JPS59107728A - Production of composite material - Google Patents

Abstract

PURPOSE:To tighten and unite an internal material by a reduced metallic cylindrical blank material to one body by disposing the prescribed internal member extending in the axial direction of the metallic cylindrical blank material in said blank material, heating the blank material and pulling axially the same. CONSTITUTION:A prescribed internal member W2 which is a rod or pipe extending in the axial direction of a prescribed metallic cylindrical blank material W1 and is to be combined with said material is disposed in said blank material. The material W1 is then heated and axially pulled so that the member W2 is tightened by the reduced material W1, thereby forming the composite material united to one body. The material W1 may be preliminarily heated before insertion of the member W2. A material, such as Cu or Al, having good conductivity is preferred for the material W1 and a material, such as steel, having relatively high hardness is preferred for the member W2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a composite material, and in particular to a method for easily manufacturing a composite (clad) material having a cylindrical, axial, or linear shape with good integrity. be.

Generally, such cladding materials are made by joining two (or more in some cases) different materials.

Since they can be obtained by integrating them, they are always useful materials because they complement each other's physical properties and save on material.

By the way, the cladding 4 has a cylindrical shape or a shaft shape like a queen's.
1 is manufactured by joining the outer material and the inner material, and various methods have been known in the past, such as shrink-fitting, press-fitting, bulge method, explosion molding method, and discharge explosion molding method. It is being

However, when joining by shrink-fitting is used in a high-temperature environment higher than the shrink-fitting temperature, the inner and outer image materials separate due to differences in expansion rates, creating gaps at the joint surface. Integrity may be lost, and press-fit bonding also has similar problems when used at high temperatures. On the other hand, in methods such as the bulge method and the explosion molding method, in which the cylindrical inner material is bulged and expanded in diameter and crimped onto the outer member, if the inner material is made of a brittle material with poor ductility, When expanding the diameter, cracks are likely to occur, making it virtually difficult to clad.
Therefore, it is unavoidable to be subject to material restrictions, and it is undeniable that manufacturing thin clad pipes is also difficult because it is difficult to apply fluid pressure, etc., and that there are restrictions in this respect as well. .

Against this background, the present invention aims to provide a method for easily manufacturing the above-mentioned cylindrical or shaft-shaped cladding material with good integrity and without being subject to restrictions such as material quality. The gist of this was to place a predetermined inner member to be composited extending in the axial direction within a predetermined metal cylindrical material to be stretched, while By heating the metal cylindrical material and pulling it in the axial direction, the inner member is tightened and integrated by the reduced diameter metal cylindrical material.

In this way, when the metal cylindrical material is heated and then stretched and reduced in diameter, the inner member is tightened to achieve good adhesion between the two, and the diameter reduction due to temperature drop in the metal cylindrical material is prevented. As a result, a further tightening force acts on the inner member, resulting in a cladding material with high compressive stress and very high integrity. Therefore, even if the product is used at high temperatures, as long as it is within the heating temperature range when the metal cylindrical material is stretched, the thermal stress caused by the difference in thermal expansion between the two materials can be absorbed, and the joint surface The integrity of the cladding structure can be maintained stably without fear of separation occurring.

In addition, since the outer metal cylindrical material is stretched and reduced in diameter, there is no risk of cracks or cracks due to diameter expansion when the inner member is a tube, unlike in the bulge method, and the inner member is Since only compressive stress is essentially generated, the metal cylindrical material and the inner member can be effectively integrated without being restricted by the material, even if the inner member is brittle against elongation. Furthermore, regardless of whether the inner member is hollow or solid, even a thin clad pipe can be easily manufactured according to the present invention.

By the way, examples of metal cylindrical materials used in the present invention include those shown in FIGS. 1 to 4 (a), for example.
As indicated by W+ in each of the above, it is preferable to use a cylindrical shape, and depending on the use and purpose of the clad material to be manufactured, ferrous metals such as steel, non-ferrous metals, or alloys can be used. An appropriate material is selected from among the following types. Note that, for example, a tapered cylindrical member or the like having a shape in which the cylindrical diameter is not uniform may also be used.

Then, in accordance with the present invention, a predetermined inner part to be composited (clad) is arranged within the metal cylindrical material so as to extend in the axial direction of the metal cylindrical material. The inner member has a cross-sectional shape that approximately corresponds to the cross section of the internal space of the cylindrical material, and has an outer diameter smaller than the inner diameter of the cylindrical material by a certain amount, and is suitable for the intended cladding material. Depending on the situation, various forms can be adopted. for example,
As shown in the inner member indicated by W2 in FIGS. 1 to 4 (a), the cross-sectional shape is a solid rod, a simple hollow pipe, or a bellows-shaped cross-section with unevenness in the axial direction. Typical examples include pipes that have The material for the inner member is selected from a variety of materials that have the required physical properties depending on the purpose.
-Although it cannot be generalized, metal is generally used. However, in some cases, the inner member may be made of a non-metal such as ceramics.

On the other hand, before or after placing the inner member inside the metal cylindrical material, the cylindrical material is heated to a predetermined temperature. Whether this heating is performed before or after placing the inner member depends on the process (e.g. heating method).
The temperature at which the metal cylindrical material should be heated is determined in an appropriate range depending on the material of the metal cylindrical material, the diameter reduction rate in the tensile process to be performed later, the tensile force, etc. The heating mode for the cylindrical material is usually such that the entire material is heated to a uniform temperature.

However, depending on the case, it may be possible to heat the lower temperature part in the axial direction of the material, for example, as conceptually shown by the approximate straight line in the graph of Fig. If a temperature distribution is formed in which high-temperature areas and low-temperature areas alternate, elongation and diameter contraction will occur mainly in the high-temperature areas during the subsequent tension stage, for example, as shown in Figure 3(b). A form as shown by W+' is obtained.

In order to obtain the above temperature distribution, you can heat the entire cylindrical material uniformly and then cool it partially, or you can select the heating area from the beginning and heat it partially. You can.

In addition to heating methods for metal cylindrical materials, all known heating methods include direct current heating, high-frequency induction heating, gas heating, infrared heating, indirect heating using an electric furnace, etc. may be adopted, and a suitable heating means is selected from among them. For example, direct energization is convenient for uniform heating. However, when heating is performed after placing the inner member inside the cylindrical material, if there is a risk that the inner member may partially contact the cylindrical material and cause temperature unevenness, high-frequency induction heating method etc. Hiring is highly recommended.

Note that it is possible to heat not only the outer metal cylindrical material but also the inner member, but if you heat both at the same time after placing the inner member, an oxide film is likely to form on the adjacent surfaces of both. In certain circumstances, it may be desirable to heat them separately and then assemble them, or to heat only the cylindrical material without heating the inner member.

Then, the cylindrical material is heated and the inner member becomes the cylindrical element F'.
! If the state placed inside (that is, the shape of the cylindrical material) is before the placement of the inner member, after the placement is completed, and if after the placement, the outer cylindrical material is placed in the state after heating is completed. is pulled in the axial direction. Due to this tension, the heated outer cylindrical material is stretched and reduced in diameter, and the gap with the inner member disappears, so that the inner member is tightened. As such a tensioning method, an appropriate method can be adopted, such as gripping both ends of the cylindrical material using an appropriate gripping means such as a chuck and pulling it, or fixing one end and pulling the other end. .

In addition, the tensile conditions such as the tensile speed, tensile force, and tensile pattern are determined as appropriate in relation to the material of the cylindrical material and the diameter reduction ratio. If the planned amount of diameter reduction is large to some extent, it is also possible to carry out not only one stage of tension but also two or more stages of tension. In addition to making the tension speed uniform, it is also possible to change the speed by increasing or decreasing it at a constant rate. For example, the inner circumference of the cylindrical material and the outer circumference of the inner member first touch each other. Depending on the specific case, a preferable tensile method may be adopted, such as pulling at a high speed until contact is made and then pulling at a relatively low speed after contact.

In any case, by tensioning and reducing the diameter of the outer cylindrical material, the material tightens the inner member and the two are integrated.For example, in the case of Fig. 1, the state shown in (a) is The entire inner circumferential surface of the cylindrical material W, / after being stretched is crimped to the entire outer circumferential surface of the rod-shaped inner member W2 without any gaps, and also in the case of FIG. Similarly, the cylindrical material W 1' is crimped to the pipe-shaped inner member W2 over the entire inner circumferential surface. In the case of the example shown in Fig. 3, (1) is achieved by heating the material W+ in a pattern in which the temperature is continuously varied in the axial direction of the cylindrical material W1 before tensioning. As shown, the high-temperature part is mainly stretched and reduced in diameter by tension, and the material W+' after tension becomes a tube (corrugated pipe) with a wave-shaped cross section.
The pipe-shaped inner member W2 is tightened and crimped mainly in each of the diameter-reduced portions (trough portions). Furthermore, in the case of FIG. 4, the cylindrical material W+', which has been stretched and reduced in diameter, is crimped onto the large diameter ridges /' of the inner member W2 in the form of a bellows tube and a corrugated pipe. As is clear from the above configuration, when the tensioning of the cylindrical material is completed, the inner member and the cylindrical material are effectively crimped together by the tightening, even if there is a difference in the whole or part of the inner surface of the material.

Furthermore, after tensioning, compressive stress is generated in the direction in which the cylindrical material further contracts and its diameter decreases due to the temperature drop in the cylindrical material, so the tightening force of the cylindrical material against the inner member becomes even greater, and therefore the tensile In some cases, solid or hollow products as shown in (13) can be obtained. Furthermore, since the inner member is a relatively thin-walled cylindrical pipe, even if there is some error in its roundness, this can be corrected by tightening the cylindrical material from the outside, and the trueness of the cylindrical inner member will be corrected. It has been confirmed that the secondary effect of increasing roundness also occurs.

The cladding material obtained in the above manner is used for a wide variety of purposes, either in its rolled form or after undergoing secondary processing. Because of its excellent integrity, it has high structural reliability, and in particular, even when used at high temperatures, the tightening action of the cylindrical material can be maintained within the heating temperature when the cylindrical material is stretched. is, a
-i Integrity is maintained well. Here, we will introduce some specific examples of its many uses.

For example, in the rad-shaped one shown in FIG. 1(b), the outer cylindrical material W1' (hereinafter referred to as outer member W+'
), copper (Cu) or aluminum (A
If the inner member W2 is made of a material with good conductivity such as steel, etc., and the inner member W2 is made of a relatively strong material such as steel, it is suitable as a conductive material. By using titanium (Ni-Ti) alloy or niobium (Nb), which is difficult to stretch against heat; F71 material, that is, a material with an extremely low coefficient of linear expansion, can be suitably used as an overhead power transmission line. In other words, even when large currents are passed through, sagging due to heat is effectively suppressed, making it possible to increase power transmission capacity while using existing steel towers in urban areas. Also, Fig. 1(b)
For example, wires with a single structure containing a composite composition (components) have poor compatibility with melting and are difficult to manufacture. , each of the composite components is divided into single components, and each inner member W2. It is clad with an outer edge of 'W+'. 1. The type shown in Fig. 2-(b) is suitable for structural purposes, for example, for the inner member W.
If 2 is made of a corrosion-resistant material such as a SUS pipe, and the outer member W+' is made of mild steel or the like, it can be suitably used as a fluid transport pipe. Furthermore, in the form shown in FIG. 3(b), since the surface area of the outer member W1' is large, it can be effectively used for heat exchange tubes, etc., depending on the material selected. Furthermore, the structure shown in FIG. 4(b) can be used for applications that take advantage of the large surface area of the inner member W2.

According to the present invention, such a useful rad material can be manufactured easily and with good integrity as described above, and its significance can be said to be very great.

Although omitted in the above explanation, the cladding material obtained through the tensile process of the cylindrical material is then used as the inner member, and a metal cylindrical body is further placed on the outside in the shape of an upper vortex. Pressure bonding is also possible, and by sequentially repeating such steps, a cladding material with a multilayer structure such as a triple pipe can be obtained.

When the inner member is placed inside the twisted cylindrical material, a third metal thin film having the function of further increasing the bonding strength is interposed between the two, and the inner and outer parts are connected through it. It is also possible to integrate each material, and in a broad sense, the entire thing inserted and arranged inside the cylindrical material can be understood as an inner member.

Furthermore, the metal cylindrical material is not necessarily limited to those with a circular cross section; for example, it is also possible to use a cylinder with a circular cross section, a cylinder with a square cross section, etc. In this case, the inner member will also be of a shape that substantially corresponds to the cross-sectional shape of the inner member.

Finally, representative examples of various tried embodiments of the present invention are shown below to clarify the present invention more specifically. Needless to say, it is not subject to any restrictions.

Example 1 A 5US316 pipe with an outer diameter of 13.8 mm and a wall thickness of 2.0 mm was cut into a length of 2000 ff711, which was used as a cylindrical material W, and each end was 50 ttty.
It was gripped with an energized chuck over a length range of t, and heated from room temperature to 800° C. in 20 seconds by direct energization heating method.

Next, the outer diameter is 9. Qmyn, wall thickness 0.5 mm, length 2
A Bunio J (Nb) pipe of 00 (C++) was used as the inner member W2, and this pipe was inserted into the heating pipe.Then, the pipe was stretched 250 times in the axial direction at a tensile rate of 20011 [/Sec]. A tensile operation was performed.

As a result, a clad pipe with a cross section as shown in FIG.
a = 78 friends. Also, both pipes W1' and W
Even when viewed under a microscope, there was no gap in the bonded portion of No. 2, and it was confirmed that the bonded portion was physically well bonded.

Example 2 Outer diameter: d4. Omtn, wall thickness 4.0*71. length 450
Qi*'s hot finished seamless carbon steel pipe is made into cylindrical material W1.
Each of the 9QIrM ends was gripped with an energizing chuck, and heated from room temperature to 760°C by direct energization heating.
The temperature was raised to ℃ in 80 seconds. On the other hand, the outer diameter is 230 horses,
A seamless nickel-chromium-iron alloy (NCFI TB) W having a wall thickness of 2.4 ytnn and a length of -4500 myn is used as the inner member W2. It was charged into a heated steel pipe. After replacing the current-carrying chuck with a tension chuck and gripping it again, the outer carbon steel pipe was axially elongated by 750 mm at a tensile rate of 100 FIi/see.

As a result, a clad pipe with a cross section as shown in FIG. 7 was obtained, and the final cross-sectional dimensions di to d8 were d+ = 29.4ffi, d2 = 22.
4 horsemen, d3 = 17.8 guns. Further, the condition of the joint was almost as good as in Example 1.

[Brief explanation of the drawing]

1 to 4 are process diagrams illustrating several specific examples of the method of the present invention, and FIG. 5 is a graph showing an example of a heating pattern for a metal cylindrical material. FIG. 6 and FIG. 7 are cross-sectional views showing respective clad pipes obtained in each example of the present invention. W]: Metal cylindrical material (before tension) W1'2 Same as above (after tension) W2: Inner member applicant Daido Steel Co., Ltd. Figure 5 Figure 6 Figure 7

Claims (4)

[Claims] (1) Placing a predetermined inner member to be combined and extending in the axial direction within a predetermined metal cylindrical material to be stretched, while heating the metal cylindrical material and pulling it in the axial direction. A method for manufacturing a composite material, characterized in that the inner member is tightened and integrated by the metal cylindrical material whose diameter has been reduced. (2) The manufacturing method according to claim 1, wherein the heating of the metal cylindrical material is performed before or after placing the inner member. (3) The manufacturing method according to claim 1 or 2, wherein the inner member is a rod or a pipe. (4) The manufacturing method according to claim 1, wherein the metal cylindrical material to be stretched partially has a low-temperature portion in its axial direction.