SU1437116A1 - Method of rolling ingots on cogging mills - Google Patents

Abstract

The invention relates to rolling production, in particular to rolling slits on squeezing mills. The purpose of the invention is to increase the productivity of the process and the durability of the rolling equipment. If you install one after another on the roller and roll end to end two or more ingots in a given mode. Each subsequent ingot is installed on the roller table with the direction of the taper; opposite to the taper of the previous ingot. Rolling, thus, reduces the dynamic loads on the equipment. 1 dw., 2 tab.

Description

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The invention relates to rolling production, in particular to rolling ingots on sizing mills.

The purpose of the invention is to increase the productivity of the process and the durability of the rolling equipment.

The drawing shows the rolling pattern.

The diagram shows ingots 1-3, live rolls 4, horizontal rolls 5, vertical rolls 6.

Each regular ingot during rolling is installed on a live roll with a taper direction opposite to that of the previous ingot.

The ingot rolling on the blooming mills begins with aisles in which the ingots are tapered in width and thickness. In these passages, the butt-rolling of ingots with the same direction of tapering turns out to be ineffective and the dynamic loads in the drive line of the rolls remain very significant. This is due to the fact that the ingots are placed on the live rolls and then rolled with the same taper direction, for example, only with narrow ends forward. Under these conditions, the rolling reduction of the ingots increases from the minimum ABmin to the maximum LCn, with the rolling of the previous ingot ending with the compression of ABax, and the rolling of the subsequent one begins with Dish. The value of bb Lmax – ABmin is determined by the conicity of the ingots and, for example, for slab ingots weighing 15–20 tons, reaches 100–120 mm. Due to the abrupt change in the reduction from ABmax to ABnmn and the load on the rolls caused by this drop, gaps in the drive line are opened. When the next ingot is seized, a shock closure of these gaps occurs and dynamic loads arise in the drive line. In addition, due to the sharp elastic unloading of the working stand, the stand vibrates, as well as the pressure mechanism. Pressure mechanism vibrations change the conditions of friction in kinematic pairs and can be a cause of self-giving. pressure screws and progressive wear of nuts.

When rolling ingots with wide ends forwards, the ingots are reduced from the maximum ABmax to the minimum AB as they pass through the deformation zone, and the previous ingot rolling ends with ANmin rolling, and the subsequent rolling begins with ABmax, i.e. in this case the jump-like change obzhati but now

already from Аммин до Ананас.

Accordingly, the reduction of the ingot reduction from its front to the rear end reduces the load on the rolls, and hence the drive of the rolls, as a result of which they are accelerated and by the time of the capture of the next ingot acquire a speed substantially greater than with the capture of the first ingot. Capture the next ingot with increased

speeds of rolls and with a maximum reduction of ABmax violates the stability of the grip, leads to slipping of the rolls and, together with this, the emergence of dynamic loads in the drive line.

The mechanical equipment of the working roller tables, individual and stationary rollers is also overloaded.

Thus, rolling ingots butt-end does not relieve the drive of rolls from significant dynamic loads in the first passes. The reason for this is a significant difference in the compression of the rear end of the previous and the front end of the subsequent ingot. This difference is due to the installation on the roller conveyor and the subsequent rolling of ingots with the same direction of taper: only narrow or only wide ends forward.

The method involves the installation on the roller conveyor and the subsequent rolling of each successive ingot with the direction of the taper opposite to the direction of the taper of the previous ingot. Due to this, the rolling of each next ingot begins with the same compression, which ends with the rolling of the previous ingot, i.e.

Q without characteristic for the known methods of stepwise change of reductions with

ANMAX UP ABmin OR from ANMII to ABmax

depending on the ingot rolling with narrow or wide ends forward), rolling without abrupt sharp changes in pressures when the previous rolls are ejected from the previous rolls and subsequent ingots are removed eliminates opening gaps, impaired gripping, slipping, etc., and at the same time prevents the occurrence of dynamic loads in line with water. As a result, the durability of parts and components of the drive line is increased, and the downtime of the rolling mill is reduced, as the number of accidental failures caused by dynamic loads is reduced.

The rolling of, for example, three ingots on slabing is carried out as follows. I-3 ingots heated to rolling temperature are installed on the roller table with 4 narrow edges, i.e. in the position of "on the edge close to each other (" butt) with

0 opposite tapering direction to each other: ingot 1 narrow, ingot 2 lyre and ingot 3 narrow ends forward. After installation of the ingots on the roller conveyor in this way, they are rolled end to end with

5 program compression in one or more edge passes in the horizontal rolls 5. Then the ingots are turned 90 ° and continue butt-rolling into the plate.

traversing aisles with wide edges crushing by horizontal rollers 5 and narrow edges by vertical rollers 6 to get slabs of the required size. In the first rib and reservoir passages, in which the tapering of the ingots is removed, the effect of reducing dynamic loads in the drive line of the horizontal rolls occurs, due to the installation on the roller table and rolling the ingots with opposite | directing the taper. A similar effect is obtained when rolling three ingots, the first of which is oriented with respect to the rolls with a wide end forward. In this case, the second ingot is installed on the roller table and rolled narrow, and the third wide ends forward.

In double-facet rolling, there are also two possible arrangements for the ingots on the roller table with respect to each other: the first ingot is narrow and the second has wide ends ahead; the first ingot wide and the second narrow ends forward. Due to the same effects as for three-plate rolling, when two-plate rolling, dynamic loads in the drive line are also reduced.

Example. At the slab 1150, boiling steel ingots are rolled, having the dimensions of the upper (smaller) and lower (larger) sections, respectively, 1425X765 and 1535X Х875 mm, height 2120 mm, weight 16.3 tons in the slab section 170X1270 mm (dimensions indicated in the cold state).

Three ingots heated in heating wells up to the rolling start temperature are placed on the receiving roller table on the edge with opposite tapering direction: the first ingot with a section of 1425x X765 mm, the second with a section of 1535X875 mm, and the third with a section of 1425X765 mm. After this, the ingots are butt-in, one after the other, rolled on a slabing with the following solutions of horizontal and vertical rolls (Table 1).

Table 1

1380

760

730

1500 1370 1390

680

1370

Continued table. one

ten

5 15

20

25

thirty

five

0

five

0

The first pass is rib, in which the taper of the narrow faces of the ingots is removed. After rolling in the rib pass, the ingots are turned 90 ° and continue rolling in the formation passages with compression of wide faces by horizontal rolls and narrow vertical ones. In the first after passage of the straightening pass, the conicity of the wide faces of the ingots is removed. In the last, i.e., in the fifteenth aisle, the horizontal rolls are diluted (indicated by the “t” symbol), set them in the position that was original before the next batch of ingots began to be rolled.

In the rib pass and the first after rib rib pass, in which the tapering of the ingot faces is removed, their front and rear ends are rolled with the following cuts determined by the difference in height of the corresponding sections and solutions of horizontal rolls.

table 2

55

Rib pass

40

155

Continued table. 2

Ground Pass

112515

215125

312515

From tab. 2 that in the rib passage the front end of the first, the rear end of the second and the front end of the third ingot are rolled with the same compression equal to 40 mm. The rear end of the first, the front end of the second and the rear end of the third ingot rolled with the same, equal to 155 mm compression.

After the rib pass, the ingots appear on the output side of the mill, after turning, rolling them in the reservoir, i.e., the second pass starts with the ingot, which finished rolling in the rib pass, setting it into rolls wide

the end. Therefore, in the first formation pass, the front end of the first, the rear end of the second, the front end of the third ingot is rolled with the same 125 mm compression, and the rear end of the first, the front end of the second, rear end of the third - with the same 15 mm compression.

Thus, in the aisles with stripping of the taper of the ingots, the proposed method allows the rear end of each previous and the front end of each subsequent ingot to be rolled with the same, i.e., without abrupt changes in compression. At the same time, the dynamic loads in the drive line of the rolls, which are characteristic of the method of rolling ingots of the prototype, are caused by a jump change in the reduction. As a result, the service life of the components and parts of the rolling mill drive line increases, and its productivity increases.

Claims (1)

Invention Formula The method of rolling ingots in the grinding mills, including the butt-compression of successively installed two or more ingots, characterized in that, in order to increase the productivity of the process and the durability of the rolling equipment, each subsequent ingot is installed with a taper direction opposite to that of the previous ingot. H) f f f ft c,