JPS61195758A - Continuous producing device for composite ingot - Google Patents

Abstract

PURPOSE:To make stable mass production of a composite ingot having good quality with good wordability by inserting a heated core material through a tundish connected to a mold open at both ends into said mold and drawing continuously the resulted composite ingot. CONSTITUTION:The molten metal 31 is supplied into the tundish 23 connected via a refractory ring 22 to the top end of the mold 21 open at both ends and is preferably sealed by an inert gas such as Ar to prevent the oxidation thereof. The core material 24 is fed into the tundish 23 through an upper aperture 25 thereof by centering rolls 26 and after the core material is heated to a prescribed temp. by a heating coil 27, the material 24 is continuously inserted into the mold 21 through the above-mentioned connecting part. The composite ingot 28 having the good adhesiveness at the joint boundary and high quality is thus formed without the intrusion of scum and the abnormal wear and is continuously drawn together with a dummy 30 by pinch rolls 29.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a composite slab having good visibility at the pedestal interface, with good production efficiency, and in a stable manner.

<Prior art and its problems> In recent years, with the rapid progress and development of industrial technology and changes in social conditions, there has been an increasing demand for materials that have various lump properties that cannot be achieved with conventionally known single materials. In order to meet these demands, various composite materials, including clad steel, have been proposed and developed.

By the way, the method of manufacturing metal cladding material is as follows.
The ``bakukan method'', ``rolling method'', ``overlay welding method'', and ``casting methodj'' are generally well known, but the former three methods all involve joining a ``laminated material'' to the surface of the base material. In contrast, the "casting method"
Is it possible to create cladding material by enclosing a composite material inside the ingot? The "casting method" has been attracting a lot of attention7 as it can be produced in large quantities because it is possible to produce 1 gram continuously.

Conventionally, composite materials were made using this "casting method"! As a practical means for continuous production, for example, Japanese Patent Application Laid-Open No. 53-25233 and Sushi Kai-Sho 54-71
75 methods were known as disclosed in Japanese Patent Laid-open No. 039 or Japanese Patent Application Laid-open No. 53-29229.

The methods described in the above-mentioned publications are intended to continuously produce composite rolls or single billets, and as shown in FIG.
Inside the horizontal mold 3 with both ends open connected to the side surface of the tundish 2, the core material 4 is
The composite material 6 is manufactured at high quality by continuously inserting the core material 4, solidifying and placing the metal bath 1 around the core material 4, and continuously pulling it out with the pinch rolls 5.

However, in such a horizontal continuous casting method, the core material 4 is supplied from the side of the tundish 2. Because it is a penetrating process, a complex and highly precise mechanism is required to prevent molten metal from leaking from the core supply section, making it extremely difficult to put it into practical use on an industrial scale.

On the other hand, as a method for manufacturing or recycling composite rolls,
Means as disclosed in Japanese Patent No. 4903 is also known.

Figure 7 is ml Kotoku Kosho 44-49
No. 03 Kogen J1 The main means of manufacturing or reproducing the composite roll shown is
11 The lower C2 thin steel plate 9 of the lighting heating type 8 which has a built-in hollow water-cooled steel coil 7 that conducts current? A graphite mold 10 and a subsequent open-end mold 11 are placed over each other through the mold 7, and a base body (worn roll or cylindrical body for new manufacturing) 12 is vertically inserted into these molds. After preheating the surface with a high-frequency wave 81 while moving the base body 12 up and down, the gold PAffg hot water 13 of the desired material is continuously injected into the desired gap between the base body 12 and the mold, and at the same time, the base body 12 is continuously lowered. Molten metal on the surface of 13? It shows how much meat is being served.

However, with this method, the graphite mold 10 for generating an initial solidification shell in the built-up metal bath Uh13 is easily worn out, so there is a problem with long-term casting, and the length of the composite slab that can be manufactured is limited at most. It was only about 4 meters long. Moreover, during the build-up work, it is necessary to constantly supply the metal bath uh with a ladle or the like to the extremely narrow gap between the base body 12 and the refractory heating mold 8, which causes severe fluctuations in the hot water level. In addition, there were problems such as scum etc. being easily drawn into the interface between the base body and the molten gold W4, further accelerating the wear and tear of the graphite mold, and the inability to perform high-speed casting. It is.

As described above, although the method disclosed in Japanese Patent Publication No. 44-4903 can be applied to the production of relatively short products such as rolls, is it possible to obtain homogeneous long products? This method cannot be said to be a preferable method when manufacturing with good workability, and is therefore unsuitable for general production such as janitorial billets made of clad material.

Means for Solving the Problems> The present invention solves the problems of the conventional continuous casting method, and produces composite slabs of good quality at high speed, with good productivity, and with stability. This was achieved through research by the present inventors, who were aiming for mass production of continuous composite slabs! ! ! ! a casting means integrally formed by connecting a tundish to one end of the mold with open ends; It is characterized in that it is equipped with a means for inserting, a means for heating the core material, and a means for pulling out the composite hook disposed on the exit side of the mold with one open end. ◎ Figure 1 shows this. Invented composite slab! ! ! An example of manufacturing equipment? Although this is a schematic configuration diagram shown in FIG.
At the top of SIN, A/201. AlN and B
A casting means is constructed by connecting a tundish 23 with a ring 22 made of a refractory material made of one or more kinds of materials such as N. A centering roll 26 is disposed for continuous (two-insertion) insertion into the both-end open mold 21 by penetrating the connection portion between the mold 23 and the both-end open mold 21, and a core material heating means accommodated from the heating coil 27 is disposed. The heating coil 27 and the hot water surface are inert.
r, etc.), the structure allows for a complete 7-rule. Further, on the exit side of the mold 21 with both ends open, a Vinci roll 29 is arranged to continuously pull out the formed composite slab 28 from inside the mold, thereby configuring a composite slab manufacturing apparatus. In addition, in FIG. 1, what is indicated by the symbol 30 is a dummy, and what is indicated by the symbol 31 is a molten metal. are shown respectively.

Now, in the apparatus shown in Fig. 1, 24 core materials are continuously inserted into the mold 21 with both ends open from above the tundish 23 while being heated by the heating coil 27, and inserted into the gap between the core material 24 and the mold wall. When the molten metal is supplied, the molten metal supply tundish 23 has a large capacity, and since the mold and the tundish are connected, the meniscus moves upward from inside the mold to form a wide molten metal surface, making it easy to supply the molten metal. Extremely quiet and smooth molten metal supply can be carried out stably, preventing scum from being entrained and molten metal and refractory f2
Place! ! 4 Not only does it not cause constant wear and tear.

@Includes in the vortex can be sufficiently floated and separated, and since the core material is preheated before being inserted into the mold, the solidification rate of the molten metal from the core material side is extremely low, so a small cladding ratio can be achieved. It is possible to achieve this.

Furthermore, the core material 24 passes from above the tundish 23 through the hot water surface to the tundish 23'? Since it is continuously inserted into the mold with both ends open, there is no fear of hot water leaking from the core insertion part.

Therefore, healthy composite slabs with a wide range of cladding ratios can be mass-produced at high speed with stable workability.

Therefore, sound composite slabs can be mass-produced at high speed with stable workability.

And the composite slab obtained in this way.

Furthermore, by performing rolling or casting, it is possible to obtain a clad material with extremely low bonding strength.

In addition, in this example, is the core material inside the mold? A centering roll 267 is commonly used as a means for continuous insertion, but the centering roll can be either driven or non-driven! It does not matter, and it may be a simple centering guide, as long as it can guide the core material 24 to a predetermined position within the mold 21 with both ends open! Can also be adopted.

Furthermore, the means for pulling out the composite slab 27 is not limited to the Bintero/I/29 shown in Figure 1.
For example, a gear tabi 2-type pulling device or multiple hydraulic cylinders with slab gripping claws are used to alternately remove slabs. Devices that can be grasped and pulled out.

Of course, either one may be applied.

By the way, the one shown in FIG.
2 is used, but SiN, AJ203.

A7! Refractory rings made of one or more of N and BN do not wear out as quickly as the graphite type in the conventional composite roll casting equipment shown in Figure '1JIJ7, and therefore, from this point of view as well. It is suitable for high efficiency casting of long composite slabs. In addition, in this invention, the desired effect can be obtained even if the casting means is constructed by directly connecting the tundish 23 and the open-end mold 21 without using the refractory ring 22 as described above. Needless to say, when connecting the two with a refractory ring, it is preferable to use a "flat type" as shown in Figure 2 or an "interpolation type" as shown in Figure 3, for example.

The shape of the core material inserted into the mold is not limited to a cylindrical shape (it may be plate-shaped, angular or cylindrical,
It is natural that the number of inserted core materials can be multiple, and
There is no problem even if the core material is made of clad material (0 composite material).

Furthermore, in the example shown in Figure 1, special preliminary processing is required! Although the core material is inserted into the mold without any construction, a slag repellent is applied to the surface of the core material (a commercially available NH, BF2-based slag repellent is sufficient)! It is extremely preferable to apply the coating in advance because it can prevent scum from being entrapped at the interface between the core material and the molten metal, and it can also prevent oxidation of the core material.

On the other hand, FIGS. 4 and 5 show the composite casting of the present invention, i4
M! FIG. 7 is a schematic configuration diagram of different examples of the H location.

Man's 4th figure is the one in which the pull-out angle of the horizontal adjustment piece is inclined,
In Figure 5, the core material to be inserted is curved so that the angle at which the composite slab is pulled out is horizontal! However, in either format, the same loose effect as shown in FIG. 1 can be obtained.

Next, an example of use of the device of the present invention will be explained.

First, we will introduce a vertical type composite slab manufacturing apparatus of the present invention as shown in Fig. 1 and a low carbon percentage composition as shown in Table 1.
(SIOC) 11! Using a cylindrical core material and stainless steel (SUS304) or high carbon steel (S65C) @ hot water, the diameter is 200.11 (mold diameter: 205 m).
) compound and let! Continuously cast.

Table 1 Note that the tundish and the mold with both ends open were connected via a refractory ring in the composite cast slab manufacturing device of the present invention used here. The composition was as shown in Table 2.

Also, exam number 8! Except for this, the core material is pre-applied with slag repellent! It was coated, but this slag repellent was
0% by weight of NH4BF4 is dispersed in a resin binder, and the slag repulsion, surface texture condition, and ffi of the bonding interface of the composite billet thus obtained are
Taste quality and scum entrainment status at the joint interface! The results are shown in Table 3 along with other manufacturing conditions.

From the results shown in @3 table, by the method of the present invention,
It is clear that a composite slab with good bonding interface density and surface texture can be obtained. By the way, what kind of trouble does this kind of composite billet manufacturing work have, given its extremely good workability? It was also established that the process could be carried out stably without any occurrences.

Here, more detailed observation results of the obtained composite billet were as follows.

In other words, the composite billet) ff surface has one pyrophysical ring in the interpolation format! In the applied device, pull-out marks peculiar to intermittent pull-out were observed, and horizontal cracks (discontinuous structure in the surface layer of the billet longitudinal section) starting from these pull-out marks had a crack depth of 1. 0-1.5
At 150 cpm drawing of test numbers 2 to 5 and 7 to 8, the crack depth was 0.5 haze or less, indicating that the horizontal cracks were reduced by high-nickel casting.

On the other hand, in the device using test number 6, a flat type refractory ring, the pull-out marks on the billet surface were unclear, and there were no cracks caused by the pull-out marks.By the way, the device i! The critical cladding ratio, that is, the minimum casting outer layer thickness when using , is determined by the thickness of the solidified shell from the insert core side.

In other words, the gap between the solidified shell surface on the core side and the inner wall of the connecting body (in other words, the solidification/el thickness on the core side is determined by T
It is determined by the cooling rate) and the drawing speed. Here, since the drawing speed is limited to 0.8 to 1.5 m/w from an operational point of view, the cladding ratio is ultimately determined by the connection method between the tundish and the mold and the cooling capacity of the core material side.

In the case of the interpolation type equipment used in test numbers 1 to 5 and 7, the cladding ratio (stainless steel ratio) was 31%.
It was confirmed that it is possible to cast up to 165m (inserted core diameter: I & large 165mφ), and in the case of the interpolation type equipment used in Test No. 6, the cladding ratio was 14.
It was found that it was possible to cast up to 495 C. However,
Inserted core material diameter: Maximum 185 φ (examined).

In addition, the one used in Test No. 8 uses an interpolated connection method, but since the inserted core material is preheated to 800°C, solidification from the core material side is very small, and the cladding ratio is 2.
It was possible to cast up to 3.4%.

In addition, the casting speed related to productivity is as shown in test numbers 2 and 3: A VE: 0.75 to 1
．． It was found that there was no particular problem in operation even when using a 35@/m speed fishing method, and the resulting composite billet had a smooth surface and was able to penetrate between the core material and molten metal as expected when using a red speed fishing method. There was almost no entrainment of scum, etc., and it was clear that the product had excellent adhesion at the bonding interface.

In particular, in the case of test number 8, the surface 3
There is no adverse effect such as oxidation, and the joint interface is completely lava.

Furthermore, in Test No. 6, there was a concern about cracks in the cast material (inserted core material diameter: 185 m, cladding ratio: 14.4%) due to solidification shrinkage, but about 2 to 34 cracks were observed in the NW at the billet stage. It was found that there was only a hole, which was crimped during the secondary processing (rolling) process, and there was no problem in practical use.

<General effects> As mentioned above, according to the present invention, it is possible to stably mass-produce composite slabs with good adhesion at the joint interface with high efficiency, and improve various performances! A versatile material? This brings about extremely useful effects industrially, such as being able to provide products at low cost.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an example of a continuous manufacturing apparatus for composite slabs according to the present invention. Figures 2 and 3 are different examples of the connection style when a refractory ring is used to connect the mold with both ends open and the tundish in position G of the present invention, Figure 4 and Figure 3 respectively. FIG. 5 is a schematic diagram showing another example of the apparatus for continuously manufacturing a composite fishing piece according to the present invention, and FIG. FIG. 7 is a schematic diagram showing a conventional composite roll manufacturing method. In the drawing. + 1.13.31... Molten metal, 2.23... Tundish. 3.11.21・-Both sides open W mold, 4.24...
Core material, 5.29...pinch roll. 6...σ composite material, 7...Natural nitride water-cooled copper coil, 8...Light heating type, 9...Thin copper plate. 10...graphitic type, 12...base, 22...
Refractory ring. 25... Upper opening of tundish, 26... Centering roll, 28... Composite slab, 30
··dummy. Applicant Sumitomo Metal Industries Co., Ltd. Agent Tomi 1) Kazuo Haka 2 people n
To C1+ ~ To C Figure 4 'l So Hand Figure 5 / Figure 6 Figure 7

Claims (1)

[Claims] a casting means integrally connected to one end of the tundish with a tundish open at both ends; a means located above the tundish for continuously inserting the core material from the upper opening of the tundish through the connecting portion into the tundish open mold; 1. An apparatus for continuously producing composite slabs, comprising means for heating the core material and means for pulling out composite slabs disposed on the exit side of a mold with both ends open.