JPS6188942A - Production of mold for continuous casting - Google Patents

Abstract

PURPOSE:To manufacture a mold for continuous casting which has high reliability with diffusion bonding by holding zigzag copper pipes into the surface grooves of divided copper alloy pieces, assembling such pieces, superposing a wear-resistant nickel plate on the surface of the outermost divided piece and subjecting the assembly to hot pressure joining in a vacuum state. CONSTITUTION:The copper pipes 3 at least one side of which is opened are held in the surface grooves 1 of the divided copper alloy pieces 2 and the pieces are assembled. The thin wear-resistant nickel or nickel alloy sheet 4 is superposed on the outside surface of the outermost piece 2. Such superposed assembly is subjected to the hot isotropic pressure joining while the spacings between the joint surfaces are maintained in a vacuum state in a vacuum furnace, etc. The mold for continuous casting which is free from water leakage and has good heat transmission and high reliability is easily manufactured by the diffusion joining between the joint surfaces. The outside joint parts may be welded by an electron beam while the spacings between the joint surfaces are maintained in a vacuum state in place of using the vacuum furnace and the pipes 3 may be made of a thermally elutable material.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is characterized in that the cooling water passage hole is completely buried in the mold body,
Moreover, the present invention relates to a method for manufacturing a continuous casting mold having a wear-resistant coating layer on its inner surface.

<Conventional technology and its problems> A common method for cooling continuous casting molds is to drill a recess in the back of the mold body and run cooling water through the space formed between the recess and the pack frame. However, due to insufficient cooling efficiency and concerns about water leakage between the back frame and the mold body, recently the mold body (1'
) A mold as shown in FIGS. 5 and 6, in which the cooling water passage hole (2') was completely buried, began to be used. However, in the mold shown in FIGS. 5 and 6, in order to form the cooling water passage hole (2'), for example, as shown in FIG. A vertical hole is opened from one side, and a cooling water supply port (3') and a cooling water discharge port (4') are opened from the back side of the mold body so as to be in contact with the vertical hole.
The method used was to first open the vertical hole and then fill in the unnecessary hole portion on the end surface side using a separate plug (5'). The method shown in Figures 5 to 7 above is a system in which cooling water is passed independently through each of the cooling water passage holes running up and down inside the mold body (1゛). , as shown in Figure 8, there are multiple cooling water holes (2') in one mold.
Connect them all together, let water pass through one cooling water supply port (3'), and drain water from one cooling water supply port (4'). In order to communicate the vertical holes at the upper and lower ends, holes were also made from the side of the mold body (1').
After that, it has to be plugged, and in either case, the manufacturing is complicated, water often leaks from the plugged part, and cooling water passage holes are rarely formed in a curved manner. It was impossible. Furthermore, continuous casting molds are usually used with a wear-resistant coating layer made of nickel or its alloy attached to the inner surface of the mold, but the wear-resistant coating layer B is firmly bonded to the mold body. Although various methods such as plating and thermal spraying have been adopted, it is currently very time-consuming to form a strong coating layer with a uniform thickness.

<Means for Solving the Problems> The present invention attempts to solve the above-mentioned problems, and uses a hot isostatic pressure bonding method as a means to solve the problems. A plurality of divided pieces made of copper or copper alloy, such as a mold body in which a conduction hole is formed, is cut in the axial direction of the cooling water conduction hole; The plurality of divided pieces are assembled into a mold shape while the one-end open pipe and the pipe are wrapped in a space that will become a cooling water passage hole, and then the divided pieces are located at the outermost side among the divided pieces. A wear-resistant thin plate made of nickel or nickel alloy on one of the outer surfaces! ! Then, the parts exposed to the outside of the joint surfaces of the two divided pieces and the pipe and the divided piece and the wear-resistant thin plate are airtightly vacuum sealed, and then subjected to hot isostatic pressing. This is a method for manufacturing a continuous casting mold, which is characterized by integral diffusion bonding using a pressure bonding method.

Note that the term "hermetically sealed in a vacuum manner" as used herein means that, if there is a gap in the sealed portion, the gap is evacuated.

<Embodiments and Effects> The present invention will be described in detail below with reference to drawings showing embodiments thereof.

ll As shown in Figure 1, each groove has a semicircular cross section on one side (
Two divided pieces (2) consisting of a copper plate with holes (1) and (
2), and the groove (1) when the two split pieces (2), (2) are overlapped so that the material surfaces of the groove (1) are aligned,
Prepare a copper pipe (3) (see Figure 2) that has a size and shape that fits exactly into the space formed by (1), and mold them into a mold shape as shown in Figure 3. After assembly, a wear-resistant thin plate (4) made of nickel and having a thickness of 0.2 mm was stacked on the upper surface of one of the divided pieces (2). Next, all the parts exposed to the outside of the joint surfaces between the wear-resistant thin plate (4) and the divided piece (2), between the divided pieces (2) and between the divided piece (2) and the pipe (3) are As shown in FIGS. 3 and 4, seal welding was performed by electron beam welding to form a seal portion (5).

The thus-treated product is charged into a hot isostatic pressurizing furnace using argon gas and maintained at 800°C and 400 atm for 2 hours, resulting in continuous casting where the whole is metallurgically integrated. A mold for use was obtained.

In the above embodiment, the divided piece (2) is composed of two pieces, but in the method of the present invention, the divided piece (2) on the side C
may be composed of three or more sheets, and the seal welding does not need to be performed by electron beam welding, but may be performed by other means as long as the above-mentioned airtight vacuum treatment is sufficiently performed.

In the method of the present invention, split pieces, pipes, and Wf41@
Since the main purpose of wearable thin plates is to cause diffusion bonding to each other and to connect them integrally, it is preferable that the pipe used be the same type as the copper or copper alloy split pieces, or a material that can be metallurgically bonded with them. However, only this pipe may be removed by melting or other means in a later process, and in such a case, the material should be one that is easy to remove in the later process.

<Effects of the Invention> As described above, according to the method of the present invention, divided pieces, pipes, and #4P made of forged products with high reliability in terms of strength are obtained.
i! Since the bottom is made of an abrasive thin plate, a mold with sufficient strength and dimensional accuracy (especially uniformity of V layer thickness) can be obtained. Even if the mold is long and curved, or has a non-circular cross section or fins, it is possible to easily obtain the desired mold by using a finned pipe with a non-circular groove. It can be done.

[Brief explanation of drawings]

Figure 1 is a parent view of the filter segment used in the method of the present invention, Figure 2 is a perspective view of the same pipe, Figure 3 is a perspective view of the pipe after sealing by the method of the present invention, and Figure 4 is a An enlarged view of the main parts, Figure 5 is an explanatory diagram showing the conventional mold manufacturing method, Figure 6 is Figure 5
7 and 8 are respectively i]
An enlarged view of main parts for explaining a conventional mold manufacturing method. In the figure: (1) Groove (2) Divided piece (3) Pipe (4) Wear-resistant thin plate (5) Seal part Patent applicant: Kuroki Kogyo Co., Ltd. Agent: Ariyoshi Kyoto Figure 3: Abrasion resistance Thin plate Fig. 5 1' Fig. 8 4'

Claims (1)

[Claims] 1. The mold body with cooling water passage holes formed inside.
A plurality of divided pieces made of copper or copper alloy, which are cut in the axial direction of the cooling water passage hole, and a pipe with at least one end open, which matches the shape of the cooling water passage hole, are used to cool the pipe. The plurality of divided pieces are assembled into a mold shape while being wrapped in the space that will become the water conduction hole, and then the outer surface of one of the outermost divided pieces is made of nickel or nickel alloy. of wear-resistant thin plates are piled up, and then the parts exposed to the outside of the joint surfaces of each of the divided pieces, the divided pieces and the pipe, and the divided pieces and the wear-resistant thin plates are sealed in an airtight vacuum, A method for manufacturing a continuous casting mold, characterized by integrally diffusion bonding using a hot isostatic pressure bonding method.