JPS6146352A - Production of clad ingot - Google Patents

Abstract

PURPOSE:To obtain a clad ingot having stable internal quality by placing horizontally a metallic billet to be insert-cast on the bottom of a casting mold, pouring the melt of the different metal for insert casting onto said billet and allowing the melt to solidify unidirectionally upward from the joint surface. CONSTITUTION:One billet 2 of the different metal to be clad is preliminarily imposed on the base of the casting mold 1 which has a large cross section, has a pouring port 5 for the molten metal on the side wall and is provided with cooling gas pipes 6 on a floor plate 7. An antioxidant 3 is coated on the surface. The melt of the different metal is poured through the port 5 onto the billet 2 and a cooling gas is passed through the pipes 6 to solidify unidirectionally the molten metal 4 from below to above. The height h1 of the billet 2 and the height h2 of the molten metal 4 are adjusted to an optional cladding ratio in this stage. The inside quality is thus stabilized and the clad ingot having the desired cladding ratio is produced.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to an improvement in a method for manufacturing clad ingots, so-called "casting method" (Prior Art) A conventional method for manufacturing clad steel plates, etc. The most common methods are the roll rolling method and the casting method.

The roll rolling method is a method in which different types of metal rot stirrup pieces to be clad are stacked on top of each other, the periphery is completely tightly welded, and the pieces are heated and rolled to compress the different types of metals.

In this method, it is difficult to avoid air remaining between the slabs when the two flange pieces are closely welded, and this residual air causes poor adhesion of the slabs due to oxidation of the metal and volumetric expansion of the air itself during hot rolling of the slabs. There are drawbacks.

On the other hand, in the conventional Tsubagurumi method, as shown in Fig. 4, one slab (23) of dissimilar metals to be clad in the plate mold (1) is set in advance in the center of the mold, and its surface is oxidized. Apply an antioxidant (3) to prevent
In this state, the other dissimilar metal molten metal (4) is poured into the slab (
2] Ingot 1! : This is the way to obtain it.

In this method, since there is a limit to the cross section of the mold, that is, the thickness (A), there is a limit to the thickness ω of the slab (2) that can be set in the mold. There are cases where the ratio cannot be obtained, and general plate molds have different head thickness (A) and bottom thickness (A) of the diagonal mold, which has a specific taper in the direction at the casting height. It has the disadvantage that it is difficult to obtain a rolled product with a uniform Rad ratio.

(Objective of the Invention) An object of the present invention is to provide a method for producing a clad ingot which is capable of obtaining a clad ingot having a stable internal quality and which also makes it possible to obtain an arbitrary cladding ratio.

(Structure of the Invention) The characteristics of the present invention are that first, a mold having a large cross section is used;
The slab of dissimilar metals to be clad is placed horizontally at the bottom of the mold, and the molten metal of the dissimilar metal to be cast is poured onto it, solidifying in one direction upward from the joint surface. To obtain an ingot with stable internal quality.

At that time, a clad ingot with an arbitrary cladding ratio can be obtained by adjusting the thickness of the slab set in advance on the bottom of the mold and the injection height of the dissimilar metal poured thereon.

That is, in the present invention, a slab of a desired thickness of one of the dissimilar metals to be clad is placed on the bottom of the mold in advance, and molten metal of the other dissimilar metal is poured onto it to a desired height. The gist of this invention is a manufacturing method that solidifies unidirectionally upward from the joint surface while pouring to obtain a clad ingot with an arbitrary cladding ratio.

By doing so, it is possible to obtain an fc ingot with stable internal quality, and also to obtain a large single weight foot ingot with an arbitrary cladding ratio. Since the ratio is constant, it is possible to obtain a uniform rad ratio even in the plate after rolling.

The invention will be described in detail below with reference to the drawings.

As shown in Figure 1, it has a large cross section with a molten metal injection hole (
5) is equipped with a cooling plate (6) on the mold floor plate (7).
c Place one slab (2) of a dissimilar metal to be clad on the bottom of the mold (1) in advance, and apply an antioxidant (
3), and pour the other molten metal (
4) through the inlet (5) and the cooling tube (6) on the floorboard.
), the injected molten metal (4) is promoted to solidify in one direction from the bottom to the top, resulting in a clad ingot having a homogeneous casting structure with little segregation.

The height of the slab obtained by this method is 1 (Fig. 2 (0) H), which is constant at any position, so compared to the cladding:
As shown in FIG. 2(b), the cladding ratios h and hl after rolling are the same and are uniform at all positions on the clad plate.

Also, the thickness of the slab (2) placed on the bottom of the mold (1) is 7A.
By adjusting the casting height (Cht) and the casting height (h) of the injected metal, it is possible to obtain an arbitrary cladding ratio even in a large single-weight ingot.

For this purpose, a vertical groove (8) is provided on the side wall of the mold to attach the injection port (8) as shown in FIG. Prepare several different types of high-temperature cast slabs on the bottom of the mold (
It is desirable to configure the position of the inlet (5) so that the position of the injection port (5) can be changed freely depending on the thickness of the container (2). do.

(Example) (Clad steel ingot of stainless steel and low carbon steel)
The method of the present invention for obtaining a large clad ingot with a planar size of 2.0 m x 1.7 m and a cladding ratio of 1o will now be described.

An Ml inner diameter size of 2.2 m x 1.9 m and a height of 1.5 m was prepared, and an injection port of 70 φ was provided on the side wall at a height of 100 W from the lower end of the mold. The floor plate on which the mold is placed has a thickness of 200M, and ten cooling pipes with 50φ heads for cooling are embedded in parallel at the center position in the thickness direction of the floor plate. Floorboards like the one above,
Using a mold, first: one metal slab with a flat size of 2. gmXl-7m, thickness-gloo'' 7f 7
V steel (18Cr-8Nl is placed on the floorboard with a hoist,
Antioxidant was sprayed onto the stainless steel, and the mold was set on the floor plate with one of the metal slabs placed in the mold, and then the injection port was installed on the side wall of the mold. . In this condition, open the inlet 162.
Molten metal of the other metal at 0°C (main component 0.05% C10,2
0% S'l-) 100 at the height in the mold from the nozzle of all ladle
At the same time, 0.1 N of room temperature air was sent to the cooling pipe installed on the floorboard to cool the floorboard. After leaving it as it was for about 6 hours, the air was poured into the cooling pipe. At the same time as stopping the air blowing, the mold was removed and allowed to cool to room temperature. In order to check the adhesion between one metal slab and the other (molten metal), part of the surface was ground with a grinder and subjected to ultrasonic waves. Upon inspection, it was found that the bonding was complete, there were no defects on the upper fully bent side, there were few inclusions on the surface, and the yield of the clay ingot was good (93%). found.

On the other hand, with the conventional method, it is impossible to obtain such a large clad ingot, and even a small clad ingot has a poor yield (89X).

(Effects of the Invention) As shown in -0 above, in the present invention, the slab of one dissimilar metal to be clad on the bottom of the mold is placed horizontally, and the molten metal of the other dissimilar metal is poured onto it. By adjusting the thickness and injection height of molten metal, it is possible to obtain a clad ingot with any desired cladding ratio and with a uniform height in all parts. The inhibitor and υ are floated and separated smoothly compared to the conventional method, and the adhesion between the slab and the molten metal is extremely good.In addition, since it solidifies in one direction upwards from the joint surface, it has a uniform structure with little segregation. The effect of obtaining clad clad ingots is greater.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an embodiment of the final method and shows a cross section. FIG. 2(a) shows a clad ingot obtained by the finishing method, and FIG. 2(b) shows the ingot after rolling, both of which are side views. FIG. 8 is a perspective view illustrating the structure of the mounting part of the molten metal inlet of the mold for performing the t-molding process. FIG. 4 is a cross-sectional view illustrating a conventional method for producing a clad ingot. 1: Mold, 2: One metal slab, 3: Antioxidant, 4:
Molten metal of the other metal, 5: Inlet, 6: Cooling gas pipe, 7:
Floorboard, 8: Vertical groove, 9, 9: Dinutanubis Figure 1, 2r! A Figure 4

Claims (1)

[Claims] (1) Place a slab of the desired thickness of one of the dissimilar metals to be clad on the bottom of the mold in advance, and pour the molten metal of the other dissimilar metal onto it to the desired height. A method for manufacturing a clad ingot, characterized by solidifying in one direction upward from the joint surface.