JPH0551608A - Production of metallic capsule for producing composite tube - Google Patents

Abstract

PURPOSE:To easily produce a metallic capsule of optional size for producing a composite tube with the lining powder sufficiently densified and with the degree of vacuum hardly leaked. CONSTITUTION:An inner cylinder 3 having about the same length as a cylindrical capsule main body 1 with an outward opening flange formed on the upper and lower ends and formed with a thin metal easy to plastically deform is inserted into the main body 1, a lining powder 4 is filled between the periphery of the main body 1 and the inner periphery of the inner cylinder 3, the outer peripheral edge of the flange of the inner cylinder 3 is welded to both end faces of the main body 1 in vacuum, end plates 9 and 10 are firmly attached to both ends of the powder-filled body 6 to close the opening of the body 6 on both ends, a pressure medium 14 is injected into the body 6, and the medium 14 is pressurized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the production of a composite pipe in which a lining layer in which powder for lining is integrated by powder metallurgy is joined and formed on the inner surface of a pipe body.

[0002]

2. Description of the Related Art As a method for producing a composite pipe having a lining layer formed on the inner surface of the pipe body, as disclosed in Japanese Patent Publication No. 1-54402, a capsule which becomes the main body of the composite pipe.
(Billet) Provide a concentric rubber cylinder inside the body,
An inner cylinder made of a thin metal that is easily plastically deformed is inserted along the inner peripheral surface of the cylindrical body, lining powder is filled between the inner cylinder and the capsule body, and rubber lids are attached to both ends thereof. Then, the powder-filled body is subjected to cold isostatic pressing (referred to as “CIP”) to integrally compress and solidify the inner cylinder and the lining powder on the inner surface of the capsule body, and then the rubber. There is a method in which the material is removed, a metal lid is welded to both end surfaces of the integrated inner cylinder to form a metal capsule, and the capsule is hot extruded. In addition, hot isostatic pressing (“HI
"P". ), The lining powder is sintered and integrated into a lining layer, and the lining layer is integrated with the capsule body, that is, the inner surface of the tube body by diffusion bonding.

[0003]

However, the lining powder filled along the inner surface of the capsule body is pressed by the CIP through the rubber cylinder and the lid provided inside and on both ends of the capsule body. Since both ends of the lining powder are pressed in the radial direction (thickness direction) and the longitudinal direction, the part where the pressing force is canceled and the powder is not compressed sufficiently, that is, the part where the powder is not densified is Occurs, which causes the product lining layer to be lacking or peeled off.

Further, since the powder filling body is pressed by CIP, the shape of the capsule is limited to the volume shape of the CIP device, and it is difficult to manufacture a metal capsule having a large diameter or a long size. Furthermore, after CIP, the thin metal inner cylinder is welded to the metal lids at both ends, but due to the uneven shrinkage of the end of the lining powder, the inner cylinder ends are not evenly deformed and the dimensional reproducibility is improved. Therefore, there is a problem that welding of the metal lid is extremely difficult, and a vacuum degree leak is likely to occur in the capsule due to defective welding, and the product yield is likely to decrease.

The present invention has been made in view of the above problems, and it is a composite in which densification of the lining powder does not occur insufficiently, powders of any size can be easily manufactured, and leakage of vacuum degree is unlikely to occur. It is an object to provide a method for producing a metal capsule for producing a tube.

[0006]

The method of manufacturing a metal capsule according to the present invention comprises a cylindrical capsule body having substantially the same length as that of the capsule body, an outer opening flange formed at the upper and lower ends thereof, and is easily plastically deformed. Insert the inner cylinder made of thin metal, fill the lining powder between the outer peripheral surface of the capsule body and the inner peripheral surface of the inner cylinder, and put the flange outer peripheral edge of the inner cylinder on both end surfaces of the capsule body under vacuum. After welding, the end plates are brought into close contact with both ends of the powder filling body to close the openings at both ends of the powder filling body, and the pressure medium is injected and filled into the inside of the powder filling body. The lining powder filled between the capsule body and the plastic body is compressed and solidified.

When closing the openings at both ends of the powder filling body, a mandrel penetrating the inside of the powder filling body is provided,
This may be supported by the end plates.

[0008]

[Function] Since the lining powder is filled between the capsule body and the inner cylinder formed of a thin metal, the flange outer peripheral edges of both ends of the inner cylinder are welded to the end surface of the capsule body under vacuum. In comparison with the case where the metal lid is welded after the inner cylinder is deformed, the sealing in the vacuum state by welding is extremely easy and reliable, and the leak of the vacuum degree can be surely prevented.

Since both end openings of the powder filling body filled with the lining powder are closed by the end plates and the pressure medium is injected, filled and pressurized into the inside thereof, the inner cylinder is radially outward. It is plastically deformed, and the lining powder is compressed and consolidated by pressure only in the radial direction. Therefore, no axial contraction occurs,
Insufficient compression does not occur at the end of the lining powder, and the lining powder is uniformly densified over the entire area. Therefore, even when the metal capsule is subjected to hot extrusion or HIP, the pipe end portion of the lining layer of the obtained composite pipe is free from chipping or peeling, and the product length yield is improved. The capsule body serves as a tube body of the composite tube, has a considerable thickness, and acts as a pressure container when the pressure medium is pressurized, and is hardly deformed as compared with the inner cylinder.

Further, when the lining powder is compressed and consolidated, a CIP device is not required, and it is sufficient to provide an end plate supporting means and a means for injecting / pressurizing a pressure medium into the inside of the powder compact, which is easy to carry out and the capsule size. It is possible to carry out without being restricted.
Further, a mandrel penetrating the inside of the powder filling body is provided,
By supporting both ends with end plates, the injection amount of the pressure medium can be reduced, and the axial force applied to the end plates by the cross-sectional integration of the mandrel can be reduced, and the powder compact and the end plates can be reduced. Positioning with and becomes easy.

[0011]

EXAMPLE To carry out the present invention, as shown in FIG.
A capsule main body 1 formed of an intended metal material that serves as the main body of the composite pipe and flanges 2 and 2 having an outer diameter slightly larger than the inner diameter of the main body 1 are provided at both ends, and the capsule main body 1 has substantially the same length as the main body 1. Cylinder
Prepare 3 and. The inner cylinder 3 is a thin metal material that is easily plastically deformed.
(For example, a mild steel plate of about 2 to 4 mm) is integrally and seamlessly molded.

As shown in FIG. 1, the capsule body 1 is erected vertically, and the lower flange 2 of the inner cylinder 3 is bent and inserted into the capsule main body 1, and the lower end of the inner cylinder 3 is inserted into the capsule body 1. Insert so that it is about 20 mm above the bottom surface. When inserted to a predetermined position, the inner cylinder 3 is held in the capsule body 1 by the elastic force of the flange 2. In this state, the lining powder 4 is charged and filled between the inner cylinder 3 and the capsule body 1 through the gap between the upper flange 2 and the upper surface of the capsule body 1.

After that, the inner cylinder 3 is pushed down to lower the inner cylinder 3
The peripheral edges of the flanges 2, 2 at both ends of are fitted and fixed in the recesses 5, 5 formed in the opening peripheral edge of the capsule body 1. This is inserted into a vacuum chamber, vacuum degassed to 0.005 Torr or less, and then the peripheral edge of the flange is welded to obtain the powder filling body 6 shown in FIG. Next, as shown in FIG. 3, the mandrel 7 was inserted into the powder filling body 6, and the end plates 9 and 10 were closely attached to both ends through the packings 8 and 8 formed of Teflon or the like, and the tie rods were attached. Tighten the powder packing 6 by 11 in the axial direction. The tightening force is approximately 1.5 to 2 times the axial force due to the internal pressure described below.

Next, for example, water is injected as the pressure medium 14 through the injection holes 12 and 13 formed at the centers of the end plate 9 and the mandrel 7 to fill the space between the powder filling body 6 and the mandrel 7.
Increase the water pressure to 5-6 Ton / cm ² with a pressure pump, and
Hold for about a minute. Thereafter, the pressure is removed, the water inside is removed, and the end plates 9 and 10 are removed to obtain the desired metal capsule.

As the capsule body 1, a material SCM44 is used.
0, outer diameter φ198 x inner diameter φ60 x length 800 l (mm), inner cylinder 3 is made of material S35C, outer diameter φ30 x inner diameter φ24
× Use 800 l (mm) length, Ni-based high alloy CrB, V between the capsule body 1 and the inner cylinder 3 as shown in Fig. 1.
The composite powder in which high quality particles such as C and Ni ₃ Si are dispersed and strengthened is filled as the lining powder 4, the outer peripheral edges of the flanges 2 and 2 are welded to both end surfaces of the capsule body 1, and then the powder is processed as shown in FIG. The inside of the filling body 6 was pressurized. As a result, the inner diameter of the capsule was expanded and uniformly deformed to φ28.5 mm. From this value, the powder packing density was calculated to be about 0.85. The powder packing density must be 0.8 or more to prevent abnormal deformation during subsequent HIP or hot extrusion.

The metal capsule in which the lining powder was densified as described above was held at 900 to 980 ° C. at a pressure of 1000 Kgf / cm ² for 4 hours and subjected to HIP treatment. As a result of measuring the dimensional change of the inner and outer diameters of the obtained composite pipe, the deviation of the inner and outer diameter concentricity was about 0.5 mm, and the bending was 0.45 mm / 800 lmm or less, and no abnormal deformation occurred.

[0017]

As described above, according to the method for producing a metal capsule for producing a composite pipe of the present invention, the lining powder is filled between the capsule body and the inner cylinder made of thin metal, and the flange of the inner cylinder is filled. Since the peripheral edge is welded to the end surface of the capsule body under vacuum, the welding is easy and reliable, and the leak of the vacuum degree can be surely prevented. In addition, the powder filling body in which the peripheral edge of the inner cylinder flange is welded closes both end openings with end plates and injects and fills a pressure medium into the inside to pressurize the inner cylinder without applying an axial force to the inner cylinder. , It is possible to apply a compressive force only in the radial direction, and it is possible to deform it uniformly in the radial direction, thereby uniformly compressing and solidifying without causing insufficient densification at the end of the lining powder. can do.

Further, when the present invention is carried out, a CIP device is unnecessary, so that there is no dimensional limitation, the equipment cost is low, and the economy is excellent.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a capsule body and an inner cylinder in a state where a lining powder is filled.

FIG. 2 is a cross-sectional view of a powder filling body.

FIG. 3 is a cross-sectional view showing an internal pressure state of the powder filling body.

[Explanation of symbols]

 1 Capsule body 2 Flange 3 Inner cylinder 4 Lining powder 6 Powder filling body 7 Mandrel 9 End plate 10 End plate 14 Pressure medium

Claims (2)

[Claims] 1. An inner cylinder, which has substantially the same length as that of the capsule body and is formed of a thin-walled metal that has outer opening flanges at the upper and lower ends and is easily plastically deformed, is inserted into the inside of the capsule body. After filling the lining powder between the outer peripheral surface and the inner peripheral surface of the inner cylinder, and welding the flange outer peripheral edge of the inner cylinder to both end surfaces of the capsule body under vacuum, end plates at both ends of the powder-filled body. Closely closing both ends of the powder filling body, injecting and filling a pressure medium into the inside, and pressurizing the pressure medium causes the inner cylinder to be plastically deformed radially outward and is filled between the capsule body. A method for producing a metal capsule for producing a composite pipe, which comprises compressing and solidifying the lining powder. 2. A mandrel which is in close contact with both ends of the powder filling body and penetrates the inside of the powder filling body is supported by the end plates, and both end openings of the powder filling body are closed by the end plates. The method for producing a metal capsule for producing a composite pipe according to 1.