JPH09182991A - End tab made of refractory material for welding and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide at low cost an end tab which is made of refractory materials for welding, which is high in quality, mechanical strength, thermal impact resistance, heat resistance, etc., and which is free from damage in use, and also to provide its manufacture. SOLUTION: In manufacturing an end tab 1 made of refractory materials, a metallic mold is used the shape of which is capable of arranging alternately a weir 21 , 21 ', 22 , 22 ' and a molten metal receiving face 3 on both front and rear faces of the end tab 1; and in this metallic mold, the powders of raw refractory materials are simply inserted that consist in weight % of 50-70% Al2 O3 , 35-50% SiO2 , 1% or less each of MgO, K2 O, Fe2 O3 and CaO, thereby uniformizinq a molding pressure at the time of press molding over the entire mold as well as the distribution of the refractory materials.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an end tub made of a refractory material for welding and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, various shapes of end tabs made of a refractory material for welding have been used. When the use surface of the end tab has a weir and a molten metal receiving surface,
It is roughly classified into a type in which the use surface is formed on only one side of the end tab, and a type in which the use surface is formed on both the front and back surfaces of the end tab. For the latter type, the weir 2 ₁ in the use surfaces of the front and back surfaces as shown in FIG. 6, 2 ₁ ', 2 _2,
2 ₂ ′ and the molten metal receiving surfaces 3, 3 ′ are symmetrical, that is,
It was generally formed on a mirror surface.

[0003] However, when an end tab having such a shape is manufactured by molding → firing, the press-molding in the molding step naturally uses a mold having such a shape. There is a problem that the powder is not uniformly distributed in the mold. As a result, there is a problem that the thickness of the end tab must be increased because a portion having insufficient strength is generated, or the end of the end tab or the end of the weir is chipped off.

[0004] Therefore, when inserting the raw material powder into the mold,
Depending on the size of the irregularities of the mold corresponding to the shape of the surface to be used, etc., a special means (for example, a mold vibrating device) was used to change the raw material supply amount and distribute it evenly throughout
Originally, the shape was such that the press molding pressure acted non-uniformly, so it was difficult to make it completely uniform. Also,
As a solution to the above-mentioned problem of the prior art, there has been proposed a device having a use surface in which a weir and a molten metal receiving surface are alternately arranged on both front and back surfaces.

On the other hand, as a material for the end tab made of a refractory material for welding, SiO ₂ : 45 to 70% by weight and Al ₂ O ₃ :
15-40%, MgO: SiO ₂ in the range of 5-30%,
It is known that the total of Al ₂ O ₃ and MgO is 90% or more and the apparent porosity is 5 to 40% (Japanese Patent Application No. Sho 5).
No. 8-129790). However, the end tab made of a refractory material for welding manufactured from this material has a disadvantage that the strength is not sufficient.

[0006]

The object of the present invention is to provide an inexpensive end tab made of a refractory material for welding which is high in quality, has high mechanical strength, high thermal shock resistance, high heat resistance and the like and is not damaged even when used. It is intended to provide a manufacturing method.

[0007]

Means for Solving the Problems In order to solve the above problems, the present inventors have conducted intensive studies on the structure and the component composition of the raw materials for the above-mentioned end tub, and as a result, have made the present invention. . That is, in the method for manufacturing a refractory end tab for welding of the present invention, a mold having a shape in which a weir and a molten metal receiving surface can be alternately arranged is used on both the front and back surfaces of the end tab, and the weight of this mold is large. Al _{2 in} %
_{O 3: 50~70%, SiO 2} : 35~50%, Mg
O, K ₂ O, Fe ₂ O ₃ and CaO: By simply inserting the raw material powder of the refractory containing 1% or less of each,
This is to make the molding pressure during press molding uniform over the entire mold and to make the distribution of the refractory material uniform.

Further, in order to solve the above-mentioned problems, in a welding refractory end tab having a weir and a molten metal receiving surface according to the present invention, the composition of the component is expressed by weight% and Al ₂ O ₃ : 5.
_{0~70%, SiO 2: 35~50%} , MgO, K
₂ O, Fe ₂ O ₃ and CaO: Each is made up of 1% or less, and both front and back surfaces are provided with use surfaces in which the weir and the molten metal receiving surface are alternately arranged.

In order to solve the above-mentioned problems, in the welding refractory end tab of the present invention, a root face is provided on the molten metal receiving surface of the welding refractory end tab. Further, in order to solve the above problems, in the welding refractory end tab of the present invention, a taper portion is provided on the molten metal receiving surface side of the weir of the welding refractory end tab.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A mold used in a method for manufacturing a refractory end tab for welding according to the present invention can have a weir and a molten metal receiving surface staggered on both front and back surfaces of the refractory end tab. It is of a shape. Further, the raw material to be molded in the mold of the present invention, that is, the refractory used for the end tab made of the refractory material of the present invention, is Al ₂ O ₃ : 50% by weight.
70%, SiO ₂ : 35 to 50%, MgO, K ₂ O, F
e ₂ O ₃ and CaO: Each is composed of 1% or less.

The reason for using Al ₂ O ₃ in this raw material is to enhance mechanical strength, thermal shock resistance, fire resistance and heat cycle resistance. If the amount used is less than 50%, the mechanical strength, thermal shock resistance, fire resistance and thermal cycle resistance will be low, and if it is more than 70%, the thermal shock resistance will be decreased, the firing temperature will be high, and the cost will be high. Because it will be higher
The range of the amount used was 50 to 70%.

The reason for using SiO ₂ is to lower the coefficient of thermal expansion and lower the firing temperature. If the amount is less than 35%, the thermal expansion coefficient increases, so that the thermal shock resistance decreases, the end tabs are easily broken, and the firing temperature increases. 50% of its usage
When the amount is larger, the amount of Al ₂ O ₃ decreases, so that the mechanical strength, fire resistance, and heat cycle resistance decrease, and the mechanical strength and the like decrease, so that the thermal shock resistance also decreases. Therefore, the range of the used amount is set to 35 to 50%.

Further, in this raw material, MgO, K ₂
The reason why each of O, Fe ₂ O ₃ and CaO is set to 1% or less is that these components are impurities. Therefore, it is preferable that the content of each component is as small as possible.
This is because the above-described characteristics are not reduced.

The method for producing a refractory end tab according to the present invention uses the above-mentioned mold and refractory, and includes, for example, the steps of mixing raw materials, granulating, inserting raw material powder into a mold, press forming, drying, and firing. Can be manufactured. The mixing of the raw materials, granulation, insertion of the raw material powder into the mold, press molding, and drying in this step may be the same as the usual methods. The calcination is preferably performed at 1200 to 1500 ° C., which is slightly higher than the normal temperature, for about 24 hours.

The end tab 1 made of a refractory material for welding according to the present invention comprises:
The component composition of the material is as described above, and an example of the structure is a weir 2 ₁ , 2 as shown in FIG. 1 ((a) front view, (b) rear view, (c) top view). ₁ '2 _2, 2 ₂ 'and has a use surface made of molten metal receiving surface 3,3', (c)
As shown in FIG. ₅ , the weirs 2 ₁ , 2 ₂ on the front surface and the molten metal receiving surface 3 and the weirs 2 ₁ ′, 2 ₂ ′ on the back surface and the molten metal receiving surface 3 ′ are arranged alternately.

[0016] the other one welding refractory steel end tab 1 of the present invention, FIG. 2 ((a) front view, (b) top view) weir as shown in 2 ₁ ,, 2 ₁ '2 _2, 2 ₂ ′ and molten metal receiving surface 3,
Have used surface made of 3', (b) weir 2 ₁ surface as shown in, 2 ₂ and the molten metal receiving surface 3 and back surface of the weir 2 ₁ '
2 ₂ ′ and the molten metal receiving surface 3 ′ are alternately arranged, and root faces 4, 4 ′ (not shown) are provided on the molten metal receiving surface 3 on the front surface and the molten metal receiving surface 3 ′ on the back surface. Is provided. This root face 4, 4
The height of ′ can be appropriately determined according to the size of the end tab 1, but is about 2 mm or more.

As shown in FIG. 2, the other end tab 1 made of refractory material for welding according to the present invention comprises the weirs 2 ₁ , 2 ₁ ′, 2 ₂ and 2 ₂ ′ on the molten metal receiving surface 3, 3 ′ side. Tapered part at the end 5 ₁ , 5
₁ ', 5 _2, 5 _2' is provided with a. The angle of this taper can be appropriately determined, but it is about 35 with respect to the vertical plane.
It is preferable that they are provided in the order of ° or arc. Also,
The weirs 2 ₂ and 2 ₂ ′ are different from the weirs 2 ₁ and 2 ₁ ′ shown in FIGS. 1 and 2.
Can be set to various angles such as 35 ° and 45 ° according to the groove angle of the welding base material.

[0018]

In the present invention, Al ₂ O ₃ : 5 is used as a raw material.
_{0~70%, SiO 2: 35~50%} , MgO, K
₂ O, Fe ₂ O _3, and CaO: By using those each containing 1% or less, the mechanical strength, thermal shock resistance, fire resistance, and heat cycle resistance of the end tab made of a refractory material for welding can be increased. You. Also, by using a mold having a shape in which weirs and molten metal receiving surfaces can be alternately arranged on both the front and back surfaces, the thickness (height) of the space in the mold becomes relatively uniform. Even if the raw material powder is simply inserted, the molding pressure at the time of press molding can be made uniform over the entire mold and the distribution of the raw material can be made uniform. As a result, it is possible to obtain an end tab made of a refractory material for welding, which is high in mechanical strength, thermal shock resistance, etc., uniform and thin.

By providing the root face, even if the welding refractory end tab 1 is peeled off from the upper portion as shown in FIG. 4, no stress acts on the hatched portion shown in FIG. 5, and the portion is damaged. Since there is no such phenomenon, the chip does not adhere to the beat surface and can be used again. In addition, 5 in FIG. 4 is a base material for welding, and 6 is a backing metal. Further, by making the weir end portion tapered, the refractory end tab 1 for welding covers the tapered portion more than the base material to be welded, so that sufficient penetration of the base material can be obtained. In addition, the corner of the end tab weir is hardly damaged by the arc during use, and the end tab is tapered, so that it is extremely easy to peel off the end tab after welding.

[0020]

【Example】

Example 1 A mold having a shape in which a weir and a molten metal receiving surface can be alternately arranged is used on both the front and back surfaces, and Al ₂ in weight% is used for this mold.
_{O 3: 50.9%, SiO 2} : 38.8%, MgO, K
₂ O, Fe ₂ O ₃ and CaO: The raw material powder consisting of 2.7% in total is blended → granulated → raw material powder is inserted into the die → press molding → drying → firing shown in Fig. 3 We manufactured end-tabs made of refractory material for welding. The drying in this manufacturing process was performed at room temperature for 48 hours. Also, firing is 1280
It was carried out at ˜1300 ° C. for 24 hours. The refractory end tab for welding did not crack, damage, or become brittle when used. Further, the molten flux adhered well to the end tub itself.

In the above embodiment, the refractory end tab for welding having the V-shaped molten metal receiving surface and the manufacturing method thereof are shown. The vertical weir 2 ₁ having the F-shaped molten metal receiving surface, that is, the V-shaped _one , also those of other shapes such that there is no 2 ₁ 'can be prepared analogously. Further, it is needless to say that the present invention is not limited to the above-mentioned embodiments and various modifications can be made without departing from the scope of the invention.

[0022]

According to the present invention, the above-described configuration enables
It has the following excellent effects. (1) An inexpensive end tab made of a refractory material for welding can be obtained with high quality, high mechanical strength, high thermal shock resistance, high fire resistance and high heat cycle resistance. (2) Since the root face is provided on the molten metal receiving surface, the lower end of the weir is not damaged, so that no chips are attached to the beat surface, and there is no damage, so it can be reused. .

[Brief description of the drawings]

FIG. 1 is a view showing an example of an end tab made of a refractory material for welding according to the present invention, in which (a) is a front view, (b) is a back view,
(C) is a top view thereof.

FIG. 2 is a view showing another example of the end tab made of a refractory material for welding according to the present invention, in which (a) is a front view and (b) is a top view.

FIG. 3 shows the shape and dimensions of an end tab made of a refractory material for welding according to one embodiment of the present invention, wherein (a) is a front view thereof,
(B) is a back view, and (c) is a top view.

FIG. 4 is an explanatory view showing a procedure for removing an end tab after welding.

FIG. 5 is a diagram showing a damaged portion of a conventional end tab.

FIG. 6 is a top view of a conventional end tab.

[Brief description of reference numerals]

1 End tabs made of refractory material for welding 2 ₁ , 2 ₁ ′, 2 ₂ , 2 ₂ ′ weir 3, 3 ′ molten metal receiving surface ₄ , 4 ′ root face part 5 ₁ , 5 ₁ ′, 5 ₂ , 5 ₂ ′ taper Part 6 Base material 7 Backing material

Claims (4)

[Claims] 1. When manufacturing a refractory end tab for welding, a mold having a shape in which a weir and a molten metal receiving surface can be arranged alternately on both front and back surfaces of the refractory end tab for welding is used. Al ₂ O ₃ by weight% in the mold: 50-70
_{%, SiO 2: 35~50%,} MgO, K 2 O, Fe 2
O ₃ and CaO: Characteristically, by uniformly inserting the raw material powder of the refractory consisting of 1% or less, the molding pressure at the time of press molding is made uniform throughout the mold, and the distribution of the refractory material is made uniform. A method for manufacturing a refractory end tab for welding. 2. A welding refractory end tub having a weir and a molten metal receiving surface, wherein the component composition is A by weight%.
_{l 2 O 3: 50~70%,} SiO 2: 35~50%, M
gO, K ₂ O, Fe ₂ O ₃ and CaO: Each is made up of 1% or less, and both front and back surfaces are provided with use surfaces in which the weir and the molten metal receiving surface are alternately arranged. End tab made of refractory material for welding. 3. The refractory end tab for welding according to claim 2, wherein a root face is provided on a molten metal receiving surface of the refractory end tab for welding. 4. The refractory end tab for welding according to claim 2, wherein a taper portion is provided on the molten metal receiving surface side of the weir of the refractory end tab for welding.