EP0876856A2 - High performance wire rolling mill - Google Patents

Abstract

• einer Umführung (6) um 180° hinter der Zwischenstraße I (5),
• einer Zwischenstraße II (7) zur Erzeugung dicker Fertigabmessungen bzw. Vorquerschnitte, in Konzeption für schnellen Gerüstwechsel,
• einer Fertigstraße (8), ebenfalls in Konzeption für schnellen Gerüstwechsel,
• der Anordnung der Fertigstraße (8) in einer zur Zwischenstraße II (7) parallelen Fertiglinie (9),
• der Zuordnung einer gemeinsamen und zwischen diesen beiden parallelen Fertiglinien (9, 10) verschiebbaren Wasserkühlstrecke (11) und
• der Zuordnung einer zwischen beiden Fertiglinien (9, 10) verschiebbaren Wickelspulenanordnung (12) anstelle einer nachgeordneten Ausgleichstrecke.

The invention relates to a high-performance wire rolling mill, comprising a wire and / or bar mill for reinforcing steel and simple carbon steels, with a CC system or a CC casting wheel (1), a direct connection of a CC system or casting wheel ( 1) to the rolling mill, a buffer furnace (3) between the CC system or the casting wheel (1) and the rolling mill to compensate for production differences and minor rolling mill malfunctions, a compact upstream (4) and intermediate line I (5) , as well as with a standard calibration for the road sections (4 or 5). Such a wire rolling mill is characterized by the features

• a detour (6) 180 ° behind the intermediate road I (5),
• an intermediate line II (7) for the production of thick finished dimensions or pre-sections, designed for quick scaffolding changes,
• a finishing train (8), also designed for quick scaffolding changes,
• the arrangement of the finishing train (8) in a finishing line (9) parallel to the intermediate road II (7),
• the assignment of a common and between these two parallel finished lines (9, 10) movable water cooling section (11) and
• the assignment of a winding spool arrangement (12) which can be displaced between the two finished lines (9, 10) instead of a downstream compensation section.

Description

• einer CC-Anlage bzw. einem CC-Gießrad für hohe Produktion,
• einer Direktanbindung von CC-Anlage bzw. -Gießrad an das Walzwerk,
• einem Puffer-Ofen zwischen der CC-Anlage bzw. dem -Gießrad und dem Walzwerk zum Ausgleich von Produktionsunterschieden sowie kleineren Walzwerksstörungen,
• einer kompakten Vor- und Zwischenstraße I
• mit einer Einheitskalibrierung für die Straßenabschnitte.

The invention relates to a high-performance wire rolling mill, comprising a wire and / or bar mill for reinforcing steel and simple carbon steels with:

• a CC system or a CC casting wheel for high production,
• a direct connection of the CC system or casting wheel to the rolling mill,
• a buffer furnace between the CC system or the casting wheel and the rolling mill to compensate for differences in production and minor malfunctions in the rolling mill,
• a compact Vorstrasse and Zwischenstrasse I
• with a uniform calibration for the road sections.

High-performance wire rod mills with the generic features in the aforementioned preamble of claim 1 are in the prior art known. This includes individual components of the system concept described, but these are not yet sufficient to in terms of the desired layout for minimized space requirements and investment costs to implement a convincing new concept.

The special print from Klepzik Fachberichte 82 (1974) 11, pp. 427/430 with the title "Single-core Morgan Siemag wire mill", author Heinz Bachmann describes the planning principles for a new wire rod mill at the Diemlach (Austria) plant, where - due to the very tight Space - a space-saving solution had to be found. Taking into account the local conditions and with the aim The only solution was the lowest possible investment cost compact single-core wire rod in U-shape. For heat treatment The wire became an elongated Morgan Street for two layers Operation. With a targeted heat treatment be achieved that the wire emerging from a wire mill after cooling, good drawing properties and as even as possible The course of the strength over the entire wire length and over has the wire cross section.

A detailed discussion of the problems and the prior art of water cooling behind wire lines can be found in the special print from "DRAHT" 29 (1978) 6, pp. 286/89. The first stage of controlled cooling from the rolling heat is usually water cooling directly behind the finishing block. Often, several cooling zones are assigned to the wire, which cool it down in stages to the desired laying temperature. Recreational routes have been set up between the individual cooling zones, which should give the wire the opportunity to equalize its temperature over the course of the cross-section. In conventional cooling sections that work with water pressures between 5 and 15 bar, heat transfer coefficients of up to 50,000 W / m ² ° C can occur at a rolling speed of 60 m / sec in the area of the nozzle. Average heat transfer coefficients are 30,000 to 40,000 W / m ² ° C. The wire surface is strongly supercooled when it exits the cooling section, while the core of the wire has remained much hotter depending on the cooling intensity and cooling time. This paper also takes into account the fact that when the wire tip enters a water-filled pipe, considerable forces can act on the wire tip, which in some cases cause the wire tip to break away.

Learn more about heat treating steel wire with over 0.4% lying carbon contents from the rolling heat are the DE-AS 1 583 411. The invention described therein lies the Task based on a method for heat treating steel wire from the rolling heat, the steel after exiting the last Scaffold intermittently quenched and through Temperature compensation with a core cross section is heated again and in the pearlite transformation region with a medium temperature from 600 to 650 ° C occurs in such a way that the previous usual lengths, considerable at increased rolling speeds which can significantly reduce cooling distances. This will be after this Document reached by quenching the wire surface intermittently up to 70 ° C above the martensite transformation temperature, at least to 400 ° C, is cooled, and that the wire of intermittent cooling for a time from 0.6 to 0.7 seconds is exposed. This is done in a manner known per se Way, water cooling quenching and temperature compensation under air cooling.

The special print from "Stahl und Eisen" 108 (1988), Eisenhüttenentag Pages 75 to 80 under the title "Temperature controlled rolling of Bar steel and wire ", the expert takes note that the Finishing roll temperature is easier to achieve and also a better one Temperature compensation is possible if only one cooling section with a long temperature compensation section is used. A Temperature reduction in the finishing train with many cooling sections, e.g. a cooling section behind each scaffold does not bring the desired one Success, but increases the length of the system and is in practical operation difficult to set. It goes on to say: The The selected plant regulations require that, contrary to the previous usual rolling practice all finished dimensions in the last two Stands are rolled and the stands in front of them during rolling thicker cross sections are omitted. The cooling section behind The task of the finishing stand is to recrystallize the austenite area to prevent, why aim at a temperature of about 650 ° C. is. This leaves the fine-grained quality achieved by the forming preserve the structure.

Another note on the design of wire mills with integrated The specialist takes a continuous caster from a translation the publication from MPT (Verlag Stahl Eisen, Düsseldorf) Vol. 15 (1992) No. 3, pp. 52/58 with the title "Connection of the continuous casting plant to fine steel or wire rod mills "by the author U. Svejkovsky. It particularly emphasizes the difficulty of harmonization between the continuous caster and the fine steel or wire rolling mill noted that these rolling mills have a wide range of products have many different dimensions and qualities as well as small lot sizes. In addition, the different Dimensions rolled in very different quantities because of the production quantity especially with small dimensions, very different from the Rolling speed is determined. That means the relative constant casting production when rolling small dimensions is not can be completely removed and for larger finished dimensions the performance of the rolling mill is greater.

For the best possible remedy, i.a. a warm operation according to the EHC process (indirect hot charging). With this The billets coming from the continuous caster are processed not fed directly to the rolling mill furnace, but rather the thermal energy the billet is used for this, the billets coming from a warehouse to warm up, exchanging heat in a heater is carried out. It is a two-storey heat store. In this are cold billet batches from the warehouse come and are put together according to the rolling program, above the billet batch coming from the continuous caster Countercurrent transported. This involves heat transfer preferably over heat radiation.

Based on this prior art, the invention lies The task is based on known individual components of the aforementioned system concepts to be combined with new device elements in such a way that the considerable hitherto usual at increased rolling speeds Lengths of the cooling section can be significantly reduced, so that in their functional interaction the concept of a particularly space-saving design of the system can be realized can.

• einer Umführung um 180° hinter der Zwischenstraße I,
• einer Zwischenstraße II zur Erzeugung dicker Fertigabmessungen bzw. Vorquerschnitte, in Konzeption für schnellen Gerüstwechsel,
• einer Fertigstraße, ebenfalls in Konzeption für schnellen Gerüstwechsel, mit
• der Anordnung der Fertigstraße in einer zur Zwischenstraße II parallelen Fertiglinie, mit
• der Zuordnung einer gemeinsamen und zwischen diesen beiden parallelen Fertiglinien verschiebbaren Wasserkühlstrecke und
• der Zuordnung einer zwischen beiden Fertiglinien verschiebbaren Wickelspulenanordnung anstelle einer nachgeordneten Ausgleichstrecke.

This object is achieved in a high-performance wire rolling mill of the type described in the preamble of claim 1,

• a detour by 180 ° behind the intermediate road I,
• an intermediate line II for the production of thick finished dimensions or pre-sections, designed for quick scaffolding changes,
• a finishing train, also designed for quick scaffolding changes, with
• the arrangement of the finishing train in a finishing line parallel to Zwischenstrasse II, with
• the assignment of a common water cooling section which can be moved between these two parallel finished lines and
• the assignment of a winding spool arrangement that can be moved between the two finished lines instead of a downstream compensation section.

With great advantage is the arrangement of a single and comparatively generously designed water cooling section a very intensive cooling of the wire is reached after the finishing train and compared to, for example, systems for intermittent cooling considerable reduction in system length achieved.

The fact that two parallel finishing lines have a common and is assigned between these slidable water cooling section saved considerably in investment volume and a very economical one Construction of the system allows.

• Ersetzen des Stelmor-Transportbandes durch die Aufwickelstation;
• Ersetzen des Kühlbettes durch die Aufwickelstation, bzw.
• Ersetzen einer Garett-Anlage durch die Aufwickelstation.

The fact that instead of a subordinate compensating section is assigned to a winding line arrangement that can be moved by two finished lines, a longer air cooling section is avoided and thus contributes in a special way to shortening the length of the installation and the space requirement. Depending on the inlet temperature of the wire from the cooling section into the winding spool arrangement, the wire, with an assumed base weight of 5 t, for example, has the possibility of developing a predeterminable microstructure per unit of time with a predetermined decrease in temperature of the coil. This is made possible by the use of cooling technology by means of cooling to the transition temperature for reinforcing steel and simple carbon steels, whereby the wire has already finished the structural transformation before winding and therefore temperature control, such as on the Stelmor conveyor belt, is no longer necessary. A considerable reduction in costs is achieved through:

• Replacement of the Stelmor conveyor belt by the winding station;
• Replacing the cooling bed with the winding station or
• Replacing a Garett system with the take-up station.

With this technology, design in conjunction with the direct use of a CC-casting plant or a CC-casting wheel for high production (CC stands for C ontinuous C asting) is an extremely compact overall system by increasing the coil weights of, for example, 2 t 5 t possible.

An embodiment of the system provides that the winding coil arrangement for wire from 6 to 16 mm and for round steel from 18 to 40 mm is designed.

The winding spools can advantageously in a winding station be arranged and they can be inside the take-up station Means for moving the winding spools between the finished lines have.

Another also advantageous embodiment provides that the Water cooling section Means for moving them to the finished lines owns. The means for moving can be a great advantage the winding coils and the means for moving the water cooling section be synchronously coupled with each other. Overall, with the Concept of the plant layout according to the invention that the The entire system can be accommodated in an area of approximately 30 x 150 m.

Details, features and advantages of the invention result from the following explanation of a schematic in the drawing illustrated embodiment.

The purely schematically shown family tree of the plant according to the invention, For example, for approx. 600,000 JATO reinforcing steel or simple carbon steels 2 shows a CC system or CC casting wheel 1 for high production. As I said, CC is an abbreviation for continuous Casting. With the preferred connection of the CC system 1 to the Rolling mill is the installation of a buffer furnace 3 to compensate for Production differences between the CC system 1 and rolling mill as well provided to compensate for smaller mill malfunctions. Following then a compact pre-4 and Intermediate road I 5, which are designed such that a roll change is only required in the weekly repair shift, where, for example, the stands with two-caliber rollers for mutual Caliber insert are equipped. The scaffolds have through short bale length, high rigidity.

This is followed by a detour 6 through 180 ° in the pedigree shown behind the intermediate road I 5, then an intermediate road II 7 to Generation of thick finished dimensions or pre-sections (e.g. 18-40 mm diameter) for the finishing train, designed for the fastest Scaffolding change. After the intermediate road II 7 branches off the Finishing line 10 from a parallel finishing line 9 in which the finishing train 8 (for example for 6-16 mm rolling stock diameter) is arranged. In The water cooling section is located on the following outlet section 11 with means 15 for displacement between the finished lines 9 and 10 is equipped. This is subordinate to the Slidable winding spool assembly 12, which also means 14 within the winding station 13 for moving between the Finished lines 9 and 10 is equipped.

Like the concept of the plant with a layout for minimized needs in space and investment costs according to the family tree shown reveals a compact system with a maximum of 30 x 150 m Space requirements and with comparatively low investment costs realized in particular in that the usually arranged Stelmor cooling section through a relatively short water cooling section is replaced. To increase the coil weights, it is proposed that to use the winding station 13 instead of the Garett system. A System concept with the interaction of all of the aforementioned individual components 1 to 15 according to the invention is the wide range not to be deduced from the technology. Therefore, the invention solves in an optimal way Wise the task at the beginning.

Claims (9)

High-performance wire rod mill, comprising a wire and / or bar mill for reinforcing steel and simple carbon steels, with: a CC system or a CC casting wheel (1), a direct connection of the CC system or casting wheel (1) to the rolling mill, a buffer furnace (3) between the CC system or the casting wheel (1) and the rolling mill to compensate for differences in production and minor malfunctions in the rolling mill, a compact upstream (4) and intermediate road I (5), as well as with a standard calibration for the road sections (4 and 5), marked by,
the characteristics a detour (6) 180 ° behind the intermediate road I (5), an intermediate line II (7) for the production of thick finished dimensions or pre-sections, designed for quick scaffolding changes, a finishing train (8), also designed for quick scaffolding changes, the arrangement of the finishing train (8) in a finishing line (9) parallel to the intermediate road II (7), the assignment of a common and between these two parallel finished lines (9, 10) movable water cooling section (11) and the assignment of a winding spool arrangement (12) which can be displaced between the two finished lines (9, 10) instead of a downstream compensation section. Wire rolling mill according to claim 1,
characterized,
that the winding coil arrangement (12) for wire (2) from 6 to 16 mm and for round steel (2) from 18 to 40 mm is designed. Wire rolling mill according to claim 1 or 2,
characterized,
that the winding spool assembly (12) is arranged in a winding station (13). Wire rolling mill according to one or more of claims 1 to 3,
characterized,
that the winding spool assembly (12) within the winding station (13) has means (14) for moving the winding spools between the finished lines (9, 10). Wire rolling mill according to one or more of claims 1 to 4,
characterized,
that the water cooling section (11) has means (15) for moving it between the finished lines (9, 10). Wire rolling mill according to one or more of claims 1 to 5,
characterized,
that the means (14) for moving the winding spools (12) and the means (15) for moving the water cooling section (11) are coupled to each other synchronously. Wire rolling mill according to one or more of claims 1 to 6,
characterized,
that the entire system can be accommodated in an area of approximately 30 x 150 m. Wire rolling mill according to one or more of claims 1 to 7,
characterized,
that Vorstraße (4) and Zwischenstrasse I (5) are of such a constructive conception that a roll change is only necessary in one weekly repair shift. Wire rolling mill according to one or more of claims 1 to 8,
characterized,
that the rolling stands of the rolling mills, in particular the compact roughing and intermediate mill (4, I 5), are equipped with two-caliber rollers for reciprocal caliber use.

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