand, the sprinkling according to the dimension (b) is obtained thanks to the rough dimension sensors which obscure a part of the total length of the spray bars so as not to subject them to cooling by curtains

of water than dimension (b).

  The invention has been described previously in reference

  a cooling machine arranged laterally

  compared to the rolling line, but it is also possible to place this cooling station

  in the line of the rollers of the rolling table.

  In this case, the cooling ramps are placed above and below the passage of the blank,

  between the rollers of the rolling mill table.

  The distance between axes of the rolling rolls is generally between 700 and 1000 mm and thus allows the implantation of these spray bars of a

cooling fluid.

  Between each roller is provided a set of lower and upper spray bars, the length of these ramps being equal to that of the rollers of the roller table Blanking devices controlled by the size sensors of the blank

  in a direction perpendicular to the direction of de-

  placement of the latter, allow to adjust the lon'g

  the effective spray of the boom in order to

  catch a coolant spray

  on the banks of the draft and thus avoid a cooling

  more important than the whole 11.

of the sketch.

  The blank is engaged at a constant speed in the group of spray bars, the action of each of these ramps being initiated a little after the passage of the front end of the blank and interrupted a little before the passage of the rear end of the blank so as to limit the temperature difference between the ends and banks, on the one hand, and most of the rest

of the sketch, on the other hand.

  The machine works on the same principle when

  it is arranged laterally or in the line of rollers of the rolling mill table, the direction of movement of the blank being always penpendicular

  to the cooling fluid spray booms.

  The in-line device in the roller table avoids transferring the blank laterally, but has the disadvantage of increasing the necessary length of the roller table, which leads to increase by the same length of the rolling line. choice between the two systems

  is to be made according to the total cost of investment

  In existing installations, the choice is, moreover, conditioned by the equipment in place, particularly the number and location of cages.

rolling available.

12.

Claims (9)

  1 Method for cooling drafts of rolling plate during rolling, characterized   in that it consists in cooling only the central part   the surface of the blank, excluding the peripheral parts. 2 Method according to claim 1, characterized in that the cooling of said central part of the blank scroll is obtained by projection   of a cooling fluid using ramps dis-   parallel to the surface of the blank and allow   pendicular to the scrolling direction of this   last, the projection being triggered, respectively   for each boom, only after the passage of the   before the roughing and being stopped before   wise of the rear end of the blank in the direction of scrolling and the useful length of projection of   each ramp being set to be less than   measuring the blank in a perpendicular direction scrolling.   Process according to claim 2, characterized   rised in that the coolant is water   sprayed by a gas under pressure.   4 Process according to any one of the   previous indications, characterized in that the cooling   dissement is carried out on the same line of rollers   the roller table of a rolling stand.   Process according to any one of the   1 to 3, characterized in that the cooling   is performed laterally at the line of rollers of   the rolling table of a rolling stand, by trans-   roughing out of this line in one direction   perpendicular to the axis of this line.   6 Machine for cooling plate blanks in scrolling, during rolling,   comprising means for supporting and guiding the   bauche (13), characterized in that it comprises cleachable cooling means (14, 15) controlled 13.   according to the passage of the blank so as not to cool   dir rough than on a central part of its surface,   excluding peripheral parties.   Machine according to claim 6, characterized   in that said cooling means are constituted by a set of cooling fluid projection ramps parallel to each other and to the surface of the blank and arranged perpendicular to the direction of movement of the roughing, these ramps being placed above and below the blank and controlled by passage sensors (16, 16a, 17, 17a, 18, 18a, etc.) and the size of the blank ( 19 19a; 20, 20 a; etc.).   Machine according to claim 6 or 7, characterized   characterized in that the cooling fluid is water sprayed with pressurized gas in the form of   of a two-dimensional web reaching the standard blank on its surface.   Machine according to any one of the claims   tions, characterized in that it is placed   in the axis of the rollers line of the rolling table   the rolling cage, the ramps being parallel   rollers and arranged respectively above and under the roller table.   Machine according to any one of the claims   6 to 8, characterized in that it is placed   side of the rollers of the rolling table of the rolling stand, so that its projection ramps are perpendicular to the rollers of the rolling mill. table.