KR890005126B1 - Method of producing a cylinder - Google Patents

Abstract

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Description

Method for manufacturing cylindrical body made of fiber reinforced alloy

1 is a cross-sectional view showing a centrifugal mold according to a first preferred embodiment of the present invention.

2 is a sectional view taken along the line II-II of FIG.

3 is an enlarged cross-sectional view of a rool manufactured using the mold shown in FIG.

FIG. 4 is an enlarged cross-sectional view of an enlarged portion of the rool shown in FIG.

Figure 5 is a longitudinal cross-sectional view showing a centrifugal mold according to another preferred embodiment of the present invention.

FIG. 6 is an enlarged view of the supporting ring used for the mold shown in FIG. In addition,

7 is a graph showing the temperature distribution in a rool prepared according to the present invention and a preceding one.

* Explanation of symbols for main parts of the drawings

2a, 2b: shroud 4: mixed pipe

5: spacer 8: rool

12: space

The present invention relates to a method for producing a cylindrical body of high heat resistant fiber reinforcement which is particularly suitable for use as a machine part material. Until now, various types of fiber reinforcing alloys (FRM) have been proposed, which are composed of metal matrices and reinforcing fibers, but these fiber reinforcing alloys are composed of metal matrix, for example aluminum or titanium, and fiber reinforcing, carbon It is a composite material composed of fibers, silica carbide fibers, boron fibers or alumina fibers.

None of these fiber-reinforced alloys have high heat resistance and thermal insulation properties, so these alloys can be subjected to high temperature conditions such as, for example, conveolaro installed inside the furnace for transportation of heat-treated materials and conveolaro for hot rolled strip transportation. It is not suitable for use as part materials for operation under

As a method for producing a cylindrical body made of a fiber reinforced alloy, a liquid phase method of flowing molten metal between reinforcing fibers is known. This liquid phase method has attracted attention because of the fact that the composite manufacturing process does not require a long time compared to the diffusion bonding method, which is another method for manufacturing fiber reinforced alloys.

Incidentally, the liquid phase method can be subdivided into a melt permeation method, a vacuum casting method, and a melt casting method, but any of these methods can be satisfactorily because the productivity cannot be sufficiently increased, and thus cannot be put to practical use.

The present invention is based on the fact that the fibrous material commonly used for the ternary curtains, the thermoprotection covers and the linings for the furnace parts can withstand 1400 or more heat and has a high tensile strength. Another object of the present invention is to provide a cylindrical body made of a fiber-reinforced alloy that can be used as a material for parts installed in the furnace by using the aforementioned refractory material and high-strength fibers as the fiber reinforcing material used for the alloy.

It is still another object of the present invention to provide an improved method for producing a fiber-reinforced alloy which can obtain relatively high productivity and can uniformly press-mold a melt between reinforcing fibers by centrifugal force.

These and other objects and features of the present invention will become apparent from the following description in connection with the preferred embodiments according to the accompanying drawings which follow.

Prior to describing the present invention, it is noted that the same parts are denoted by the same reference numerals throughout the accompanying drawings. In addition, for the sake of simplicity in describing the fiber reinforcing alloy of the present invention, it is clarified that a rool having a fiber reinforcing alloy manufactured according to the centrifugal casting method and embedded in a rool is described as an example. 1 to 4 show the mold 1 of the centrifugal casting machine.

The mold 1 is generally a cylindrical shape in which both ends are open, and protection plates 2a and 2b provided with a small hole 6a in the center are provided to close both openings of the mold 1. It is a cylindrical rool in which the fiber reinforcing alloy layer of the present invention is buried in the outer surface indicated by (8) in FIG. 3, which is usually a tubular fibrous reinforcing agent by mixing reinforcing fibers on the outer peripheral surface. The support discs 3a and 3b provided with the hole 6b in the center part are joined to the both ends of the mixed pipe 4 of fiber, and they are installed on the same axis in the mold 1. In order to prevent the outer circumferential surface of the mixed pipe 4 and the inner circumferential surface of the mold 1 from contacting each other during the casting process, a plurality of annular spacers are provided outside the mixed pipe 4, and these spaces The same spaced each other along the longitudinal direction of the mold 1 was arrange | positioned. By providing a gap 12 between the protective plate 2a and the support disc 3a, it is possible to avoid the molten metal being directly supplied to the inner surface of the mixed pipe 4, and to prevent the eccentric formation and the disturbance of the mixed pipe 4 It is intended to do.

Instead of using a plurality of annular spacers 5, it is found that a single coil made of iron wire can be used as a spacer for carrying out this object. Reinforcing fibers used to make the composite pipe 4, preferably, 62% by weight, 14% by weight of alumina (Al ₂ O ₃ ), boron oxide (B ₂ O ₃ ) and silica (SiO ₂ ), and And tri-element type oils containing 24% by weight.

The composition of the furnace rate 8 is 25Cr-20Ni metal alloy (C: 0.41 weight% Si: 1.18 weight%, Ni: 20.28 weight%, Mn: 1.02 weight% P: 0.015 weight%, S: 0.011 weight%, Cr: 24.41 Weight% and MO: 0.05 weight%) the center hole 6b of the support disc 3a joined with the mixed pipe 4 supported by the above-mentioned method through the center hole 6a of the protection plate 2a. It is fed into the mold (1) through.

Next, by rotating the mold 1 in one direction, the molten metal receives a radial force that can adhere to the main surface of the mold 1 by centrifugal force.

While casting is performed in this way, the molten metal passes not only through the pores 4a (see FIG. 4) formed in the blend tube 4, but also between the reinforcing fibers formed in the blend tube 4, and the mold 1 and the blend tube (4) It flows on the inner peripheral surface of the mold 1 through the gap formed by the intermediate spacer 5. In practice, the amount of molten metal supplied into the mold 1 is selected so that the mixed pipe 4 can be completely buried in the outer wall of the manufactured bowl 8 as shown in FIG. After the molten metal in the mold has solidified, the prepared rool 8 is separated from the mold 1.

The rool 8 produced as shown in FIG. 4 is initially referred to as a mixed tube 4, and the mixed tube 4 is also placed radially inwardly from the outer circumferential surface of the erool to the molten metal. After being buried, it was referred to as a reinforcing fiber layer (A).

In order to complete the manufacture of the rool 8 on the outer circumferential surface completely covered with the reinforcing fiber layer A, the cast rool 8 is removed by reinforcing the surface portion 7 of the rool 8 according to a known grinding method. The fiber layer (A) is exposed to the outside. However, depending on the application in which the rool is used, there may be cases in which the removal operation of the surface portion 7 by polishing is not necessary.

In the above-described embodiment, the number of fiber reinforcements shown as a mixed pipe is not necessarily limited to one as shown, but may be two or more. When the fiber reinforcing agent has a layer structure, that is, when two or more mixed pipes are stacked and used as layers, the molten alloy may not reach the inner circumferential surface of the mold 1 during the centrifugal casting operation period.

In such a case, instead of using the annular spacer 5, a molten metal such as A1 or Zn, such as A1 or Zn, flows into the mold by casting a low melting point metal having a Fe lattice constant of ± 15 or less on the inner circumferential surface of the mold 1, You may attach a tubular fiber reinforced composite pipe inside it.

In this case, coagulated products such as A1 and Zn are then melted in the centrifugal casting layer by the heat of the injected molten metal to form a molten metal and a diffusion solid solution. In addition, even if the number of the mixed pipes 4 is two or more or the wall thickness of one mixed pipe is too thick, the molten metal injection molten metal passes radially outwards during the centrifugal casting operation even if the improved method described above is used. In the case where it is difficult to flow into the mold, the mixed pipe is installed in the immediate vicinity of the central hole 6a with one or more direct passages, and the molten metal injected into the mold 1 through the central hole 6a is also directly connected during the casting operation period. It should be noted that the furnace is designed to flow through the gap between the mixed pipe (4) and the mold (1).

In addition, when the used reinforcing fiber has a property that is easy to dissolve when contacted with the molten alloy, it may be coated with a heat-resistant coating to prevent the dissolution of such reinforcing fiber.

In the above-described embodiment, the reinforcing fiber layer embedded in the rool is exposed to the outside by polishing the outer surface of the rool, and this polishing operation is also necessary to remove the traces left on the outer surface of the rool by the spacer 5. The concept of the present invention can be equally used in the manufacture of a rool having a layer of reinforcing fibers embedded in the entire middle part of the wall thickness.

This is explained in detail as the following FIGS. 5 and 6. As shown in detail in FIG. 5, the outer and inner steel pipes 9a and 9b can be inserted side by side with the spacer 5 dashes used in the above-described embodiment, and can be used for supporting the mixed pipe 4.

In addition, each of the support discs 3a and 3b used in the embodiments shown in FIGS. 5 and 6 has an outer diameter that is exactly the same as the inner diameter of the mold 1 and extends radially outward therefrom. And a plurality of spacer protrusions 10 provided at equal intervals on the circumference of each other.

Each of the support discs 3a and 3b forms outer and inner circular grooves 11a and 11b coaxially with the axis of rotation of the mold 1 on these surfaces. The composite pipe 4 is inserted into the circular space formed between the outer and inner steel pipes 9a and 9b and then the outer and inner sides in the coupling support disks 3a and 3b as detailed in FIG. The ends of the steel pipes 9a and 9b are fixed to the circular grooves 11a and 11b, respectively, and can be supported in the mold 1.

Due to the specific arrangement of the support discs 3a and 3b as shown in FIG. 6, the metal alloy melt supplied to the mold 1 through the center hole 6a is transferred to the inner steel pipe through the center hole 6b. It can be seen immediately that the arch passage formed between not only the inside of 9b but also two adjacent radial outward protrusions 10 can be formed to flow into the space between the inner surface of the mold 1 and the outer steel pipe 9a. have. Injection into the mold 1 through the central hole 6a on the gap 12 between the protective plate 2a and the support disc 3a during the actual casting process as a mold 1 rotating in one direction about the middle axis of the mold. The molten 25Cr-20Ni alloy molten metal first flows between the mold 1 and the outer steel pipe 9a through a jade passage, and then the inner steel pipe 9b through the central hole 6b in the support disc 3a. Will flow into the. The molten metal introduced into the inner steel pipe 9b is influenced by the centrifugal force while the mold 1 continues to rotate, and the outer and inner steel pipes 9a and 9b through the perforations of the inner steel pipe 9b. Inflow into the space between and at the same time the outer and inner steel pipes (9a) and (9b) is melted at the moment of contact with the high temperature of the charging molten metal. A rool made in accordance with a second preferred embodiment also has a reinforcing fiber layer (A) embedded in the middle of the sidewall substantially the same as shown in FIG.

According to the second preferred embodiment of the present invention, when a rool having a side wall thickness of 30 mm at 1600 ° C. was tested using a centrifugal force of 58 g, the rool had a temperature distribution such as a dotted line shown in FIG. 7.

For comparison purposes, the temperature distribution of the diesel oil produced in the conventional material of the same material as the sidewall thickness of 30 mm without embedding the reinforcing fiber layer is indicated by a thick line in FIG. 7.

In the FIG. 7 graph, the side wall thicknesses "0" and "30" represent the inner and outer circumferential surfaces of the rool, respectively. These temperature distributions were obtained by exposing the inner circumferential surface and the outer circumferential surface of the rool according to the present invention and the rool according to the prior method to 350 ° C. and 1300 ° C. air stream, respectively.

Although the present invention has been described fully in connection with the preferred embodiments thereof, it should be understood that many modifications and variations can be made by those skilled in the art. Accordingly, such modifications and variations should be considered to be included in the present invention without departing from the scope of the appended claims.

Claims (2)

A tubular fiber-reinforced trace tube is installed in the mold of the centrifugal casting machine at a predetermined interval from the mold inner peripheral surface, and then molten metal is injected into the mold, and a certain interval is maintained during the operation of the centrifugal casting machine. A method for producing a cylindrical body made of a fiber reinforced alloy, wherein the molten metal is pressurized by centrifugal force. The method of manufacturing a fiber reinforced alloy according to claim 1, wherein the fiber reinforced composite pipe is composed of three element fibers of alumina, boron oxide and silica.

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