JPH06218494A - Method for arranging runner brick in base board for bottom pouring ingot making - Google Patents

Abstract

PURPOSE:To enable the arranging work of runner bricks without using gap packing material of sand, mortar, etc. CONSTITUTION:At the time of arranging the runner bricks 1 having the height A and width B in the cross section in a groove 2a arranging a base board 2, the following inequalities related to a gap C in the height direction and gaps D, E in the width direction between the groove 2a and the runner brick arranged in a groove 1 are made to satisfy or the interval adjusting plates are interposed between the groove 2a and the runner brick 1 so as to satisfy the following inequalities. C<=AX(Z/100)+0.5, D+E<=BX(Z/100)+0.5. Wherein, Z: hot linear expansion coefficient (%) of the runner brick from the room temp. to 1000 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a runway brick lining method for a surface plate (hereinafter, simply referred to as "surface plate") in a lower pouring ingot making method.

[0002]

2. Description of the Related Art In the bottom pouring ingot method, molten steel supplied to a mold placed on a surface plate is stretched from an injection pipe erected on the surface plate into a groove of the surface plate, which is made of a refractory brick. To guide you through.

By the way, conventionally, when the runner brick is stretched in the groove of the lower pouring surface plate, sand is put in the groove so that the upper surface height of the runner brick is equal to or slightly higher than the height of the surface plate surface. The joints of the runner bricks are mortared or fireproof packing is added to connect them one after another to form the runners, and finally the gap between the groove and both sides of the runner bricks is formed. A method has been adopted in which sand or the like is packed and then the upper surface is fixed with mortar.

That is, in the conventional runner brick lining method, the runner bricks are restrained by the sand and the mortar interposed between the groove and the runner bricks, and the runner brick 1 caused by the heat shock of molten steel shown in FIG. Vertical cracks 1a as shown in Fig. 4 and horizontal cracks 1b as shown in Fig. 4
To prevent the occurrence and spread of.

However, the workability is poor in such a method, and in the processing of the surface plate after use, dust such as sand and mortar is combined with the high temperature of the surface plate to make the work environment very bad.

In view of this, in Japanese Patent Publication No. Sho 53-35897, when the runway brick is set in the groove of the surface plate, the gap between both sides of the runway brick and the groove is set to 6 mm or less, respectively, or the above-mentioned. As a method of interposing a material having a quenching effect such as an iron plate so that the gap becomes 6 mm or less when the gap exceeds 6 mm, a method of stretching a runner brick without using sand has been proposed.

In the method according to Japanese Patent Publication No. S35-35897, the above-mentioned method is adopted to prevent the runner brick from cracking and expanding due to the heat shock of the molten steel, and it is assumed that cracking occurs. It is said that the molten steel can be prevented from flowing out by the quenching effect of the iron plate placed in the side surface of the surface plate groove or in the gap.

[0008]

However, in actual operation, 1 m as in JP-B-53-35897 is used.
If there is a large gap of m-order, cracks of runner bricks will expand to several mm and it will be impossible to prevent molten steel from flowing out. Therefore, as in the conventional method, use fillers such as sand and mortar. I have no choice. In addition, Japanese Examined Japanese Patent Publication 53-358
In the method according to Japanese Patent Laid-Open No. 97, no mention is made of the gap in the height direction between the groove and the runway brick, but the experiments by the present inventors that this gap in the height direction is also related to the outflow of molten steel. Has been found in.

An object of the present invention is to provide a runner brick laying method for a surface plate for lower pouring ingots, which can solve the problems in the conventional runway brick laying methods.

[0010]

In view of the above-mentioned conventional problems, the inventors of the present invention relate to a method of tensioning a runner brick in a groove of a surface plate without using sand or mortar. As a result of various experiments and studies on the size of the groove and the size of the gap between the two and the form of cracking, the following findings were obtained.

That is, according to the experiments by the present inventors, when the runway brick is cracked and the gap exceeds 0.5 mm, the wettability of the runway brick and the molten steel and the viscosity of the molten steel show a relationship. , It is difficult to prevent the outflow of molten steel from the gap by the cooling effect of the interval adjusting plate such as an iron plate arranged in the side surface of the surface plate groove or in the space between the groove and the runway brick. It was found that since the cracks of the slab brick are often one on each side of the runway brick, it is rare that two or more cracks are formed on each side.

Considering the above knowledge and the volume expansion due to the molten steel heat during casting of the runner brick, even if the runner brick is cracked by the thermal shock of the molten steel, the molten steel flows out from the cracks generated at that time. The following method of the present invention was established as a method for tensioning runner bricks in the grooves of the surface plate so that sufficient cracks would not occur.

That is, the runway brick lining method for the bottom pouring ingot surface plate of the present invention is such that a runway brick having a height A and a width B in a transverse section is placed in a groove provided in the bottom pouring surface plate. At the time of stretching, the gap C in the height direction between the groove and the runner brick stretched in the groove and the gaps D and E in the width direction satisfy the following formula 1 or the following formula 1 The gist of the invention is to provide a gap adjusting plate between the groove and the runway brick.

[0014]

[Equation 1] C ≦ A × (Z / 100) +0.5 [mm] D + E ≦ B × (Z / 100) +0.5 [mm] where Z: heat of the runway brick between room temperature and 1000 ° C. Coefficient of linear expansion (%)

[0015]

Examples Table 4 showing the results of experiments conducted to confirm the effects of the method of the present invention will be described below. FIG. 1 is an explanatory view of a method for laying runner bricks on a surface plate for lower pouring ingots according to the present invention.

Table 5 shows the components shown in Table 1 or Table 2, and the runway brick 1 having the dimensions and linear expansion coefficients shown in Table 4 is shown in Table 4 of the surface plate 2 so as to satisfy the conditions of the method of the present invention. After being stretched in the groove 2a having a size, the presence or absence of outflow of molten steel at the time of injecting molten steel of the components shown in Table 3 at 1570 ° C. was compared with the results of the case of not satisfying the conditions of the present invention. The results are shown.

[0017]

[Table 1]

[0018]

[Table 2]

[0019]

[Table 3]

[0020]

[Table 4]

[0021]

[Table 5]

In Table 5, Nos. 1 to 5, 12 and 14 are examples in which nothing is provided in the gaps D, E and C between the groove 2a and the runway brick 1. Of these, the conditions of the present invention Satisfy N
In o.1, 2.12, there was no molten steel outflow and good casting was possible, but the part marked with * in Table 5 does not satisfy the conditions of the present invention No. 3 to 5, 14 In molten steel, the outflow of molten steel occurred at a frequency of 25% or more.

Nos. 6 to 11 and 13 are examples of the case where an iron plate is provided as a gap adjusting plate in the gaps D, E, and C between the groove 2a and the runway brick 1, of which the conditions of the present invention are satisfied. In Nos. 6 to 8 and 13 satisfying the above conditions, molten steel did not flow out at all and could be satisfactorily cast, but the part marked with * in Table 5 does not satisfy the conditions of the present invention. In No. 11, outflow of molten steel occurred at a frequency of 25% or more. Thus, the experimental results shown in Table 5 proved the effect of the method of the present invention.

Although the above-mentioned experiment is for a runway brick having a rectangular cross section shown in FIG. 1, the method of the present invention is limited to only a runway brick having a rectangular cross section as shown in FIG. Of course, the cross section as shown in FIG. 2 may be a hexagonal shape in which the two lower surfaces of the rectangle are chamfered.

However, in the case of the runway brick having the shape shown in FIG. 2, in addition to the conditions for the runway brick 1 having the shape shown in FIG. 1, a gap H between the chamfered portion and the groove 2a is further added. , I
Must satisfy the condition of Equation 2 below.

[0026]

[Equation 2] H ≦ F × (Z / 100) +0.5 [mm] I ≦ G × (Z / 100) +0.5 [mm]

[0027]

As described above, according to the method of the present invention, in the runner brick lining method for the surface plate for under-pouring ingot, the runner brick is used without using the gap filling material such as sand or mortar. As a result, the work environment can be significantly improved and the quality of the cast product is improved because the filler is not mixed with the molten steel. In addition, according to the method of the present invention, the working speed is improved by 50%.

[Brief description of drawings]

FIG. 1 is an explanatory view of a runway brick lining method for a surface plate for lower pouring ingots according to the present invention.

FIG. 2 is another explanatory view of the method for laying bricks for runners on the surface plate for under-pouring ingots according to the present invention.

FIG. 3 is an explanatory diagram of vertical cracks generated in a runway brick.

FIG. 4 is an explanatory diagram of lateral cracks that occur in a runway brick.

[Explanation of symbols]

 1 runway brick 2 surface plate 2a groove

Claims (1)

[Claims] 1. When a runway brick having a height A and a width B in a transverse section is stretched in a groove provided on a surface plate for under-pouring and ingot making, the runway brick and the runway brick stretched in the groove are provided. Gap C in the height direction of
And the gaps D and E in the width direction satisfy the following formula, or a gap adjusting plate is provided between the groove and the runway brick so as to satisfy the following formula. How to lay bricks on the surface plate. C ≦ A × (Z / 100) +0.5 [mm] D + E ≦ B × (Z / 100) +0.5 [mm] where Z: hot linear expansion coefficient of the runway brick between room temperature and 1000 ° C. (%)