RU87945U1 - INTERMEDIATE BUCKET FOR CONTINUOUS METAL CASTING - Google Patents

Abstract

An intermediate ladle for continuous casting of metal, including a metal casing, refractory lining of the walls and the bottom, consisting of heat-insulating, intermediate, reinforcing and working layers, a receiving and casting chamber separated by a partition with channels, a steel outlet cup in the socket block and a stopper are installed in the bottom of the casting chamber for locking the steel outlet with the ability to move in the vertical direction, characterized in that between the reinforcing and working layers of the bottom is made additional loizolyatsionny layer and between the working and the reinforcing layers of walls formed gap filled with a refractory powder, a thickness of 0.007 ... 0.008 longitudinal length of the lining walls of the ladle.

Description

The utility model relates to metallurgy, and more particularly to continuous casting of metal.

Known intermediate bucket containing a metal casing, a refractory lining made of piece fireclay refractories and containing a reinforcing and working layer, a receiving casting chamber, separated by a refractory partition with channels for the flow of steel from the receiving chamber into the casting, steel outlet, installed in the nest unit in the bottom a casting chamber and a stopper for locking a steel outlet cup (see patent No. 2185261, Russia IPC ⁷ V22D 41/00).

The disadvantage of this bucket is the low resistance of chamotte brick lining and the high content of non-metallic inclusions in steel.

This is due to the high wear rate of the fireclay lining during all interaction with the slag metal melt, the reduction of silicon oxide (SiO ₂ ) with metallic aluminum dissolved in liquid steel to metallic silicon and its subsequent oxidation with steel oxygen with the formation of non-metallic inclusions. In addition, when removing slag metal hardened residues during processing of the ladle after casting, the working and reinforcing layer of the lining is destroyed, resulting in a decrease in the durability of the intermediate ladle.

The closest in technical essence of the problem to be solved is an intermediate bucket containing a metal casing, a refractory lining, consisting of a heat-insulating layer made of mullite-siliceous cardboard of the MKRKG brand, an intermediate layer of fireclay refractories, a monolithic reinforcing layer made of high-alumina concrete, a working layer made of high-alumina concrete gunite masses of periclase or periclase-chromite composition with a density of 1.4 g / cm ³ containing a receiving and casting chamber separated by refractory a septum with channels for steel to flow from the receiving chamber into the casting and containing steel cup installed in the nesting block in the bottom of the casting chamber and a stopper with the possibility of vertical movement to lock the steel outlet channel (see patent No. 75973, Russia MKI ³ V22D 41/08, 11/10).

A disadvantage of the closest analogue is the low resistance of the working layer of a lining made of a gunite mass of periclase composition with a MgO content of> 75%, for example, PTMS grade or imported analogue Ankertun 217, and the increased content of nonmetallic inclusions in steel, since the working layer of shotcrete mass has high porosity, more than 30%, low density - 1.4 g / cm ³ and low mechanical strength - 1.2 N / mm ² , is washed away by the flows of molten steel during casting, shotcrete particles are pulled into the mold and degrade the quality of the steel.

The technical problem solved by the utility model is to increase the durability of the working layer of the lining and improve the quality of steel by reducing the content of non-metallic inclusions in steel.

The solution to the technical problem is achieved by the fact that in the intermediate ladle for continuous casting of metal, including a metal casing, refractory lining of the walls and the bottom, consisting of heat-insulating, intermediate, reinforcing and working layers, a receiving and casting chamber, separated by a partition with channels, in the bottom of the casting chamber a steel outlet cup is installed in the socket unit and a stopper for locking the steel outlet cup with the possibility of moving in the vertical direction, in contrast to the closest analogue between rmaturnym and bottom working layers formed an additional heat insulating layer and between the working and the reinforcing layers of walls formed gap filled with a refractory powder, a thickness of 0.007 ... 0.008 longitudinal length of the lining walls of the ladle.

An increase in the durability of the tundish will occur due to the fact that periclase-chromite bricks have a high density of 3.0 g / cm ³ , low porosity of 16-23%, high mechanical strength of 35 N / mm ² compared to shotcrete, which provides high metal and Slag resistance of the lining and increases the durability of the tundish.

The essence of the utility model is that in order to reduce the wear of the working layer of the lining in the tundish, by increasing the density, mechanical strength and low porosity of the working layer, the working layer is made of fired bricks of periclase-chromite composition containing magnesium oxide (MgO) in an amount not less than 70%, chromium oxide (Cr ₂ O ₃ ) from 7 to 15%, having a mechanical strength of 35 N / mm ² or more, a density of 2.9-3.0 g / cm ³ , porosity in the range of 16-23%, while on the end walls of the bucket, the working layer is made with a gap of 0.007-0, 008 the length of the lining of the bucket, and on the reinforcing concrete layer is placed sheet asbestos with a thickness of 3-5 mm, which reduces heat losses through the lining of the bucket with molten steel and preserves the specified speed mode of metal casting. As a result, the wear rate and thermal conductivity of the lining are reduced, the durability of the tundish is increased, the content of non-metallic inclusions is reduced, and the quality of steel is improved.

If the thickness of the end gap is less than 0.007 of the length of the lining of the longitudinal wall of the bucket, then due to the temperature growth of the lining, heating of the ladle and casting of steel in the brick will cause stresses, which will lead to chipping of the lining and reduce the durability of the lining of the bucket.

If the thickness of the end gap is more than 0.008 of the lining of the longitudinal wall of the bucket, then the lining joints may diverge under the pressure of molten steel, metal seeps into the lining joints, increased wear of the lining, and reduced durability of the bucket.

The essence of the utility model is illustrated by the drawing, in which Fig. 1 shows a sectional general view of an intermediate bucket.

An intermediate ladle for continuous casting of metal includes a metal casing 1, a heat-insulating layer 2 made of mullite-siliceous cardboard of the MKRKG-400 brand, for example, 10 mm thick, an intermediate layer 3 of fireclay bricks, for example, 65 mm thick, a reinforcing layer 4 of high-alumina concrete, for example SKB-93, or BShK (spinel-corundum concrete) 120 mm thick, an additional heat-insulating layer of the bottom 5 of sheet asbestos, for example, 3 mm thick, a working layer 6 of fired periclase-chromite brick grade P CS with sizes 80 * 100 * 300 mm, for example, 80 mm thick, gap 7 filled with refractory powder, for example, grade ПШК (large chamotte powder), receiving 8 and pouring chamber 9, partitions 10 with channels 11 for overflowing steel from the receiving chamber 8 in casting 9, steel outlet glass 12, socket block 13, stopper 14.

The proposed intermediate bucket works as follows.

A stream of steel from the steel pouring ladle (not shown in the figure) enters the receiving chamber - 8 and through the overflow channels - 11 partitions - 10 flows into the casting chamber - 9 and fills it with the stopper closed - 14. After filling the ladle with metal, 2/3 of it the volume of the stopper 14 rises and opens the steel outlet glass - 12, the liquid steel enters the mold of the continuous casting plant (not shown in the figure). During operation, liquid steel is in contact with the working layer 6 of periclase-chromite brick lining, non-metallic particles are deposited on the surface of the working layer, the quality of steel and the durability of the bucket increase.

Table 1 shows examples of specific designs for the bucket.

Table 1
- Examples of specific performance Options Examples one 2 3 four Bucket capacity, t 45 45 45 45 Lining length of the longitudinal wall of the bucket, L, mm 8600 860 8600 8600 The size (width) of the end gap, 1, mm fifty 60 70 80 The ratio of the size of the end gap to the length of the lining of the longitudinal wall of the bucket, 1 / L 0.006 0.007 0.008 0.009 Durability of the working lining, a series of heats 7 12 12 6

The proposed utility model has been pilot-tested in the oxygen-converter shop of OJSC MMK.

A comparative assessment of the sorting of the sheet by the defect of the film from non-metallic inclusions (HB) using a serial and proposed device.

table 2
- Sorting of the sheet in the LPC according to the defect of the captivity from HB depending on the type of lining of the intermediate bucket Number of swimming trunks Bucket Lining Type Metal processing, t Sorted by t % 2110 Gunite mass 168899.0 917.0 0.54 1395 Periclase-chromite brick 111642 152.0 0.14

Claims (1)

An intermediate ladle for continuous casting of metal, including a metal casing, refractory lining of the walls and the bottom, consisting of heat-insulating, intermediate, reinforcing and working layers, a receiving and casting chamber separated by a partition with channels, a steel outlet cup in the socket block and a stopper are installed in the bottom of the casting chamber for locking the steel outlet with the ability to move in the vertical direction, characterized in that between the reinforcing and working layers of the bottom is made additional loizolyatsionny layer and between the working and the reinforcing layers of walls formed gap filled with a refractory powder, a thickness of 0.007 ... 0.008 longitudinal length of the lining walls of the ladle.