JPS62282750A - Ingot making method - Google Patents

Abstract

PURPOSE:To improve the surface characteristic of an ingot feeder head by making the ingot as setting a heat insulating feeder head flask in place of a casting flask after the solidified shell in molten metal formed at the casting flask part on upper part of a mold for ingot making becomes to level of no occurrence of breakout. CONSTITUTION:The casting flask 3 composing of material having erosion resistance to the molten metal to make the ingot is set together with a casting flask holding body 4 as shiftable by hanging on the upper part of the mold 2 for ingot making setting on a bottom plate 1. Next, the molten metal 5 is poured into the mold 2 and in succession into the casting flask 3, and after the solidified shell 5a formed at the casting flask 3 part becomes to level of no occurrence of breakout, the casting flask 3 is removed together with the holding body 4. In succession, in place of the casting flask 3, the feeder head 6 composing of material having excellent heat insulating, is quickly set on the upper part of the mold 2 together with the casting flask holding body 4 to execute the ingot making. In this way, the surface characteristic of the ingot at connecting part with the casting flask is improved.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Object of the Invention] (Field of Industrial Application) The present invention relates to an ingot-forming method used for forming molten metal into an ingot.

(Prior Art) Molten metal melted in various furnaces is supplied from the upper part of the continuous casting mold G through a tundish from a ladle, for example, and is continuously drawn out from the bottom of the mold to form a slab ( Slabs, blooms), or are supplied into an ingot mold by top pouring or bottom pouring from a ladle and solidified in the mold to become an ingot, which is then subjected to blooming rolling, product rolling and forging. etc.

Among these, the ingot casting molds used for producing ingots are usually installed in multiple numbers on a surface plate, and the shrinkage after solidification of the ingots causes cavities to form at the top of the ingots. A heat-insulating feeder frame is often provided at the top of the mold in order to prevent the formation of cavities inside and to collect segregation in the upper part to improve the homogeneity of the main body.

(Problems to be Solved by the Invention) However, when ingot making is carried out by providing an insulating feeder frame above the mold, the surface of the ingot in contact with the insulating feeder frame is The problem was that the properties were not very good and the surface was prone to scratches.

(Purpose of the Invention) This invention was made by focusing on the above-mentioned problems of the conventional technology, and by providing an insulating feeder frame on the top of the ingot casting mold, evacuation cavities are concentrated on the top of the ingot. To provide an ingot making method capable of improving the surface properties of the ingot at the part in contact with the riser frame even when the ingot is formed in the upper part and segregation is collected in the upper part. The purpose is to

[Structure of the Invention] (Means for Solving the Problems) This invention provides that when supplying molten metal into an ingot mold by top pouring, bottom pouring, etc. to obtain an ingot, the upper part of the ingot mold is A casting flask made of a material that is resistant to erosion by the molten metal to be ingot is installed, and the molten metal is poured into the ingot forming mold and subsequently into the flask, and the casting flask is After the solidified shell of the molten metal that is formed reaches a level that does not cause breakout, the flask is removed, and a riser frame made of a material with excellent heat retention is installed in place of the flask to form an ingot. It is characterized by the fact that

(Example) Figures 1 to 3 show examples of this invention.
In each figure, 1 is a surface plate, and 2 is an ingot mold placed on the surface plate 1. As the ingot mold 2, any type such as a flat type, a camber type, etc. can be used.

Therefore, when forming an ingot, first, as shown in FIG. 1, a casting flask 3 made of a material that is resistant to erosion by the molten metal to be formed into an ingot is installed above the ingot forming mold 2. In this case, the flask 3 is lifted and movable by a flask holder 4 having lifting parts 4a and 4b, and the flask 3 and the flask holder 4 are installed on the upper part of the ingot mold 2. Ru.

As mentioned above, the flask 3 is made of a material that is resistant to erosion by the molten metal to be ingot-formed, and when the molten metal is molten steel, the flask 3 is made of cast iron. , graphite, fine ceramics (1 & dense ceramics; fired refractories), etc. are used. Further, the flask holder 4 is made of cast iron, for example.

Next, as described above, after installing the flask 3 on top of the ingot mold 2, a top pouring method or a bottom pouring method is used to fill the ingot mold 2 and subsequently the flask 3. Molten metal 5 is injected as shown in FIG. In this case, when using the top pouring method, for example, a splash prevention plate may be used on the surface plate 1 in the ingot mold 2, and when using the bottom pouring method, a runner is provided in the surface plate 1.

In this way, the molten metal 5 is injected into the ingot mold 2 and the flask 3, and the molten metal 5 is formed in the flask 3.
After the solidified shell 5a (see Fig. 2) becomes thick enough to prevent breakout, the flask 3 is removed together with the flask holder 4, and the solidified shell 5a is temporarily removed as shown in Fig. 2.
is exposed.

In this case, the solidified shell 5a is formed along the inner wall surface of the flask 3, which is made of a material that is resistant to erosion by the molten metal 5, so its surface texture is similar to that of a conventional riser frame. It is significantly better than.

Subsequently, as soon as possible after removing the flask 3, a riser frame 6 made of a material with excellent heat retention is installed on top of the ingot mold 2 in place of the flask 3, as shown in FIG. do.

In this case, the feeder frame 6 can be lifted and moved by a feeder frame holder 7 having lifting parts 7a and 7b,
The feeder frame 6 and the feeder frame holder 7 are installed on the upper part of the ingot forming mold 2.

As mentioned above, the feeder frame 6 is made of a material with excellent heat retention properties, and for example, as a heat-generating material, M
-An: 26-32%.

Al2O3: 5-1O%, 5i02: 15-20%
, FeO+Fe203: 3~9%, MgO: 15~
For example, as a heat insulating material, Al2O3: 2 to 3%, 5i02: 80 to
85%, RO: 2.5-4.0%, Ig, 1oss: 1
Those consisting of 1 to 13% are used. Furthermore, if necessary, a feeder heat insulator (for example, M・Ai: 1
9-21%, Al2O3: 35-55%, 5i02:
4-10%, FeO+Fe2O3: 1-5%.

T-C: 5 to 10%, etc.), hot water surface protectants (e.g., A1203: 9% or less, SiO
2: 41-45%, Fe2O3: 4% or less, Na2O
: 2-4%, CaO: 33-37%, TC: 3-4%
etc.) are used.

In this way, by installing the riser frame 6 made of a material with excellent heat retention in the upper part of the ingot-forming mold 2, solidification is delayed and the ingot 8 is shrunk in the feeder frame 6. It becomes possible to prevent the occurrence of shrinkage cavities inside the ingot 8, and also to concentrate segregation in the upper part of the ingot 8.

Therefore, the top part of the obtained ingot 8 has a good surface quality and at the same time has a sufficient feeder effect, preventing the occurrence of surface defects and greatly improving the ingot yield. can do.

[Effects of the Invention] As explained above, in the ingot making method according to the present invention, when an ingot is obtained using an ingot making mold, the upper part of the ingot making mold is not eroded by the molten metal to be made. A casting flask made of desired material is installed, and molten metal is poured into the ingot mold and subsequently into the flask, and a solidified shell of the molten metal formed in the flask portion breaks out. After the mold reached the point where no heat was generated, the flask was removed and a riser frame made of a material with excellent heat retention was installed in place of the flask for ingot making. Even when a feeder frame is provided to allow the formation of evacuation cavities to concentrate at the top of the ingot and to collect segregation at the top, the ingot in the part that comes into contact with the feeder frame is It is possible to improve the surface quality of the steel, and it is possible to prevent surface defects and improve the ingot yield, which is a very excellent effect.

[Brief explanation of drawings]

FIGS. 1 to 3 are explanatory longitudinal cross-sectional views sequentially showing the agglomeration process of the agglomeration method according to the embodiment of the present invention. 2... Ingot forming mold, 3... Casting flask, 5... Molten metal, 6... Riser frame, 8... Ingot.

Claims (1)

[Claims] (1) When obtaining an ingot using an ingot casting mold, a casting flask made of a material that is resistant to erosion by the molten metal to be made is installed above the ingot casting mold, and Subsequently, molten metal is poured into the flask, and after the solidified shell of the molten metal formed in the flask reaches a level that does not cause breakout, the flask is removed, and the flask is removed. Instead, this ingot making method is characterized by installing a feeder frame made of a material with excellent heat retention and making ingots.