FR2526344A1 - METHOD AND APPARATUS FOR SCREENING CIRCULAR CAST PIECES - Google Patents

Abstract

THE INVENTION CONCERNS A PROCESS AND AN APPARATUS FOR SHREDDING CIRCULAR INGOTS. JUST AFTER THE CASTING OF AN INGOT W INTO A SLING 2, WITH GRADUAL LOWERING OF THE LATTER, THE INGOT IS TRANSPORTED AT LOW SPEED AND, AFTER DISMOLDING, ARRIVES A 17-18 ROTARY SHAKING APPARATUS WHICH REMOVES A LARGER QUANTITY MATERIAL IN THE CENTER OF THE INGOT ONLY ON THE EDGES.

Description

The present invention relates to a casting and processing method

automatic steel ingot

  intended to form forgings and laminates of for-

  me circular, for example wheels of transport vehicles, as well as a device used directly

  for the implementation of the process.

  When the cast steel ingot is subjected to

  a slashing, according to a current operation, a whitewash

  meau moves in certain directions G, H, 1, J, K

  passing through the center of the manual debited area-

  ingot W, the circumference being divided at

  equal tervalles as shown in FIG. la, so that the central part of the surface of the part W, generally having a greater segregation,

is decried more often.

  However, according to this method, the manual peeling is carried out so that the section of the ingot,

  after decripping, has radially several sur-

  bumpy irregular faces which reduce the regularity as shown in Figure lb In addition, the long time

  Degreaking kits are problematic, and over-

  face may not be formed with a section

uniform conical desirable.

  The invention relates to problem solving.

  my aforementioned and more specifically a casting and treatment method according to which the casting and the treatment of a steel ingot are carried out quickly while

  hot ingot, operation, from casting to

  that in the cracking, being continuous so that the ingot formed has a uniform quality without dispersion when it is transmitted to the next rolling operation so that the productivity of the process is high, in particular during

  of mass production.

  According to the invention, the cast ingot, preferably still hot, is subjected to rotary scarring by relative rotation of the ingot and of the stripping apparatus, so that the central part of the ingot

  with greater segregation be removed pre-

  preferentially. The invention also relates to an apparatus for

  ripping that includes a radially arranged torch

  directly in front of a steel ingot, so that the cha-

  lumen and the ingot rotate relative to each other, the circumferential speed of each point varying in radial direction relative to the ingot, so that the torch ensures the cracking, in all points in radial direction relative to the ingot , at different circumferential speeds, the cracked surface

formed being smooth -

  Other characteristics and advantages of the invention will be better understood on reading the

  description which will follow of exemplary embodiments and

  with reference to the appended drawings in which: FIG. 1a is a plan view illustrating the implementation of a conventional manual hauling; Figure 1b is a section through a cracked ingot as shown in Figure la;

  Figure 2 is a block diagram il-

  polishing an operation implementing the casting and treatment method according to the invention; Figure 3 shows part of a machine

  casting of ingots in which the description is made

quage according to the invention;

  FIG. 4 a schematically represents the ap-

  the same as the cutout according to the invention;

  Figure 4b is a section of an ingot

  cracked as shown in Figure 4a; and FIG. 5 is a graph representing the variation in the depth of cutout obtained using the cutter apparatus according to the invention, in

  depending on the distance to the edge of the room.

  Figures la and lb having already been shown

  Figure 2 is a block diagram illus-

  trant a treatment method according to the invention implemented in an installation comprising a section A for preparing an ingot mold, a section B for casting and

  an ingot mold section C, placed successively-

  ment in the form of an endless loop, arranged along

  a rectangular diagram for example, lines of treatment

  starting in derivation from section C so that

  cast steel ingots are transported to an opera-

  next section, i.e. to section D of the description

  quage, a reheating furnace E and a section F of the

mining.

  As shown in Figure 3, a cou-

  circle covers the upper face of the molten steel W

  with an insulating agent 15 preventing the formation of waves

  lations on the surface of the molten steel and ensuring the iso-

  thermal lation during transport of molten steel.

  After casting, the molten steel is not transported to

  high speed thanks to the vi adjustment assembly 16

  tesse which maintains this at the minimum value pos-

  sible Thus, during transport, the ingot keeps

  enough heat to be able to dry

  de Dripping while hot and undulating

  lation so that the internal quality of the ingot changes

little and the surface remains smooth.

  Then, although the figure does not represent it

  not feel, the ingot mold 2 'is lowered in the ingot mold section C and the steel ingot is removed

  of the mold while it is hot so that it

  come to the next section D of the husking.

  In section D of the husking and as

  shown in Figure 3, the ingot W of steel is placed

  cé on two cylinders 17 so that these drive it in rotation in the direction of the arrow A torch 18

  is placed opposite the surface to be cut on the linen

  got W and is directed radially with respect to the ingot.

  The torch nozzle comprises an oxygen projection channel and gas projection channels arranged around the oxygen projection channel In addition, one of the cylinders 17 which rotates the ingot W is a driving cylinder while the the other is a driven cylinder, and the speed of rotation of the cylinders is adjustable to any desired value under the control of a

  speed setting which is not shown in the

  sin In addition, in another embodiment of the

  process, the position of ingot W is fixed, and the heat

  meau 18 placed in front of the ingot turns on a cir-

  ring placed at the outer periphery of ingot W so

  that it ensures similar decripping In addition, the lime-

  meau 18 is intended to move radially with respect

  port in the center of the ingot W. When the intended debarking is carried out by implementing the preceding embodiments, the nozzles of the torch 18 are directed from the external periphery of the rotary ingot W towards the center, a lateral nozzle being placed opposite the center of ingot W and the remaining nozzles being arranged at locations

  ingots of ingot W progressively shifted to

  at the outer periphery while the circumferential speed

  of the ingot W varies towards the periphery ex-

  dull. So when the decripping is done

  based on the difference between the circumferential speeds

  nozzles, the corresponding points of ingot W

  form a V-shaped or sensing groove X

  slightly conical as shown in Figure 4 b In other words, in ingot W, the depth of

  skidding in the defective parts of the central area

  which has the greatest segregation is the most

  and furthermore the groove X has a surface

  smooth and non-irregular as in a maize cracking

  classic guide giving the result represented in FIG. 1b. We now consider an example of

  treatment of an ingot according to the invention This example con-

  identifies the cracking of the end surface of a lin-

got steel of 500 mm in diameter.

  (1) Working temperature: tempera-

ambient ture.

  (2) Blowtorch: blowtorch with

250 t (oxyacetylene type).

  (3) Material treated: SU material.

  (4) Frequency of rotation of the part

7 rpm.

(5) Cracking time: 8.6 / s.

  When the cut-off is thus carried out in one go, the cut-out depth is as represented by the solid line curve in the figure. In addition, the dashed line curve represents the

  depth obtained by a second cracking.

  Thus, the cutting device according to the invention, unlike conventional manual cutting,

  ensures the cracking of the steel ingot thanks to the different

  rence of circumferential speeds of the different points in the radial direction when the part rotates relative

  with a blowtorch, the central part having surfaces

  cracked deeply while the external parts have

  less and less decrepit surfaces when reconciling

  towards the outer periphery, and the surfaces of the cracked parts are not only regular and smooth but can also be formed automatically into a

  very short time, the effect being remarkable and does not require

  not experienced staff.

  In addition, the cutting device according to the invention allows a wider cutting than when

  the use of conventional manual hauling, and the use of

  sation of large torches allowing efficient cracking for a significantly reduced time. In addition, although the large blowtorch

  dimension includes gas projection channels

  created around an oxygen projection channel as a

  shown in Figure 4a, multiple torches at one

  outlet can be used, depending on a

special storage.

  We now consider a mode of realization

  particular action of an apparatus which ensures the cracking of steel ingots and gives the results of Tables I and II under the following conditions: (1) Material of the submerged nozzle: silica

fondue, internal diameter 40.

  Projection channel: two horizontal channels

rate O 25 x 2.

  (2) Quantity of coating (15) to be used:

2 kg / t.

  Composition: Si O 2 45 Z, Co 0.8 Z, A 1203

Z, C 16 Z.

  (3) Quantity of insulating agent to use:

4 kg / t.

  Composition: Mo Al 15 Z, AI 203 40 Z, Si O 2 Z. (4) Steel ingot: unit weight 440 kg,

diameter 500, height 285.

  (5) Ingot mold: unit weight 1400 kg

(ingot mold and support plate).

  (6) Nature of steel: C 0.60, Si 0.25,

Mn 0.60.

(7) Casting speed: 15 kg / s.

(8) Dimension of the steel ingot:

  height / diameter less than 1.0.

  (9) Height reduction at the piriphi- part

  external risk more than 10 mm (10 mm is the thickness

  material with segregation).

TABLE I

  Casting -Drifting Test Number of unitary mass Standard deviation Mass time withdrawn Average casting time, kg a (kg) casting kg min. , 7 2.7 70 15.1 34 third 149 441.5 2.9 71 14.3 33 fourth 150 440.0 2.1 72 14.4 3 Co M i

TABLE II

  (: Quality) Percentage of wheels Percentage of wheels <Faulty defective test after treatment (: :) (First:) (Second: O) C) (Third O O) (Fourth O O)

  As the above description indicates,

  The following advantages are obtained: (1) Homogeneous steel ingots can be quickly cast and decrypted without quality dispersion, for example without hot inclusion, in a continuous process.

  naked from casting to husking, before transmission to la-

  subsequent mining so that productivity can be increased

  raw, during rapidly executed operations.

  (2) As usually the hand cutting is performed by relative rotation of the torch

  and room, using differences in vi-

  circumferential braids at different points in di-

  radial rection, the central part of the part can have deeper cracked surfaces, the others

  parts being less and less deep towards the peri-

  In addition, not only the surfaces ob-

  outfits are regular and smooth after decripping but still the operation can be performed automatically

  for a very short time so that he was not born

  necessary to use experienced personnel to

  achieving a remarkable effect In addition, compared to

  worn in conventional cracking, steel ingots of very different types can be cracked, a large blowtorch can be used even in large pieces, the treatment time being reduced significantly while the cracking is effective. (3) As the molten steel is transported to the stripping operation with reduction of the traveling speed so that the surface of the molten steel is not corrugated after casting, the internal quality and smoothness of the surface of molten steel can be

kept during transport.

  Of course, various modifications can be made by those skilled in the art to the devices and methods which have just been described solely by way of

  non-limiting examples without departing from the scope of the in-

vention.

Claims (4)

  1 Method for debarking a circular cast steel ingot, characterized in that it consists in subjecting the ingot to rotary debarking by placing   in relative rotation of the ingot and the de-   cracking, so that the central part of the ingot pre-   feeling greater segregation be removed pre-   preferentially. 2 Method according to claim 1, characterized   by the fact that the decripping is carried out on the lin- O 10 got poured while hot.   3 Cracking device for setting up   implements the process according to claim 1 or 2, charac-   terized in that it comprises a torch (18) arranged radially opposite a steel ingot (W), so that the torch and the ingot rotate relative to each other, the circumferential speed of each point varying in radial direction with respect to the ingot, so that the torch ensures the cracking, in all the points in radial direction relative to the ingot, to   different circumferential speeds.   4 Apparatus according to claim 3, characterized in that the torch (18) is fixed and the ingot (W)   rotates under the cylinder control (17).   Apparatus according to claim 3, characterized in that the ingot (W) is fixed and the torch rotates around a circular rail.   6 Apparatus according to claim 4 or 5, characterized   in that the torch (18) has several nozzles   laid radially in relation to the ingot.