JPH064198B2 - Manufacturing method of fitting parts for pipe connection made of dissimilar metal materials - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a joint part used for connecting pipes made of dissimilar metal materials which are difficult to weld.

[Prior Art] A joint component used for the above purpose is conventionally manufactured as follows. That is, a plate is formed from a clad material on a plate formed by explosively joining two plate materials made of dissimilar metal materials that are difficult to weld (each of which is the same material as the above-mentioned pipes and will be referred to as material A and material B, respectively). An element bonded body cut out in the thickness direction is prepared. Next, a first member made of the same kind of material as the A material is provided at the end of the A material of the elementally bonded body, and a second member made of the same kind of material as the B material is provided at the end of the B material of the elementally joined body. The members are respectively joined by a friction joining method, and finally the whole is finished to a predetermined dimension as a joint part.

In order to connect two pipes made of different metal materials using this joint part, a pipe made of the same kind of metal material as that is welded to the end of the first member of the joint part, while the second member is connected. A pipe made of the same kind of metal material as that may be welded to the end of the. This makes it possible to connect pipes that are difficult to weld directly through the joint component.

Japanese Patent Application Laid-Open No. 61-172 discloses the related art as described above
No. 692 is cited.

[Problems to be Solved by the Invention] In a clad material formed by explosively joining two plates made of different materials, one of the plates is generally thinner than the other plate. This thinner plate material is referred to as a laminated material, and the other plate material is referred to as a base material. The thickness of the laminated material differs depending on the material, but with general structural metal materials, the maximum is about 15 to 20 mm, and it is technically difficult to exceed this, and it is generally difficult to perform explosive joining of dissimilar metals. The plate thickness of the laminated material that can be formed is 5 to 15 mm.

Therefore, in the above-described conventional method for manufacturing a joint component, when a member made of the same kind of metal is friction-bonded to the mating material side of the element-bonded body cut out from the explosive-bonded clad material, the friction-bonded surface is made by explosive bonding of different materials. There will be very little distance from the surface. In addition to this, friction pressure and joining pressure are applied to the joining surface during the friction joining process, the molten metal on the joining surface is discharged as burrs, and the mating material is consumed. Therefore, the above distance becomes shorter and shorter. . For this reason, in the above-mentioned conventional technique, the explosive joining surface of different materials is also exposed to a relatively high temperature when at least the same kind of metal is friction-bonded to the mating material side. Thermal stress and brittle intermetallic compounds are generated due to the difference, and the risk of peeling increases.

Further, it is possible to use a method such as covered arc welding, TIG welding or the like instead of the friction welding described above, but in these methods, a groove is generally formed in the welded portion for facilitating welding work and preventing welding defects. The method of taking is adopted. However, since the welded part approaches the explosive joint surface by taking the groove, there is a concern that the performance of the explosive joint surface may be deteriorated due to the influence of welding heat.

As described above, in the conventional technology, consideration is not given to the temperature rise of the explosive joint of dissimilar materials when welding the same kind of metal to at least the mating material side of the raw joined body cut out from the explosive joining clad material, There is a problem that the reliability of the joint is impaired.

An object of the present invention is to reduce the temperature rise of a joint portion of dissimilar materials as much as possible when welding a metal member of the same material to at least a mating material side of a raw joined body formed by joining members of different metal materials. Another object of the present invention is to provide a method of manufacturing a joint part for connecting dissimilar material pipes, which does not impair the reliability of a joint between dissimilar materials.

[Means for Solving the Problems] The above object can be achieved by the method for manufacturing a joint part according to the claims.

[Operation] The element bonded body in each claim has a solid rod shape and has an extremely large heat capacity, and the electron beam welding or laser beam welding in each claim uses a high-density energy beam as a heat source. Since pass-through welding is possible, it is not necessary to provide a welding groove, and the melt width of the weld metal is extremely small as compared with friction welding and arc welding. For this reason, the amount of heat required for welding is small and the distance between the weld and the joint of different material members does not become small. Therefore, the thermal effect on the joint of the dissimilar material member of the element joint body is greatly reduced. Or, it can be none. Further, at this time, a cooling jig made of copper for speeding up cooling may be attached in the vicinity of the welded portion for welding.

A reference example which is a premise of the embodiment of the present invention will be described below. The joint component made by this reference example is for connecting a stainless steel pipe and a zirconium pipe which are difficult to be directly welded to each other.

As shown in FIG. 2, a tantalum thin plate 9 for improving the bondability is previously explosively bonded to a stainless steel plate 7 (base material), and a zirconium plate 8 having a smaller thickness than the plate 7 is formed thereon.
A plate-like clad material obtained by explosively joining (a composite material) is prepared, and the element pipe 10 is cut out from this clad material as an element-bonded body as illustrated.

Next, as shown in FIG. 1, a zirconium tube 11 that is substantially the same material as the zirconium material 8 of the element tube 10 and has substantially the same inner and outer diameters as the element tube 10 is used as the zirconium material 8 of the element tube. Butt at the groove 12 and electron beam welding is performed. The groove at this time is an I groove in which the zirconium material 8, the zirconium tube 11, and each flat end surface are butted. Therefore, since the groove surface of the zirconium material 8 uses the surface of the clad material as it is, the thickness of the zirconium material 8 is hardly reduced. The distance to the part) is secured sufficiently.

On the inner diameter side of the groove 12, a backing plate 14 made of substantially the same material as the zirconium tube 11 is provided all around. The groove 12
The backing metal 14 may be omitted when the welding is performed under ideal electron beam welding conditions and the backside wave shape is good, or when the amount of grinding increases due to the machining performed on the inner diameter side later. Further, when the groove alignment for the welding is completed, the cooling jigs 15, 15 ', 16, 16' made of copper are brought into close contact with the inner and outer surfaces of the pipe by an appropriate method. In these cooling jigs as well, part or all of them may be omitted if the joint between the dissimilar materials 7 and 8 does not rise to at least 500 ° C. or more when the electron beam welding is performed, but it is preferable to omit them. The electron beam welding is performed by setting this cooling jig.

After that, the cooling jig is removed, and the tubular body composed of the portions 7, 8, 9, 11 is finished as shown in FIG. 5 to complete the joint component.

When the stainless steel pipe and the zirconium pipe are connected by this joint component, the zirconium pipe is connected to the end of the zirconium part 11 and the stainless steel pipe is connected to the end of the stainless steel part 7 by a usual appropriate welding method. Weld it.

In this reference example, the stainless steel plate 7 is JIS G4304 SUS304L plate thickness 40 mm, the tantalum plate 9 is JIS H4701 TaP-0 equivalent material thickness 1 mm, and the zirconium plate 8 is ASTM B551 R60702 equivalent material thickness 10 mm. I was there. A blank 10 having an outer diameter of 36 mm and an inner diameter of 20 mm was cut out from the clad material obtained by explosively joining these materials as shown in FIG. The inner and outer diameters of the zirconium tube 11 were also set to be substantially the same as those of the raw tube 10. These were set as shown in FIG. 1 and the zirconium material 8 and the zirconium tube 11 were subjected to electron beam welding. The condition is acceleration voltage 150k
V, beam current 37 mA, welding speed 500 mm / min. At this time, the average width of the welded portion 13 is about 2.2 mm, which is about 1/5 to 1/4 the width of ordinary arc welding. As a result of conducting a tensile test on the joint part including the explosive joint portion and the electron beam welded portion manufactured in this way, the joint strength shows 38 kgf / mm ² which is equivalent to the strength of the zirconium material, and fractures at the zirconium material portion. . Also, in the corrosion test of immersion in a 14N boiling nitric acid solution containing 500 ppm of trivalent ruthenium ions for 48 hours, no local corrosion occurred in either the explosive joint or the electron beam weld.

In the above reference example, the intended purpose can be achieved as described above, but it cannot be said that the point of cooling the welded portion is sufficiently solved.

The present invention provides a better method for manufacturing a joint component by further advancing the above-mentioned reference example, and an example thereof will be described below.

[Example] FIG. 3 shows a first example of the present invention. In the present embodiment, a solid rod-shaped elemental joined body is cut out from the clad material shown in FIG. 2 instead of a tube shape, and only the portion to be electron beam welded is machined as shown in FIG. The joined body is butt-electron beam welded to the zirconium tube 11 while maintaining the substantially solid rod shape, and finally finished as shown by the broken line to obtain the shape shown in FIG. In this method, since the area of the joined body is large with respect to the amount of welding, the extent to which the temperature of the explosive joining boundary increases due to the electron beam welding is small, and the thermal effect on the explosive joining boundary is small.

FIG. 4 shows a second embodiment of the present invention. In this embodiment, a round bar-shaped element bonded body is cut out from the clad material shown in FIG. 2, and a zirconium round bar 11 'is electron beam welded to this. The electron beam welded portion 13 is slightly thicker than the pipe wall thickness shown by the broken line, but the entire cross section of the bar need not be welded. After the completion of this electron beam welding, the cross-sectional shape of the broken line is processed into the shape shown in FIG. In this method, the shape of the material to be welded is extremely larger than that of the welded portion, so that the thermal effect on the explosive joining boundary is substantially eliminated. In each of the above embodiments, the cooling jig shown in FIG. 1 is used if necessary.

In each of the above embodiments, the length of the zirconium tube 11 is such that the temperature of the explosive joint does not rise above about 500 ° C. due to the heat generated when the zirconium pipe is subsequently welded to the end thereof. . In addition, when the length of the stainless steel portion 7 is such a length that the heat at the time of welding the stainless steel pipe to the end surface thereof will adversely affect the explosive joint, that is, the base material of the clad material in FIG. In such a case, the stainless steel pipe is also electron beam welded to the stainless steel portion 7 in addition to the zirconium pipe 11 in each of the above embodiments. Can be a joint part.

Laser beam welding may be used instead of electron beam welding in the above description.

EFFECT OF THE INVENTION According to the method for manufacturing a joint component of the present invention, a solid rod-shaped elemental joined body made of different kinds of metal materials is prepared, and at least the axially thinner member of the elemental joined body is prepared. A tube or rod of the same quality as the part is welded to the end surface by electron beam or the like, and the whole is processed into a shape of a hollow tubular joint part having a predetermined length and inner and outer diameters. Temperature rise can be reduced, generation of undesired thermal stress at the joint boundary and generation of intermetallic compounds that cause embrittlement can be prevented, and joint strength,
A joint component for pipe connection made of a different metal material having high reliability without deterioration of corrosion resistance can be obtained.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a reference example according to the present invention,
The figure is a perspective view showing the cutting of a blank tube from the clad material,
FIG. 4 is a sectional view for explaining the first embodiment of the present invention, FIG. 4 is a sectional view for explaining the second embodiment of the present invention, and FIG. 5 is a joint part made according to each embodiment of the present invention. FIG. 7 ... Stainless steel, 8 ... Zirconium, 9 ... Tantalum, 10 ... Element pipe, 11 ... Zirconium pipe, 12 ... Groove, 13 ... Electron beam welded part, 14 ... Zirconium metal, 15, 15 ', 16, 16' … Copper cooling jig.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasukata Tamai 3-1-1, Saiwaicho, Hitachi City, Ibaraki Hitachi Ltd. Hitachi factory (56) References JP-A-60-115381 (JP, A) )

Claims (3)

[Claims] 1. A solid rod-shaped elemental joined body composed of members made of dissimilar metal materials joined to each other in the axial direction is prepared, and the end surface of the elemental joined body having at least the axially thin thickness. After the electron beam welding or laser beam welding of the pipe material of the same material as the member, the whole is processed into the shape of a hollow tubular joint part having a predetermined length and inner and outer diameters, which is difficult to weld. A method of manufacturing a fitting part for connecting a pipe made of a metal material. 2. A solid rod-shaped elemental joined body made of members made of dissimilar metal materials joined to each other in the axial direction is prepared, and an end face of the elemental joined body having at least the axially thin thickness. Dissimilar metal material that is difficult to weld, characterized in that, after electron beam welding or laser beam welding of a bar material of the same material as the member, the whole is processed into the shape of a joint part having a predetermined length and inner and outer diameters. Manufacturing method of joint parts for pipe connection. 3. The method for manufacturing a joint component according to claim 1, wherein a cooling jig for cooling the vicinity of the welded portion is used during the electron beam welding or the laser beam welding.