JPS58154445A - Continuous casting method - Google Patents

Abstract

PURPOSE:To reduce the length of a shrinkpipe in the terminal part of a continuous casting ingot and to improve the yield of the continuous casting ingot by covering the surface of the molten metal in a casting mold for continuous casting with a specific refractory heat insulating material. CONSTITUTION:Upon ending of charging of molten metal 2 from an immersion nozzle 4 of a tundish into a casting mold 1 for continuous casting, powder of refractories such as lime, alumina, dolomite or the like and an oil 7 are packed on the surface of said molten metal so as to provide a lubricant in the stage of taking off a cast ingot 2' from the mold 1. A refractory heat insulating material 8 consisting of a thermit heating material as refractories such as line, silica, alumina, dolomite or the like, or a mixture of powder of metallic aluminum and metallic oxides is covered thereon. Since the final end part of the ingot 2 is heated or insulated with the above-described material 8, the length of a pipe 3 is made shorter, and the yield of the continuous casting ingot is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous casting method in which molten metal is poured from a melting furnace through a ladle and a tundish into the upper part of the mold (1-1) and the molten metal thus cast is continuously withdrawn from the mold.

In the above-mentioned continuous casting method, the upper surface of the molten metal poured into the mold is heated to decompose oil such as vegetable oil such as rapeseed oil, sesame oil, cottonseed oil, etc., and/or lime, silica, etc.
Refractory powder such as alumina, dolomite, etc. (1) Prevents contact between the molten metal and air to prevent 1# hot water from oxidizing, 4) It is used as a lubricant for removing slabs from moss molds. More again? Water is poured from above to cool the layer of oil and refractory powder. When the injection of molten metal into the mold is completed (this is the final end of the mold, a cavity called a pipe is formed during the cooling process. This state is shown in Figure 1).
This is shown. In Figure e, (1) is the mold, (2) is the molten metal, and at the final end of the molten metal (2), a cavity called a pipe (3) is formed during the cooling process 1. The upper part of the pipe (3) is covered with steel skin (2) A. Such a pipe (3) is caused by the volumetric contraction that occurs during the cooling process of the molten metal. Therefore, it is necessary to cut off the portion forming the pipe (3) at the final end of the bath (2) from, for example, the dotted line in FIG. 1 in the form of a timepiece after cooling. From the perspective of sparrow resources f9, such truncated portions should be minimized as much as possible.

The purpose of the present invention is to reduce the cut-off portion at the end of the collar piece jl as much as possible through continuous casting.
The main point is to keep the final m'z of the slab warm.

To explain one embodiment of the non-invention as shown in Figure 2, it is a nozzle for a mold (
Bath water (2) is injected through the nozzle (4) from the top of 1). Mold (1) riMold (1) made of copper, for example
The walls are water-cooled. The molten metal (2) solidifies in the mold (1) and becomes two slabs, which are taken out from the bottom of the mold (1) by a take-up roll 1 (not shown).
2)'l-j: Time mold 1) Take out from the bottom 1st. At this position, water may be sprayed with a spray nozzle t5), 151, etc. to cool the area. The above pipe (
, 3) In order to reduce the total size as much as possible, such water cooling is not desirable. Molten metal (2) in the mold (1)
) The upper surface of the mold (
It is used as a lubricant when removing the casting tip (2)' from 1).

Furthermore, it is covered with a fire-resistant heat insulating material (8) from above.

The refractory heat insulating material (8) is made of refractories such as lime, silica, alumina, and dolomite, or exothermic materials that generate heat using the tellemit reaction by mixing metal aluminum and other metal oxides. Become. When continuous casting is performed with the above configuration t, the final end t of the slab (2)'
In this case, the heat insulating effect of the heat insulating material (8) as shown in Fig. 3e (therefore, the skin covering (2) A as shown in Fig. 1t) is not formed, and 1 of the wall surface of the pipe (3) The slope is also gentle
Now, the length of the pipe (3) is longer than the conventional one.
t shortened. For example, if the conventional mold (1) was heated and only the refractory powder and/or oil was applied to the surface of the molten metal (21), the length of the moss pipe (3) would be approximately 1.
3 m1 In the present invention, if the heat insulating material (8) is placed over the ridge, the length will be about 1.0 to 1.3 m. The reason why the length of the T-pipe (3) is shortened is that the length of the T-pipe (3) is shortened.
) When the part A is filled with pipe (3) f, the performance of the tall pipe (3) is reduced, and the cooling and solidification rate of the molten metal (2) is reduced as a result of the heat retention effect of the heat insulating material 18). 3) It is thought that when the shape of the tip becomes rounded, the problem becomes more pronounced.

The present invention is not limited to the above-mentioned implementation number, and for example, refractory powder and oil are not essential to the present invention, and water cooling immediately after casting iron is drawn out from the mold (1) is also not limited. It is also not required.

The present invention provides a mold e in the continuous casting method as described in 7 above.
Cover the top surface of the poured molten metal with a fire-resistant heat insulating material.
A skin is formed at the final end of the cast iron, and the shape of the pipe that is formed also becomes rounded as the solidification rate of the molten metal decreases. The length of the kebab is shortened by that amount, and the cut-off portion is therefore reduced, which is extremely advantageous in terms of resource saving and cost savings. Also, since water is not filled, the risk of steam explosion (boiling) and problems such as molten metal cooling and solidifying in the tundish nozzle and clogging can be eliminated.

[Brief explanation of the drawing]

Figure 1 is a side sectional view of the conventional example, Figure 2 is a side sectional view of an embodiment of the present invention, and Figure 3 is a side sectional view of the final end portion of the slab in the embodiment t. In the figure, (1)... Mold, (2)... Molten metal, (2
)'...Blast slab, (6)...Refractory powder, (7)...
...Oil, (8) ...1 Fireproof insulation material patent applicant Daido Steel Co., Ltd. Procedural amendment dated March 79, 19602, Title of invention Continuous casting method 3, Case of person making amendment Relationship with Patent Applicant Representative Director Takeshi 1) Kizo 4, Agent 〒Il Otsu 7 6 Number of inventions increased by amendment 7, drawings subject to amendment 8 Contents of amendment A 1 [2] B 2 Zen,; ~ ~ 1 2 ~ ~ ~ + Maete l ° ~ 2 5, i:, 5 ”-2' J-=-m- ~-------- -------- 1-1-2 -------;;- 111-1-1111o 3- 7.4 252-

Claims (1)

[Claims] 1. A continuous casting method characterized in that immediately after pouring the molten metal from the molten metal container into the mold, the upper surface of the molten metal is covered with a refractory heat insulating material. Claims: In the continuous casting method 1 described herein, the refractory heat insulating material consists of a mixture of metallic aluminum and other metal oxides. 3. Claims 1 and 2 In the continuous casting method described above, the refractory heat insulating material is coated on the upper surface of the molten metal via refractory powder and/or oil.