EP0403916B1 - Method for production of ribbed reinforcing steel - Google Patents

Method for production of ribbed reinforcing steel Download PDF

Info

Publication number
EP0403916B1
EP0403916B1 EP90111026A EP90111026A EP0403916B1 EP 0403916 B1 EP0403916 B1 EP 0403916B1 EP 90111026 A EP90111026 A EP 90111026A EP 90111026 A EP90111026 A EP 90111026A EP 0403916 B1 EP0403916 B1 EP 0403916B1
Authority
EP
European Patent Office
Prior art keywords
stretching
steel wire
process according
elongation
steel
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP90111026A
Other languages
German (de)
French (fr)
Other versions
EP0403916A1 (en
Inventor
Klaus Theis
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
KT - BAUSTAHL Vertriebsgesellschaft mbH
Original Assignee
KT - BAUSTAHL Vertriebsgesellschaft mbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by KT - BAUSTAHL Vertriebsgesellschaft mbH filed Critical KT - BAUSTAHL Vertriebsgesellschaft mbH
Priority to AT90111026T priority Critical patent/ATE95453T1/en
Publication of EP0403916A1 publication Critical patent/EP0403916A1/en
Application granted granted Critical
Publication of EP0403916B1 publication Critical patent/EP0403916B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C1/00—Manufacture of metal sheets, metal wire, metal rods, metal tubes by drawing
    • B21C1/02—Drawing metal wire or like flexible metallic material by drawing machines or apparatus in which the drawing action is effected by drums
    • B21C1/12—Regulating or controlling speed of drawing drums, e.g. to influence tension; Drives; Stop or relief mechanisms
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21F—WORKING OR PROCESSING OF METAL WIRE
    • B21F9/00—Straining wire
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21F—WORKING OR PROCESSING OF METAL WIRE
    • B21F9/00—Straining wire
    • B21F9/007—Straining wire to induce a plastic deformation of the wire
    • 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
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
    • C21D8/08—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires for concrete reinforcement

Definitions

  • the invention relates to a method for producing ribbed reinforcing steel, wherein a steel wire is produced by hot rolling and is thereby provided with inclined ribs and possibly longitudinal ribs (in particular according to DIN 488), and the steel wire which has been hot-ribbed in this way is subjected to cold stretching and thereby in relation to it is adjusted to the yield strength and the elongation. It is essential for this process that the rib-forming shape takes place during rolling and is a so-called hot rib. In contrast, stretching takes place as cold stretching. It is understood that the yield strength and the elongation are set so that the prescribed, standardized values are observed.
  • the stretching results from a torsional deformation with the aid of a torsional machine which operates discontinuously.
  • the discontinuous procedure interferes with the operational process.
  • Relatively large, unavoidable tolerances must be permitted or taken into account for the yield strength to be set and for the stretching to be set.
  • the values for the yield strength and the stretching over the length of a reinforcing steel are not very uniform in accordance with the different stretching sections which belong to the discontinuous procedure.
  • the fatigue strength of the stretched reinforcing steel is often unsatisfactory. There is a risk of fatigue failure in the event of vibration stress. On the other hand, practice increasingly demands high values for the fatigue strength.
  • the continuous cold stretching of a steel wire is basically known (DE-AS 24 49 268).
  • a non-ribbed steel wire is stretched in that on the one hand it wraps around a driven drum serving as a pulling device and on the other hand it wraps around a non-driven, braked drum.
  • the accuracy of the setting of the yield strength and elongation of the steel wire leaves something to be desired here.
  • the invention has for its object to carry out the method described above so that the yield strength and the elongation can be set very precisely and also other physical properties of the reinforcing steel, in particular its fatigue behavior, are improved.
  • the invention teaches that the steel wire is continuously stretched and, for this purpose, is guided over at least two driven stretching disks (or stretching rollers) which are operated with different Circumferential speeds work on the steel wire, that the degree of stretching is controlled via the difference in circumferential speed of the two stretching disks, and that the yield strength and the elongation are controlled via the stretching speed.
  • the invention is based on the knowledge that with a continuous linear stretching there is the possibility, for a given degree of stretching, of intervening to optimize the process in the sense that very precise values for the yield strength and the elongation can be specified and maintained. In addition to the stretching speed, the degree of stretching is still an influencing variable which can be varied.
  • the reinforcing steel produced in this way is also characterized by a very high fatigue strength.
  • the stretching speed should be selected so that the specified values for the yield point and the elongation are maintained, but the stretching speed should be selected as low as possible within this condition.
  • - Degree of stretching denotes the elongation that the steel wire or a unit of length of the steel wire undergoes during stretching, in percent.
  • Stretching speed denotes the permanent change in length of the steel wire or a unit of length of the steel wire in the area between the two stretching disks in the unit of time. According to the invention, both variables can be set and maintained by influencing the peripheral speeds of the stretching disks.
  • the steel wire is guided over the stretching disks without slipping.
  • This can be accomplished in several ways, e.g. B. by vulcanized rubber-elastic pads on the tread of the stretching discs, by form-fitting training that correspond to the ribs on the steel wires.
  • This can also be achieved in other ways, under certain circumstances also by multiple wrapping of the stretching discs.
  • it is always advantageous to guide the steel wire over the stretching discs without damaging the ribs. In this respect, too, rubber-elastic pads and adapted form-fitting designs have proven to be advantageous.
  • the yield strength and the elongation can be set and maintained very precisely.
  • a surprising reduction in susceptibility to fatigue fracture is also achieved.
  • the fatigue fractures often also start from microcracks in the surface area of the steel wires, which in turn are based on damage to the ribs or other defects.
  • the formation of microcracks which are disruptive to this extent can largely be avoided by adjusting the stretching speed, but the yield strength and the elongation can nevertheless be controlled very precisely.
  • the drawing shows a schematic representation of a plant which is particularly suitable for carrying out the described method.
  • the stretching disks 1 or 2 have a radius of at least 500 mm. They can be driven via the motor / gear unit 3 or 4 with a predeterminable peripheral speed and a predeterminable peripheral speed difference.
  • the steel wire 5 is guided around the two stretching discs 1 and 2 in an S-shape. It can be fed to the inlet stretching disk 1 with a tangential inlet section 6 and can be removed from the outlet stretching disk 2 with a tangential outlet section 7.
  • the hot-ribbed steel wire 5 which was deposited with a permanent torsional deformation of 360 ° per turn via a winding layer out of the rolling heat, is drawn off from a beater 8 in the cold state with this twisting deformation.
  • a recovery device 9 for this torsional deformation.
  • the reshaping device 9 works with reshaping rollers 10. It goes without saying that the stretching disks 1 and 2 are designed such that they guide the steel wire 5 without slipping. The design is also made so that the ribs of the steel wire 5 on the stretching discs 1 and 2 and in the recovery device 9 are not damaged.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Thermal Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Ropes Or Cables (AREA)
  • Wire Processing (AREA)
  • Heat Treatment Of Steel (AREA)
  • Metal Rolling (AREA)

Abstract

Method for production of ribbed reinforcing steel, a steel wire being produced by hot rolling and, in the process, provided with oblique ribs and, if required, longitudinal ribs (in particular according to DIN 488). The steel wire (5) hot-ribbed in this way is subjected to cold stretching and its yield strength and elongation are thereby adjusted. The steel wire (5) is stretched continuously and, for this purpose, is guided over at least two driven stretching pulleys (1, 2) (or stretching rolls) working at different peripheral speeds on the steel wire (5). The degree of stretching is controlled via the difference in the peripheral speed of the two stretching pulleys (1, 2). The yield strength and elongation are controlled via the stretching rate. The invention also discloses an arrangement for carrying out the method. <IMAGE>

Description

Die Erfindung betrifft ein Verfahren zur Herstellung von geripptem Betonstahl, wobei ein Stahldraht durch Warmwalzen hergestellt und dabei mit Schrägrippen sowie ggf. Längsrippen (insbesondere nach DIN 488) versehen wird, und wobei der auf diese Weise warmgerippte Stahldraht kalt einer Reckung unterworfen sowie dadurch in bezug auf die Streckgrenze und die Dehnung eingestellt wird. Wesentlich für dieses Verfahren ist, daß die rippenbildende Formgebung beim Walzen erfolgt und eine sogenannte Warmrippung ist. Demgegenüber erfolgt die Reckung als Kaltreckung. Es versteht sich, daß die Streckgrenze und die Dehnung so eingestellt werden, daß die vorgeschriebenen, normierten Werte eingehalten sind.The invention relates to a method for producing ribbed reinforcing steel, wherein a steel wire is produced by hot rolling and is thereby provided with inclined ribs and possibly longitudinal ribs (in particular according to DIN 488), and the steel wire which has been hot-ribbed in this way is subjected to cold stretching and thereby in relation to it is adjusted to the yield strength and the elongation. It is essential for this process that the rib-forming shape takes place during rolling and is a so-called hot rib. In contrast, stretching takes place as cold stretching. It is understood that the yield strength and the elongation are set so that the prescribed, standardized values are observed.

Bei dem großtechnisch ausgeführten, bekannten Verfahren, von dem die Erfindung ausgeht, resultiert das Recken aus einer Torsionsverformung mit Hilfe einer Torsionsmaschine, die diskontinuierlich arbeitet. Die diskontinuierliche Verfahrensführung stört den betrieblichen Ablauf. Für die einzustellende Streckgrenze sowie für die einzustellende Reckung müssen verhältnismäßig große, unvermeidbare Toleranzen zugelassen oder berücksichtigt werden. Insbesondere sind die Werte für die Streckgrenze und die Reckung über die Länge eines Betonstahls nach Maßgabe der unterschiedlichen Reckungsabschnitte, die zu der diskontinuierlichen Verfahrenweise gehören, wenig gleichmäßig. Die Dauerschwingungsfestigkeit des so gereckten Betonstahls ist häufig unbefriedigend. Es besteht bei Schwingungsbeanspruchungen Dauerbruchgefahr. Andererseits verlangt die Praxis in zunehmendem Maße auch hohe Werte für die Dauerschwingungsfestigkeit. - Wegen der beschriebenen Probleme wird, um bei Betonstahl die vorgeschriebenen Werte für die Streckgrenze und die Dehnung einzuhalten, häufig von der beschriebenen Kaltreckung durch Torsion Abstand genommen und werden die vorgeschriebenen physikalischen Eigenschaften durch Microlegierung eingestellt, insbesondere durch Zugabe von Vanadium. Das führt zu befriedigenden Ergebnissen. Das ist jedoch wegen der Notwendigkeit, Vanadium zuzulegieren, aufwendig, zumal die Vanadium-Preise in der Tendenz seit vielen Jahren steigen und weitere Steigungen zu erwarten sind.In the known, large-scale process from which the invention is based, the stretching results from a torsional deformation with the aid of a torsional machine which operates discontinuously. The discontinuous procedure interferes with the operational process. Relatively large, unavoidable tolerances must be permitted or taken into account for the yield strength to be set and for the stretching to be set. In particular, the values for the yield strength and the stretching over the length of a reinforcing steel are not very uniform in accordance with the different stretching sections which belong to the discontinuous procedure. The fatigue strength of the stretched reinforcing steel is often unsatisfactory. There is a risk of fatigue failure in the event of vibration stress. On the other hand, practice increasingly demands high values for the fatigue strength. - Because of the problems described, in order to reinforcing steel the prescribed values for the yield strength and the elongation are observed, often the cold stretching described by torsion is removed and the prescribed physical properties are set by microalloying, in particular by adding vanadium. This leads to satisfactory results. However, this is complex because of the need to add vanadium, especially since the vanadium prices have been rising for many years and further increases are expected.

In neuerer Zeit ist über Versuche berichtet worden, die nicht zum Stand der Technik gehören und die sich bemühen, das Microlegieren durch ein kontinuierliches Recken zu ersetzen ( Werkzeitschrift "Report" der Hamburger Stahlwerke Gesellschaft mit beschränkter Haftung vom 22. Juni 1989, Seite 11). Diese Versuche wurden mit einer Reckmaschine durchgeführt, die zwei mit unterschiedlicher Umfangsgeschwindigkeit arbeitende Reckscheiben aufweisen. Die Erfindung schließt an diese Versuche an.There have been recent reports of attempts which do not belong to the prior art and which attempt to replace microalloying with continuous stretching (work magazine "Report" of the Hamburger Stahlwerke Gesellschaft mit Limited Liability of June 22, 1989, page 11) . These tests were carried out using a stretching machine which has two stretching disks operating at different peripheral speeds. The invention follows on from these experiments.

Das kontinuierliche Kaltrecken eines Stahldrahtes ist im übrigen grundsätzlich bekannt (DE-AS 24 49 268). Im Rahmen dieser bekannten Maßnahmen wird ein nicht gerippter Stahldraht dadurch gereckt, daß er einerseits eine angetriebene, als Zugvorrichtung dienende Trommel umschlingt und andererseits eine nicht angetriebene, gebremste Trommel umschlingt. Die Genauigkeit der Einstellung von Streckgrenze und Dehnung des Stahldrahtes läßt hier zu wünschen übrig.The continuous cold stretching of a steel wire is basically known (DE-AS 24 49 268). In the context of these known measures, a non-ribbed steel wire is stretched in that on the one hand it wraps around a driven drum serving as a pulling device and on the other hand it wraps around a non-driven, braked drum. The accuracy of the setting of the yield strength and elongation of the steel wire leaves something to be desired here.

Der Erfindung liegt die Aufgabe zugrunde, das eingangs beschriebene Verfahren so zu führen, daß die Streckgrenze und die Dehnung sehr genau eingestellt werden können und auch weitere physikalische Eigenschaften des Betonstahls, insbesondere sein Dauerschwingungsverhalten, verbessert werden.The invention has for its object to carry out the method described above so that the yield strength and the elongation can be set very precisely and also other physical properties of the reinforcing steel, in particular its fatigue behavior, are improved.

Zur Lösung dieser Aufgabe lehrt die Erfindung, daß der Stahldraht kontinuierlich gereckt wird und dazu über zumindest zwei angetriebene Reckscheiben (oder Reckwalzen) geführt wird, die mit unterschiedlichen Umfangsgeschwindigkeiten auf dem Stahldraht arbeiten, daß über die Umfangsgeschwindigkeitsdifferenz der beiden Reckscheiben der Reckgrad gesteuert wird und daß über die Reckgeschwindigkeit die Streckgrenze und die Dehnung gesteuert werden. - Die Erfindung geht von der Erkenntnis aus, daß bei einem kontinuierlichen linearen Recken die Möglichkeit besteht, bei vorgegebenem Reckgrad durch die Reckgeschwindigkeit in den Prozeß in dem Sinne optimierend einzugreifen, daß sehr genaue Werte für die Streckgrenze und die Dehnung vorgegeben und eingehalten werden können. Dabei ist neben der Reckgeschwindigkeit nach wie vor der Reckgrad eine Einflußgröße, die variiert werden kann. Überraschenderweise zeichnen sich die so hergestellten Betonstähle auch durch eine sehr hohe Dauerschwingungsfestigkeit aus. Insoweit soll die Reckgeschwindigkeit zwar so gewählt werden, daß die vorgegebenen Werte für die Streckgrenze und die Dehnung eingehalten werden, jedoch soll die Reckgeschwindigkeit innerhalb dieser Bedingung so niedrig wie möglich gewählt werden. - Reckgrad bezeichnet die Längung, die der Stahldraht bzw. eine Längeneinheit des Stahldrahtes bei der Reckung erfährt, in Prozent. Reckgeschwindigkeit bezeichnet die bleibende Längenänderung des Stahldrahtes bzw. einer Längeneinheit des Stahldrahtes im Bereich zwischen den beiden Reckscheiben in der Zeiteinheit. Beide Größen können erfindungsgemäß durch Einflußnahme auf die Umfangsgeschwindigkeiten der Reckscheiben eingestellt und eingehalten werden. Im Rahmen der Erfindung werden keine absoluten Zahlen für die Reckgeschwindigkeit angegeben, weil die optimalen absoluten Zahlen auch von dem Reckgrad und dem Krümmungsradius abhängen, den der Stahldraht bei der Umschlingung der Reckscheiben erfährt. Mit der Lehre, daß über die Reckgeschwindigkeit die Streckgrenze und die Dehnung gesteuert werden, lassen sich die absoluten Werte für die Reckgeschwindigkeit bei vorgegebenem Durchmesser der Reckscheiben unschwer experimentell ermitteln. Im Sinne einer Optimierung ist es zweckmäßig, den Stahldraht mit einem Mindestkrümmungsradius von 500 mm über die Reckscheiben zu führen. Das gilt für alle übliche Stahldrahtdicken. Diese Maßnahme stellt sicher, daß sich eine störende, in bezug auf den Stahldrahtquerschnitt unsymmetrische Biegekaltverformung der linearen Reckung nicht überlagert. Um die Zahlenwerte in bezug auf den Reckgrad und die Reckgeschwindigkeit genau einzuhalten, wird nach bevorzugter Ausführungsform der Erfindung der Stahldraht schlupffrei über die Reckscheiben geführt. Das kann auf verschiedene Weise erreicht werden, z. B. durch aufvulkanisierte gummielastische Auflagen auf der Lauffläche der Reckscheiben, durch Formschlußausbildungen, die mit den Rippen auf den Stahldrähten korrespondieren. Das kann auch auf andere Weise erreicht werden, unter Umständen auch durch Mehrfachumschlingung der Reckscheiben. Es ist jedoch stets vorteilhaft, den Stahldraht rippenschadenfrei über die Reckscheiben zu führen. Auch insoweit erweisen sich gummielastische Auflagen und angepaßte Formschlußausbildungen als vorteilhaft. - Arbeitet man in der beschriebenen Weise, so ist nicht nur sichergestellt, daß die Streckgrenze und die Dehnung, wie vorgegeben, sehr genau eingestellt und eingehalten werden können. Man erzielt, wie bereits betont, auch eine überraschende Reduzierung der Dauerbruchempfindlichkeit. Tatsächlich gehen im Rahmen der bekannten Maßnahmen die Dauerbrüche häufig auch von Microrissen im Oberflächenbereich der Stahldrähte aus, die ihrerseits auf Schäden an den Rippen oder auf anderen Fehlern beruhen. Die Bildung von insoweit störenden Microrissen läßt sich erfindungsgemäß durch Einstellung der Reckgeschwindigkeit weitgehend vermeiden, wobei nichtsdestoweniger die Streckgrenze und die Dehnung sehr genau gesteuert werden können.To achieve this object, the invention teaches that the steel wire is continuously stretched and, for this purpose, is guided over at least two driven stretching disks (or stretching rollers) which are operated with different Circumferential speeds work on the steel wire, that the degree of stretching is controlled via the difference in circumferential speed of the two stretching disks, and that the yield strength and the elongation are controlled via the stretching speed. - The invention is based on the knowledge that with a continuous linear stretching there is the possibility, for a given degree of stretching, of intervening to optimize the process in the sense that very precise values for the yield strength and the elongation can be specified and maintained. In addition to the stretching speed, the degree of stretching is still an influencing variable which can be varied. Surprisingly, the reinforcing steel produced in this way is also characterized by a very high fatigue strength. In this respect, the stretching speed should be selected so that the specified values for the yield point and the elongation are maintained, but the stretching speed should be selected as low as possible within this condition. - Degree of stretching denotes the elongation that the steel wire or a unit of length of the steel wire undergoes during stretching, in percent. Stretching speed denotes the permanent change in length of the steel wire or a unit of length of the steel wire in the area between the two stretching disks in the unit of time. According to the invention, both variables can be set and maintained by influencing the peripheral speeds of the stretching disks. In the context of the invention, no absolute numbers are given for the stretching speed, because the optimal absolute numbers also depend on the degree of stretching and the radius of curvature which the steel wire experiences during the wrapping of the stretching disks. With the teaching that the yield strength and the elongation are controlled via the stretching speed, the absolute values for the stretching speed can be given at a given value Easily determine the diameter of the stretching discs experimentally. In the interest of optimization, it is advisable to guide the steel wire over the stretching disks with a minimum radius of curvature of 500 mm. This applies to all common steel wire thicknesses. This measure ensures that a disruptive bending cold deformation that is asymmetrical with respect to the steel wire cross section is not superimposed on the linear stretching. In order to adhere exactly to the numerical values with regard to the degree of stretching and the stretching speed, according to a preferred embodiment of the invention, the steel wire is guided over the stretching disks without slipping. This can be accomplished in several ways, e.g. B. by vulcanized rubber-elastic pads on the tread of the stretching discs, by form-fitting training that correspond to the ribs on the steel wires. This can also be achieved in other ways, under certain circumstances also by multiple wrapping of the stretching discs. However, it is always advantageous to guide the steel wire over the stretching discs without damaging the ribs. In this respect, too, rubber-elastic pads and adapted form-fitting designs have proven to be advantageous. - If you work in the manner described, it is not only ensured that the yield strength and the elongation, as specified, can be set and maintained very precisely. As already emphasized, a surprising reduction in susceptibility to fatigue fracture is also achieved. In fact, in the context of the known measures, the fatigue fractures often also start from microcracks in the surface area of the steel wires, which in turn are based on damage to the ribs or other defects. According to the invention, the formation of microcracks which are disruptive to this extent can largely be avoided by adjusting the stretching speed, but the yield strength and the elongation can nevertheless be controlled very precisely.

In der Ausführungsform, bei der warmgerippter Stahldraht über einen Windungsleger aus der Walzhitze heraus mit einer bleibenden Tordierungsverformung von 360°C pro Windung abgelegt wird und mit dieser Tordierungsverformung im kalten Zustand von einem Schlaghaspel abgezogen wird, besteht im Rahmen der Erfindung die Möglichkeit, der beschriebenen vorteilhaften linearen Reckung eine Torsionsreckung zu überlagern. Dazu lehrt die Erfindung, daß der von dem Schlaghaspel abgezogene Stahldraht vor der Zuführung zu der ersten Reckscheibe einer Rückverformung unterworfen wird, die die Trodierungsverformung aufhebt oder weitgehend reduziert.In the embodiment in which hot-ribbed steel wire is deposited out of the rolling heat using a winding layer with a permanent twist deformation of 360 ° C. per turn and is pulled off from a beater reel with this twist deformation in the cold state, there is the possibility within the scope of the invention that described advantageous linear stretching to superimpose a torsional stretch. To this end, the invention teaches that the steel wire drawn off from the beater reel is subjected to a return deformation prior to being fed to the first stretching disk, which cancels or largely reduces the trodden deformation.

Das erfindungsgemäße Verfahren hat sich besonders bewährt für die speziellen Stähle, die in den Ansprüchen 6 und 7 behandelt sind, wenn die in diesen Ansprüchen angegebenen Verfahrensparameter eingehalten werden. Werden diese eingehalten, so lassen sich im allgemeinen Betriebsverhältnisse verwirklichen, bei denen mit einer Umfangsgeschwindigkeit der Reckscheiben von mindestens 1,0 m/sek. bis maximal 8,0 m/sek. gearbeitet wird. Es versteht sich, daß die Umfangsgeschwindigkeit in diesem Bereich in Abhängigkeit vom Drahtdurchmesser optimierend eingestellt wird.The process according to the invention has proven particularly useful for the special steels which are dealt with in claims 6 and 7 if the process parameters specified in these claims are observed. If these are observed, general operating conditions can be achieved in which the circumferential speed of the stretching discs is at least 1.0 m / sec. up to a maximum of 8.0 m / sec. is worked. It goes without saying that the peripheral speed in this area is set in an optimizing manner as a function of the wire diameter.

Die Zeichnung zeigt eine schematische Darstellung einer Anlage, die für die Durchführung des beschriebenen Verfahrens besonders geeignet ist.The drawing shows a schematic representation of a plant which is particularly suitable for carrying out the described method.

Man erkennt in der Zeichnung eine Einlaufreckscheibe 1, eine Ablaufreckscheibe 2 und ein Motor/Getriebe-Aggregat 3 bzw. 4 an jeder der Reckscheiben 1 bzw. 2. Die Reckscheiben 1 bzw. 2 besitzen einen Radius von zumindest 500 mm. Sie sind über das Motor/Getriebe-Aggregat 3 bzw. 4 mit vorgebbarer Umfangsgeschwindigkeit und vorgebbarer Umfangsgeschwindigkeitsdifferenz antreibbar. Der Stahldraht 5 ist um die beiden Reckscheiben 1 bzw. 2 S-förmig geführt. Er ist der Einlaufreckscheibe 1 mit einem tangentialen Einlaufabschnitt 6 zuführbar und von der Ablaufreckscheibe 2 mit einem tangentialen Ablaufabschnitt 7 abführbar. Angedeutet wurde, daß der warmgerippte Stahldraht 5, der über einen Windungsleger aus der Walzhitze heraus mit einer bleibenden Torsionsverformung von 360° pro Windung abgelegt wurde, mit dieser Tordierungsverformung im kalten Zustand von einem Schlaghaspel 8 abgezogen wird. Im Bereich des tangentialen Einlaufabschnittes 6 dieses Stahldrahtes befindet sich eine Rückverformungseinrichtung 9 für diese Torsionsverformung. Die Rückverformungseinrichtung 9 arbeitet mit Rückverformungsrollen 10. Es versteht sich, daß die Reckscheiben 1 bzw. 2 so ausgelegt sind, daß sie den Stahldraht 5 schlupffrei führen. Die Auslegung ist fernerhin so getroffen, daß die Rippen des Stahldrahtes 5 auf den Reckscheiben 1 bzw. 2 und in der Rückverformungseinrichtung 9 keinen Schaden nehmen.One can see in the drawing an inlet stretching disk 1, a discharge stretching disk 2 and a motor / gear unit 3 or 4 on each of the stretching disks 1 or 2. The stretching disks 1 or 2 have a radius of at least 500 mm. They can be driven via the motor / gear unit 3 or 4 with a predeterminable peripheral speed and a predeterminable peripheral speed difference. The steel wire 5 is guided around the two stretching discs 1 and 2 in an S-shape. It can be fed to the inlet stretching disk 1 with a tangential inlet section 6 and can be removed from the outlet stretching disk 2 with a tangential outlet section 7. It was indicated that the hot-ribbed steel wire 5, which was deposited with a permanent torsional deformation of 360 ° per turn via a winding layer out of the rolling heat, is drawn off from a beater 8 in the cold state with this twisting deformation. In the area of the tangential inlet section 6 of this steel wire there is a recovery device 9 for this torsional deformation. The reshaping device 9 works with reshaping rollers 10. It goes without saying that the stretching disks 1 and 2 are designed such that they guide the steel wire 5 without slipping. The design is also made so that the ribs of the steel wire 5 on the stretching discs 1 and 2 and in the recovery device 9 are not damaged.

Claims (8)

  1. A process for manufacturing concrete-reinforcing steel, wherein a steel wire (5) is manufactured by hot-rolling and is provided at the same time with oblique ribs and optionally with longitudinal ribs (particularly in accordance with DIN 488), and wherein the steel wire (5) which is hot-ribbed in this manner is subjected to cold stretching and by this means its apparent yield point and elongation are adjusted, characterised in that the steel wire (5) is continuously stretched and is passed for this purpose over at least two driven stretching wheels (1, 2) (or stretch rolls) which act on the steel wire (5) at different peripheral speeds, that the degree of stretching is controlled via the difference in the peripheral speeds of the two stretching wheels (1, 2), and that the apparent yield point and the elongation are controlled (or adjusted) via the stretching rate.
  2. A process according to claim 1, characterised in that the steel wire (5) is passed over the stretching wheels (1, 2) with a minimum radius of curvature of 500 mm.
  3. A process according to one of claims 1 or 2, characterised in that the steel wire (5) is passed over the stretching wheels (1, 2) without slip.
  4. A process according to any one of claims 1 to 3, characterised in that the steel wire (5) is passed over the stretching wheels (1, 2) without damaging the ribs.
  5. A process according to any one of claims 1 to 4, in its form of implementation in which the hot-ribbed steel wire (5) is laid down out of the heat of the rolls, via a laying head, with a residual torsional deformation of 360° per winding, and is pulled off from a rocking coil-holder (8) in the cold state with this torsional deformation, characterised in that the steel wire (5) pulled off from the rocking coil-holder (8) is subjected to a reverse deformation, which eliminates or substantially reduces the torsional deformation, before being fed to the first stretching wheel (1).
  6. A process according to any one of claims 1 to 5, characterised in that a steel wire (5) is employed, the analysis of which is within the range
    carbon   : 0.14 to 0.22 %,
    silicon   : 0.15 to 0.40 %,
    manganese   : 0.60 to 1.30 %,
       balance iron and permissible trace elements and added elements,
    that stretching is performed with a maximum degree of stretching of 6 %, and that the stretching rate is selected so that the stretched concrete-reinforcing steel has an apparent yield point greater than 500 N/mm² and an elongation of at least 15%.
  7. A process according to claim 6, characterised in that a steel wire (5) is employed of analysis
    carbon   : 0.18 %,
    silicon   : 0.24 %,
    manganese   : 0.80 %,
       balance iron and permissible trace elements and added elements,
    that stretching is performed with a degree of stretching of 5.7 %, and that the stretching rate is selected so that the stretched concrete-reinforcing steel has an apparent yield point of about 521 N/mm² and an elongation of 18.3%.
  8. A process according to any one of claims 1 to 7, characterised in that the peripheral speed of the stretching discs (1, 2) which is employed is from at least 1.0 m/second up to a maximum of 8.0 m/second.
EP90111026A 1989-06-14 1990-06-12 Method for production of ribbed reinforcing steel Expired - Lifetime EP0403916B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT90111026T ATE95453T1 (en) 1989-06-14 1990-06-12 METHOD OF MANUFACTURING RIBBED REINFORCEMENT STEEL.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3919382A DE3919382A1 (en) 1989-06-14 1989-06-14 DEVICE FOR INCREASING THE STRETCH LIMIT OF HOT ROLLED WIRE
DE3919382 1989-06-14

Publications (2)

Publication Number Publication Date
EP0403916A1 EP0403916A1 (en) 1990-12-27
EP0403916B1 true EP0403916B1 (en) 1993-10-06

Family

ID=6382709

Family Applications (1)

Application Number Title Priority Date Filing Date
EP90111026A Expired - Lifetime EP0403916B1 (en) 1989-06-14 1990-06-12 Method for production of ribbed reinforcing steel

Country Status (4)

Country Link
EP (1) EP0403916B1 (en)
AT (1) ATE95453T1 (en)
DE (2) DE3919382A1 (en)
ES (1) ES2048363T3 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4024653C1 (en) * 1990-08-03 1991-07-25 Hanse-Montan Hanseatische Montanhandelsges. M.B.H., 2103 Hamburg, De
KR102389355B1 (en) * 2020-11-10 2022-04-21 한국재료연구원 Wire rod having uniform hardness and method of manufacturing the same

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1907350A1 (en) * 1969-02-14 1970-09-03 Siemens Ag Wire-drawing installation
AT339852B (en) * 1973-10-19 1977-11-10 Voest Ag DEVICE FOR CONTINUOUS COLD STRENGTHENING OF ROLLED METALLIC ROLLED, ESPECIALLY STEEL WIRE
FR2355579A1 (en) * 1976-02-23 1978-01-20 Crouzet Sa ADVANCED THREADING MACHINE
JPS5335666A (en) * 1976-09-14 1978-04-03 Sumitomo Electric Industries Method and device for continuous hot stretching strand wires
FR2395791A2 (en) * 1977-07-01 1979-01-26 Crouzet Sa ADVANCED THREADING MACHINE

Also Published As

Publication number Publication date
DE3919382A1 (en) 1991-01-03
ATE95453T1 (en) 1993-10-15
ES2048363T3 (en) 1994-03-16
EP0403916A1 (en) 1990-12-27
DE59002981D1 (en) 1993-11-11

Similar Documents

Publication Publication Date Title
DE3204045C2 (en)
DE102008024013B3 (en) Method and device for straightening a metal strip
DE2408388A1 (en) WIRE DRAWN UNDER TWIST, AND THE METHOD AND DEVICE FOR THE PRODUCTION THEREOF
DE112010002252T5 (en) TIRE WIRE WIRE AND MANUFACTURING METHOD THEREFOR
DE1602371C3 (en) Method of increasing elongation of strand material
DE1140891B (en) Method for straightening metal strip
EP0403916B1 (en) Method for production of ribbed reinforcing steel
DE1933273B1 (en) Rolling process for the production of wire or other rod-shaped rolling stock
DE1080441B (en) Method and device for manufacturing steel wire ropes
DE2651812A1 (en) METHOD AND DEVICE FOR COLD FORMING OF LONG-DRAWN STEEL PIECES
DE2734500A1 (en) PROCESS FOR MANUFACTURING ELECTRIC SHEETS AND STRIPS, IN PARTICULAR FE-SI SHEETS AND STRIPS
DE10053933B4 (en) Method for straightening a rail
DE2439784A1 (en) Concrete reinforcing rods - are quenched after hot rolling and profiling
DE2216368B2 (en) Method and device for the production of cold-worked ribbed steel
DE4233462C2 (en) Process for increasing the tensile strength and toughness of martensitic steel wires and device for carrying out the process
EP0263300A1 (en) Method and apparatus for manufacturing coil springs
EP0469410B1 (en) Method and device for strengthening of reinforcing bars for concrete
EP0344568A1 (en) Method for making a reinforcing cord consisting of two steel wires, and reinforcing cord made by this method
CH669128A5 (en) High yield strength precision wire rod prodn. - by stretching and calibrating, useful for reinforcing rod mfr.
AT232249B (en) Reinforcement for composite bodies and method and device for their manufacture
AT208904B (en) Method and device for increasing the yield strength and the strength of rolled steel products, in particular concrete reinforcing steel
DE102017101777B4 (en) Bend-straightening machine and method for bend-straightening a metallic flat product
AT389125B (en) Process for the heat treatment of rolled products, device for carrying out the process and reinforcing bar produced using the process
DE1508448C3 (en) Application of the process for the production of concrete reinforcing bars with surface profiles deviating from rotational symmetry
DE3325168C2 (en)

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19901103

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IT LI LU NL SE

17Q First examination report despatched

Effective date: 19920527

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH DE DK ES FR GB GR IT LI LU NL SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19931006

Ref country code: NL

Effective date: 19931006

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 19931006

Ref country code: DK

Effective date: 19931006

Ref country code: BE

Effective date: 19931006

REF Corresponds to:

Ref document number: 95453

Country of ref document: AT

Date of ref document: 19931015

Kind code of ref document: T

REF Corresponds to:

Ref document number: 59002981

Country of ref document: DE

Date of ref document: 19931111

ITF It: translation for a ep patent filed

Owner name: ING. A. GIAMBROCONO & C. S.R.L.

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 19940113

ET Fr: translation filed
NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2048363

Country of ref document: ES

Kind code of ref document: T3

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19940612

Ref country code: AT

Effective date: 19940612

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19940613

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19940630

Ref country code: LI

Effective date: 19940630

Ref country code: CH

Effective date: 19940630

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19940612

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19950228

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19950301

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20000503

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20050612