DE1202944B - Continuous casting plant for the continuous casting of strands and methods for operating them - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

B22d

German class: 31c-21

Number: 1202 944

File number: Sch 30822 VI a / 31 c

Filing date: January 13, 1962

Opening day: October 14, 1965

The present invention relates to a continuous casting plant for the continuous casting of one or multiple strands and a method of operating them.

So far, the bending and subsequent straightening of, for example, in the vertical could be continuous cast strands only with relatively small billet dimensions without impairment the quality of the product can be achieved while using this process for larger strand dimensions in particular with wide slabs led to difficulties because the strand in general or cooled too much locally up to the straightening unit. For this reason, the only realize the known idea of the direct connection between continuous casting and rolling process, that either the rolling process was combined with the lowering process in the vertical to in this way to obtain smaller dimensions for turning, or one limited oneself to the casting of smaller dimensions, a heating furnace being provided after the straightening unit in the horizontal plane was to the temperature of the product necessary for the subsequent rolling process to obtain.

A combination of the lowering with a rolling process in the vertical has, among other things Disadvantage that because of the subsequent bending of the rolled product, the activation of an annealing process possibly in combination with a quenching process in the bending sector.

It would be conceivable per se, the disadvantageous cooling that the strand after exiting the secondary cooling section until the straightening unit learns to be taken into account in the secondary cooling section. Here However, it would have to be ensured that the strand core cooled down so far after leaving the cooling chamber is that it is no longer liquid. This is the only way to ensure that there are none in the area of the drive rollers Breakthroughs from still liquid material are to be feared. At low continuous casting speeds, as required for strands with larger cross-sections, there is no such security. In this case, the strand temperature at the exit of the cooling chamber would have to be particularly high, as the strand moves as a result of the longer time it takes to travel from the exit of the cooling chamber to the To get to the straightening roller table, cools down particularly strongly. This shows that the consideration of the Cooling of the strand on its way to the roller table in the secondary cooling section only up to one certain casting speed would be feasible.

Continuous casting plant for continuous casting
of strands as well as procedures for operating
the same

Applicant:

Schloemann Aktiengesellschaft,

Düsseldorf, Steinstr. 13th

Named as inventor:

Walter Hess, Düsseldorf;

Dipl.-Ing. Klaus Heck, Zurich (Switzerland)

Claimed priority:

Switzerland of January 17, 1961 (543)

In addition, this type of temperature influence can result in uneven cooling of the Do not effectively prevent strand in relation to its cross-section.

The object of the invention is to create the possibility of the strand in the mold downstream cooling chamber to be able to cool so far that its core is the Liquidus limit falls below and therefore no risk of strand break-through in the area of the drive rollers is to be feared and at the same time to carry out the straightening process without loss of quality of the strand can.

According to the invention, this is achieved in that between the bending device and straightening machine temperature-influencing agents are assigned to the strand or strands. Through the assignment temperature-influencing means for the strand on its way between the secondary cooling section and Straightening roller table, the strand can be fed to the straightening machine at the most favorable temperature in each case and at the same time the heat distribution in the strand cross-section can be influenced in such a way that no cracks as a result uneven heat distribution can occur.

Another advantage of the invention can be seen in the fact that the strand at rolling temperature corresponds to the straightening roller table can be fed, so that immediately behind it rolling mills for continuous further processing of the strand can be arranged. In this case, the area between the bending device or secondary cooling section and straightening

509 717/348

The continuous casting machine is advantageously used to adjust the strand to the required level Bring the rolling temperature or keep it at this temperature.

In the figures, which illustrate exemplary embodiments of the invention, the invention and its advantageous further embodiment explained in more detail. It shows

F i g. 1 is a schematic representation of a continuous casting plant with bending and straight bending device,

Fi g. 2 a section from the system in the bending area of the strand according to FIG. 1, on an enlarged scale,

F i g. 3 and 4 variants of the embodiment according to FIG. 2.

The in F i g. 1 shown plant for the continuous casting of one or more strands has a tilting pan 1 and an intermediate container 2 for receiving the closed goods. Underneath the intermediate container 2 is the mold 3, from which a strand 4 after casting during casting is deducted below. This strand 4 is in the edge zones after it emerges from the mold solidified and liquid inside. As it descends, the core of strand 4. Two also solidifies Pairs of rollers 5 and 6 hold strand 4 and lower it downwards. The pairs of rollers exercise depending on the operating conditions a holding, braking effect or a lowering, pulling effect, however this is not intended to be a rolling effect.

The strand 4 is then bent out of the vertical by the bending roller 7 and then through the shaft 8, which is provided with guides and rollers, to the straightening unit with the rollers 9, 10 and 11, 12 where it is bent back to the horizontal. This shaft 8 is followed by a detailed one described function. It has a support surface on the side of the largest bending diameter 14, e.g. B. in the form of a rail or a cooled tube (see FIG. F i g. 2).

While it is due to the temperature of the strand 4 after passing through the roller pairs 5 and 6 is still possible, the strand without any damage, z. B. Cracks, to bend and To steer out of the vertical, this is no longer the case for bending back into the horizontal. Of the The strand has cooled down too much, especially on its surface and on its edges. So if the If the strand is bent back into this state, the dreaded stress cracks occur, which the Reduce the quality of the cast material significantly.

In order to avoid this difficulty and also to be able to bend strings of larger dimensions, it has proven necessary to generally and selectively adjust the temperature of the strand in the bending sector influence. The reduction in the amount of heat radiated by the strand or that to be supplied to the strand The amount of heat depends on the desired temperature fields over the cross-section of the strand as well as on its surfaces, which in turn depend on the strand material and its dimensions as well as the bending radius and the casting speed. In Fig. 2 is an excerpt with the bending sector of the strand shown. In order to straighten the strand, i. H. when bending back into the Horizontal, not to damage it in any way, generally and locally, a certain temperature is not allowed are undercut. In view of the stresses that arise during straightening, it can too It may be advantageous to keep the strand at different temperatures locally.

According to the embodiment of FIG. 2, the strand 4 is below the roller pairs 5 and 6 and the Bending roll? directed into the shaft, which as insulated pipe bend is formed. The purpose of the refractory lining or the insulation layer the reduction of the heat given off by the strand during the bending and diversion process. The material thickness The insulation can be of varying strength around the circumference in order to achieve a desired temperature field to generate on the strand surface. Before entering the straightening rollers 9, 10 and 11, 12 the Strand 4 have an optimal temperature distribution for bending back. It's already in the shaft support surface 14 described is arranged.

However, there is also the possibility of straightening with a subsequent rolling process combine; whereby the corresponding temperature conditions must be met.

F i g. 3 shows an addition to the embodiment according to FIG. 2. There are also 8 in the shaft Gas or oil burners 13 are provided, which, distributed over the circumference, generally and locally determine the surface temperature affect the strand. The burners can be adjusted with a regulating device (not shown) are provided, by means of which a prescribed temperature field of the strand 4 is achieved and can be held permanently. The flame sizes are preferably regulated.

Instead of gas or oil heating, an electric heater can be used, be it as a resistance heater or as induction heating.

In Fig. 4 shows a shaft 8 which is connected to burners 13 acting in the strand feed axis is provided.

It is also possible to combine the mentioned methods of influencing the temperature with one another. Influence can also take place in stages via the strand axis, so that different temperature zones develop. Preheating the shaft to operating temperature before casting begins significantly improves the start-up conditions.

To protect the strand, it can be advantageous to create a protective gas atmosphere in the shaft, e.g. B. by means of N ₂ or CO ₂ .

Claims (6)

Patent claims: 1. Continuous casting plant for casting one or more strands, in which the or without preceding shaping processing in the horizontal arc-shaped bent strands before further processing of a straightening machine for Straight bending are supplied, characterized in that between the bending device (7) and straightening machine (9,10,11,12) dem Strand (4) or the strands are assigned temperature-influencing agents. 2. Continuous casting plant according to claim 1, characterized in that the temperature is influenced under a protective gas atmosphere. 3. Continuous casting plant according to claims 1 and 2 or one of the same, characterized in that that the or the strands through a heat insulating arranged in front of the straightening machine Shaft (8) are performed. 4. Continuous casting plant according to claim 3, characterized in that the shaft (8) can be heated is trained. 5. Continuous casting plant according to claim 4, characterized in that in the case of gas or oil heating, burners (13) are provided in the shaft (8) which are directed perpendicularly or approximately tangentially to the strand surface. . 6. A method for operating the continuous casting plant according to claims 1 to 5 or one the same, characterized in that the influencing of the temperature of the cast material is selective takes place in such a way that the neutral deformation zone of the strand in the bending sector, their Location determined by the temperature-dependent strength of the various layers of the cast material is approximately in the axis of symmetry of the strand. Considered publications:
Herrmann, Handbuch des Stranggießens, 1958, pp. 450, 451, 688. 1 sheet of drawings 509 717/348 10.65 © Bundesdruckerei Berlin