JP2012115884A - Method of joining metal structures - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of joining metal structures, by which an excellent friction-press joining can be performed for structures having large diameters.SOLUTION: The method of joining the metal structures includes: a step of holding turbine rotor structures 10 and 20 coaxially; a step of subjecting at least one of joint parts 11 and 21 of the turbine rotor structures 10 and 20 to non-contact heating; and a step of subjecting the turbine rotor structures 10 and 20 to friction bonding by rotating at least one of the turbine rotor structures 10 and 20 while joint end surfaces 13 and 23 of the joint parts 11 and 21 in the turbine rotor structures 10 and 20 are butted and axially pressed after the joint parts 11 and 21 thus heated reach a predetermined temperature.

Description

  Embodiments described herein relate generally to a method for joining metal structures.

  Conventionally, a turbine rotor structure, which is a large metal structure, is joined mainly by arc welding. In particular, in a structure that rotates at high speed in a high-temperature atmosphere such as a turbine rotor, attention must be paid to deformation, residual stress, welding defects, and the like.

  Further, a friction welding method is applied as a method of joining the rotating body structures. A rotating body structure to which this friction welding method is applied is a round bar or hollow bar having a relatively small diameter up to about 100 mm. In the friction welding, one structure is rotated, the other structure is fixed, the two structures are brought into contact with each other and rubbed together, and bonding is performed by the generated frictional heat. This joining method is also suitable for joining between structures made of different materials, and is characterized by small deformation and residual stress and few manufacturing defects.

JP 2003-53557 A

  In the friction welding described above, a considerable rotational torque is required for the joining device in order to generate frictional heat, and it is necessary to obtain the amount of heat necessary for joining by frictional heat. In addition, in the center portion and the outer diameter portion of the joining surface, and in the hollow member, the generation of frictional heat may be uneven due to the relative speed difference between the inner diameter portion and the outer diameter portion.

  For these reasons, friction welding is suitable for joining structures with a small diameter (up to about 100 mm in diameter), but for joining structures with a large diameter exceeding 100 mm, the device torque, It was difficult to apply friction welding from the viewpoint of the uniformity of the joint and the heat capacity. For example, when friction welding is applied to the joining of a turbine rotor structure, which is a large metal structure, the rotational torque required for the joining device increases, and sufficient frictional heat necessary for joining is obtained at the joint. Problems such as not occurring.

  The problem to be solved by the present invention is to provide a joining method between metal structures capable of performing good friction welding between large diameter structures.

  In the joining method between metal structures of the embodiment, the first structure and the second structure are joined by friction welding. In the joining method between the metal structures, the step of holding the first structure and the second structure on the same axis, and the joining portion of the first structure and the second structure And a step of heating at least one of the joints in a non-contact manner. Further, after the heated joint portion reaches a predetermined temperature, the joint end surfaces of the joint portions of the first structure and the second structure are brought into contact with each other, and the first end is pressed in the axial direction. The method includes a step of frictionally joining the first structure and the second structure by rotating either one of the structure and the second structure.

It is a figure for demonstrating the joining method between the metal structures of 1st Embodiment which concerns on this invention. It is the figure which showed the cross section containing the central axis of the structure joined by the joining method between the metal structures of 1st Embodiment which concerns on this invention. It is a flowchart for demonstrating the process of the joining method between the metal structures of 1st Embodiment which concerns on this invention. It is a figure for demonstrating the process of the joining method between the metal structures of 1st Embodiment which concerns on this invention, and is a side view of the state in which the turbine rotor structure was hold | maintained. It is the figure which showed the cross section containing the central axis of the structure for demonstrating the joining process of the joining method of the metal structure of 1st Embodiment which concerns on this invention. It is the figure which showed the cross section containing the central axis of the structure joined by the joining method between the metal structures of 2nd Embodiment which concerns on this invention. It is a perspective view of a structure for demonstrating the other structure of the heating means provided in the junction part of the structure joined by the joining method between the metal structures of 2nd Embodiment which concerns on this invention. It is the figure which showed the cross section containing the central axis of the structure joined by the joining method between the metal structures of 3rd Embodiment which concerns on this invention. It is the figure which showed the cross section containing the central axis of the structure joined by the joining method between the metal structures of 4th Embodiment which concerns on this invention. It is a figure for demonstrating the process of the joining method between the metal structures of 5th Embodiment which concerns on this invention, and is a side view of the state by which the turbine rotor structure was hold | maintained. It is the figure which showed the cross section containing the central axis of the structure joined by the joining method between the metal structures of 5th Embodiment concerning this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a view for explaining a joining method between metal structures according to the first embodiment of the present invention. FIG. 2 is a view showing a cross section including a central axis of a structure to be joined by the joining method between metal structures according to the first embodiment of the present invention. In the embodiments described below, the same components are denoted by the same reference numerals, and redundant descriptions are omitted or simplified.

  Here, the turbine rotor structures 10 and 20 will be described as examples of the structure. The turbine rotor structure 10 functions as a first structure, and the turbine rotor structure 20 functions as a second structure. A turbine rotor can be configured by joining the joint portion 11 of the turbine rotor structure 10 and the joint portion 21 of the turbine rotor structure 20 by the joining method between metal structures of the first embodiment. it can.

  The turbine rotor structures 10 and 20 are made of, for example, a cylindrical metal material having an outer diameter of 500 to 700 mm. As the metal material, for example, CrMoV steel, high Cr steel, Ni-base alloy and the like are used. Further, the turbine rotor structure 10 and the turbine rotor structure 20 may be made of the same material or different materials.

  As shown in FIG. 2, the joint portions 11 and 21 of the turbine rotor structures 10 and 20 form columnar groove portions 12 and 22 having an outer diameter of 200 to 400 mm, for example, at the center of the cylindrical metal material described above. It is composed by doing. The outer diameters of the turbine rotor structures 10 and 20 and the outer diameters of the groove portions 12 and 22 are not limited to the above ranges. The joining method between the metal structures of 1st Embodiment is suitable for joining between structures with a large diameter in which a diameter exceeds 100 mm, for example.

  The joint end faces 13 and 23 of the joint portions 11 and 21 of the turbine rotor structures 10 and 20 shown in FIG. 2 are configured by planes perpendicular to the turbine rotor axial direction. In other words, the angle formed by the joint end faces 13 and 23 of the joint portions 11 and 21 of the turbine rotor structures 10 and 20 and the free edges 14 and 24 of the turbine rotor structures 10 and 20 is formed at 90 degrees. .

  Around the joints 11 and 21 of the turbine rotor structures 10 and 20, heating means 15 and 25 for heating the joints 11 and 21 in a non-contact manner with a predetermined distance from the outer surface of the joints 11 and 21. Is provided. These heating means 15 and 25 are comprised by the coil for high frequency induction heating, etc., for example. By adjusting the high-frequency current flowing through the coil, the temperatures of the joints 11 and 21 can be adjusted. The heating means 15 and 25 may be provided so as to be movable along the outer surfaces of the joint portions 11 and 21 while maintaining a predetermined distance from the outer surfaces of the joint portions 11 and 21.

  In addition, the heating means 15 and 25 are not restricted to high frequency induction heating, What is necessary is just the method of heating the junction parts 11 and 21 non-contactingly. For example, the heating means 15 and 25 may be configured to irradiate the joints 11 and 21 with laser light.

  Here, an example in which the heating means 15 and 25 are provided around both the joint portions 11 and 21 of the turbine rotor structures 10 and 20 is shown. However, the heating means 15 and 25 are connected to the turbine rotor structure 10. It is only necessary to be provided around at least one of the portion 11 and the joint portion 21 of the turbine rotor structure 20. For example, when the turbine rotor structure 10 is made of a material having a higher melting point than the turbine rotor structure 20, the joint end surface 13 of the joint 11 of the turbine rotor structure 10 is softened by frictional heat during friction welding. Requires more heat than the turbine rotor structure 20. Therefore, it is preferable to provide a heating means at least around the joint 11 of the turbine rotor structure 10.

  Next, the joining process between metal structures will be described.

  FIG. 3 is a flowchart for explaining the steps of the joining method between metal structures according to the first embodiment of the present invention. FIG. 4 is a view for explaining the steps of the joining method between metal structures according to the first embodiment of the present invention, and is a side view showing a state in which the turbine rotor structures 10 and 20 are held. . FIG. 5 is a view showing a cross section including the central axis of the structure for explaining the joining step of the joining method between the metal structures of the first embodiment according to the present invention.

  First, the turbine rotor structure 10 and the turbine rotor structure 20 are held coaxially (structure holding process (step S30)). The other end of the turbine rotor structure 10 on the side different from the joint portion 11 is chucked by a fixing member (not shown), and the turbine rotor structure 10 is fixed so as not to rotate. On the other hand, the other end of the turbine rotor structure 20 on the side different from the joint portion 21 is chucked by a rotatable fixing member (not shown), and the turbine rotor structure 20 is rotatably fixed. .

  Here, as shown in FIG. 4, a bearing 40 is preferably provided between the joint 11 and the other end of the turbine rotor structure 10. In addition, a bearing 41 is preferably provided between the joint 21 and the other end of the turbine rotor structure 20. The bearings 40 and 41 are configured by, for example, a rolling bearing or a sliding bearing. Thus, by providing the rotating turbine rotor structure 20 with the bearing 41, it is possible to suppress bending due to its own weight and rotational vibration during rotation. On the other hand, in the turbine rotor structure 10 on the stationary side, by providing the bearing 40, bending due to its own weight can be suppressed. By these, the turbine rotor structure 10 and the turbine rotor structure 20 can be joined in a state of being held coaxially.

  Subsequently, the joint portions 11 and 21 of the turbine rotor structures 10 and 20 are heated in a non-contact manner (heating step (step S31)). Here, when the turbine rotor structure 10 and the turbine rotor structure 20 are made of the same material, they are heated by the heating means 15 and 25 under the same conditions. The turbine rotor structure 10 and the turbine rotor structure 20 are made of different materials. For example, when the material constituting the turbine rotor structure 10 has a higher melting point, the heating means 15 and the heating means 25 are different from each other. Acting at conditions, the turbine rotor structure 10 is adjusted to actively heat. In this case, the heating means 25 may not be provided around the joint 21 of the turbine rotor structure 20.

  Further, the material of the turbine rotor structure 10, 20, the shape of the turbine rotor structure 10, 20 (area of the joining end faces 13, 23, dimensions of the turbine rotor structure 10, 20, etc.), the turbine rotor structure 20 is rotated. Based on the speed, the pressing pressure between the turbine rotor structure 10 and the turbine rotor structure 20 at the time of joining, and the like by numerical calculation in advance, for example, input to the heating means 15 and 25 (the heating means 15 and 25 are In the case of a high-frequency induction heating coil, the relationship between the high-frequency current flowing through the coil) and the temperature of the joints 11 and 21 is calculated. And based on the calculated database, the input to the heating means 15 and 25, a heating time, etc. are set, and the junction parts 11 and 21 are heated to predetermined temperature. Here, the predetermined temperature is a temperature at which a sufficient amount of heat can be supplied only by frictional heat in order to perform appropriate friction welding.

  The heating means 15 and 25 are provided with a control unit and a storage unit for storing the database. The control unit is configured to input the heating means 15 and 25, the heating time, and the like based on the database stored in the storage unit. You may comprise so that it may set and control.

  Subsequently, after the heated joints 11 and 21 reach the above-described predetermined temperature, the joint end face 13 of the joint 11 of the turbine rotor structure 10 and the joint end face of the joint 21 of the turbine rotor structure 20 are detected. Match 23. Then, as shown in FIG. 5, while applying axial pressure, the turbine rotor structure 20 is rotated to join the turbine rotor structure 10 and the turbine rotor structure 20 by friction welding (joining process ( Step S32)).

  Here, in the joining step, the joining of the joint 11 of the turbine rotor structure 10 and the joint 21 of the turbine rotor structure 20 is preferably performed in an inert gas atmosphere. Therefore, an inert gas tank 50 filled with an inert gas is provided, and in the joining step, as shown in FIG. 1, at least both joints 11 and 21 are positioned in the inert gas tank 50. It is preferable to configure. In the structure holding step (step S30) or the heating step (step S31), both the joints 11 and 21 may be positioned in the inert gas tank 50. For example, argon (Ar) or the like can be used as the inert gas. Thus, by joining in an inert gas atmosphere, oxidation of the joints 11 and 21 during joining can be prevented.

  Here, although an example in which the turbine rotor structure 20 is rotated and the friction welding is performed is shown, the turbine rotor structure 10 may be rotated and the friction welding may be performed.

  According to the joining method between the metal structures of the first embodiment, the heating means 15 and 25 are provided, and the joints 11 and 21 of the turbine rotor structures 10 and 20 are heated in a non-contact manner, thereby causing friction. When joining by pressure welding, even in a large structure, the temperature of the joining end face can be easily raised to near the melting point. As a result, the amount of heat necessary for joining can be obtained, good friction welding can be performed, and the rotational torque of the rotating device that rotates the turbine rotor structure 20 can be reduced. In addition, by adjusting the temperatures of the joint portions 11 and 21 of the turbine rotor structures 10 and 20, even if different materials having different melting points are used, good friction welding can be performed.

(Second Embodiment)
In the joining method between metal structures according to the second embodiment of the present invention, the turbine rotor structure 10 and the turbine rotor structure 20 are made of different materials, and the material constituting the turbine rotor structure 10 is made of. A case where the melting point is higher than the melting point of the material constituting the turbine rotor structure 20 will be described.

  Moreover, in the joining method between the metal structures of 2nd Embodiment, except the shape of the junction part 11 of the turbine rotor structure 10 differs fundamentally, between the metal structures of 1st Embodiment. It is the same as the structure in the joining method.

  FIG. 6 is a view showing a cross section including a central axis of a structure to be joined by the joining method between metal structures according to the second embodiment of the present invention. FIG. 7 is a perspective view of the structure for explaining another configuration of the heating means provided at the joint portion of the structure to be joined by the joining method between the metal structures according to the second embodiment of the present invention. FIG.

  As shown in FIG. 6, the outer surface 13a of the joint 11 of the turbine rotor structure 10 made of a material having a melting point higher than the melting point of the material constituting the turbine rotor structure 20 becomes closer to the tip. The inclined surface is gradually inclined from the free edge 14 side toward the center side.

  A heating means 15 is provided around the joint 11 of the turbine rotor structure 10 along the outer surface 13a of the joint 11 with a predetermined distance from the outer surface 13a of the joints 11 and 21. ing. Note that a heating means 25 is provided around the joint 21 of the turbine rotor structure 20 as in the first embodiment.

  Further, when the heating means 15 is constituted by, for example, a coil for high-frequency induction heating, the heating means 15 is arranged in the circumferential direction of the joint portion 11 of the turbine rotor structure 10 as shown in FIG. A plurality of the outer surfaces 13a may be arranged at a predetermined interval. Further, the coil may be provided so as to be movable along the outer surface 13a of the joint portion 11 while maintaining a predetermined distance from the outer surface 13a of the joint portion 11. By configuring the heating means 15 as described above, even when the joint portion 11 is deformed by friction welding and the length of the outer surface 13a becomes shorter, the heating means follows the change in the length of the outer surface 13a. 15 can be moved. Therefore, the joining portion 21 can be heated by the heating means 15 during the joining process by friction welding. The material constituting the turbine rotor structure 20 has a lower melting point than the material constituting the turbine rotor structure 10, and thus the heating means 25 can be omitted.

  In addition, about the joining process between metal structures, it is the same as the joining method between the metal structures of 1st Embodiment. Further, here, an example in which the turbine rotor structure 20 is rotated and the friction welding is performed is shown, but the turbine rotor structure 10 may be rotated and the friction welding may be performed.

  According to the joining method between metal structures of the second embodiment, when the turbine rotor structure 10 and the turbine rotor structure 20 are made of different materials, the turbine rotor structure having a high melting point of the material. By configuring the outer surface 13a of the ten joint portions 11 with an inclined surface, the heat capacity of the joint portion 11 can be reduced. Therefore, the temperature of the joining end surface 13 of the joining part 11 can be easily raised to near the melting point even in a large structure by the heating means 15 when joining by friction welding. As a result, the amount of heat necessary for joining can be obtained, good friction welding can be performed, and the rotational torque of the rotating device that rotates the turbine rotor structure 20 can be reduced. In addition, by adjusting the temperatures of the joint portions 11 and 21 of the turbine rotor structures 10 and 20, even if different materials having different melting points are used, good friction welding can be performed.

(Third embodiment)
Generally, in friction welding, when the joint end faces of a structure come into contact with each other, the speed of the joint end face is different between the inner diameter side of the joint end face and the outer diameter side of the joint end face, and the outer diameter side of the joint end face is more The speed is greater than the inner diameter side of the joining end face. For this reason, the outer diameter side of the joining end surface is at a higher temperature than the inner diameter side of the joining end surface. Further, due to the difference in linear expansion caused by the temperature difference between the outer diameter side and the inner diameter side of the joining end face, the pressing pressure on the outer diameter side may increase in the initial stage of joining, and the pressing pressure on the inner diameter side may become uneven. The difference in speed between the outer diameter side and the inner diameter side of the joining end surface becomes more significant as the structure becomes larger. Therefore, the larger the structure, the more uneven the pressing pressure of the joining end face, and the joining heterogeneity between the outer diameter side and the inner diameter side of the joining end face occurs.

  Then, in the joining method between the metal structures of the 3rd Embodiment concerning this invention, the joining method which suppresses that the pressing pressure of a joining end surface becomes uneven in the case of friction welding is shown.

  FIG. 8 is a view showing a cross section including the central axis of the structure to be joined by the joining method between metal structures of the third embodiment according to the present invention.

  As shown in FIG. 8, the angle α formed between the joint end surface 13 of the joint 11 of the turbine rotor structure 10 and the free edge 14 is the joint end surface 23 of the joint 21 of the turbine rotor structure 20 and the free edge 24. The angle β is larger than the angle β. Further, the angle α and the angle β are set to 90 degrees or more, and here, the angle β is set to 90 degrees.

  Further, in the initial joining process, in order to reduce the difference in surface pressure distribution on the contact surface until the inner diameter side comes into contact, the contact portion gradually increases toward the outer diameter side, and the entire surface comes into contact, the angle α and It is preferable to set the angle β in the range of about 90 to 95 degrees. These angles α and β are appropriately set within this range in accordance with the thickness in the radial direction of the joining end faces 13 and 23 and the temperature condition.

  By configuring the joint end surfaces 13 and 23 in this way, when the joint end surface 13 of the turbine rotor structure 10 and the joint end surface 23 of the turbine rotor structure 20 are abutted, the space between the joint end surface 13 and the joint end surface 23 is obtained. In addition, a gap in which the width in the axial direction increases toward the outer diameter side is formed in the circumferential direction.

  FIG. 8 shows a configuration in which the angle α is larger than the angle β, but the angle β may be larger than the angle α. In this case, the angle β is set in the range of the angle α described above, and the angle α is set in the range of the angle β described above.

  That is, each joint end surface 13 and 23 is formed between the joint end surface 13 and the joint end surface 23 as described above so that a gap in which the axial width increases toward the outer diameter side is formed in the circumferential direction. It only has to be. Therefore, the angle formed by the joint end surface of one of the joint end surfaces 13 and 23 of the joint portions 11 and 21 of the turbine rotor structure 10 and the turbine rotor structure 20 and the free edge is the other joint. What is necessary is just to be larger than the angle which the joining end surface of a part and a free edge make, and each angle should be comprised 90 degrees or more.

  The above-described configuration can be applied regardless of whether the material constituting the turbine rotor structure 10 and the material constituting the turbine rotor structure 20 are the same or different.

  In addition, about the joining process between metal structures, it is the same as the joining method between the metal structures of 1st Embodiment.

  According to the joining method between metal structures of the third embodiment, a gap is formed in the circumferential direction between the joining end face 13 and the joining end face 23 so that the axial width increases toward the outer diameter side. Thus, the difference in linear expansion caused by the temperature difference between the outer diameter side and the inner diameter side of the joining end faces 13 and 23 can be absorbed. Thereby, the pressing pressure of the joining end faces 13 and 23 can be made uniform in the initial joining process. Furthermore, by adjusting the heating means 15 and 25, the linear expansion on the outer diameter side of the joining end faces 13 and 23 can be controlled.

(Fourth embodiment)
The joining method between the metal structures of the fourth embodiment according to the present invention is the same as the joining method between the metal structures of the first embodiment described above. A mechanism for adjusting the temperature of 21 is provided. Here, this different configuration will be mainly described.

  FIG. 9 is a view showing a cross section including a central axis of a structure to be joined by the joining method between metal structures according to the fourth embodiment of the present invention.

  As shown in FIG. 9, cooling gas jetting means 60 for jetting cooling gas is provided at the joints 11 and 21 of the turbine rotor structures 10 and 20. As described above, since the friction welding is performed in the inert gas tank 50 filled with the inert gas, the cooling gas ejected from the cooling gas ejection means 60 is an inert gas such as Ar. Is preferred.

  Further, the material of the turbine rotor structure 10, 20, the shape of the turbine rotor structure 10, 20 (area of the joining end faces 13, 23, dimensions of the turbine rotor structure 10, 20, etc.), the turbine rotor structure 20 is rotated. Based on the speed, the pressing pressure between the turbine rotor structure 10 and the turbine rotor structure 20 at the time of joining, the temperature heated by the heating means 15, 25, the joining process elapsed time, the temperature of the cooling gas, etc. The timing of jetting the cooling gas, the jetting time, the jetting flow rate, etc. are calculated by calculation. And based on the calculated database, the timing of jetting the cooling gas, the jetting time, the jetting flow rate, etc. are set to adjust the temperature of the joints 11 and 21. The cooling gas jetting means 60 provided on the joint 11 side of the turbine rotor structure 10 and the cooling gas jetting means 60 provided on the joint 21 side of the turbine rotor structure 20 operate under different conditions. Can be made.

  The cooling gas ejection means 60 includes a control unit and a storage unit that stores the database, and the control unit ejects cooling gas based on the database stored in the storage unit, the ejection time, the ejection flow rate, and the like. You may comprise so that setting and control may be performed.

  In addition, about the joining process between metal structures, it is the same as the joining method between the metal structures of 1st Embodiment, and the cooling gas ejection means 60 is operated in the joining process. By cooling gas jetting to the outer peripheral surfaces of the joints 11 and 21 of the turbine rotor structures 10 and 20 by the cooling gas jetting means 60, the outer diameter side of the joint end surface that becomes high temperature is mainly cooled at the time of friction welding. Is done.

  According to the joining method between the metal structures of the fourth embodiment, by providing the cooling gas jetting means 60, it is possible to mainly cool the outer diameter side of the joining end face that becomes a high temperature during the friction welding. In addition, the temperature difference between the outer diameter side and the inner diameter side of the joining end faces 13 and 23 of the turbine rotor structures 10 and 20 can be reduced. Thereby, the pressing pressure of the joining end faces 13 and 23 can be made uniform in the initial joining process. Furthermore, by adjusting the heating means 15 and 25, the linear expansion on the outer diameter side of the joining end faces 13 and 23 can be controlled.

  It should be noted that not only the method for joining metal structures of the fourth embodiment, but also the method for joining metal structures of the second embodiment or the third embodiment, the cooling gas ejection means 60 is used. Temperature adjustment can be performed.

(Fifth embodiment)
FIG. 10 is a view for explaining the steps of the method for joining metal structures according to the fifth embodiment of the present invention, and is a side view showing a state in which the turbine rotor structures 10 and 20 are held. . FIG. 11: is the figure which showed the cross section containing the central axis of the structure joined by the joining method between the metal structures of 5th Embodiment concerning this invention.

  As shown in FIG. 10, an intermediate structure 70 is provided between the turbine rotor structure 10 and the turbine rotor structure 20, and the turbine rotor structure 10, the turbine rotor structure 20, and the intermediate structure 70 are It is held on the same axis. Moreover, in order to suppress the bending by the dead weight of the turbine rotor structures 10 and 20, as shown in FIG. 10, the bearing 40 is provided between the junction part 11 and the other end part of the turbine rotor structure 10, and a turbine is provided. A bearing 41 is preferably provided between the joint 21 and the other end of the rotor structure 20.

  The intermediate structure 70 is held by a clamp jig 80 that is a fastener. The clamp jig 80 is rotatably provided by power from the power source 81. That is, by driving the power source 81, the intermediate structure 70 held by the clamp jig 80 rotates.

  As shown in FIG. 11, the intermediate structure 70 is made of a cylindrical metal material having the same outer diameter as that of the turbine rotor structures 10 and 20. In addition, joint portions 71 and 72 that are joined to the joint portion 11 of the turbine rotor structure 10 and the joint portion 21 of the turbine rotor structure 20 are provided. The joint portions 71 and 72 of the intermediate structure 70 are configured by forming columnar groove portions 73 and 74 in the center of the cylindrical metal material described above. Further, the outer diameters of the groove portions 73 and 74 are the same as the outer diameters of the groove portions 12 and 22 of the turbine rotor structures 10 and 20.

  The joint end faces 13 and 23 of the joint portions 11 and 21 of the turbine rotor structures 10 and 20 shown in FIG. 11 are configured by planes perpendicular to the turbine rotor axial direction. In other words, the angle formed by the joint end faces 13 and 23 of the joint portions 11 and 21 of the turbine rotor structures 10 and 20 and the free edges 14 and 24 of the turbine rotor structures 10 and 20 is formed at 90 degrees. . Moreover, the joining end surfaces 74 and 75 of the joining parts 71 and 72 of the intermediate structure 70 are configured by planes perpendicular to the turbine rotor axial direction. In other words, the angle formed by the joining end faces 74 and 75 of the joining portions 71 and 72 of the intermediate structure 70 and the free edge 76 of the intermediate structure 70 is formed at 90 degrees.

  As a metal material constituting the intermediate structure 70, for example, CrMoV steel, high Cr steel, Ni-based alloy, or the like is used. Here, when the turbine rotor structure 10 and the turbine rotor structure 20 are made of the same material, the intermediate structure 70 is also made of the same metal material as the metal material constituting the turbine rotor structures 10 and 20. Consists of.

  Further, when the turbine rotor structure 10 and the turbine rotor structure 20 are made of different materials, the intermediate structure 70 has a melting point out of the metal materials constituting the turbine rotor structures 10 and 20. It is made of a metal material having the same melting point, heat resistance, mechanical strength, linear expansion coefficient, and thermal conductivity as the higher metal material.

  In this case, the intermediate structure 70 is made of a metal material that is the same as or equivalent to the metal material having a higher melting point, so that the joint 71 of the intermediate structure 70 and the joint 11 of the turbine rotor structure 10 The strength at the bonding interface can be maintained at a high level. In other words, it is possible to reduce a portion where the strength is low, such as a joint interface between the joint portion 72 of the intermediate structure 70 and the joint portion 21 of the turbine rotor structure 20 to one place.

  The joint part 11 of the turbine rotor structure 10 and the joint part 71 of the intermediate structure 70 and the joint part 21 of the turbine rotor structure 20 and the joint part 72 of the intermediate structure 70 are used as the metal structure of the fifth embodiment. A turbine rotor can be comprised by joining by the joining method between.

  Next, the joining process between metal structures will be described.

  Since the process of the joining method between metal structures is the same as the process shown by FIG. 3, the joining process between metal structures is demonstrated with reference to FIG.

  First, the intermediate structure 70 is installed between the turbine rotor structure 10 and the turbine rotor structure 20, and the intermediate structure 70, the turbine rotor structure 10, and the turbine rotor structure 20 are held coaxially (structure). Object holding step (step S30)).

  The other end of the turbine rotor structure 10 on the side different from the joint portion 11 is chucked by a fixing member (not shown), and the turbine rotor structure 10 is fixed so as not to rotate. The other end of the turbine rotor structure 20 on the side different from the joint 21 is chucked by a fixing member (not shown), and the turbine rotor structure 20 is fixed so as not to rotate. Further, as described above, the intermediate structure 70 is held by the rotatable clamp jig 80.

  Subsequently, the joint portions 11 and 21 of the turbine rotor structures 10 and 20 are heated in a non-contact manner (heating step (step S31)).

  Here, when the turbine rotor structure 10 and the turbine rotor structure 20 are made of the same material, they are heated by the heating means 15 and 25 under the same conditions. In this case, the intermediate structure 70 is also made of the same material as the turbine rotor structures 10 and 20. Therefore, instead of providing the heating means 15 and 25 around the joints 11 and 21 of the turbine rotor structures 10 and 20, the heating means 15 and 25 may be provided around the joints 71 and 72 of the intermediate structure 70.

  On the other hand, when the turbine rotor structure 10 and the turbine rotor structure 20 are made of different materials, for example, when the material constituting the turbine rotor structure 10 has a higher melting point, the intermediate structure 70 has the turbine rotor structure. The metal material is the same as or equivalent to the object 10. Therefore, the heating unit 25 is preferably provided around the joint portion 72 of the intermediate structure 70. In addition, in FIG. 11, the arrangement | positioning position of the heating means 15 and 25 in case the turbine rotor structure 10 and the turbine rotor structure 20 are comprised with the same material is shown.

  Further, the material of the turbine rotor structures 10 and 20 and the intermediate structure 70, the shape of the turbine rotor structures 10 and 20 and the intermediate structure 70 (the area of the joining end faces 13, 23, 74, and 75, the turbine rotor structure 10, 20 and the dimensions of the intermediate structure 70), the rotation speed of the intermediate structure 70, the pressing pressure of the turbine rotor structure 10 and the intermediate structure 70, and the turbine rotor structure 20 and the intermediate structure 70 at the time of joining, etc. Based on the above, by numerical calculation in advance, for example, the input to the heating means 15 and 25 (if the heating means 15 and 25 are coils for high frequency induction heating) and the joint 11 , 21, 71, 72 and the relationship with the temperature. Then, based on the calculated database, the input to the heating means 15 and 25, the heating time, and the like are set, and the heating means 15 and 25 heat the joint provided around to a predetermined temperature. Here, the predetermined temperature is a temperature at which a sufficient amount of heat can be supplied only by frictional heat in order to perform appropriate friction welding.

  The heating means 15 and 25 are provided with a control unit and a storage unit for storing the database. The control unit is configured to input the heating means 15 and 25, the heating time, and the like based on the database stored in the storage unit. You may comprise so that it may set and control.

  Subsequently, after the heated joints 11 and 21 reach the above-described predetermined temperature, the joint end surface 13 of the joint 11 of the turbine rotor structure 10 and the joint end surface 74 of the joint 71 of the intermediate structure 70, The joint end surface 23 of the joint 21 of the turbine rotor structure 20 and the joint end surface 75 of the joint 72 of the intermediate structure 70 are abutted. Then, while applying axial pressure, the power source 81 is driven to rotate the intermediate structure 70, and the turbine rotor structure 10 and the intermediate structure 70, and the turbine rotor structure 20 and the intermediate structure 70 are rotated. Joining by friction welding (joining process (step S32)).

  Here, similarly to the above-described embodiment, it is preferable to provide the inert gas tank 50 and perform friction welding in an inert gas atmosphere. Thus, by joining in an inert gas atmosphere, oxidation of the joints 11, 21, 71, 72 during joining can be prevented.

  According to the joining method between the metal structures of the fifth embodiment, the intermediate structure 70 which is a small structure is rotated without rotating the turbine rotor structures 10 and 20 which are large structures. By performing the friction welding, the stability in construction can be improved and the rotational torque of the power source 81 can be kept small. In addition, even when the turbine rotor structures 10 and 20 are long, good friction welding can be performed.

  The configurations of the joint end surfaces 13 and 23 of the joint portions 11 and 21 of the turbine rotor structures 10 and 20 and the joint end surfaces 74 and 75 of the joint portions 71 and 72 of the intermediate structure 70 are not limited to the above-described configurations. Absent. For example, when the turbine rotor structure 10 and the turbine rotor structure 20 are made of different materials, and the intermediate structure 70 is made of the same or equivalent metal material as the turbine rotor structure 10 having a high melting point. In addition, as shown in the second embodiment, the outer surface of the joint portion 72 of the intermediate structure 70 may be an inclined surface.

  Further, the joining end faces 13 and 23 of the joining parts 11 and 21 of the turbine rotor structures 10 and 20 and the joining end faces 74 and 75 of the joining parts 71 and 72 of the intermediate structure 70 are shown in the third embodiment. You may make it the shape of an end surface. In this case, of the joint end surfaces 13 and 74 of the joint portions 11 and 71 of the turbine rotor structure 10 and the intermediate structure 70, for example, the joint end surface 13 of the joint portion 11 of the turbine rotor structure 10 and the free edge 14 An angle γ formed is configured to be larger than an angle δ formed between the joint end surface 74 of the joint portion 71 of the intermediate structure 70 and the free edge 76. Further, of the joint end surfaces 23 and 75 of the joint portions 21 and 72 of the turbine rotor structure 20 and the intermediate structure 70, for example, the joint end surface 23 of the joint portion 21 of the turbine rotor structure 20 and the free edge 24 are formed. The angle ε is configured to be larger than the angle ζ formed by the joint end surface 75 of the joint portion 72 of the intermediate structure 70 and the free edge 76. The angles γ, δ, ε, and ζ are 90 degrees or more. Note that the angle δ may be configured to be larger than the angle γ. Further, the angle ζ may be configured to be larger than the angle ε.

  By configuring the joint end face in this manner, the joint end face 13 of the turbine rotor structure 10 and the joint end face 74 of the intermediate structure 70 and the joint end face 23 of the turbine rotor structure 20 and the intermediate structure 70 are joined. A gap can be formed between the end surface 75 and the end surface 75 in the circumferential direction in which the axial width increases toward the outer diameter side. Thereby, the linear expansion difference resulting from the temperature difference between the outer diameter side and the inner diameter side of the joining end faces 13, 23, 74, 75 can be absorbed, and the joining end faces 13, 23, 74, 75 are pressed in the initial joining process. The pressure can be made uniform.

  Furthermore, the cooling gas injection means 60 of 4th Embodiment is provided, and a cooling gas is injected to the outer peripheral surface of the junction parts 11 and 21 of the turbine rotor structures 10 and 20, and the junction parts 71 and 72 of the intermediate structure 70. Thus, the temperature of the joints 11 and 21 of the turbine rotor structures 10 and 20 and the joints 71 and 72 of the intermediate structure 70 may be adjusted.

  In the said embodiment, although the turbine rotor structure was illustrated and the joining method between the metal structures of embodiment which concerns on this invention was demonstrated, the joining method between the metal structures of embodiment which concerns on this invention is For example, the present invention can be applied to a large-diameter high-temperature high-pressure pipe. And the same effect as mentioned above can be obtained.

  According to the embodiment described above, it is possible to perform good friction welding between large-diameter structures by adjusting the temperature of the joint portion of the structures.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention.

  DESCRIPTION OF SYMBOLS 10,20 ... Turbine rotor structure 11, 21, 71, 72 ... Joining part, 12, 22, 73, 74 ... Groove part, 13, 23, 74, 75 ... Joining end surface, 13a ... Outer side surface, 14, 24, 76: Free edge, 15, 25 ... Heating means, 40, 41 ... Bearing, 50 ... Inert gas tank, 60 ... Cooling gas ejection means, 70 ... Intermediate structure, 80 ... Clamp jig, 81 ... Power source.

Claims (13)

In the joining method between metal structures for joining the first structure and the second structure by friction welding,
Holding the first structure and the second structure coaxially;
Non-contact heating of at least one of the first structure and the joint of the second structure; and
After the heated joint has reached a predetermined temperature, the first structure and the second structure are joined to each other at the joint end surfaces of the joint and the first structure is pressed while being pressed in the axial direction. And a step of frictionally joining the first structure and the second structure by rotating any one of the object and the second structure between the metal structures Joining method.   The joint is heated by high-frequency induction heating, and a coil for performing the high-frequency induction heating is disposed around the joint to be heated with a predetermined interval from the outer surface of the joint. The method for joining metal structures according to claim 1, wherein:   A plurality of the coils are arranged in the circumferential direction of the joint to be heated, and are provided so as to be movable along the outer surface of the joint while maintaining a predetermined distance from the outer surface of the joint. The method for joining metal structures according to claim 2, wherein the metal structures are joined together.   4. When performing the friction welding, the joint portion of the first structure and the joint portion of the second structure are joined in an inert gas atmosphere. The joining method between the metal structures of description.   Of the joint end surfaces of the joint portions of the first structure and the second structure, an angle α formed by the joint end surface of one of the joint portions and the free edge is the joint end surface of the other joint portion. 5. The method for joining metal structures according to claim 1, wherein the angle α is larger than an angle β formed with a free edge, and the angles α and β are 90 degrees or more.   When the first structure and the second structure are made of different materials, the structure made of a material having a high melting point out of the first structure and the second structure. 5. The metal according to claim 1, wherein the outer surface of the joint portion is formed of an inclined surface that gradually inclines from the free edge side toward the center side as it goes to the tip. Bonding method between structures.   In the joining step, a cooling gas is jetted onto the outer peripheral surfaces of the first structure and the second structure to adjust the temperature of the joint portion between the first structure and the second structure. The method for joining metal structures according to any one of claims 1 to 5, characterized in that: An intermediate structure configured to be rotatable is installed between the first structure and the second structure, and the intermediate structure, the first structure, and the second structure are coaxially arranged. A step of holding
Non-contact heating of at least any one of the intermediate structure, the first structure, and the second structure joint; and
After the heated joint portion reaches a predetermined temperature, the joint end surface of the joint portion of the first structure is pivoted from one side in the axial direction to the joint end surface of the second structure. From the other side of the direction, the intermediate structure is abutted against the joint end surface of the intermediate structure, and the intermediate structure is rotated while being pressed in the axial direction, so that the first structure and the second structure are respectively in the middle And a method of joining metal structures, characterized by comprising the step of friction joining to structures.   The joint is heated by high-frequency induction heating, and a coil for performing the high-frequency induction heating is disposed around the joint to be heated with a predetermined interval from the outer surface of the joint. The method for joining metal structures according to claim 8, wherein:   A plurality of the coils are arranged in the circumferential direction of the joint to be heated, and are provided so as to be movable along the outer surface of the joint while maintaining a predetermined distance from the outer surface of the joint. The joining method between the metal structures of Claim 9 characterized by the above-mentioned.   When performing the friction welding, the joint portion of the first structure and the joint portion of the intermediate structure, and the joint portion of the second structure and the joint portion of the intermediate structure are in an inert gas atmosphere. The method for joining metal structures according to any one of claims 8 to 10, wherein joining is performed.   The angle γ formed by the joint end surface of one of the joint portions and the free edge of the joint end surfaces of the joint portion of the first structure and the intermediate structure is free from the joint end surface of the other joint portion. An angle ε formed by a free edge and an angle δ formed by an edge and larger than an angle δ formed by the edge and formed by a joint end surface of any one of the joint ends of the second structure and the intermediate structure. The angle γ formed by the joint end surface of the other joint and the free edge is larger, and the angles γ, δ, ε, and ζ are 90 degrees or more. A method for joining metal structures according to claim 1.   In the joining step, a cooling gas is jetted to the outer peripheral surfaces of the first structure, the second structure, and the intermediate structure, and the first structure, the second structure, and the intermediate The method for joining metal structures according to any one of claims 8 to 12, wherein the temperature of the joint portion of the structure is adjusted.

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