SU419009A3 - METHOD FOR ROLLING - Google Patents

Description

one

Known methods of rolling rails with alternate compression of the rolling and side surfaces of the rail head in duo and universal gauges with free broadening in each pass of the non-compressible surface. Achievable while the strength of the working surface of the head is insufficient.

The described method differs from the known ones in that the rolling (or lateral) surface of the rail head in each pass is compressed in conjunction with their corresponding rounding.

These differences increase the strength of the working surfaces of the rail head.

FIG. 1 and 2 schematically shows the principle of rolling but the proposed method; in fig. 3 - cross section of a universal four-caliber caliber; in fig. 4 - cross section of duo caliber; in fig. 5-And schematically given the various phases of continuous rolling by the described method; in fig. 12 is a cross-section of the finishing gauge.

The proposed method of rolling the rails consists in alternating cuts of the head parts with free broadening of the uncompressed part in this aisle, each time in conjunction with the corresponding roundings. These crimps are alternated in universal and duo calibers.

In the cervical phase, compression occurs in a universal caliber (Fig. 3). This gauge is formed by two horizontal rolls 1 and 2 arranged one above the other, a vertical roll 3 to form the upper rail line 4; roll 5 for rolling the rail foot. The rail neck 6 is calibrated with horizontal rollers 1 and 2, as shown in FIG. 1. strong produced by these rollers act in the directions indicated by arrows H and N. The upper plane 4 is formed by roller 3 along the contour C-B-A-A-B-C. The crimping force acts in the direction indicated by the arrows G and G. A broadening occurs on the side surfaces of the head, as indicated by the dotted lines D and D.

From the universal gauge, the billet is directed to the gauge duo (Fig. 4) with two rolls 7 and 8, in which compression is performed along contours B-C-D-E and B-C-D-, thus eliminating the broadening of the DD, which is more when rolling in the previous caliber (crimping is done in the directions indicated by arrow marks R). Now, the free fall is broadened on section A-A of the upper plane 4. Rolls 7 and 8 do not touch the neck of the workpiece, starting from point G. This is done in order, on the one hand, to reduce the rolling force, and on the other,

Do not increase the broadening excessively over the LL line.

The schematic diagrams in FIG. Figures 1 and 2 show that by continuous rolling in this way, finishing off constantly rounding BC and BC and alternately B-L-L-C and C-D-C-D contours, you can get the final shape of the rail head.

The rolling of the sole is carried out with the help of a smooth roll 5, like beams, and does not cause any difficulties.

By this principle, rolling continues further and ends with calibration (see FIG. 11).

FIG. 5-And shows the successive phases of the calibration method described.

The billet (Fig. 5) was obtained by preliminary classical rolling with the help of a duo or trio reversing cage located in front of the universal cages. In this roughing stand, the workpiece is driven 4-6 times.

Sequential crimping to which this billet is subjected further (Fig. 5-10) results in a profile ready for finish rolling (Fig. 10).

Rolling (Figs. 5, 7 and 9) is carried out in universal four-roll cages, similar to that schematically shown in Figs. 3, namely: the upper roller 1, the lower roller 2; side roller 3 and side smooth roller 5; rolling according to FIG. 6, 8 and 10 are produced in duo cells similar to that shown in fig. four.

Rolling on these cages the duo conducts continuously with universal cages. The upper roll of such duo cages is shown schematically at number 7, and the lower roll - at number 8 (Fig. 4).

Clean rolling is carried out with the help of the stand and the cage (Fig. 12). In the finishing phase, the head and the neck of the rail are finally calibrated between the horizontal rolls 9 and 10 (Fig. 11), and the foot receives orthogonal pressure with respect to the direction of the main rolling by means of the vertical roll 11.

In order for the calibration in the finishing stand (Fig. 11) to be flawless, it is necessary that the workpiece be passed through each stand only once, i.e., continuous rolling should be carried out.

However, the described method can also be used if there is reversing rolling equipment (universal stand, crimping stand and duo and universal clean stand), which is used in many plants for rolling I-beams.

In this case, the rolling pressure should be reduced by approximately 30% and the calibration should be changed.

The change in calibration is caused by the fact that, when rolled in the duo cages, the heads are slightly longer than the soles.

In connection with this, the workpiece tends to be bent, and this bending is greater, the more significant the compression of the profile during rolling. Therefore, it is necessary to reduce the bend by loosening the crimping force when rolling in universal and duo cages, and this, in turn, causes an increase in the number of passes through the cages. Practically, they need to be brought up to five instead of three in each type of calibration, as is done during continuous rolling.

However, the force of the vertical rolls of the universal reversing stand must also be changed in order to achieve the same elongation of the sole and the head. The roll of the head must be inserted much faster than the roll of the sole, and this ratio must be inverse to the width of the rolled metal in order to achieve equal elongation in the die and in the sole. If this condition is not fulfilled, the billet will bend at the exit from the universal stand and will not enter the duo gauge, due to which rolling will be impossible. This repositioning of the vertical rolls can be accomplished without much difficulty in the classic universal cages that are used for rolling I-beams.

Subject invention

The method of rolling rails, which includes alternating compression of the rolling and side surfaces of the rail head in duo and universal gauges, with free expansion in each pass of the non-clamped surface, characterized in that, for the purpose of strengthening the rail head, rolling (lateral) surface of the rail head in each the passage is burned. they are combined with their adjacent skruglepi.

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