EP0469410B1 - Method and device for strengthening of reinforcing bars for concrete - Google Patents

Method and device for strengthening of reinforcing bars for concrete Download PDF

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Publication number
EP0469410B1
EP0469410B1 EP91112149A EP91112149A EP0469410B1 EP 0469410 B1 EP0469410 B1 EP 0469410B1 EP 91112149 A EP91112149 A EP 91112149A EP 91112149 A EP91112149 A EP 91112149A EP 0469410 B1 EP0469410 B1 EP 0469410B1
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EP
European Patent Office
Prior art keywords
reinforcing steel
bending
concrete
process according
hardening
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EP91112149A
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German (de)
French (fr)
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EP0469410A1 (en
Inventor
Robert Thiesbürger
Wolfgang Preiss
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HANSE-MONTAN HANSEATISCHE MONTANHANDELSGESELLSCHAFT mbH
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HANSE-MONTAN HANSEATISCHE MONTANHANDELSGESELLSCHAFT mbH
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    • 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
    • B21F9/005—Straining wire to affect the material properties of the wire
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D3/00—Straightening or restoring form of metal rods, metal tubes, metal profiles, or specific articles made therefrom, whether or not in combination with sheet metal parts
    • B21D3/02—Straightening or restoring form of metal rods, metal tubes, metal profiles, or specific articles made therefrom, whether or not in combination with sheet metal parts by rollers
    • B21D3/05—Straightening or restoring form of metal rods, metal tubes, metal profiles, or specific articles made therefrom, whether or not in combination with sheet metal parts by rollers arranged on axes rectangular to the path of the work
    • 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
    • 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
    • C21D7/00—Modifying the physical properties of iron or steel by deformation
    • C21D7/02—Modifying the physical properties of iron or steel by deformation by cold working
    • C21D7/10—Modifying the physical properties of iron or steel by deformation by cold working of the whole cross-section, e.g. of concrete reinforcing bars
    • C21D7/105—Modifying the physical properties of iron or steel by deformation by cold working of the whole cross-section, e.g. of concrete reinforcing bars of concrete reinforcing bars

Definitions

  • the invention relates to a method for the strengthening of reinforcing steel, in particular weldable reinforcing steel, which was produced by hot rolling, the reinforcing steel being subjected to mechanical deformation in a cold and continuous manner in the torsion-free pass in various bending planes and thereby adjusted, inter alia, with regard to its yield strength and its elongation becomes.
  • reinforcing steel denotes ribbed and non-ribbed reinforcing steel, in particular also reinforcing steel with oblique ribs and optionally longitudinal ribs, e.g. Reinforcing steel according to DIN 488.
  • the invention further relates to a system for performing the described method.
  • the mechanical deformation is cold stretching.
  • the stretching results from a torsional deformation with the aid of a torsional machine that works discontinuously.
  • the discontinuous procedure interferes with the operational process.
  • Relatively large, unavoidable tolerances must be permitted and taken into account for the yield point to be set and 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 bending deformation on the stretching discs is sparse. It is set up in such a way that the frictional forces acting on the reinforcing steel are sufficient to take the reinforcing steel sufficiently slip-free and cause the stretching described in the area between the two stretching disks.
  • the bending deformation on the stretching discs does not have any effect which significantly contributes to the strengthening itself.
  • the stretching takes place in the longitudinal direction of the reinforcing steel.
  • the hardening generated is a uniaxial strain hardening with considerable anisotropy across the cross-section of the reinforcing steel.
  • the quality improvements that can be achieved through this strain hardening can be impaired by the Bauschinger effect, which is disruptive for certain applications of the manufactured and hardened reinforcing steel.
  • the Bauschinger effect describes a special physical appearance: The plastic deformation of a material in one direction is based on the knowledge of Bauschinger the elastic limit with subsequent deformation in the opposite direction. The Bauschinger effect is based on the formation of internal stresses that are effective against the original direction of deformation.
  • the Bauschinger effect also has an effect in a generic method in which the reinforcing steel is deformed in two bending planes arranged orthogonally to one another (EP-A-0 194 478).
  • the invention has for its object to perform the method described above so that a very isotropic strain hardening is achieved over the cross section of the reinforcing steel.
  • the invention is further based on the object of specifying a system which is particularly suitable for carrying out the method according to the invention.
  • the invention teaches from a process engineering point of view that the reinforcing steel in three different bending planes, which are offset by approximately 120 ° from one another, is subjected to a multi-stage bending deformation around bending rollers and is thus superposed multi-axially strain-hardened in the bending planes, whereby an extension of the reinforcing steel is achieved and that the yield strength and the elongation are set by the extent of the extension.
  • the reinforcing steel is preferably subjected to a three-stage bending deformation in three different bending planes which are offset from one another by approximately 120 °.
  • the reinforcing steel can be subjected to multi-stage bending deformation at a throughput speed of 1 to 25 m / sec.
  • the reinforcing steel undergoes a bending in bending planes that are offset from one another as described, it can be said that a multi-axis bending state or a multi-axis strain hardening state can be spoken about the reinforcing steel axis.
  • this leads to the fact that every point on the reinforcing steel surface is subjected to this stress in a continuously changing manner.
  • the result is a very even and very isotropic hardening and a very defined and even decrease in cross-section. Surprisingly, the annoying Bauschinger effect disappears.
  • the quality values of the reinforcing steel in terms of yield strength, tensile strength and Elongation at break is significantly improved and can be adjusted or controlled via the extension, ie the degree of stretching.
  • the effects according to the invention are particularly pronounced when working with three bending planes as described.
  • a preferred embodiment of the invention is characterized in that an extension of the reinforcing steel of at least 5% is used. It is understood that within the scope of the invention a sufficiently pronounced bending deformation must be realized. It has been proven that the reinforcing steel is guided on the individual bending rollers with a wrap angle of 100 to 150 °. It can be worked with bending rollers that have a diameter in the diameter range that has been specified in claim 6.
  • the hardening can be set up and controlled via the extension that the reinforcing steel is subjected to in the method according to the invention.
  • the invention teaches in detail that the extension which the reinforcing steel undergoes during the hardening, and thus the hardening, is set up, even at a predetermined throughput speed, by selecting the diameter of the bending rollers and / or varying the wrap angle. It is within the scope of the invention to set the diameter of the bending roller and / or the wrap angle differently in the individual bending deformation stages. In any case, the wrap angle can be adjusted operationally.
  • the method according to the invention is suitable for a wide variety of reinforcing steels customary in the construction industry.
  • the method has proven particularly useful when working with a reinforcing steel in the diameter range of 6 to 14 mm.
  • the object of the invention is in particular that a reinforcing steel according to DIN 488 is subjected to the method according to the invention. Following the consolidation can with usual Aids a straightening of the reinforcing steel are carried out, during or after the usual cutting to the lengths that the reinforcing steel must have for use.
  • the invention also relates to a plant for the strengthening of reinforcing steel, in particular weldable reinforcing steel, which was produced by hot rolling, with a plurality of roller straightening units which are arranged one behind the other in different bending planes in the direction of travel of the reinforcing steel, characterized by three roller straightening units, each with a defined bending plane, around each other 120 ° offset, each roller straightener has two support rollers and a bending roller arranged in the area between the support rollers.
  • the bending roller is adjustable relative to the support rollers and the wrap angle is thereby adjustable.
  • the reinforcing steel 4 is subjected to a three-stage bending deformation by one bending roller 6 in each case in the torsion-free passage in three different bending planes A, B, C, which are offset by approximately 120 ° from one another. As a result, it is superposed triple-axis strain hardened in the three bending planes A, B, C.
  • An extension of the reinforcing steel 4 is achieved.
  • the yield point and the elongation can be adjusted by the length of the extension.
  • the bending rollers 6 can be specially selected with respect to the bending roller diameter d, and the wrap angle ⁇ can be particularly adjusted. - Proceed accordingly if you work with more than three bending levels.
  • the bending-hardening process is followed by a continuously working straightening system, which straightens the solidified material and cuts it to bars of a defined length. Both systems are set up in a line and work synchronously.
  • the straightened material can be used as primary material for bending and reinforcement companies.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Wire Processing (AREA)
  • Reinforcement Elements For Buildings (AREA)
  • Artificial Fish Reefs (AREA)
  • On-Site Construction Work That Accompanies The Preparation And Application Of Concrete (AREA)
  • Heat Treatment Of Steel (AREA)

Abstract

Method for hardening reinforcing bars for concrete, in particular weldable reinforcing bars produced by hot rolling, the reinforcing bars being subjected to cold mechanical deformation in a continuous process and thereby adjusted, inter alia, in respect of their yield strength and breaking elongation. The reinforcing bars are subjected to multi-stage bending, without torsion, around a bending roller (5, 6) in various equidistant, mutually offset bending planes and thereby cold work/hardened in the bending planes along a plurality of superposed axes. In the process, a lengthening of the reinforcing rods is achieved. The yield strength and breaking elongation are adjusted by the extent of this lengthening. A device for carrying out the method is also disclosed. <IMAGE>

Description

Die Erfindung betrifft ein Verfahren zur Verfestigung von Betonstahl, insbesondere von schweißbarem Betonstahl, der durch Warmwalzen hergestellt wurde, wobei der Betonstahl kalt und kontinuierlich im torsionsfreien Durchlauf in verschiedenen Biegeebenen einer mechanischen Verformung unterworfen und dadurch unter anderem in bezug auf seine Streckgrenze und seine Dehnung eingestellt wird. Der Ausdruck Betonstahl bezeichnet im Rahmen der Erfindung gerippten und ungerippten Betonstahl, insbesondere auch Betonstahl mit Schrägrippen sowie gegebenenfalls Längsrippen, z.B. Betonstahl nach DIN 488. Die Erfindung betrifft fernerhin eine Anlage zur Durchführung des beschriebenen Verfahrens.The invention relates to a method for the strengthening of reinforcing steel, in particular weldable reinforcing steel, which was produced by hot rolling, the reinforcing steel being subjected to mechanical deformation in a cold and continuous manner in the torsion-free pass in various bending planes and thereby adjusted, inter alia, with regard to its yield strength and its elongation becomes. In the context of the invention, the term reinforcing steel denotes ribbed and non-ribbed reinforcing steel, in particular also reinforcing steel with oblique ribs and optionally longitudinal ribs, e.g. Reinforcing steel according to DIN 488. The invention further relates to a system for performing the described method.

Im Rahmen bekannter Maßnahmen ist die mechanische Verformung eine Kaltreckung. Bei einem in die großtechnische Praxis eingeführten Verfahren 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 und 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 Verfahrensweise gehören, wenig gleichmäßig. Die Dauerschwingungsfestigkeit des so gestreckten Betonstahls ist häufig unbefriedigend. Es besteht bei Schwingungsbeanspruchungen Dauerbruchgefahr. Andererseits verlangt die Praxis im zunehmenden 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 context of known measures, the mechanical deformation is cold stretching. In a process that has been introduced into large-scale industrial practice, the stretching results from a torsional deformation with the aid of a torsional machine that works discontinuously. The discontinuous procedure interferes with the operational process. Relatively large, unavoidable tolerances must be permitted and taken into account for the yield point to be set and 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 comply with the prescribed values for the yield strength and the elongation for reinforcing steel, the cold stretching described by torsion is often avoided and the prescribed physical properties are adjusted by microalloying, in particular by adding vanadium. That leads to satisfactory Results. However, this is expensive 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 darüber berichtet worden, daß das Microlegieren durch ein kontinuierliches Recken ersetzt werden kann (Werkzeitschrift "Report" der Hamburger Stahlwerke Gesellschaft mit beschränkter Haftung vom 22. Juni 1989, Seite 11). Hier wurde mit einer Reckmaschine gearbeitet, die zwei mit unterschiedlicher Umfangsgeschwindigkeit arbeitende Reckscheiben aufweist. In diesen Zusammenhang gehört eine ältere Patentanmeldung (EP 90 111 026.2, PatG § 3 (2)), die lehrt, daß der Stahldraht kontinuierlich gereckt wird und dazu über zumindest zwei angetriebene Reckscheiben oder Reckwalzen geführt wird, die mit unterschiedlichen Umfangsgeschwindigkeiten auf den Stahldraht arbeiten, daß über die Umfangsgeschwindigkeitsdifferenz der beiden Reckscheiben der Reckgrad gesteuert wird, und daß über die Reckgeschwindigkeit die Streckgrenze und die Dehnung gesteuert bzw. eingestellt werden. Dabei wird der Stahldraht mit einem Mindestkrümmungsradius von 500 mm über die Reckscheiben geführt. Im Rahmen dieser Maßnahmen ist die Biegeverformung an den Reckscheiben spärlich. Sie wird so eingerichtet, daß die Reibungskräfte, die auf den Betonstahl einwirken, zur ausreichend schlupffreien Mitnahme des Betonstahls ausreichen und die beschriebene Reckung im Bereich zwischen den beiden Reckscheiben bewirken. Die Biegeverformung an den Reckscheiben bewirkt keinen zur Verfestigung selbst erheblich beitragenden Effekt. Die Reckung erfolgt in Längsrichtung des Betonstahls. Die erzeugte Verfestigung ist insoweit eine einachsige Kaltverfestigung mit beachtlicher Anisotropie über den Querschnitt des Betonstahls. Die durch diese Kaltverfestigung erreichbaren Qualitätsverbesserungen können durch den Bauschinger Effekt beeinträchtigt sein, was für bestimmte Anwendungen des hergestellten und verfestigten Betonstahls stört. - Der Bauschinger Effekt beschreibt eine besondere physikalische Erscheinung: Die plastische Verformung eines Werkstoffes in einer Richtung setzt nach den Erkenntnissen von Bauschinger die Elastizitätsgrenze bei anschließender Verformung in entgegengesetzter Richtung herab. Der Bauschinger Effekt beruht auf der Ausbildung von inneren Spannungen, die entgegen der ursprünglichen Verformungsrichtung wirksam sind.It has recently been reported that microalloying can be replaced by continuous stretching (work magazine "Report" of the Hamburger Stahlwerke Gesellschaft with limited liability of June 22, 1989, page 11). Here, a stretching machine was used, which has two stretching disks working at different peripheral speeds. In this context belongs an older patent application (EP 90 111 026.2, PatG § 3 (2)), which teaches that the steel wire is continuously stretched and is guided over at least two driven stretching disks or stretching rollers that work on the steel wire at different peripheral speeds that the degree of stretching is controlled via the difference in circumferential speed of the two stretching disks, and that the stretching limit and the elongation are controlled or set via the stretching speed. The steel wire is guided over the stretching discs with a minimum radius of curvature of 500 mm. As part of these measures, the bending deformation on the stretching discs is sparse. It is set up in such a way that the frictional forces acting on the reinforcing steel are sufficient to take the reinforcing steel sufficiently slip-free and cause the stretching described in the area between the two stretching disks. The bending deformation on the stretching discs does not have any effect which significantly contributes to the strengthening itself. The stretching takes place in the longitudinal direction of the reinforcing steel. In this respect, the hardening generated is a uniaxial strain hardening with considerable anisotropy across the cross-section of the reinforcing steel. The quality improvements that can be achieved through this strain hardening can be impaired by the Bauschinger effect, which is disruptive for certain applications of the manufactured and hardened reinforcing steel. - The Bauschinger effect describes a special physical appearance: The plastic deformation of a material in one direction is based on the knowledge of Bauschinger the elastic limit with subsequent deformation in the opposite direction. The Bauschinger effect is based on the formation of internal stresses that are effective against the original direction of deformation.

Der Bauschinger Effekt wirkt sich auch aus bei einem gattungsgemäßen Verfahren, bei dem der Betonstahl in zwei orthogonal zueinander angeordneten Biegeebenen verformt wird (EP-A-0 194 478).The Bauschinger effect also has an effect in a generic method in which the reinforcing steel is deformed in two bending planes arranged orthogonally to one another (EP-A-0 194 478).

Der Erfindung liegt die Aufgabe zugrunde, das eingangs beschriebene Verfahren so zu führen, daß eine über den Querschnitt des Betonstahls sehr isotrope Kaltverfestigung erreicht wird. Der Erfindung liegt fernerhin die Aufgabe zugrunde, eine Anlage anzugeben, die zur Durchführung des erfindungsgemäßen Verfahrens besonders geeignet ist.The invention has for its object to perform the method described above so that a very isotropic strain hardening is achieved over the cross section of the reinforcing steel. The invention is further based on the object of specifying a system which is particularly suitable for carrying out the method according to the invention.

Zur Lösung dieser Aufgabe lehrt die Erfindung in verfahrenstechnischer Hinsicht, daß der Betonstahl in drei verschiedenen Biegeebenen, die um etwa 120° gegeneinander versetzt sind, einer mehrstufigen Biegeverformung um Biegerollen unterworfen sowie dadurch in den Biegeebenen superponiert mehrachsig kaltverfestigt wird, wobei eine Verlängerung des Betonstahls erreicht wird, und daß die Streckgrenze sowie die Dehnung durch das Maß der Verlängerung eingestellt werden. Vorzugsweise wird der Betonstahl in drei verschiedenen Biegeebenen, die um etwa 120° gegeneinander versetzt sind, einer dreistufigen Biegeverformung unterworfen. Der Betonstahl kann mit einer Durchlaufgeschwindigkeit von 1 bis 25 m/sec der mehrstufigen Biegeverformung unterworfen werden. - Da erfindungsgemäß der Betonstahl eine Biegung in gegeneinander wie beschrieben versetzten Biegeebenen erfährt, kann insoweit, um die Betonstahlachse betrachtet, von einem mehrachsigen Biegezustand oder auch von einem mehrachsigen Kaltverfestigungszustand gesprochen werden. Das führt im Durchlaufverfahren dazu, daß jeder Punkt der Betonstahloberfläche kontinuierlich wechselnd dieser Beanspruchung unterworfen wird. Das Resultat besteht in einer sehr gleichmäßigen und sehr isotropen Verfestigung und einer sehr definierten und gleichmäßigen Querschnittsabnahme. Überraschenderweise verschwindet der störende Bauschinger Effekt. Die Qualitätswerte des Betonstahls in bezug auf Streckgrenze, Zugfestigkeit und Bruchdehnung werden wesentlich verbessert und lassen sich über die Verlängerung, d.h. den Reckgrad, einstellen bzw. steuern. Die erfindungsgemäßen Effekte sind besonders ausgeprägt, wenn mit drei Biegeebenen wie beschrieben gearbeitet wird.To achieve this object, the invention teaches from a process engineering point of view that the reinforcing steel in three different bending planes, which are offset by approximately 120 ° from one another, is subjected to a multi-stage bending deformation around bending rollers and is thus superposed multi-axially strain-hardened in the bending planes, whereby an extension of the reinforcing steel is achieved and that the yield strength and the elongation are set by the extent of the extension. The reinforcing steel is preferably subjected to a three-stage bending deformation in three different bending planes which are offset from one another by approximately 120 °. The reinforcing steel can be subjected to multi-stage bending deformation at a throughput speed of 1 to 25 m / sec. - Since, according to the invention, the reinforcing steel undergoes a bending in bending planes that are offset from one another as described, it can be said that a multi-axis bending state or a multi-axis strain hardening state can be spoken about the reinforcing steel axis. In the continuous process, this leads to the fact that every point on the reinforcing steel surface is subjected to this stress in a continuously changing manner. The The result is a very even and very isotropic hardening and a very defined and even decrease in cross-section. Surprisingly, the annoying Bauschinger effect disappears. The quality values of the reinforcing steel in terms of yield strength, tensile strength and Elongation at break is significantly improved and can be adjusted or controlled via the extension, ie the degree of stretching. The effects according to the invention are particularly pronounced when working with three bending planes as described.

Im einzelnen bestehen im Rahmen der Erfindung mehrere Möglichkeiten der weiteren Ausbildung und Gestaltung. So ist eine bevorzugte Ausführungsform der Erfindung dadurch gekennzeichnet, daß mit einem Verlängerungsgrad des Betonstahls von zumindest 5% gearbeitet wird. Es versteht sich, daß im Rahmen der Erfindung eine ausreichend ausgeprägte Biegeverformung verwirklicht werden muß. Bewährt hat sich, daß der Betonstahl an den einzelnen Biegerollen mit einem Umschlingungswinkel von 100 bis 150° geführt wird. Dabei kann mit Biegerollen gearbeitet werden, die einen Durchmesser in dem Durchmesserbereich aufweisen, der im Patentanspruch 6 angegeben worden ist.There are several options for further training and design within the scope of the invention. For example, a preferred embodiment of the invention is characterized in that an extension of the reinforcing steel of at least 5% is used. It is understood that within the scope of the invention a sufficiently pronounced bending deformation must be realized. It has been proven that the reinforcing steel is guided on the individual bending rollers with a wrap angle of 100 to 150 °. It can be worked with bending rollers that have a diameter in the diameter range that has been specified in claim 6.

Im Rahmen der Erfindung ist die Verfestigung über die Verlängerung, die der Betonstahl im erfindungsgemäßen Verfahren erfährt, einrichtbar und steuerbar. Dazu lehrt die Erfindung im einzelnen, daß die Verlängerung, die der Betonstahl bei der Verfestigung erfährt, und damit die Verfestigung, selbst bei vorgegebener Durchlaufgeschwindigkeit durch Auswahl des Durchmessers der Biegerollen und/oder Variation des Umschlingungswinkels eingerichtet wird. Im Rahmen der Erfindung liegt es, den Durchmesser der Biegerolle und/oder den Umschlingungswinkel in den einzelnen Biegeverformungsstufen unterschiedlich einzustellen. Jedenfalls kann der Umschlingungswinkel betriebsmäßig verstellt werden.Within the scope of the invention, the hardening can be set up and controlled via the extension that the reinforcing steel is subjected to in the method according to the invention. To this end, the invention teaches in detail that the extension which the reinforcing steel undergoes during the hardening, and thus the hardening, is set up, even at a predetermined throughput speed, by selecting the diameter of the bending rollers and / or varying the wrap angle. It is within the scope of the invention to set the diameter of the bending roller and / or the wrap angle differently in the individual bending deformation stages. In any case, the wrap angle can be adjusted operationally.

Das erfindungsgemäße Verfahren eignet sich für die verschiedensten, in der Bauindustrie üblichen Betonstähle. Bewährt hat sich das Verfahren insbesondere, wenn mit einem Betonstahl im Durchmesserbereich von 6 bis 14 mm gearbeitet wird. Gegenstand der Erfindung ist es insbesondere, daß ein Betonstahl nach DIN 488 dem erfindungsgemäßen Verfahren unterworfen wird. Im Anschluß an die Verfestigung kann mit üblichen Hilfsmitteln ein Richten des Betonstahls durchgeführt werden, dabei oder danach erfolgt das übliche Ablängen auf die Längen, die der Betonstahl für die Verwendung haben muß.The method according to the invention is suitable for a wide variety of reinforcing steels customary in the construction industry. The method has proven particularly useful when working with a reinforcing steel in the diameter range of 6 to 14 mm. The object of the invention is in particular that a reinforcing steel according to DIN 488 is subjected to the method according to the invention. Following the consolidation can with usual Aids a straightening of the reinforcing steel are carried out, during or after the usual cutting to the lengths that the reinforcing steel must have for use.

Gegenstand der Erfindung ist auch eine Anlage zur Verfestigung von Betonstahl, insbesondere schweißbarem Betonstahl, der durch Warmwalzen hergestellt wurde, - mit mehreren Rollenrichtwerken die in Durchlaufrichtung des Betonstahls hintereinander in unterschiedlichen Biegeebenen angeordnet sind, gekennzeichnet durch drei Rollenrichtwerke mit jeweils definierter Biegeebene, die gegeneinander um 120° versetzt angeordnet sind, wobei jedes Rollenrichtwerk zwei Stützrollen und eine im Bereich zwischen den Stützrollen angeordnete Biegerolle aufweist. Nach bevorzugter Ausführungsform der Erfindung ist die Biegerolle gegenüber den Stützrollen verstellbar und ist dadurch der Umschlingungswinkel einstellbar.The invention also relates to a plant for the strengthening of reinforcing steel, in particular weldable reinforcing steel, which was produced by hot rolling, with a plurality of roller straightening units which are arranged one behind the other in different bending planes in the direction of travel of the reinforcing steel, characterized by three roller straightening units, each with a defined bending plane, around each other 120 ° offset, each roller straightener has two support rollers and a bending roller arranged in the area between the support rollers. According to a preferred embodiment of the invention, the bending roller is adjustable relative to the support rollers and the wrap angle is thereby adjustable.

Im folgenden wird die Erfindung anhand einer lediglich ein Ausführungsbeispiel darstellenden Zeichnung ausführlicher erläutert. Es zeigen in schematischer Darstellung

Fig. 1
die Rollenanordnung einer Anlage für die Durchführung des beschriebenen Verfahrens,
Fig. 2
eine Ansicht des Gegenstandes der Fig. 1 in Durchlaufrichtung, in gegenüber der Fig. 1 wesentlich vergrößertem Maßstab.
In the following, the invention will be explained in more detail with reference to a drawing showing only one exemplary embodiment. They show a schematic representation
Fig. 1
the arrangement of roles of a plant for the implementation of the described method,
Fig. 2
a view of the object of FIG. 1 in the direction of passage, on a significantly enlarged scale compared to FIG. 1.

In den Fig. 1 und 2 erkennt man drei Rollenrichtwerke 1, 2, 3 mit jeweils definierter Biegeebene A, B, C, die in Durchlaufrichtung des Betonstahls 4 hintereinander angeordnet sind. Sie sind gegeneinander um etwa 120° versetzt, wozu insbesondere auf die Fig. 2 verwiesen wird. Aus der Fig. 1 entnimmt man, daß jedes Rollenrichtwerk 1, 2, 3 zwei Stützrollen 5 und eine im Bereich zwischen den Stützrollen 5 angeordnete Biegerolle 6 aufweist. Diese ist in Richtung des Pfeiles, der in Fig. 1 im Bereich der Mitte angeordnet worden ist, verstellbar.1 and 2 one can see three roller straightening units 1, 2, 3, each with a defined bending plane A, B, C, which are arranged one behind the other in the direction in which the reinforcing steel 4 passes. They are offset from one another by approximately 120 °, for which reference is made in particular to FIG. 2. 1 that each roller straightener 1, 2, 3 has two support rollers 5 and a bending roller 6 arranged in the area between the support rollers 5. This can be adjusted in the direction of the arrow, which has been arranged in the middle in FIG. 1.

Arbeitet man mit der erfindungsgemäßen Anlage, so wird der Betonstahl 4 im torsionsfreien Durchlauf in drei verschiedenen Biegeebenen A, B, C, die um etwa 120° gegeneinander versetzt sind, einer dreistufigen Biegeverformung um jeweils eine Biegerolle 6 unterworfen. Er wird dadurch in den drei Biegeebenen A, B, C superponiert dreiachsig kaltverfestigt. Dabei wird eine Verlängerung des Betonstahls 4 erreicht. Die Streckgrenze und die Dehnung können durch das Maß der Verlängerung eingestellt werden. Dazu können die Biegerollen 6 bezüglich des Biegerollendurchmessers d besonders ausgewählt und kann der Umschlingungswinkel α besonders eingestellt werden. - Entsprechend verfährt man, wenn mit mehr als drei Biegeebenen gearbeitet wird.If you work with the system according to the invention, the reinforcing steel 4 is subjected to a three-stage bending deformation by one bending roller 6 in each case in the torsion-free passage in three different bending planes A, B, C, which are offset by approximately 120 ° from one another. As a result, it is superposed triple-axis strain hardened in the three bending planes A, B, C. An extension of the reinforcing steel 4 is achieved. The yield point and the elongation can be adjusted by the length of the extension. For this purpose, the bending rollers 6 can be specially selected with respect to the bending roller diameter d, and the wrap angle α can be particularly adjusted. - Proceed accordingly if you work with more than three bending levels.

AusführungsbeispielEmbodiment

Ein gerippter Walzdraht der Abmessung 10 mm, Rippung gem. DIN 488, Stahl IV, und folgender Analyse:

Kohlenstoff
: 0,19 %
Silizium
: 0,23 %
Mangan
: 0,79 %
A corrugated wire rod with the dimension 10 mm, corrugation acc. DIN 488, steel IV, and the following analysis:
carbon
: 0.19%
silicon
: 0.23%
manganese
: 0.79%

Rest Eisen und übliche Beimengungen weisen im warmgewalzten Zustand folgende mechanische Eigenschaften auf:

Streckgrenze Rp0,2
: 361 N/mm²
Zugfestigkeit Rm
: 562 N/mm²
Bruchdehnung A₁₀
: 24,7 %
Verhältnis Rm/Rp0,2
: 1,56
The rest of iron and usual additives have the following mechanical properties when hot-rolled:
Yield strength Rp0.2
: 361 N / mm²
Tensile strength Rm
: 562 N / mm²
Elongation at break A₁₀
: 24.7%
Rm / Rp0.2 ratio
: 1.56

Dieser warmgerippte Walzdraht wird über die beschriebene Anordnung geführt. Der Verlängerungsgrad beträgt ca. 6 %. Nach diesem kontinuierlichen Prozeß der Verfestigung ergaben sich folgende mechanische Eigenschaften (ohne künstliche Alterungsbehandlung):

Streckgrenze Rp0,2
: 509 N/mm²
Zugfestigkeit Rm
: 626 N/mm²
Bruchdehnung A₁₀
: 19,2 %
Gleichmaßdehnung A10Gl
: 9,6 %
Verhältnis Rm/Rp0,2
: 1,23
This hot-finned wire rod is guided over the arrangement described. The degree of extension is approx. 6%. After this continuous process of solidification, the following mechanical properties (without artificial aging treatment) resulted:
Yield strength Rp0.2
: 509 N / mm²
Tensile strength Rm
: 626 N / mm²
Elongation at break A₁₀
: 19.2%
Uniform expansion A 10Gl
: 9.6%
Rm / Rp0.2 ratio
: 1.23

Damit entspricht dieses Material den Anforderungen der DIN 488 Sorte B St 500 S.This material thus meets the requirements of DIN 488 grade B St 500 S.

Das Biege-Verfestigungs-Verfahren wird bevorzugt mit Betonstahl in folgendem Analysenrahmen ausgeführt:

Kohlenstoff
: 0,14 - 0,22 %
Silizium
: 0,15 - 0,40 %
Mangan
: 0,60 - 1,30 %
The bending strengthening process is preferably carried out with reinforcing steel in the following analysis frame:
carbon
: 0.14 - 0.22%
silicon
: 0.15 - 0.40%
manganese
: 0.60 - 1.30%

Rest Eisen und Beimengungen-Gehalte entsprechen der Vorgaben des Instituts für Bautechnik, Berlin.The rest of the iron and admixture contents correspond to the specifications of the Institut für Bautechnik, Berlin.

Dem Biege-Verfestigungs-Vorgang nachgeschaltet ist eine kontinuierlich arbeitende Richtanlage, die das so verfestigte Material richtet und zu Stäbe definierter Länge ablängt. Beide Anlagen sind in Linie aufgestellt und arbeiten synchron. Das gerichtete Material kann als Vormaterial für Biege- und Bewehrungsbetriebe verwandt werden.The bending-hardening process is followed by a continuously working straightening system, which straightens the solidified material and cuts it to bars of a defined length. Both systems are set up in a line and work synchronously. The straightened material can be used as primary material for bending and reinforcement companies.

Claims (11)

  1. A process for hardening concrete-reinforcing steel (4), particularly weldable concrete-reinforcing steel, which has been manufactured by hot-rolling, wherein the concrete-reinforcing steel (4) is subjected cold, continuously and in torsion-free throughput, to a mechanical deformation in different bending planes, and by this means is adjusted with regard to its apparent limit of elasticity and its elongation, amongst other properties, characterised in that the concrete-reinforcing steel (4) is subjected to a multi-stage bending deformation around bending rolls (6) in three different bending planes (A, B, C) which are offset by about 120° in relation to each other, and by this means undergoes superimposed multi-axial strain-hardening in the bending planes (A, B, C), wherein a lengthening of the concrete-reinforcing steel (4) is obtained, and that the apparent limit of elasticity and the elongation are adjusted by the extent of this lengthening.
  2. A process according to claim 1, characterised in that the concrete-reinforcing steel (4) is subjected to the three-stage bending deformation at a throughput rate of 1 to 25 m/sec.
  3. A process according to either one of claims 1 or 2, characterised in that a degree of lengthening of the concrete-reinforcing steel (4) of at least 5%, preferably of at least 7%, is employed.
  4. A process according to any one of claims 1 to 3, characterised in that the concrete-reinforcing steel (4) is fed to the individual bending rolls (6) at an angle of wrap (2) of 100 to 150°.
  5. A process according to any one of claims 1 to 4, characterised in that bending rolls (6) are employed which have a diameter in the range of 70 to 250 mm.
  6. A process according to any one of claims 1 to 5, characterised in that the lengthening which the concrete-reinforcing steel (4) experiences during hardening, and thus the hardening, is established at a predetermined throughput rate by the selection of the diameter of the bending rolls (6) and/or by variation of the angle of wrap (2).
  7. A process according to any one of claims 1 to 6, characterised in that the diameter of the bending roll (6) and/or the angle of wrap (2) are adjusted differently in the individual bending deformation stages.
  8. A process according to any one of claims 1 to 7, characterised in that a concrete-reinforcing steel (4) in the diameter range of 6 to 14 mm is employed.
  9. A process according to any one of claims 1 to 8, characterised in that a concrete-reinforcing steel (4) according to DIN 488 is subjected to the hardening.
  10. An installation for hardening concrete-reinforcing steel, particularly weldable concrete-reinforcing steel, which has been manufactured by hot-rolling, - with a plurality of roller straightening units which are disposed in series in different bending planes in the direction of throughput of the concrete-reinforcing steel, characterised by three roller-straightening units (1, 2, 3), each with a defined bending plane (A, B, C), which are offset in relation to each other by about 120°, wherein each roller-straightening unit (1, 2, 3) has two back-up rolls (5) and a bending roll (6) disposed in the region between the back-up rolls (5).
  11. An installation according to claim 10, characterised in that the bending roll (6) can be adjusted in relation to the back-up rolls (5) and by this means the angle of wrap (α) can be set.
EP91112149A 1990-08-03 1991-07-20 Method and device for strengthening of reinforcing bars for concrete Expired - Lifetime EP0469410B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4024653 1990-08-03
DE4024653A DE4024653C1 (en) 1990-08-03 1990-08-03

Publications (2)

Publication Number Publication Date
EP0469410A1 EP0469410A1 (en) 1992-02-05
EP0469410B1 true EP0469410B1 (en) 1994-06-01

Family

ID=6411580

Family Applications (1)

Application Number Title Priority Date Filing Date
EP91112149A Expired - Lifetime EP0469410B1 (en) 1990-08-03 1991-07-20 Method and device for strengthening of reinforcing bars for concrete

Country Status (5)

Country Link
EP (1) EP0469410B1 (en)
AT (1) ATE106287T1 (en)
DE (2) DE4024653C1 (en)
DK (1) DK0469410T3 (en)
ES (1) ES2054405T3 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107604139A (en) * 2017-11-06 2018-01-19 舟山市7412工厂 The curing system and its method for curing of a kind of raw metal

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE626756C (en) * 1934-07-28 1936-03-02 Alfred Varley Sims Automatic valve
DE746251C (en) * 1941-05-13 1945-01-08 Kohle- Und Eisenforschung Gmbh Process for increasing the number of bends and twists of steel wires that have been spun in operation
DE1533992A1 (en) * 1967-05-16 1970-02-19 Rehm Gallus Process for increasing the elastic limit, the yield strength and, if necessary, the breaking strength of steel by cold deformation
AT339852B (en) * 1973-10-19 1977-11-10 Voest Ag DEVICE FOR CONTINUOUS COLD STRENGTHENING OF ROLLED METALLIC ROLLED, ESPECIALLY STEEL WIRE
US4216666A (en) * 1978-09-18 1980-08-12 Extruded Metals Method of relieving stress in extruded sections
EP0194478B1 (en) * 1985-03-08 1989-12-06 M.E.P. Macchine Elettroniche Piegatrici S.p.A. Device for straightening rods or wire without relative rotation of succeeding elements of material about the longitudinal axis
DE3919382A1 (en) * 1989-06-14 1991-01-03 Kt Baustahl Vertrieb DEVICE FOR INCREASING THE STRETCH LIMIT OF HOT ROLLED WIRE

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107604139A (en) * 2017-11-06 2018-01-19 舟山市7412工厂 The curing system and its method for curing of a kind of raw metal

Also Published As

Publication number Publication date
ES2054405T3 (en) 1994-08-01
DE4024653C1 (en) 1991-07-25
ATE106287T1 (en) 1994-06-15
DK0469410T3 (en) 1994-07-11
DE9106386U1 (en) 1991-08-08
EP0469410A1 (en) 1992-02-05

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