UA142033U - METHOD OF REPAIRING PALLETS FOR THROUGH CASTINGS - Google Patents

Abstract

A method of repairing pallets for through molds, in which the pallet is placed attachments. In the center of the solid pallet make a hole under the condition D1 / 2 / R, where D1 is the diameter of the hole in the pallet, R is the maximum distance from the axis of the pallet to the edge of ignition, then in the pallet hole place attachments with the corresponding hole in the pallet diameter.

Description

A useful model belongs to metallurgy and foundry production, namely, it concerns the pouring of steel with the receipt of ingots in through castings using a pallet in the form of a monolithic slab.

When pouring steel, the unprotected surface of the pallet is destroyed, as it is subjected to thermocyclic stresses when hot metal hits it, and its central part undergoes the maximum temperature difference, as a result of which cracks are formed on the surface of the pallet.

Defects of the pallet in the form of sparks prevent its further operation, while the manufacture of new metallurgical equipment is a long and laborious process. In the conditions of metallurgical production, in order to reduce material costs for the manufacture of equipment, pallets for foundries are restored by, for example, surfacing or coating. i2Io2Npisgui|.

From the state of the art, there is a known method of repairing pallets by brewing kindling with iron melt, which is obtained by burning the ferrous thermal mixture applied to the pallet (ЗО Mo 706218, B220 7/06, Byul. Mo 48, 01.03.80.

The disadvantage of this method of repair is the subsequent change in the chemical composition of the ingot due to the interaction of aluminum powder (ferrothermal mixture) with liquid metal, as well as the need for repeated applications of the ferrothermal mixture during the continuation of the development of flares and shells.

There is also a well-known method of repairing pallets for through-flow castings, which consists in replacing the insert (rod), obtained by filling the space inside the casing with liquid cast iron, which has splits and a detachable casing concentrically located on the axis. The outer casing of the pallet is made of two parts, on each of which there are wedge edges on the outer side, which expand upwards and are needed to connect both parts with the help of a wedge pad, which is inserted from below. The inner surface of the casing is curved so that the insert is not removed together with the ingot (ЗО Mo 372020, В220 7/06, Byul. Mo 13, 08.05.73.

The closest analogue is the method of repairing pallets for through-flow pourers

With the invention Me 372020.

The disadvantages of this method of pallet repair, which negatively affect their service life,

There are: the presence of structural inhomogeneity of the insert in the area of its contact with the casing, formed during the crystallization of liquid cast iron in the inner cavity of the casing, which reduces its performance and service life, as there is a rapid formation and development of cracks during further use of the pallet; the presence of a connector along the axis of the casing in the vertical plane. In the case of failure or deformation of wedge pads, as a result of mechanical action or as a result of the effect of alternating temperature stresses caused by constant heating and cooling of the pallet, a gap may form between the component parts of the casing. When pouring forging ingots, in this case, liquid metal may leak into the gap, as well as premature wear and failure of the pallet casing.

The basis of the useful model is the task of creating a way to repair pallets for through castings, which ensures the necessary performance, functionality and increase in the service life (exploitation) of pallets with the minimization of the costs of obtaining ingots.

The technical result consists in eliminating the formation of structural inhomogeneity and cracks in the pallet.

The task is solved by the fact that: after the appearance of sparks in the central part of the surface of the pallet, which make it difficult to obtain high-quality ingots and lead to failure of the pallet, a hole (with boring) is mechanically made in the center of the pallet (in line with it). The diameter 01 of the hole in the pallet is chosen so that the flares are inside it, that is, О01/2 is not less than B, where A is the maximum distance from the axis of the pallet to the edge of the flare, while the drilling is located in the lower part of the pallet; inserts with a diameter of O2 are placed in the opening of the pallet, while their connection is ensured (for example, by a fit with tension), and the end of the side of the insert with a technological hole is placed in the same plane as the lower surface of the pallet, provided that the surface of the pallet is restored (the upper end surface of the insert repeats the geometry of the pallet before repair); depending on the technological features of using the pallet, the inserts are fixed in the pallet 60 (for example, with the help of a threaded or welding connection);

in the future, after the appearance of ignition on the insert, it is replaced and, if necessary, the diameter of the hole 0: in the tray and, accordingly, the diameter О2 of the insert are increased, while the diameter О: of the hole in the tray should not exceed 2/3 of the diameter Oz of the tray.

The known and claimed methods have the following similar characteristics: a method of repairing pallets for through-flow pourers, in which inserts are placed in the pallet.

The declared method of repairing pallets for through-flow castings has the following distinctive features: in the center of the solid-cast pallet, a hole is made from the condition О0:/22Н8, where Ю: - the diameter of the hole in the pallet,

A is the maximum distance from the axis of the pallet to the edge of the flare, after which an insert with a diameter corresponding to the hole in the pallet is placed in the opening of the pallet.

In addition, the hole in the pallet is made with drilling, and the inserts - with a side and a technological hole, while the end of the side of the insert is placed in the same plane with the lower surface of the pallet under the condition of restoring the surface of the pallet, and the inserts are fixed in the pallet using a threaded or welding connection .

Also, the diameter 0: of the hole in the pallet is increased from the condition О1«2.Оз3/3, where Оз is the diameter of the pallet, after which the inserts of the corresponding parameters are placed in the opening of the pallet.

There is a cause and effect relationship between the distinguishing features of a useful model and the technical result achieved.

Due to the use of a metal liner made mechanically with O2 of the liner equal to the Oi of the hole in the pallet, the possibility of structural inhomogeneity in it is excluded, which is formed during the crystallization of liquid cast iron when filling the inner cavity of the casing, which prevents the formation of cracks in the liner during operation, as well as increases the performance of the pallet and its service life.

Making a hole in the pallet with a diameter of 0; from condition О01/228 provides removal of kindling from the surface of the pallet.

Making the insert and the hole in the pallet with a rim in the lower part is necessary so that when the ingot is separated from the pallet, the inserts do not remain on the ingot, but are separated together with the pallet.

The use of a pallet in the form of a monolithic plate reduces the probability of metal coming out of the pallet connector when pouring ingots on this pallet, and also increases its reliability and durability.

Due to the replacement of the insert and the possibility of increasing the diameter of the hole in the pallet for inserts of increased diameter, the service life of the pallets is additionally increased.

Increasing the hole in the pallet with a diameter of 0 from the condition 01«2:Oz3/3 ensures preservation of the strength of the pallet.

As a result of this, the working capacity and the increase in the service life of the pallets used in pouring forging ingots are ensured.

In addition, in connection with the duration of the manufacturing cycle of this equipment, the claimed method of repair allows to reduce the time spent on restoring pallets in the technological cycle of metallurgical production. Due to the application of this technical solution for the repair of pallets for through castings, it became possible to reduce the specific costs of pallets per ton of molten steel.

Exclusion of at least one of them from the above set of distinguishing features does not ensure the achievement of the specified technical result.

The essence of a useful model is more fully revealed with the help of graphic materials, which are shown in: fig. 1 - a pallet with kindling (before making a hole); fig. 2 - AA in fig. 1; fig. C - a pallet with a hole made; fig. 4 - a tray with an insert.

According to the declared utility model, the declared method of repairing pallets for ingots weighing up to 5.7 tons was implemented at the Novokramatorsk Machine-Building Plant (MKM2).

Operation and repair of pallets was carried out as follows. As a result of the use of an all-cast pallet with a diameter of 1150 mm (millimeters) (Fig. 1), when hot metal was poured into the mold, cracks appeared on its surface in zone 1 from the center of the pallet to the edge, with the maximum distance from the axis of the pallet to the edge of the annealing A -210 mm (Fig. 2). In the center of the pallet, coaxially with it, a hole with a diameter of 011-450 mm (Fig. 3) was mechanically drilled (in the lower part of the pallet). The diameter of the hole 0: was chosen so that the spans were in the middle of it from the condition 01/228, i.e. 450 mm/22210 mm. Boring was performed with a diameter of 01-25 mm in the lower part of the pallet so that when the ingot was separated from the 60 pallet, the insert 2 (Fig. 4) did not remain on the ingot, but was separated together with the pallet.

Inserts 2 (fig. 4) with a diameter of 02-01-50 mm and a rim in its lower part were placed in the hole with a diameter of 0: (fig. 3). The upper end surface of insert 2 repeated the geometry of the pallet before repair, and the lower end of the side of insert a 2 was placed in the same plane as the lower surface of the pallet to restore the surface of the pallet. Inserts 2 were fixed in the pallet with a threaded pin MZ36 (not shown in Fig. 1-4).

In the future, insert 2 was replaced several times and the diameter of the hole in the tray and the diameter of the insert were increased to 01-02-700 mm. At the same time, the condition O1«2.Oz/3 was fulfilled.

Thus, the use of the claimed method of pallet repair for through castings eliminates the formation of structural inhomogeneity of the insert, ensures the workability of the pallet, allows you to extend the service life of metallurgical equipment, and also significantly reduce the specific costs of pallets per ton of molten steel.

Claims (2)

USEFUL MODEL FORMULA 1. The method of repairing pallets for through-fillers, in which an insert is placed in the pallet, which differs in that a hole is made in the center of the solid-cast pallet according to condition О01/22В, where Ох is the diameter of the hole in the pallet, А is the maximum distance from the pallet axis to the edge kindling, after which an insert with a diameter corresponding to the hole in the pallet is placed in the opening of the pallet. 2. The method according to claim 1, which differs in that the hole in the pallet is made with drilling, and the inserts are made with an edge and a technological hole, while the end of the edge of the insert is placed in the same plane with the lower surface of the pallet under the condition of restoring the surface of the pallet, and the inserts are fixed in a pallet using a threaded or welding connection. C. The method according to one of claims 1 or 2, which differs in that the diameter O: of the hole in the pallet is increased from the condition O1«2-O3/3, where Oz is the diameter of the pallet, after which inserts of the corresponding parameters are placed in the pallet opening. B o i Shk and you: o Fig. 1 Keya dum i di : : shcha She dya kit i Y Fig. 2 Fig. Z tru What I In g, still There would be x OO Fig. 4