DE1427800A1 - Rolling mill systems for the production of heavy and medium plates from raw, pre-cast or continuous cast slabs and processes for operating such rolling mill systems - Google Patents

Description

Rolling mills for the production of heavy and medium plates from raw, Pre-cast or continuously cast slabs and processes for operating such rolling mills The invention relates to a method for the production of heavy and medium plates from raw, pre-cast or continuous cast slabs and a rolling mill to carry out the Process consisting of one or more vertical and horizontal reversing stands, a slab shear and a holding furnace o Such rolling mills exist either from a single: inverting frame, usually a heavy vertical upsetting frame or from two reversing stands arranged one behind the other, with the first Stand usually for pre-rolling the raw slabs used, in particular to width them on the intended sheet width and the second stand for the finish rolling of the heavy plates serves. .

The slabs for processing on such rolling mills can also be rolled into pre-slabs on an upstream slab mill be cropped with a pair of slitting shears and, if necessary, divided. Rolling out the Steel mill blocks can be done in one heat. When the slabs are in cold condition are to be freed of steelworks defects, the previously cleaned ones are rolled out Pre-milling in a second heat.-The dimensions and weights of the material to be used Raw or pre-slabs are determined by the end product to be produced, whereby one Care is taken to ensure that the raw material is used rationally with as little loss as possible To achieve the production of the desired end products.

Because of the extensive range of heavy plate dimensions, this The requirement has so far only been met more or less imperfectly. It is so far as is known, not possible to use several sheets of different widths and / or corresponding thicknesses without any loss of material from a single input weight to roll the raw or slab. The rapid cooling of the rolling stock during rolling of thinner and wider grades of heavy plate only allows low insert weights of raw and rough slabs, quite apart from the fact that the rolling of these sheets in Lower temperature ranges require more time and rolling energy and increased roller wear occurs. Those at low (lower) final rolling temperatures Finished-rolled thin coarse and middle plates usually require a rolling downstream annealing treatment. However, not all of them can get through the low Final rolling temperature unfavorably influenced technological properties eliminated will.

Annealing treatment also always results in scaling of the sheets with it, which cannot be accepted for all purposes. About that In addition, the production capacity of known rolling mills of this type is through the low operating weights are significantly reduced.

Previous attempts at solving the above-mentioned deficiencies are increasing the drive line, the rolling stands, to through larger decreases for the individual rolling passes, the rolling time in favor of higher final rolling temperatures, to shorten larger operating weights and larger rolling surfaces. Furthermore will instead of the original duo or trio scaffolding, four-high scaffolding used, their thinner work rolls in connection with larger backup rolls more favorable torque conditions create and allow higher rolling force.

A shortening of the rolling time in sheet metal rolling is also achieved by the use of pre-blocked slabs, which are converted into a long plate in one operation rolled out and cut into short lengths. Then be these lengths individually but at the same time to a corresponding number of roll stands transported and in finish-rolled into sheets at the same heat. To the However, a large number of roll stands are necessary to carry out this process.

The object of the present invention is to increase the production capacity of single and multi-stand rolling mills as well as of comparable plants for the production of heavy plates, to improve the rolling conditions in particular for the thinner and wider coarse and medium sheet grades and thus the quality of the product to be manufactured without to have to undertake substantial and always very expensive plant expansions for this purpose. .

This aim of the invention is achieved in that a slab shear furnace and an intermediate heating furnace are arranged parallel to the Haugit rolling line of the rolling mill installation next to the rolling stands. The mother slab emerging from the single reversing stand - in the case of a two-stand system from the roughing stand - is made according to the invention. the main Walt line by means of a transverse tractor and a]? arailelrol-lgangeo the slab cutter for the purpose of cutting e supplied # and then this mother slab sections respectively brought into DEAE intermediate heat oven to warm up and / or for keeping .. is divided the Mutterbramme after the Zwischenwärmeefeä. to warm up or keep warm.

In the course of the further rolling treatment , the sections of the good slab -. Valuable also by means of a parallel roller table and cross tug - either the single reversing stand or the rolling stands in the case of a two-stand system either the finishing train arranged parallel to the roughing train or the gate train again for rolling the subdivided mother slab sections into heavy plates of certain desired dimensions .

This circulation of the pre-rolled mother slab makes it special The advantage achieved is that - regardless of the 'time of transverse dragging, of cutting the mother slab heating up and / or keeping the cut pieces warm in the Irärmeofen - at the same time either previously rolled cut and heated sections a mother slab or a new etching slab from the slab heating furnace to one Mother slab or finished heavy plate can be rolled out without loss of time.

The present invention therefore brings about the significant hospitality This has the advantage that the rolling out of the Bineatzbramme to a mother slab 'mit a certain slab width (which is achieved by cross or diagonal rolling of the insert slab happens) for all parts included in the slab in one work step takes place, the time saved thereby completely reducing the production of the system can increase considerably, practically double.

Since the insert slabs rolled out to the intended width still have a sufficient thickness due to their initial cross-section, the sides of the slab can be compressed to the desired degree with sharp edges and straight lines without bulging across the slab width, so that even with thin heavy plates there is a uniform and minimal edge scrap results. This is advantageous both for rolling and for trimming the metal sheets, and thus for good ejection. Another advantage of the invention is, among other things, that in addition to the common spreading of the predetermined sections of the mother slab, further stitches can be carried out jointly, which are then used to manufacture the gnd product (heavy or central sheets of predetermined dimensions). In addition, cut sections can be finish-rolled under the most favorable temperature and rolling conditions within a very short time after passing through the intermediate heating furnace. As a result of the higher final rolling temperatures, sheets can therefore also be rolled in greater lengths than usual, with technological properties being achieved that make subsequent annealing treatment largely superfluous, even with thin sheets: The rolling mill system according to the invention also has the advantage that the pieces of texas that are cut from a mother slab to produce specified heavy plates, according to the dimensions of the desired end product, each can be divided independently of one another. In this way, the order dimensions need the. sheets to be rolled - to be taken into account only at a point in time immediately before the finish rolling. In a rolling mill installation according to the invention, primary rams from a small number of uniform formats can be used with the greatest possible weight . Such insert slabs can be produced with economic advantage in the steelworks both as raw slabs and, in particular, as continuously cast slabs. The use of large, uniform slab formats brings in. inventive rolling mill has the advantage of optimal utilization of the slab heating furnaces and thus a high degree of efficiency of the furnace system.

The increase in performance achieved by the invention compared to conventional systems and procedures in the production of particularly thin and wide heavy plates is to be made clear by the following comparative examples. Comparison i: Conventional procedure Procedure according to the invention way Rolling mill plant- y @ rolling mill plant B1 Single heavy plate stand with single heavy plate stand with heavy vertical upsetting heavy vertical upsetting rUet rüet, slab shears and heating furnace in the parallel - route Bet bet 1 # Raw slab, on average, continuously cast slab 700 x 280 x 1500 1550 x 250 x 3900 mm Weight after d. Crop weight 1196 t 2 t pre-rolling d. Mother slab '2500x30x20 000 Sheet metal 2500x5x20 500 cut into 4 sections 2500x30x5000 _ Rolling time (theoretical rolling time 9o seco y 120 sec. Slab follow-up time - 120 + 20% = 144 seconds. Production / hour - - 60, #, O x 2 50 t . 144 Use 2t Use d. Parts 2500 a 30 x 5000 - - 'Weight 2.9 t each Sheet metal 2500 x, 5 x 30000 Rolling time for 't plate 68 sec. Rolling time for 4 sheets 272 sec. Rolling time for 1 mother slab - 90 ffeke - total rolling time (theoretical); 362 sec. Slab follow-up time 362 + 20 ¢ = 434 sec. - Production / hour 6 a 11.6 = 96 t 434 Comparison 2:. Conventional method, method according to the invention wise wise Rolling mill plant A2: Rolling mill plant B2: 2-stand Heavy plate mill Block slab mill heavy plate roughing stand with heavy Vertical upsetting frame Slab shears Slab shears, intermediate heating furnace Single heavy plate stand (in the parallel section) Heavy plate finishing stand Use 1t Use 1: Ingot mill in the middle of heavy plate roughing stand Ingot 1500x650x2000 Continuously cast slab 1500x250x3900 Weight after d. Hop weight 11.6 t 11.6 t Pre-slab 1400x100x10 500 Mother slab 2500x30x20 000 containing containing 6 slabs A 1400x100x1750 4 slabs 2500x30x5000 Rolling time (theoretical): rolling time (theoretical :) 90 sec. 90 sec. Cutting through slab scissors Mission 2: Mission 2: Single heavy plate stand Heavy plate finishing stand Slab 14002100x1750 mother slab section 2500x30x5000 Weight 1.93 t, weight 2.9 t Sheet metal 2500x5x19700 sheet metal 2500x5x30000 Rolling time for 1 sheet Rolling time for 1 sheet 75 sec. 68 sec. Follow-up time Follow-up time. 75 + 20% = 90 sec. 68 + 20% = 82 sec. Production / hour Production / stdo 3600x1.93 = 77t 3600x2.9 = 127t 90 82 The invention is intended to end on the basis of two schematic tical implementation examples can be given. Show it: Fig: 1 = a two-stand rolling line and Fig. 2 and 3 two adjacent two-branch robust rolling lines. All the exemplary embodiments as shown in FIGS. 1 to 3 are found to have a 8.81 Besides rolling line with the Slab shears 9 and the intermediate heating furnace 10, The Ne- Benwalzlinie 8.81 is by means of the cross tugs 7 and 12 with the rolling line 1 or, by means of the cross tractors 7t, 12 ' connected to the rolling line-2 to form a circuit, -In the embodiment of Fig, 1 is on the a vertical upsetting stand 3, denoted by 1 and a horizontal upsetting stand 4 arranged after the Rolled stock consisting of raw, pre-cast or continuous cast slabs has passed through roll stands 3 and 4, the so- resulting mother slab by means of the cross tractor 7 and of the parallel roller table 8 of the slab shears 9 is supplied and cut into pieces according to the end product, in the intermediate heating furnace 10 to the required temperature temperature and from there, if necessary, via the par, allele roller table 81 and the cross tractor 12 again the rolling line 1 for finishing rolling are fed, In the embodiment according to FIGS. 2 and 3 with two equivalent rolling lines, the main rolling line 1 and the Auxiliary rolling line 2 and the auxiliary rolling line parallel to it 898t result in the following options for the process of the Rolling process: 1) The rolling stock. passes the rolling line 1 with the roughing stand'3,4, on the diri pre-rolling of the insert slab an 'idüt ° terbramme follows the -then- across the = be'eper, - ° '7 Jznd;' den-`Paralheröllgang 8 -der slab- Scissors 9 is fed. There, the mother slab is cut into pieces which, after passing through the intermediate heating furnace 10, are then fed to the rolling line 2 with the rolling stand 5, 6 for finish rolling. As a variation, the rolling stock can first come to the rolling line 2 for rough rolling (while on the rolling line 1, for example, rolling stock is still being finish-rolled) and then pass through the secondary rolling line 8, 8 'in order to get to the rolling line 1 for finish rolling at the appropriate time.

2) The rolling stock passes through the rolling line 1 for rough rolling, then arrives via the cross tractor 7 on the secondary rolling line 8981 for dividing and intermediate heating and once again passes through the rolling line 1, with the rolling stand 3, 4. on which the finish rolling now also takes place, while the rolling line 2 is free for other work. As a variation to this, the rolling stock can first pass on the rolling line 2 for rough rolling. It goes through as a consequence the side rolling line 8.81 to the parts and intermediate heats and reaches then back to the rolling line 2 for finish rolling, while now the rolling line 1 for other work is free.

3) The rolling stock comes first on one of the rolling lines 1 or 2 for rough rolling, passes through the secondary rolling line 89 8p for dividing and intermediate heating and then arrives at both rolling line 1 and rolling line 2 for finish rolling. This both Walzliniut 1 and 2 as needed, both for rough-rolling and for Per-_ tigwalzen be charged with the appropriate rolling .. so that optimum utilization of both $ mill stands 3 'and 5.6 achieved wird® Gleiehzeitig results in a great flexibility in the Production of heavy plates of different dimensions,

Claims (2)

. A N S P R Ü G H E 1) Process for the production of heavy and medium plates_ in a rolling mill plant, characterized in that initially in a main rolling line (1) large, heated steel ingots pre-rolled into mother slabs of suitable dimensions, then the same in a separate slab circulation parallel to this rolling line j8,81) divided into several sections by means of slab shears (9) or the like as well as kept warm in a furnace system (10) and finally these parts again the same main rolling line (1) - or otherwise an additional auxiliary rolling line (2) - fed to finish rolling. 2) Rolling mill to carry out the method according to claim 1, consisting of a vertical and a horizontal reversing stand, a slab shear or similar dividing device and a holding device to oven, characterized in that the two rolling stands (3 and 4) formed main rolling line (1) a secondary line (8, 8 ') is parallel, in which the slab shears (9) or the like and the holding furnace (10) are arranged, the feed and discharge roller tables (1 or 8981) of these two lines are connected at their ends by cross tugs (7 and 12) to form a closed circuit (Fig.-1). 3) rolling mill installation for carrying out the method according to claim 1, with two separate rolling lines and a slab shear and a holding furnace, characterized in that between the main rolling line (1) and auxiliary rolling line (2) in a parallel subsidiary line, the slab shears (-9) or the like and the holding furnace. are connected in the sense of a continuous passage of the rolling stock (Figo 2 and 3) 0