FR2585368A1 - METHOD AND DEVICE FOR MANUFACTURING A CONCRETE ROUND - Google Patents

Abstract

MANUFACTURE OF A ROUND OF CONCRETE STEEL. THE ROLLED WIRE IS COOLED ON A COOLING COURSE 2 BEFORE A FIRST WIRE DRIVE 3, THE TEMPERATURE BALANCING BETWEEN THIS LAST AND A SECOND WIRE DRIVE 5. BETWEEN THESE TWO DRIVE 3 AND 5 THE WIRE PASSES THROUGH A GUIDING DEVICE 4. AFTER THE WIRE DRIVE 5 IS PROVIDED A LAYER OF COILS 6 INCLINED OF APPROXIMATELY 10 BY WHICH THE CONCRETE ROUND WHOSE HEAT TREATMENT AND STRUCTURAL FORMATION ARE COMPLETED IS DEPOSITED IN ORDERED COILS. USE IN MODERN WIRE TRAINS.

Description

The invention relates to a method and a device for

  manufacture of a round of concrete steel with

  high tensile strengths and weldability on modern wire trains, the selected steel being heat treated after leaving the

  deny processing stage, a rolling block of wires.

  To meet the requirements of round users

  concrete steel, that is to say for these products to be

  at the same time as a high resistance a good aptitude

  welding, the steel reinforcing steel round is subjected during its

  manufacture on high-speed single-process trains

  temperature, so that a surface layer is formed

  the improved martensite and the core of the steel round

  has a mixed structure of ferrite and pearlite.

  Thus, the DE-PS 23 45 738 presents a thread of

  and a method of making the yarn in which the core of the steel wire comprises fine-banded perlite which is surrounded by a martensite layer having undergone complete recovery on the outer surface of the yarn which, in section

  cross-section, represents a maximum of 33% of the trans-

  versale of the wire. From the heat of rolling, the steel wire, after leaving the finisher group of the wire train, is subjected to a water cooling polyétagé and,

  after being rolled up, is cooled down

  in the open air at room temperature, the wire of

  after having been heated before water-mixed cooling to a temperature of 850 to 910 C and then cooled to below the martensite start temperature on its surface by water cooling in several stages

about 0.2 seconds.

  In another earlier patent, DE-PS 29 00 271, it is

  the fact that the reinforcing steel bars are ribbed and

  on a wire train. In this case too, after

  leaving the finishing group, the rolled product is often

  intensive cooling during which the surface of the rolled product is cooled to a lower temperature

  at the start temperature of the martensite. Cooling

  must be carried out with such an intensity that the equilibrium temperature between the core and the surface is reached before the transformation into bainite, ferrite or perlite can be triggered, the equilibrium temperature

  being in the temperature range where

  kill as early as possible austenite transformation into ferrite and pearlite. After the equilibrium temperature has been reached, the temperature is kept substantially constant until the end of the transformation.

  perlite, then the rolled product is slow

  froidissement. According to this method also, the concrete bar after being cooled on appropriate devices is

  coiled on winders and air-cooled in crowns.

  The disadvantages of known solutions lie in

  the fact that they can only be applied for

  determined lengths and that the rolled product is wound

  making necessary installations and devices necessary

plementary.

  The object of the invention is to propose a method for

  swimming concrete steel rounds taking place in condi-

  normal operating conditions in a wire train which

  can be implemented under good conditions of quality

  and cost using known equipment.

  The problem to be solved consists in creating a method of manufacturing a high-quality concrete ring in crowns having an outer layer of martensite returned for a range of diameters greater than or equal to 10 mm, on high-speed wire trains, with which the concrete bar has an apparent yield strength greater than or equal to 500 MPa, a tensile strength greater than or equal to 570 MPa and a minimum extension of 10%. It is also necessary to create an appropriate device which, thanks to an adapted arrangement, enables the process to be implemented in a train.

with high speed wires.

  This result is obtained by the invention by means of a procedure

  d that takes place on a high-speed wire train such that after leaving the wire rolling block, the concrete ring follows a cooling path supplied with water and that the necessary cooling of the concrete ring is completed when he reached and went through a first

  wire drive installation. Cooling water

  It is brought into the cooling path by suitable devices and under conditions which vary according to the rolled product and the rolling speed.

  Feeding the water cooling path

  only when the end of the rolled wire has passed the cooling path.After the rebar has finished

  drive, it passes through a guide installation.

  in which the necessary balancing of the temperatures between the core and the surface layer takes place, at the same time that an outer layer of complete martensite is formed on the surface of the rolled product and is present in the cross-sectional area. transversal core a ferrite and perlite structure. Then the concrete bar arrives in a second wire drive and receives the kinetic energy necessary to be subsequently deposited by means of a high-quality coil turns on a line of percussion rollers. Then the

  rolled concrete is handed over to a spiral conveyor,

  a second cooling and arrives through the

  of a collecting roller table in a collector duct

  where the concrete slab is laid in marketable crowns. This second cooling is done with

  air and depending on the alloy composition of the

  mined so that the gamma-alpha transformation is performed

practically in the pearlite stage.

  The essential point of the invention is that

  the cooling of the round & concrete is completed before a first

  first wire drive, that the balancing of

  temperatures occur between the first and second dis-

  positive wire drive and then the concrete ring

  has a temperature that makes it easy to train

  turn the turns in the winder by means of the rotating laying tube. At this moment the heat treatment and the

  Structural training of the concrete slab is already complete.

  Another remarkable point of the invention is that the cooling of the steel reinforcing bar is carried out without there having been in the meantime balancing of the temperatures and the necessarily rapid cooling is obtained thanks to

  the fact that the static pressure in the

  cooling constituted by cooling pipes

  elementary elements arranged one behind the other is

  thanks to the fact that the stripping nozzles provided between the cooling pipes are fed with water

  under pressure whose pressure corresponds to the pressure of

  riveted cooling water for the cooling device

  froidissement. Elementary stripping nozzles are available

  at a certain distance from the cooling pipe

  corresponding from the end of the cooling pipe

  until the beginning of the stripping nozzles, is sensitive

  twice as large as the inner diameter of the

  cooling pipe. Balancing is easy

  temperatures by driving off the concrete slab, before it enters the balancing zone, the cooling water

  by means of pressurized water and compressed air. For this

  re it is expected after the last cooling pipe

  and before the guiding device a water nozzle and a bu-

air.

  In the device according to the invention there are provided two wire drive devices arranged in the high-speed wire train. A first wire drive is disposed behind the cooling path and a second wire drive is disposed

  before the coil setter. Between the two devices

  wire feed is provided a guiding device, said guide chute, made of cast iron castings.It

  It is also provided according to the invention that the

  cooling is constituted by cooling pipes

  elementary schools with corresponding baffles and it is

  between the cooling tubes of the stripping nozzles

  page fed with water under pressure while

  before the guide chute, a water nozzle and a

air.

  Another remarkable point of the invention consists in

  that the coil setter is inclined by about 10.

  It also belongs to the invention the particular shape

  re of the outlet opening of the rotary laying tube in the winder. In this case, it is particularly taken into account that, for different temperatures,

  the cooled concrete reinforcing bar has different rigidities

  fences that cause differences in deposition during the deployment and laying of the turns. To remedy this, the laying pipe is beveled at an angle on the outlet side and is provided with a flat baffle plate. The angle is about 3 to 5 while the distance c is 3 to 5 mm. This distance c is the distance between the middle of the laying pipe and the baffle plate measured at the opening

  of exit, one can naturally also provide a chamfer-

  bilaterally and in this case also the mounting of

baffle on both sides.

  The concrete slab manufactured by this method on a train

  high-flow yarn has been thermally treated in

  propriety and present in the field of quality of

  an apparent elastic limit greater than or equal to

  500} Pa, an equal or superior tensile strength value

  less than 570 MPa and a minimum extension of 10%. This concrete slab also has good weldability. The advantage obtained from the arrangement of two wire drive devices is that they are adjusted relative to one another so that the traction exerted on the concrete bar between the drive devices wire is just enough to pull the concrete bar through the

  guiding device without risking buckling and for

  put a pose of turns of good quality.

  The features and advantages of the invention

  from the following description,

  for example, with reference to the appended drawing in which:

  FIG. 1 schematically represents the part of

  plant for the heat treatment of the concrete slab; Figure 2 is a longitudinal sectional view of a portion of the cooling path;

  FIG. 3 shows in section detail A of FIG.

re 2;

  FIG. 4 shows in section detail B of FIG.

  re 2; Figure 5 is an elevational view of the fixing of the laying pipe of the coil setter; Figure 6 is a section along line C-C of Figure 5 shown rotated; FIG. 7 is a section along line D-D of FIG.

Figure 5 shown tour.

  The overview of the heat treatment part of a high-speed wire rolling mill is shown in FIG. 1. Following the rolling block 1 shown is placed the cooling path 2 which is followed by

  first wire drive, that is to say the

  3, the guide device 4 which is con-

  formed by an assembly of cast iron moldings forming a guide chute, and a wire trainer 5 forming the

  second thread drive device. The spider

  6 is further inclined at an angle of 10 following the wire drive 5. Further downstream there is successively provided a line of percussion rollers 7, a spiral conveyor 8, a collection roller line 9 and further this collector casing 11 with collecting mandrel 10. In the collector casing 11 is a scissors shear 12.

  air cooling device 19 is located in

  under the spiral conveyor 8. The round of concrete steel that

  we will designate from now on by the name of

  mine whose final rolling was carried out in the block of

  Wire rolling 1 enters the cooling path-

  It is cooled so that a layer of surface martensite of a determined thickness is formed. The first wire coach 3 located behind the course of

  The role of cooling is to overcome the braking force

  This is due to the cooling water acting on the rolled wire and ensuring that the movement of the rolled wire continues without incident. This is done in a device

  4 and in the second fifth wire trainer

  The distance between the end of the cooling path 2 and the coil setter 6 is such that the travel time of the rolled wire is sufficient to complete the balancing of the wires. temperatures between the core and the superficial zone and thus complete the necessary income of the layer of marten-

  superficial site. This is necessary for the training

  turns in the coil setter 6 is carried out without

  obstacle, the rolled wire in front of it to present a re-

  resistance to deformation as small as possible. It is essentially the second lead trainer 5 that ensures

  the movement of the rolled wire through the rotatable laying tube 22

  6. Under the action of the coil setter 6, the rolled wire is continuously deposited in elementary turns on a moving drum train 7 and is put back on the coil conveyor 8 where it is transferred by the collecting roller train 9 to the collecting sheath 11 o the wire ring is formed on the collecting mandrel

  10. The ends of rolled wire of unsatisfactory quality

  te, for example uncooled, can be cut with the

  shear to be cropped 12 and then removed separately.

  Figure 2 shows the structure of the route of

  2. The cooling path 2 is con-

  here by several cooling pipes 13 elemen-

  which are mounted on prisms 21 and housed in tanks 20. Behind each of the cooling pipes 13 which are followed by other cooling pipes 13 is disposed a stripping nozzle 14. Behind the last of the

  cooling pipes 13 a stripping nozzle is provided

  combined page consisting of a water nozzle 17 and an air nozzle 18, the air nozzle 18 being disposed behind the water nozzle 17. The water nozzle 17 here plays the same role and at the same

form as the stripping nozzle 14.

  The cooling of the rolled wire is carried out in a manner known per se in the different cooling pipes 13 arranged one behind the other by feeding the cooling pipes 13 in cold water in the direction of

  walking laminated wire. The strengthening of the cooling effect

  Dilation by increasing the turbulence of the water passing through the pipes is obtained by mounting in the pipes of the turbulence-enhancing elements. The cooling of the rolled wire is thus carried out at a cooling speed

  maximum by reducing to a minimum the braking force acting

  on the rolled wire. For this purpose, the ratio between the inside diameter of the cooling pipe D and the diameter of the rolled wire d must not be greater or less than

  a value of 2 to 3. To constantly maintain the wire

  born in the center of the cooling pipe 13 in order to get

  uniform cooling of this wire on its trans-

  the wire passes through guide bushes 15 (FIG.

  re 3) inside the cooling pipe head

  13 and in guides 16 inside the stripping nozzle

  page 14, the water nozzle 17 and the air nozzle 18 (Figure 4). The inside diameter D of guide bushes 15 and guides 16 must be with the rolled wire diameter d in a ratio which must not be greater or less than a value of 1.5 to 2.5. Cooling hoses 13

  mounted behind each other provide cooling

  uninterrupted rolled wire without being carried out in between balancing temperatures. To obtain the necessary cooling speed, the static pressure

  in the cooling pipe 13 is increased in

  both stripping nozzles 14 arranged between the pipes of

  cooling 13 with pressurized water whose pressure

  is the inlet pressure of the cooling water

  drainage for the cooling pipe 13 and giving

  at the distance a between the end of the cooling pipe

  13 and the beginning of the stripping nozzle 14 or the water nozzle 17 is twice the value of the inside diameter of the cooling pipe 13. To obtain an assured stripping

  cooling water after the last hose

  cooling 13 that is to say at the end of the cooling path 2, and thus ensure in any event the necessary balancing of temperatures, the stripping of the cooling water is performed with water by the

  water nozzle 17 and with air through the air nozzle. The pressure

  the water in the water nozzle 17 has a value that is one and a half times greater than the water inlet pressure

  cooling at the last cooling pipe 13.

  Figure 5 shows the coil setter 6 with the laying tube 22 and the baffle 23 disposed at the outlet of the laying tube. When laminating a thermally solidified concrete slab with a surface layer of tempered martensite, it is necessary for the water cooling process to be triggered

  only after the beginning of the rolled wire has been

  if by the lead trainer 3. Given that the setting

  When the cooling water is cooked in a very short time, there is a very abrupt transition between the beginning of uncooled wire and the cooled wire which follows. To minimize the scrap part, this transition is an advantage, but the difference in

  resulting wire stiffness also causes a change in

  sudden quotation of speed A at which the turns of

  wire from the coil setter 6. This phenomenon has been

  in the practice of rolling operation can be explained by the fact that, due to the greater rigidity of the cooled wire, its guiding conditions in the laying tube 22 are modified. If the rolled wire is not cooled below 800-750 ° C, its guidance is stably in zone b of the outlet opening of the tube

laying (Figure 6).

  If the cooling is pushed to a temperature of

  equal to or less than 6000C the increase in stiffness

  wire leads to a modification of the path in the tu-

  pose, which in the extreme case may even be

  placed on the other inner side of the tube and this ex-

  the change in the output speed of the wire from the winder 6. There is an increase in

  the exit angle, that is to say the pitch of the turns of the wire.

  If starting from a current inside diameter of the laying tube

  22 equal to 35 to 40 mm, this change of pace is considered

  saddle. Due to the very short time required to turn on the cooling water as well as

  mentioned above, this phenomenon leads to overlapping

  harmful to quality, turns of wire on the

  percussion roll train 7 and on the spider conveyor

  res 8 following the setter of turns 6 and then is the

  cause of operational incidents in the collector

  11. The wire turns cooled to about 6000C

  and in some way exceed those which are not cooled. In order to prevent these overlaps of wire turns, it is provided according to the invention that at the outlet of the laying tube a baffle 23 is mounted. For this purpose, the laying tube 22 is preferably chamfered at an angle (from 3 to 50. The lateral opening of the laying tube thus formed is closed by a plane baffle plate 23 which extends to a distance c of 3 to 5 mm from the middle of the tube (FIG. can not be pushed back or jammed in the laying tube 22. When the water cooling starts, the wire is guided by the baffle plate 23, which means that the pitch change is halved and that

  recoveries detrimental to the collection of turns are thus

if avoided.

Claims (9)

  1. Device for manufacturing on a high-speed wire trains of a round of concrete steel which has good welding properties, and undergoes heat treatment as a result of which it forms in the cross-section of the core a structure of ferrite and perlite while the surface has a closed back martensite layer, characterized in that the cooling of the   rolled wire is finished before a first training device   wire, that the temperature equilibration is effected between the first and a second wire drive device and that the concrete steel round thus produced   then a temperature which ensures a formation without   spirals, heat treatment and the formation of   the structure of the concrete slab was already completed at that time.   the. 2. Method according to claim 1, characterized in that after spinning the concrete bar, it undergoes a new air cooling, cooling eéant conducted according to the alloy content of the rolled wire, so that the gamma-alpha conversion is carried out in full on the perlite floor.   3. Method according to claim 1, characterized in that the cooling of the steel round is carried out uninterruptedly and without it being meanwhile carried out at a time.   balancing of temperatures and getting a cooling   fast quenching by increasing the static pressure   cooling water using stripping devices   page fed with water under pressure.   Device for carrying out the method according to claim 1, characterized in that in the part of the heat treatment plant located behind the cooling path (2) which is formed by cooling pipes ( 13), there is provided a first wire drive (3) and a guide device (4) and a second wire drive (5) is arranged following the guide device (4) but before   the coil setter (6) inclined by 10.   5. Device according to claim 4, characterized   in that the cooling pipes (13) are   on prisms (21) and arranged in tanks (20) and between the different cooling pipes (13) are arranged stripping nozzles (14) fed at the same pressure as that of the cooling water while disposed between the last cooling pipe (13) and the guiding device (4) a combined stripping nozzle   constituted by a water nozzle (17) fed under a pressure   equal to one and a half times the pressure of the cooling water   and by an air nozzle (18).   6. Device according to claim 5, characterized in that the stripping nozzles (14) and the water nozzles   (17) play the same role and have the same form and are   at a determined distance from the end of the corresponding cooling pipe (13), this distance (a) being   equal to twice the inside diameter of the cooling pipes dissement (13).   7. Device according to claim 5, characterized by   the fact that it is provided in the heads of the cooling pipes   directing (13) of the guide bushes (15) and that the stripping nozzles (14) and the water (17) and air (18) nozzles have guides whose inside diameter (D ') is with the diameter of rolled wire (d) in a ratio of 1.5   up to 2.5, which must not be exceeded either above or below   souse. 8. Device according to claim 4, characterized in that the cooling pipes (13) have an inner diameter (D) which is in a ratio of 2 to 3 with the diameter (d) of the rolled wire, this ratio does not to be in front   exceeded neither above nor below.   9. Device according to claim 4, characterized in that the coil setter (6) is equipped with a laying tube (22) whose outlet orifice is narrowing and is   provided with a baffle plate (23) which is close to the original   fice output to a distance c = 3 to 5 mm and that is   disposed at an angle dC = 3 to 5e.