JPS59212146A - Horizontal type continuous casting method - Google Patents

Abstract

PURPOSE:To obtain a cast ingot having the structure in which crystal grains are made finer and more uniform by supplying a molten metal in the form of stirring and rotating flow to the inside of a water-cooled casting mold. CONSTITUTION:A molten metal 19 emerging from a holding furnace is first stirred and rotated in the entirely unsolidified state by the rotating magnetic field generated from an electromagnetic stirrer 4 in a conduit part 12 for molten metal and is supplied in the form of the stirring and rotating flow shown by arrows to a water-cooled casting mold part. The rotating flow of the molten metal solidifies to form a billet 6 having a prescribed shape at the same instant when said flow enters the part 14. The crystal grains are thus finely and uniformly dispersed and are hardly influenced by the difference in the temp. between the upper and lower parts of the water-cooled casting mold.

Description

DETAILED DESCRIPTION OF THE INVENTION In continuous steel casting equipment, a magnetic stirring device is used for the purpose of improving the quality of slabs. As a conventional electromagnetic stirring device, the installation position 1 in the casting process? A device for stirring the mold and applying it to the ζtQM product after it has come out of the mold is known, and these devices are used alone or in combination.

However, in conventional mold-based stirring, an electromagnetic stirring device is attached to the outer periphery or inside of the mold, so the gap between the stirring device and the molten metal is large, and metal objects (such as copper alloy molds, solidified layers, water-cooled Coupled with the fact that there is often a jacket device, etc.), there is a lot of leakage magnetic flux, and the magnetomotive force has to be increased to the required level.

In addition, in continuous casting Alt of copper or copper alloy, since copper has much better thermal conductivity and electrical conductivity than iron, the conventional ') It 40,000 stirring method used in the case of steel is However, it was not possible to improve the quality of the 4'j'J or ijlld alloy element η pieces.

In other words, in the case of steel, when a thin solidified shell is formed in the mold, it then passes through the mold and enters the secondary cooling zone, where the solidified shell gradually becomes thicker. f′7+: Stirring and stingray? While anti-magnetic stirring is effective in the casting part that has been released from the mold, materials with good thermal conductivity, such as nonferrous metals, especially copper, copper alloys, and aluminum alloys, must be completely solidified in the mold before casting. Attaching an electromagnetic stirring device to the inside of the mold and to the castings pulled out of the casting i<9 to draw the product out of the mold has little or no effect.

Furthermore, in horizontal continuous casting, '4' in the water-cooled mold
)Jm Because defects such as temperature difference between the upper and lower sides and non-uniform distribution due to solidification or floating of intermetallic compounds with light specific gravity are likely to be added, horizontal continuous casting of copper or copper alloys in particular Quality defects were likely to occur.

In view of these circumstances, the inventors of the present invention have conducted intensive research into improving the horizontal continuous casting method, and have found that the quality of castings can be significantly improved even in horizontal continuous casting of copper or copper alloys. This enabled us to develop a horizontal continuous casting method.

The present invention will be explained below based on the drawings.

Figures 1 and 2 are schematic vertical cross-sectional views of the sprue thread of a horizontal continuous casting machine using the method according to the embodiment of the present invention. Figure 1 is for casting copper alloy billet material, and Figure 2 is for casting copper alloy pipe material. This is an example about time.

In the figure, 1 is a molten metal holding furnace wall, 2 is graphite T1.8 is a heat insulating material, 4 is an electromagnetic stirring device, 5 is a water cooling jacket, and 6 is a slab.

The graphite tube 2 has an inner diameter DI shaped like the outer diameter of the slab 6, its base end 7 is tightly fitted into the opening 9 of the holding furnace wall 1, and is held so as to protrude horizontally. The portion 10 has a length corresponding to the other end 11 of the water cooling jacket 5.

Therefore, this graphite pipe 2 is sequentially transferred from the holding furnace to the lead pipe section 1.
It is divided into two parts: 2 and a mold body part 13. That is, in this embodiment, the molten metal guide pipe section 12 and the mold body section 13 are made of the same material and are integrally connected.

The outer periphery of the hot water pipe section 12 is covered with a heat insulating material AA 3, and a magnetic stirrer 4 (rotating coil in this example) 111 is disposed through the heat insulating material 3.

In the mold main body part 13 which is parallel to the molten metal introduction pipe part 12, a water-cooled jack nut 5 is covered over the entire surface on the outside/i'd side, thereby forming a so-called water-cooled mold part 14. This water-cooled mold part 14 is fixed in a horizontal state as shown in the figure, and a water supply '14' 15 and a drain pipe 16 are connected to the water-cooled jacket 5.

When casting pipe materials, as shown in Figure 2,
A core mold 17 is installed within the graphite tube 2 .

This core mold J-shaped 17 extends from the base end 7 of the graphite tube 2 to near the other end lO, and the core mold 17 is attached to the base t.
'9518 is fitted onto the base end 7 of the graphite tube 2 to hold it fixedly.

In the sprue system of the above embodiment configured in this way, the molten metal 19 discharged from the holding furnace is first stirred and rotated by the rotating magnetic field generated by the i+1 magnetic stirrer 4 in a state in which the molten metal 19 is not solidified at all in the 4 molten metal tube portions 12. Then, it is supplied to the water-cooled mold section 14 as a stirring rotational flow as shown by the arrow.

This rotating flow of molten metal solidifies once it enters the water-cooled mold section 14, forming a slab 6 of a predetermined shape.

Figure 3 shows a schematic diagram of the macrometallic structure (Figure 3(a)) of the combination 4P material 20 (hereinafter referred to as "Example product 2υJ") which was initially purified in this way, and Tit (cU without agitation). This figure shows a comparison with the macrometallic structure diagram (IN(b)) of a conventional copper alloy vibrator casting product (hereinafter referred to as "conventional product 21J"), and the example product 20 has fine crystal grains 22. It is evenly distributed, and is almost unaffected by the temperature difference between the upper and lower parts of the water-cooled mold, which is the fate of horizontal mitts. (If it stands vertically and is uniform), a vertical coagulation zone 23 is formed, and there is no uneven thickness or bending, and the roundness of the inner diameter is very good.

On the other hand, the conventional product 21 mainly consists of columnar crystals 25 with 3 sets of I & 2, and td l, l, 1 zone 2: ( is strongly affected by the temperature difference between 1°1 and This is due to the temperature difference between the upper and lower parts of the U and I parts.
't: At the same time as the S solidification stage ii (+ ires), the core mold 17 is tapered to reduce the pull-out resistance (L), so uneven flash 26 and bending occur, and the inner diameter is perfectly round. The situation is in very bad condition.

As explained above, according to the method of the present invention, the molten metal coming out of the holding furnace is A rotating magnetic field generated by an electromagnetic stirrer exerts a rotational force in the 4-molten water pipe section, and a stirring rotational flow is supplied to the water-cooled mold section.

Therefore, even when compared with conventional water-cooled mold type stirring, there is less leakage magnetic flux, and the molten metal can be efficiently stirred and rotated.

In addition, since the F4 hot water is supplied into the water-cooled mold as a stirring rotational flow, the influence of the temperature difference between the top and bottom of the casting, which is the fate of horizontal continuous casting, is completely eliminated, and the crystal grains are made finer and more uniform. It is possible to obtain an ingot having a textured structure.

In addition, it is possible to produce sound castings by uniformly dispersing intermetallic compounds that have a high crystallization temperature and a large difference in ratio tU compared to the matrix, so it is possible to produce sound castings.
This is the best method for producing wearable copper alloy castings.

In addition, the copper or copper alloy billet material (9 pieces, square material) or pipe material produced by the method of the present invention has very good roundness and straightness, and the pipe material has a very small l1ul thickness. . In addition, since the crystal \Il was changed to +aH1llI and uniformly dispersed, casting defects such as filler holes and blowholes were significantly reduced, and a remarkable effect was seen in improving the quality of FGiS in the slab.

In addition, the electromagnetic P^1 stirring device 6 used here is ■Rotary coil type, ■Linear coil type.

■Effectiveness was observed in all solenoid filters.

[Brief explanation of the drawing]

Figures 1 and 2 are schematic longitudinal diagrams of the sprue system of a horizontal continuous casting machine using the method of this embodiment. This is an example of the casting of copper alloy pipe material. Fig. 3 is a comparison of macrostructure schematic diagrams of cross-sections of pipe material castings between the method of the embodiment of the present invention and conventional method 11. Fig. 61 shows a conventional pipe material without electromagnetic stirring. 8...Insulating material 4...Electromagnetic stirring device 12...j
Hot water pipe t'A 13... vJ type main body part 3 Figure Procedure Sleeve Book dated 73rd May, 1920 Showa f2 Commissioner of the Patent Office Name Mr. Kazuo Sugi 1 Display of the case 1982 Special J11'' Application No. 085481 @2 Title of the invention Horizontal continuous casting method 3. Person making the amendment! ] 1 Relationship with IT Patent applicant (1 location Name of Nishiawara Shinto, Tateyama-machi, Nakashinyo-gun, Tomi 111 Prefecture (Yyama)) Chuetsu Alloy Foundry Co., Ltd. Representative Hideo Honda 4th Representative

Claims (1)

[Claims] 1) In the horizontal continuous casting method, in which horizontal water-cooled molds are installed side by side in instant contact with the bottom side wall of a holding furnace, and the molten metal from the holding furnace is solidified in the horizontal water-cooled molds to form slabs of a predetermined shape; A molten metal introducing pipe section is provided horizontally between the furnace and the horizontal water-cooled mold, and an electromagnetic stirring device is provided on the outer periphery of this molten metal introducing pipe section to stir the molten metal in the molten metal pipe section into a rotating flow. A horizontal continuous casting method characterized in that a flowing molten metal is supplied into the water-cooled mold section.