EP0560115B1 - Method and rolling mill for precision rolling wire or stock having a circular cross-section - Google Patents

Abstract

The invention relates to a method for rolling wire or stock having a circular cross-section made of special steel or some other alloy steel in a high-duty small-section/wire rod train. In order to be able to achieve the narrowest possible wire tolerances, it is proposed to roll the stock 5 in the rerolling block 6 of the train with a significantly smaller pass reduction than the reduction passes carried out in the finishing block 1 of the wire rod train. The wire rod train consists of a roughing train having in each case a plurality of roll stands or rolling units, at least one intermediate train and a subsequent finishing train, and the latter is, in particular, designed as a finishing block. Arranged on the output side of the finishing block is an at least two-stand rerolling block 6 and arranged between the finishing block and the rerolling block there is, if required, a cooling section 13 and/or a temperature equalising device 14. In order to be able to use the rerolling block as a precision rolling block, it is fitted with a change gear 15 for changing it into a temper (skin pass) or precision rolling stand. <IMAGE>

Description

The invention relates to a method and a rolling mill for rolling out wire with a round cross-section made of stainless steel or other alloy steel in a high-performance wire mill with in each case several roughing stands comprising a roughing mill, at least one intermediate mill and with one finishing mill block, the finishing mill block being followed by a finish mill block and between the finish mill block and a roughing block, a cooling section and / or temperature compensation device is optionally arranged.

Modern high-performance fine steel / wire mills usually consist of a roughing mill, one or more intermediate mills and a finishing block for the rolling stock behind the furnace system. The mill stands in the Vorstrasse and Zwischenstrasse are robustly built and designed for high rolling demands. In the Vorstraße there are generally single scaffolds. In the intermediate line there are preferably compact stands with a horizontal / vertical arrangement of the rollers. A finishing mill is understood to mean rolling machines that consist of several, usually six to ten, alternately offset 90 ° rolling units, which are housed in a cassette in the rolling line, and which are driven directly and jointly by a drive via a transfer case.

After the finish rolling block, there is a water cooling section with an integrated temperature compensation section for the rolling stock. Depending on the size and quality of the rolling stock, the cooling zones can be set Control in such a way that the required temperature profile is achieved in the rolling stock even at maximum rolling speed. Behind the water cooling section, the rolling stock is air-cooled, for example, on a Stelmor system. At the end of the Stelmor system there is an adjustable drop step with subsequent chain transport. The wire windings enter the bundle forming chambers via the chain transport. The bundles formed are placed on a hook conveyor via a tipping chair unloading station and from there go into the binding machines and the dispatch.

The European patent application EP 0 512 735 A2 is concerned with the content of a method for producing wire rod in a roughing train, an intermediate train and a finishing train. A roughing block is arranged behind the finishing train. Cooling devices or temperature compensation devices can be arranged between the end of the finishing train and the roughing block. The roughing block consists of at least two reduction stands, which are followed by at least two precision stands. The wire is rolled out in a round-round sequence in the two precision stands. In the roughing, intermediate and finishing lines, the rolling stock is reduced by 15 to 30% with standard passes. A reduction of the round cross-section to the round cross-section between 2 and 15% is proposed within the roughing block and between the precision stands. This document should only be observed with regard to Article 54, paragraph 3 and paragraph 4 EPC; it gives no references to the rolling process claimed by the present patent application and to the claimed rolling mill.

The object of the present invention is to further develop a rolling method and a rolling mill in order to be able to guarantee even the tightest wire tolerances with a high performance level of the rolling mill.

This object is achieved according to the invention with the features of claim 1, namely with a method for rolling out wire with a round cross-section made of stainless steel or other alloy steel in a high-performance wire mill, each with a plurality of mill stands, a roughing mill, at least one intermediate mill and with a finishing block, whereby a finishing block is arranged downstream of the finishing roll block and a cooling section and / or temperature compensation device is optionally arranged between finishing roll block and finishing roll block, the wire being rolled out in a two-stand finishing roll block with a significantly lower pass reduction compared to the take-off passes performed in the finishing roll block, the one coming from the finishing roll block Wire in the first stand of the roughing block is rolled out with a standard pass, and the wire in the outlet stand of the roughing block is significantly smaller than the previous acceptance decrease of about 5 to 15% is rolled out.

The object is further achieved by a rolling mill for rolling out wire with a round cross-section made of stainless steel or other alloy steel in a high-performance wire mill with a roughing mill each having a plurality of mill stands, at least one intermediate mill and with a finishing mill block, the finishing mill block being followed by a finish mill block and between the finish mill block and Post-rolling block, optionally, a cooling section and / or temperature compensation device is arranged, the post-rolling block consisting only of two stand cassettes and between the stand cassettes has a changeover gear for switching it to a skin pass or precision roll block, and the transmission ratio of the changeover gear in the range between 1: 1.25 up to 1: 1.15. Manual transmissions in hitherto familiar arrangements of rolling mills to reduce the acceptance ratios may be known per se. To enrich the known rolling mill technology, the switchover of the roughing block or certain framework cassettes of the roughing block proposed here enables production narrowest tolerances of rolling stock and the adaptation, especially of existing rolling mills, to a wide range of products.

It is also advantageous if the calibration of the rolls in the finishing block can be adapted to the precision rolling.

• einen Ausschnitt aus einer Walzstraße mit einem Fertigwalzblock, einer Kühl- und Ausgleichsvorrichtung und mit einem schaltbaren Nachwalzblock als Präzisionswalzgerüst.

The invention is described below using an exemplary embodiment for a fine steel / wire mill. This shows:

• a section of a rolling mill with a finishing mill, a cooling and compensating device and with a switchable finishing mill as a precision mill.

The generic fine steel / wire mill generally consists of a preheating chamber in which the pre-block to be rolled out, usually a billet, is preheated before it is heated to rolling temperature in a pusher furnace, for example. The billet comes out of the pusher furnace after descaling the press water into a multi-stand roughing mill, in which the billet cross section is reduced to a round cross section. Crank, cropping and chopping shears are usually installed after the roughing mill and are able to prepare the cropping end for the intermediate mill. The rolling core passes through the intermediate line, in which the cross section of the round rolling stock is further reduced in several passes. Subsequently, after a renewed cropping of the roll ends, the roll core passes into the finishing roll block 1 shown schematically in FIG. 1.

The finishing mill 1 has ten swirl-free stand cassettes in a 45 ° arrangement. The horizontal stand cassettes 16 are drawn in the schematic plan view perpendicular to the rolling core 5 and drawn out with a reinforced line. The vertical stand cassettes 17 are shown as opposing rolling rings. The finishing mill block 1 is connected to a transfer case 2, from which an output shaft 3 is laid to the horizontal stand cassettes and an output shaft 4 to the vertical stand cassettes.

The section of the fine steel / wire mill shown also shows a two-stand roughing block 6, the vertical stand cassette 6 'and the horizontal stand cassette 6' 'being arranged at a 90 ° angle to one another. The finishing mill 1 and the finishing mill 6 are aligned with each other in the rolling line. The roughing block 6 is connected to a manual transmission 7, from which an output shaft 8 is guided to the horizontal stand cassette and an output shaft 9 to the vertical stand cassette. The input shafts 10, 11 of the transfer case 2 or of the manual transmission 7 are directly coupled to three DC motors 12 of the same power rating. The DC motors are used to drive the finishing block and the finishing block. A water box 13 for cooling the rolling stock and a compensation section 14 for temperature compensation of the rolling stock are provided between the transfer case 2 and the manual transmission 7.

The roughing block 6 has a changeover gear 15 between the vertical stand cassette 6 'and the horizontal stand cassette 6''in order to be able to use the roughing block as a precision rolling stand if required. The gear ratio of the changeover gear 15 is approximately 1: 1.25 to 1: 1.15. If the re-rolling block is used as a precision roll stand, the calibration of the rolls of the discharge stand or the stand cassette 6 '' is adapted to the specified precision roll.

Behind the re-rolling block, a further water cooling section is optionally arranged, which was not shown in more detail, as well as a Stelmor system, a bundle forming chamber and a hook track for the cooled wire bundles that were prepared for dispatch.

The pre-rolled and cropped wire from the intermediate line, not shown, enters the finishing mill 1 and is reduced in a twist-free manner in its ten stand cassettes to, for example, 5.5 mm in diameter at a final rolling speed of about 85 m / sec. The wire is then passed through the water tank 13, cooled in it and then passed through the temperature compensation section 14. The temperature cooling and the temperature compensation are regulated depending on the wire alloy and the desired quality profile. If necessary, a cooling / compensation arrangement of the finishing block 1 can be switched on. The wire then reaches the roughing block 6 and is rolled out in the first vertical stand cassette in a standard pass to initially 5 mm in diameter. Then it arrives in the horizontal scaffold cassette 6 '' and is rolled out in this discharge scaffold with a significantly lower stitch decrease, i.e. the wire only experiences a diameter decrease of about 5 to 15% in the discharge stand. With a correspondingly adapted calibration of the rolling rings in the discharge stand 6 ″ of the roughing block, the narrowest wire tolerances are achieved in this way with the unchanged high performance level of the rolling mill.

The rolling mill of the type defined here becomes even more adaptable to the different rolled product products and rolled material qualities by switching the post-rolling block into a precision rolling stand according to the invention.

Reference symbol overview

1

Finishing block

2nd

Transfer case

3rd

Output shaft

4th

Output shaft

5

Rolling wire / rolling stock

6

Roughing block

6 '

vertical scaffold cassette

6 ''

horizontal scaffold cassette

7

Manual transmission

8th

Output shaft

9

Output shaft

10th

Input shaft transfer case

11

Input shaft manual transmission

12th

DC motor

13

Water tank

14

Compensation distance

15

Reverse gear

16

horizontal scaffold cassette

17th

vertical scaffold cassette

Claims (3)

1. Method for the rolling down of wire (5) with round cross-section from high quantity steel or other alloyed steel in a high performance wire rolling train with roughing trains each having several roll stands, at least one intermediate rolling train and a finishing rolling block (1), wherein a subsequent rolling block (6) is arranged downstream of the finishing rolling block and in a given case a cooling path (13) and/or temperature balancing device (14) is arranged between finishing rolling block (1) and subsequent rolling block (6), wherein the wire (5) is rolled down in a double-stand subsequent rolling block (6) with a pass reduction which is significantly smaller compared to the reducing passes carried out in the finishing rolling block (1), wherein further the wire coming from the finishing rolling block (6) is rolled down in the first stand (6') of the subsequent rolling block (6) by a standard pass and the wire (5) is rolled down in the outlet stand (6'') of the subsequent rolling block (6) with a pass reduction, which is significantly smaller compared to the reduction previously undertaken, of 5 to 15%.
2. Rolling train for the rolling down of wire (5) with round cross-section from high quantity steel or other alloyed steel in a high performance wire rolling train with roughing trains each having several roll stands, at least one intermediate rolling train and a finishing rolling block (1), wherein a subsequent rolling block (6) is arranged downstream of the finishing rolling block and in a given case a cooling path (13) and/or temperature balancing device (14) is arranged between finishing rolling block (1) and subsequent rolling block (6), wherein the subsequent rolling block (6) consists of only two stand modules (6', 6'') and between the stand modules comprises a changeover gear (15) for changing it over to a dressing or precision rolling block and wherein the translation ratio of the changeover gear (15) is the range between 1:1.25 to 1:1.15.
3. Rolling train according to claim 2, characterised thereby that design of the rolls in the subsequent rolling block (6) can be matched to the precision rolling.

Images