EP0347699B1 - Verfahren und Vorrichtung zum Einstellen eines homogenen austenitischen Gefüges - Google Patents

Verfahren und Vorrichtung zum Einstellen eines homogenen austenitischen Gefüges Download PDF

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Publication number
EP0347699B1
EP0347699B1 EP89110580A EP89110580A EP0347699B1 EP 0347699 B1 EP0347699 B1 EP 0347699B1 EP 89110580 A EP89110580 A EP 89110580A EP 89110580 A EP89110580 A EP 89110580A EP 0347699 B1 EP0347699 B1 EP 0347699B1
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EP
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Prior art keywords
wire
tube
gas
temperature
pearlitisation
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English (en)
French (fr)
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EP0347699A1 (de
Inventor
André Reiniche
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Compagnie Generale des Etablissements Michelin SCA
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Compagnie Generale des Etablissements Michelin SCA
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    • 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
    • C21D9/56—Continuous furnaces for strip or wire
    • C21D9/63—Continuous furnaces for strip or wire the strip being supported by a cushion of gas
    • 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
    • C21D9/56—Continuous furnaces for strip or wire
    • C21D9/561—Continuous furnaces for strip or wire with a controlled atmosphere or vacuum
    • 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
    • C21D9/64—Patenting furnaces

Definitions

  • the invention relates to methods and devices for thermally treating carbon steel wires so as to obtain a homogeneous austenite structure, these wires being for example capable of undergoing another heat treatment to obtain a fine pearlitic structure. .
  • Document DE-A-2 111 631 describes a device for thermally treating metal wires so as to obtain a pearlitic structure. At the start of this treatment, the wires pass through a combustion oven or an electric oven to undergo an austenitization. The wires thus reach a temperature of 900 ° C to 1000 ° C.
  • Patent EP-B-0 326 005 describes a process and a device making it possible to heat treat at least one carbon steel wire so as to obtain a fine pearlitic structure by passing the wire through at least one tube containing a gas practically without forced ventilation, the tube being surrounded by a heat transfer fluid.
  • the object of the invention is to obtain heating times of less than 4 seconds per millimeter of wire diameter, during an austenitization treatment, which makes it possible to have higher production rates than with known installations, and which also makes it possible to reduce the lengths of the installations.
  • the invention also relates to the methods and complete installations for heat treatment of carbon steel wires using the methods and / or the devices described above.
  • FIG. 1 is a section of the device 100 along the axis xx ′ of this device
  • FIG. 2 is a section perpendicular to this axis xx ′, the section of FIG. 2 being shown diagrammatically by the straight line segments II-II to Figure 1.
  • the device 100 comprises a tube 2, for example ceramic, refractory steel or tungsten carbide, in which the wire 1 runs in carbon steel along arrow F, along the axis xx ′.
  • the wire drive means 1 are known means not shown in these Figures 1 and 2 for the purpose of simplification, these means comprising for example a winder actuated by a motor, for winding the wire after treatment.
  • the space 3 between the wire 1 and the internal wall 20 of the tube 2 is filled with a gas 4.
  • This gas 4 is directly in contact with the wire 1 and the internal wall 20.
  • the gas 4 remains in the space 3 during the treatment of the wire 1, the device 100 being devoid of means capable of allowing forced ventilation of the gas 4, that is to say that the gas 4 without forced ventilation is possibly set in motion in space 3 as by the displacement of the wire 1 according to arrow F.
  • This gas is for example hydrogen, a mixture of hydrogen and nitrogen, a mixture of hydrogen and methane, a mixture of hydrogen, nitrogen, and methane, helium, a mixture of helium and methane.
  • the wire 1 is guided by two wire guides 5, for example made of ceramic or tungsten carbide located at the entry and the exit of the wire 1 in the tube 2.
  • the tube 2 is heated externally by an electric resistance 6 wound around the tube 2 and outside this tube 2 against the external wall 21 of the tube 2.
  • the tube 2 is thermally insulated from the outside by the sleeve 7 surrounding the tube 2 and by the two plates 8 located at the ends of the tube 2.
  • Tube 2 is also electrically isolated in case where it is metallic.
  • the plates 8 and the sleeve 7 are for example made with sintered refractory fibers.
  • the tube 2, the heating resistor 6, the sleeve 7 and the plates 8 are placed inside a metal tube 9 which is cooled by a hollow tube 10 wound around the tube 9, this hollow tube 10 being traversed by a cooling fluid 11, for example water.
  • the device 100 is closed at both ends by circular plates 12 which are applied to the flanges 90 of the tube 9, by means of gas-tight seals 13.
  • the sealed passage 14 allows the electrical supply of the resistor 6.
  • This passage 14 is crossed by two electric wires 15 each connected to one end of the resistor 6 (this connection is not shown in the drawing for the purpose of simplification) .
  • This sealed passage 14 is fixed to one of the two circular plates 12 with gas-tight seals 16.
  • the device 100 comprises an expansion clearance 17, the springs 18 act on the plate 19 serving for the distribution of the forces, which makes it possible to maintain the tube 2 in the middle of the sleeve 7 whatever its temperature.
  • D f represents the diameter of the wire 1
  • D ti represents the internal diameter of the tube 2 (diameter of the internal wall 20)
  • D te represents the external diameter of the tube 2 (diameter of the external wall 21).
  • ⁇ is the conductivity of gas 4 determined at 800 ° C, this conductivity being expressed in watts.m ⁇ 1. ° K ⁇ 1.
  • the invention thus makes it possible, unexpectedly, to heat the wire 1 from a temperature below the transformation temperature AC3, for example from ambient temperature, to a temperature above the transformation temperature AC3, so as to obtain a homogeneous austenite structure, and this for a very short time less than 4 seconds per millimeter in diameter of the wire D f .
  • the nature of the gas 4 so that it exerts a chemical action on the surface of the wire, for example a deoxidizing, fuel or decarburizing action.
  • the ratio R is close to 1 and the use of a very good heat conducting gas, for example hydrogen, then becomes necessary.
  • the diameter D f of the wire is at least equal to 0.4 mm and at most equal to 6 mm.
  • FIGS. 3 and 4 represent another device 200 according to the invention, this device making it possible to simultaneously treat several wires 1, for example six, FIG. 3 being a section of this device along the axis yy ′ of this device and the FIG. 4 being a section perpendicular to the axis of this device, the axis yy ′ being represented by the reference "y" in FIG. 4.
  • the structure of this device 200 is similar to that of the device 100 with the difference that six tubes 2 are arranged in the enclosure 9 constituted by a steel tube, around the axis yy ′ which is the axis of this tube 9.
  • a wire 1 passes through each tube 2, the gas 4 being placed inside the tubes 2 which are each heated by a resistor 6 as previously described for the device 100, the insulating sleeve 7 being arranged around the six tubes 2 .
  • the diameter D f of the wire 1 and the nature of the gas 4 which is a mixture of hydrogen and nitrogen are varied and therefore the values of ⁇ , R and K.
  • the following table 2 gives the values of D f , the volumetric% of gas 4 in hydrogen, the values of ⁇ , R, K, as well as the production of wire 1.
  • the heating time per millimeter of wire diameter (T c / D f ) varies from 1.46 to 3.1 sec / mm; Table 2 Wire diameter 1 (mm) (D f ) R % H2 ⁇ at 800 ° C (Wm ⁇ 1. ° K ⁇ 1) K Yarn production 1 in kg / hour 1.75 1.43 100 0.487 2.24 158.0 1.55 1.61 98 0.472 2.43 124.0 1.30 1.92 90 0.418 2.64 87.0 0.94 2.66 69 0.297 2.91 45.8 0.82 3.05 62 0.263 2.85 35.0
  • a multitubular device similar to the device 200 described above is used, but with ten tubes 2.
  • This example is carried out under the same conditions and with the same results as example n ° 2 but by replacing the cracked ammonia with a gas 4 maintaining the thermodynamic equilibrium with the carbon of the steel at 800 ° C., this gas 4 having the following composition (% by volume): 74% hydrogen; 24% nitrogen; 2% methane.
  • This example is carried out under the same conditions as example n ° 2 but the cracked ammonia is replaced by a fuel gas making it possible to correct a decarburization which occurred in the previous operations.
  • the composition of gas 4 is as follows in this example (% volumetric): 85% hydrogen, 15% methane.
  • the other conditions and results are the same as for Example 2 with the following differences: the heating time goes from 2.97 to 2.75 seconds, the ratio T c / D f then being equal to 1.57 sec / mm, the wire running speed is 2.18 m / sec. a thickness of superficial recarburization is obtained on the order of 2 ⁇ m. No graphite deposition is observed on wire 1.
  • the invention makes it possible to obtain a very precise wire temperature at the outlet of the treatment, this temperature not varying by more than 1.5 ° C. by excess or by default of the temperature indicated at the outlet of the tubes 2, for the examples 1 to 8, which guarantees good consistency in the quality of the wire.
  • Examples 9 to 12 which follow are produced in a device similar to the device 100 previously described, but these examples are not in accordance with the invention.
  • the characteristics of the wire 1 and of this device are given in the following table 3. These examples are characterized by a ratio T c / D f notably greater than 4 seconds per mm of diameter of the wire, the values of the ratios R and K not corresponding to the set of relations (1) and (2) previously indicated and the austenitization does not can not then be performed with the advantages described above.
  • FIG. 6 represents the curve ⁇ showing the evolution of the temperature of the steel wire 1 as a function of time, when this wire crosses the zones Z2 to Z5.
  • This figure also represents the curve x1 corresponding to the start of the transformation of metastable austenite into perlite and the curve x2 corresponding to the end of the transformation of metastable austenite into perlite, for the steel of this wire.
  • the abscissa axis corresponds to time T and the ordinate axis corresponds to temperature ⁇ , the origin of times corresponding to point A.
  • the wire 1 Prior to the pearlitization treatment, the wire 1 is heated and maintained at a temperature higher than the transformation temperature AC3 so as to obtain a homogeneous austenite, this temperature ⁇ A , for example between 900 ° C and 1000 ° C, corresponding to point A in FIG. 6.
  • the point known as "pearlitic nose” corresponds to the minimum time T m of the curve x1, the temperature of this pearlitic nose being referenced ⁇ P.
  • the wire 1 is then cooled until it reaches a temperature below the transformation temperature AC1, the state of the wire after this cooling corresponding to point B, the temperature obtained at this point B at the end of time T B being referenced ⁇ B.
  • This temperature ⁇ B has been shown in FIG. 6 as being higher than the temperature ⁇ P of the pearlitic nose, which is the most frequent in practice, without being absolutely necessary.
  • This cooling of the wire between points A and B there is transformation of stable austenite into metastable austenite, as soon as the temperature of the wire drops below the transformation point AC3, and "seeds" appear at the grain boundaries of the metastable austenite.
  • the area between the curves x1, x2 is referenced ⁇ .
  • Perlitization consists in passing the thread from the state represented by point B, to the left of zone ⁇ , to a state represented by point C, to the right of zone ⁇ .
  • This transformation of the wire is for example shown diagrammatically by the straight line segment BC which intersects the curve x1 at B x and the curve x2 at C x , but the invention also applies to cases where the variation in temperature of the wire between the points B and C is not linear.
  • the wire is cooled, for example to room temperature, this cooling, preferably rapid, being shown diagrammatically for example by the curved line segment CD, the temperature at D being referenced ⁇ D.
  • the zone Z1 corresponds to the heating of the wire 1 to bring it to the state corresponding to the point A
  • the zone Z2 corresponds to the cooling represented by the portion AB of the curve ⁇
  • the zone Z3 corresponds to the portion BC of the curve ⁇
  • the zones Z4 and Z5 together correspond to the cooling represented by the portion CD of the curve ⁇ .
  • the zone Z1 is produced for example with the device 100 according to the invention described above.
  • the zone Z2 is produced for example in accordance with the French patent application n ° 88/00904.
  • the device 32 corresponding to this zone Z2 is shown in FIGS. 7 and 8.
  • This device 32 is a heat exchanger comprising an enclosure 33 in the form of a tube with an internal diameter D ′ ti and an external diameter D ′ te in which the wire 1 to be treated travels along the arrow F, of diameter D f .
  • FIG. 7 is a section taken along the axis xx ′ of the wire 1 which is also the axis of the device 32
  • FIG. 8 is a section made perpendicular to this axis xx ′, the section of FIG. 8 being shown diagrammatically by the straight line segments VIII-VIII, in FIG. 7, the axis xx ′ being shown diagrammatically by the letter "x" in FIG. 8.
  • the space 34 between the wire 1 and the tube 33 is filled with a gas 35 which is directly in contact with the wire 1 and the inner wall 330 of the tube 33.
  • the gas 35 remains in the space 34 during the treatment of the wire 1, the device 32 being devoid of means capable of allowing forced ventilation of the gas 35, that is to say that the gas 35 practically without forced ventilation is possibly set in motion in the space 34 only by the displacement of the wire 1 according to arrow F.
  • ⁇ ′ is the conductivity of gas 35 d complete at 600 ° C. This conductivity is expressed in watts.m ⁇ 1.
  • the wire 1 is guided by two wire guides 36 made for example of ceramic or tungsten carbide, these guides 36 being located one at the inlet, the other at the outlet of the wire 1 in the tube 33.
  • the tube 33 is cooled externally by a heat transfer fluid 37, for example water circulating in an annular sleeve 38 which surrounds the tube 33.
  • This sleeve 38 has a length L ′ m , an internal diameter D ′ mi , an external diameter D ′ Me .
  • the sleeve 38 is supplied with water 37 through the tubing 39, the water 37 leaves the sleeve 38 through the tubing 40, the flow of water 37 along the tube 33 thus taking place in the opposite direction to the direction F
  • the seal between the zone 41 containing water 37 (interior volume of the sleeve 38) and the space 34 containing the gas 35 is obtained using seals 42 produced for example in elastomers.
  • the length of the tube 33 in contact with the fluid 37 is referenced L ′ t in FIG. 7.
  • the exchanger 32 can in itself constitute a device for the zone Z2. It is also possible to assemble several exchangers 32, along the axis xx ', by means of the flanges 43 constituting the ends of the sleeve 38, the wire 1 then passing through several exchangers 32 arranged in series along the axis xx'.
  • the gas 35 is for example hydrogen, nitrogen, helium, a mixture of hydrogen and nitrogen, hydrogen and methane, nitrogen and methane, helium and methane, d 'hydrogen, nitrogen and methane.
  • the ratio R 'between the internal diameter D' ti and the diameter D f of the wire must be close to 1, and the use of a very conductive gas 35, for example hydrogen , becomes necessary.
  • the zone Z3 of the installation 300 is produced for example by using several exchangers 32 arranged in series, under the conditions described below.
  • the steps of transformation of the wire 1 shown diagrammatically by the line BC in FIG. 1 are carried out at a temperature which varies as little as possible, the temperature of the wire 1, for example, not differing by more than 10 ° C by excess or by default of the temperature ⁇ B obtained after the cooling shown diagrammatically by the line AB.
  • This limitation of the variation in temperature is therefore carried out for a time greater than the pearlitization time, this pearlitization time corresponding to the segment B x C x .
  • the temperature of the wire 1 does not differ by more than 5 ° C by excess or by default of the temperature ⁇ B on this line BC.
  • FIG. 6 represents for example the ideal case where the temperature is constant and equal to ⁇ B during the stages shown diagrammatically by the line BC which is therefore a line segment parallel to the abscissa axis.
  • This modulation can preferably be carried out by varying either the internal diameter D ′ ti of the tubes 33 through which the wire passes, or the length L ′ t of the various tubes 33 through which the wire passes, as described in the patent application French aforementioned No. 88/00904.
  • the zone Z4 is constituted for example by an exchanger 32 verifying the relationships (3) and (4) previously defined.
  • the wire 1 then enters the zone Z5 where it is brought to a temperature close to ambient temperature, by example from 20 to 50 ° C, by immersion in water.
  • the wire 1 treated in the installation 300 has the same structure as that obtained by the known lead patenting process, that is to say a fine pearlitic structure.
  • This structure consists of cementite lamellae separated by ferrite lamellae.
  • FIG. 9 represents in section a portion 50 of such a fine pearlitic structure.
  • This portion 50 comprises two substantially parallel cementite lamellae 51 separated by a ferrite lamella 52.
  • the thickness of the cementite lamellae 51 is represented by "i” and the thickness of the ferrite lamellae 52 is represented by "e”.
  • the pearlitic structure is fine, that is to say that the average value i + e is at most equal to 1000 ⁇ , with a standard deviation of 250 ⁇ .
  • Such a wire can be used, for example, to reinforce articles made of plastics or rubbers, in particular tire casings.

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Claims (27)

  1. Verfahren zur thermischen Behandlung von mindestens einem Draht (1) aus Kohlenstoffstahl, zur Erzeugung eines homogenen Austenitgefüges, das folgende Merkmale aufweist:
    a) Erhitzen des Drahts (1) durch Führen durch mindestens ein Rohr (2), das ein Gas (4) praktisch ohne Zwangsventilation enthält, wobei das Gas (4) in direktem Kontakt mit dem Draht (1) steht und die Erhitzungszeit des Drahts unter 4 Sekunden pro Millimeter Drahtdurchmesser liegt;
    b) die Kenngrößen des Rohrs (2), des Drahts (1) und des Gases (4) so gewählt sind, daß folgende Beziehungen eingehalten werden:

    1,05 ≦ R ≦ 7   (1)
    Figure imgb0058

    0,6 ≦ K ≦ 8   (2)
    Figure imgb0059

    mit den Definitionen

    R = D ti /D f
    Figure imgb0060
    K = [Log(D ti /D f )] x D f ²/λ,
    Figure imgb0061

    wobei Dti den Innendurchmesser des Rohrs, ausgedrückt in Millimetern, Df den Durchmesser des Drahts, ausgedrückt in Millimetern, λ die Wärmeleitfähigkeit des Gases, gemessen bei 800 °C, ausgedrückt in Watt/mK und Log den natürlichen Logarithmus bedeuten.
  2. Verfahren nach Anspruch 1,
    dadurch gekennzeichnet, daß
    das Rohr (2) von außen durch einen elektrischen Widerstand (6) erhitzt wird.
  3. Verfahren nach Anspruch 1 oder 2,
    dadurch gekennzeichnet, daß
    das Gas (4) im thermodynamischen Gleichgewicht mit dem Kohlenstoff des Stahls des Drahts (1) ist.
  4. Verfahren nach Anspruch 1 oder 2,
    dadurch gekennzeichnet, daß
    das Gas (4) eine oberflächliche Recarbonisierung des Stahls des Drahts ermöglicht.
  5. Verfahren nach einem der Ansprüche 1 bis 4,
    dadurch gekennzeichnet, daß
    das Gas eine reduzierende Wirkung auf die Oberfläche des Drahts (1) hat.
  6. Verfahren nach einem der Ansprüche 1 bis 5,
    dadurch gekennzeichnet, daß
    anschließend eine Perlitisierungsbehandlung auf dem Draht (1) vorgenommen wird.
  7. Verfahren nach Anspruch 6,
    das folgende Merkmale aufweist:
    c) Abkühlen des Drahts (1) von einer Temperatur oberhalb der Umwandlungstemperatur AC3 bis auf eine Temperatur unterhalb der Umwandlungstemperatur AC1;
    d) anschließende Durchführung der Perlitisierungsbehandlung bei einer Temperatur unterhalb der Umwandlungstemperatur AC1;
    e) Durchführung dieser Abkühlungs- und Perlitisierungsbehandlung durch Führen des Drahts (1) durch mindestens ein Rohr (33), das ein Gas (35) praktisch ohne Zwangsventilation enthält, wobei das Rohr von einem Wärmeträgerfluid umgeben ist, so daß eine Wärmeübertragung vom Draht über das Gas und das Rohr auf das Wärmetauscherfluid abläuft;
    f) die Kenngrößen des Rohrs (33), des Drahts (1) und des Gases (35) sind so gewählt, daß mindestens während der Abkühlung vor der Perlitisierung die folgenden Beziehungen eingehalten werden:

    1,05 ≦ R' < 15   (3)
    Figure imgb0062

    5 ≦ K' ≦ 10   (4)
    Figure imgb0063

    mit den Definitionen

    R' = D' ti /D f
    Figure imgb0064
    K' = [Log(D' ti /D f )] x D f ²/λ' ,
    Figure imgb0065

    wobei D'ti den Innendurchmesser des Rohrs, ausgedrückt in Millimetern, Df den Durchmesser des Drahts, ausgedrückt in Millimetern, λ' die Wärmeleitfähigkeit des Gases, gemessen bei 600 °C, ausgedrückt in W/mK und Log den natürlichen Logarithmus bedeuten.
  8. Verfahren nach Anspruch 7,
    dadurch gekennzeichnet, daß
    nach Abkühlen des Drahts (1) von einer Temperatur oberhalb der Umwandlungstemperatur AC3 auf eine gegebene Temperatur unterhalb der Umwandlungstemperatur AC1 der Draht während einer Zeit, die größer ist als die Perlitisierungszeit, auf einer Temperatur gehalten wird, die um nicht mehr als 10 °C nach oben oder unten von dieser gegebenen Temperatur abweicht, unter Modulation des Wärmeaustausches, wobei in dem oder den Abschnitten des oder der Rohre (33), in denen die Perlitisierungsgeschwindigkeit am größten ist, folgende Beziehungen eingehalten werden:

    1,05 ≦ R' ≦ 8   (5)
    Figure imgb0066

    3 ≦ K' ≦ 8   (6).
    Figure imgb0067
  9. Verfahren nach Anspruch 8,
    dadurch gekennzeichnet, daß
    der Draht (1) auf einer Temperatur gehalten wird, die um nicht mehr als 5 °C nach oben oder unten von dieser gegebenen Temperatur abweicht.
  10. Verfahren nach Anspruch 8 oder 9,
    dadurch gekennzeichnet, daß
    die Modulation durch Verändern des Innendurchmessers (D'ti) des Rohrs (33) oder mindestens eines Rohrs (33) durchgeführt wird.
  11. Verfahren nach einem der Ansprüche 8 bis 10,
    dadurch gekennzeichnet, daß
    die Modulation durch Verwendung mehrerer Rohre (33) durchgeführt wird, deren Länge (L't) verändert wird.
  12. Verfahren nach einem der Ansprüche 6 bis 11,
    dadurch gekennzeichnet, daß
    anschließend der Draht (1) abgekühlt wird.
  13. Vorrichtung (100) zur thermischen Behandlung von mindestens einem Draht (1) aus Kohlenstoffstahl zur Erzeugung eines homogenen Austenitgefüges, wobei die Vorrichtung folgende Merkmale aufweist:
    a) Sie umfaßt mindestens ein Rohr (2) und Mittel, die es ermöglichen, den Draht durch das Rohr zu führen; das Rohr (2) enthält ein Gas (4) praktisch ohne Zwangsventilation in direktem Kontakt mit dem Draht, wobei die Vorrichtung Mittel zum Erhitzen des Gases umfaßt; die Mittel, die es ermöglichen, den Draht durch das Rohr zu führen sind so, daß die Kontaktzeit des Drahts mit dem Gas kleiner als 4 Sekunden pro Millimeter Drahtdurchmesser ist;
    b) die Kenngrößen des Rohrs (2), des Drahts (1) und des Gases (4) sind so gewählt, daß folgende Beziehungen eingehalten werden:

    1,05 ≦ R ≦ 7   (1)
    Figure imgb0068

    0,6 ≦ K ≦ 8   (2)
    Figure imgb0069

    mit den Definitionen

    R = D ti /D f
    Figure imgb0070
    K = [Log(D ti /D f )] x D f ²/λ,
    Figure imgb0071

    wobei Dti den Innendurchmesser des Rohrs, ausgedrückt in Millimetern, Df den Durchmesser des Drahts, ausgedrückt in Millimetern, λ die Wärmeleitfähigkeit des Gases, gemessen bei 800 °C, ausgedrückt in Watt/mK und Log den natürlichen Logarithmus bedeuten.
  14. Vorrichtung (100) nach Anspruch 13,
    dadurch gekennzeichnet, daß
    sie einen elektrischen Widerstand (6) aufweist, der außen am Rohr angebracht ist, um es zu erhitzen.
  15. Vorrichtung (100) nach Anspruch 13 oder 14,
    dadurch gekennzeichnet, daß
    das Gas (4) in thermodynamischem Gleichgewicht mit dem Kohlenstoff des Stahls des Drahts ist.
  16. Vorrichtung (100) nach Anspruch 13 oder 14,
    dadurch gekennzeichnet, daß
    das Gas (4) eine oberflächliche Recarbonisierung des Stahls des Drahts (1) ermöglicht.
  17. Vorrichtung (100) nach einem der Ansprüche 13 bis 16,
    dadurch gekennzeichnet, daß
    das Gas (4) eine reduzierende Wirkung auf die Oberfläche des Drahts (1) ausüben kann.
  18. Vorrichtung (200) nach einem der Ansprüche 13 bis 17,
    dadurch gekennzeichnet, daß
    sie eine Umhüllung (9) aufweist, in der mehrere Rohre (2) angeordnet sind.
  19. Vorrichtung (100, 200) nach einem der Ansprüche 13 bis 18, dadurch gekennzeichnet, daß der Durchmesser (Df) des Drahts (1) sich von 0,4 bis 6 mm ändert.
  20. Vorrichtung (100, 200) nach einem der Ansprüche 13 bis 19, dadurch gekennzeichnet, daß
    sie die Behandlung von Drähten (1) mit einem Verhältnis der Durchmesser Df von 1 bis 5 ermöglicht.
  21. Einrichtung (300) zur thermischen Behandlung von mindestens einem Draht (1) aus Hohlenstoffstahl, die mindestens eine Vorrichtung (100, 200) gemäß einem der Ansprüche 13 bis 20 umfaßt.
  22. Einrichtung (300) zur thermischen Behandlung nach Anspruch 21,
    dadurch gekennzeichnet, daß
    sie nach der Austenitisierungsvorrichtung (100, 200) Mittel umfaßt, die es ermöglichen, den Draht (1) abzukühlen und ein feines perlitisches Gefüge zu erhalten, wobei diese Mittel folgende Merkmale aufweisen:
    c) Diese Mittel zur Abkühlung und Perlitisierung umfassen mindestens ein Rohr (33), das ein Gas (35) praktisch ohne Zwangsventilation enthält, wobei das Rohr von einem Wärmeträgerfluid (37) so umgeben ist, daß eine Wärmeübertragung vom Draht über das Gas und das Rohr auf das Wärmeträgerfluid abläuft;
    d) die Kenngrößen des Rohrs (33), des Drahts (1) und des Gases (35) sind so gewählt, daß mindestens während der Abkühlung vor der Perlitisierung die folgenden Beziehungen eingehalten werden:

    1,05 ≦ R' ≦ 15   (3)
    Figure imgb0072

    5 ≦ K' ≦ 10   (4),
    Figure imgb0073

    mit den Definitionen

    R' = D' ti /D f
    Figure imgb0074
    K' = [Log(D' ti /D f )] x D f ²/λ' ,
    Figure imgb0075

    wobei D'ti den Innendurchmesser des Rohrs, ausgedrückt in Millimetern, Df den Durchmesser des Drahts ausgedrückt in Millimetern, λ' die Wärmeleitfähigkeit des Gases, gemessen bei 600 °C, ausgedrückt in Watt/mK und Log den natürlichen Logarithmus bedeuten.
  23. Einrichtung (300) nach Anspruch 22,
    dadurch gekennzeichnet, daß
    ein oder mehrere Rohre (33) so angelegt sind, daß sie nach Abkühlung des Drahts (1) von einer Temperatur oberhalb der Umwandlungstemperatur AC3 auf eine gegebene Temperatur unterhalb der Umwandlungstemperatur AC1 es ermöglichen, den Draht (1) während einer Zeit, die größer ist als die Perlitisierungszeit auf einer Temperatur zu halten, die um nicht mehr als 10 °C nach oben oder unten von dieser gegebenen Temperatur abweicht, durch Modulation des Wärmeaustausches, wobei die folgenden Beziehungen in dem oder den Abschnitten des oder der Rohre, wo die Geschwindigkeit der Perlitisierung am größten ist, eingehalten wird:

    1,05 ≦ R' ≦ 8   (5)
    Figure imgb0076

    3 ≦ K' ≦ 8   (6).
    Figure imgb0077
  24. Einrichtung (300) nach Anspruch 23,
    dadurch gekennzeichnet, daß
    das oder die Rohre (33) so angelegt sind, daß die Temperatur des Drahts (1) um nicht mehr als 5 °C nach oben oder unten von der gegebenen Temperatur abweicht.
  25. Einrichtung (300) nach einem der Ansprüche 23 oder 24,
    dadurch gekennzeichnet, daß
    sich der Innendurchmesser (D'ti) des oder mindestens eines Rohres (33) in den Perlitisierungsmitteln ändert.
  26. Einrichtung (300) nach einem der Ansprüche 23 bis 25,
    dadurch gekennzeichnet, daß
    sie in den Perlitisierungsmitteln mehrere Rohre (33) umfaßt, deren Länge (L't) sich ändert.
  27. Einrichtung (300) nach einem der Ansprüche 21 bis 26,
    dadurch gekennzeichnet, daß
    sie Mittel aufweist, die es ermöglichen, den Draht (1) nach der Perlitisierung abzukühlen.
EP89110580A 1988-06-21 1989-06-12 Verfahren und Vorrichtung zum Einstellen eines homogenen austenitischen Gefüges Expired - Lifetime EP0347699B1 (de)

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FR8808425 1988-06-21
FR8808425A FR2632973B1 (fr) 1988-06-21 1988-06-21 Procedes et dispositifs pour obtenir une structure d'austenite homogene

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DE8803700U1 (de) * 1988-03-18 1989-07-13 Vereinigte Aluminium-Werke AG, 1000 Berlin und 5300 Bonn Rohrreaktor, insbesondere für den Hochtemperaturaufschluß böhmit- und diasporhaltiger Bauxite
FR2650296B1 (fr) * 1989-07-26 1991-10-11 Michelin & Cie Procede et dispositif pour traiter thermiquement au moins un fil metallique avec des plaques de transfert thermique
US6198083B1 (en) * 2000-04-12 2001-03-06 American Spring Wire Corp. Method and apparatus for heat treating wires

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR604885A (fr) * 1924-11-01 1926-05-15 Siemens Schuckertwerke Gmbh Four électrique à recuire à blanc pour la recuisson à blanc en continu
DE586977C (de) * 1930-05-01 1933-10-28 Aeg Wasserstoffofen zum Blankgluehen von Metallen
US2218177A (en) * 1939-02-28 1940-10-15 Rca Corp Wire treating furnace
DE2111631A1 (de) * 1970-03-13 1972-03-30 Pirelli Vorrichtung zum Haerten von Stahldraht
US3900347A (en) * 1974-08-27 1975-08-19 Armco Steel Corp Cold-drawn, straightened and stress relieved steel wire for prestressed concrete and method for production thereof
JPS5827006Y2 (ja) * 1979-03-13 1983-06-11 日立電線株式会社 線材の焼鈍装置
GB2174485A (en) * 1985-04-23 1986-11-05 Jeffery Boardman Annealing furnaces
KR880701060A (ko) * 1985-11-12 1988-04-22 원본미기재 유도 가열된 물질의 냉각 장치 및 방법
GB8600533D0 (en) * 1986-01-10 1986-02-19 Bekaert Sa Nv Manufacturing pearlitic steel wire
FR2607519B1 (fr) * 1986-11-27 1989-02-17 Michelin & Cie Procede et dispositif pour traiter thermiquement un fil d'acier
FR2626290B1 (fr) * 1988-01-25 1990-06-01 Michelin & Cie Procedes et dispositifs permettant de traiter thermiquement des fils d'acier au carbone de facon a obtenir une structure perlitique fine

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PROSPECTUS BBC, no. EO 1054: "Patentier- und Durchlaufhärteanlagen für die Drahtindustrie" *

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ATE97698T1 (de) 1993-12-15
BR8903004A (pt) 1990-02-06
OA09079A (fr) 1991-10-31
AU627463B2 (en) 1992-08-27
JP2885831B2 (ja) 1999-04-26
IE65167B1 (en) 1995-10-04
JPH0243325A (ja) 1990-02-13
EP0347699A1 (de) 1989-12-27
DE68910887D1 (de) 1994-01-05
CN1018931B (zh) 1992-11-04
FR2632973B1 (fr) 1993-01-15
DE68910887T2 (de) 1994-03-17
ES2046373T3 (es) 1994-02-01
KR900000486A (ko) 1990-01-30
AU3662289A (en) 1990-01-04
US5032191A (en) 1991-07-16
CN1039062A (zh) 1990-01-24
FR2632973A1 (fr) 1989-12-22
IE892007L (en) 1989-12-21
ZA894706B (en) 1990-02-28
CA1333250C (fr) 1994-11-29

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