JP2013198919A - Build-up welding method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a build-up welding method and a device capable of forming a base material in an excellent shape by build-up welding with a filling welding material.SOLUTION: A filling welding material 300 is build-up welded at a surface welded position 211 of a phase transformation base material 200, and a build-up welded part of the phase transformation base material 200 with a filling welding material 300 is heated from a base material rear face 220 up to a phase transformation temperature. Even when welding deformation such as vertical shrinkage or vertical bending deformation, shrinkage strain or the like generates in the surface welded position 211 build-up welded with the filling welding material 300 or the build-up welded phase transformation base material 200, the welding deformation, the shrinkage strain or the like is canceled and relaxed due to expansion strain caused by phase transformation of the base material rear face side 220 of the phase transformation base material 200 by heating the part of the phase transformation base material 200 build-up welded with the filling welding material 300 up to the phase transformation temperature.

Description

  The present invention relates to an overlay welding method and apparatus for overlay welding a filling overlay material to a base material.

  At present, erosion is a problem in turbine blades of steam turbines. Therefore, as a countermeasure against such erosion, a metal having high wear resistance is attached to the front edge portion of the turbine blade.

  In such a turbine blade, a wear-resistant metal plate is brazed with a gas burner at the front edge thereof. However, when such welding is performed, welding deformation such as so-called longitudinal shrinkage and longitudinal bending deformation, shrinkage distortion, and the like occur.

  Therefore, various proposals have been made to alleviate such welding deformation and shrinkage distortion. For example, there has been proposed a technique for reducing welding deformation and shrinkage distortion by reducing the total heat input of the base material by laser welding instead of brazing by the gas burner as described above (see, for example, Patent Document 1). ).

In addition, a technique has been proposed in which a welded steel plate is laser-heated while being pressed in a direction opposite to the generated welding deformation, and the welding deformation and shrinkage distortion are alleviated (for example, see Patent Document 2). further,
Although this technique is not a technique for alleviating welding deformation and shrinkage distortion, there is also a technique for accurately measuring welding deformation and shrinkage distortion by scanning the surface of a steel sheet with a laser beam from a single laser light source (see, for example, Patent Document 3).

JP 2008-055952 A Japanese Patent Laid-Open No. 06-063644 JP 2010-156622 A

  However, the invention described in Patent Document 1 only reduces welding deformation and shrinkage distortion by reducing the total heat input of the base material by laser welding, and cannot sufficiently reduce welding deformation and shrinkage distortion. .

  The invention described in Patent Document 2 is heated while being mechanically pressed in order to alleviate the welding deformation generated in the steel plate by welding. For this reason, for example, when a build-up material is welded to the base material, there is a concern that breakage may occur if the base material or the build-up material has high hardness.

  The invention described in Patent Document 3 only measures welding deformation and shrinkage distortion accurately, and cannot reduce welding deformation and shrinkage distortion as it is.

  The present invention has been made in view of the problems as described above, and provides a build-up welding method and apparatus capable of forming a phase transformation base material on which a build-up build-up material is build-up welded into a good shape. To do.

  In order to solve the above-described problems, the overlay welding method of the present invention fills at least a part of the surface of the base material of the phase transformation base material formed in a shape having a base material surface and a base material back surface. A build-up welding method for overlay welding a build-up material, wherein the build-up build-up material is build-up welded to the surface build-up position of the phase-transform base material, and the fill-up build-up material of the phase change base material is The welded portion is heated from the back surface of the base metal to a temperature not lower than the phase transformation temperature and not higher than the melting temperature of the filling cladding.

  Therefore, in the overlay welding method of the present invention, welding deformation such as longitudinal shrinkage and longitudinal bending deformation, shrinkage distortion, etc. are generated in the surface overlay position of the filling overlay material and the phase transformation base material subjected to overlay welding. However, the back surface of the base material of the phase transformation base material is heated by heating the portion where the overlaying material of the phase change base material is overlay welded to a temperature not lower than the phase transformation temperature and not higher than the melting temperature of the above material. Due to the expansion strain due to the phase transformation on the side, welding deformation, shrinkage strain, etc. are offset and alleviated. In addition, since the heating with the phase transformation base material as the phase transformation temperature is performed on the back surface of the base material, this heating does not affect the filling overlay material that has been welded to the surface overlay position.

  In the overlay welding method of the present invention, the supplementary cladding material is heated and welded at the surface overlay position of the phase transformation base material, and the supplementary cladding material of the phase transformation base material is overlay welding. The formed portion is heated from the back surface of the base material to a temperature not lower than the phase transformation temperature and not higher than the melting temperature of the supplementary cladding material.

  Therefore, in the overlay welding method of the present invention, the portion of the phase change base material on which the overlay cladding is overlay welded is a temperature that is higher than the phase transformation temperature and lower than the melting temperature of the supplement overlay as it is cooled. Can be heated up to. For this reason, the output of the back side laser beam can be minimized, and the overlay welding can be completed quickly.

  In the overlay welding method of the present invention, overlay welding is performed by heating the supplementary overlay material with a front side laser beam at the surface overlay position of the phase transformation base material. Therefore, in the overlay welding method of the present invention, since the heating for overlay welding the supplementary cladding material is performed by the front side laser beam, the total heat input amount of the supplementary cladding material and the phase transformation base material as compared with the gas burner. , And welding deformation such as longitudinal shrinkage and longitudinal bending deformation is suppressed.

  In the overlay welding method of the present invention, the portion of the phase change base metal on which the fill overlay material is overlay welded is not less than the phase transformation temperature from the back side of the base material with the laser beam below the melting temperature of the fill overlay material. Heat to the temperature of. Therefore, in the overlay welding method of the present invention, the heating with the filling cladding material as the phase transformation temperature is performed by the back side laser beam, so that the total heat input of the phase transformation matrix is reduced as compared with the gas burner. For this reason, the influence on the dilution of the supplementary cladding material to the phase transformation base material is suppressed, and the hardness of the supplementary cladding material is prevented from being lowered.

  In the overlay welding method of the present invention, the surface laser beam is condensed and scanned at the surface overlay position of the phase transformation base material, and the supplementary overlay material of the phase transformation base material is overlay welded. The back side laser beam is condensed on the back surface of the portion of the base material, and scanning is performed so as to follow the preceding scan of the front side laser beam.

  Therefore, in the overlay welding method of the present invention, since the heating for overlay welding the supplementary cladding material is performed by scanning the focused front side laser beam, the supplementary cladding material and the phase transformation base material The total heat input is reduced, and welding deformation such as longitudinal shrinkage and longitudinal bending deformation is suppressed.

  In this way, the portion of the phase transformation base material heated from the surface of the base metal by overlay welding of the supplementary cladding material with the front side laser light that is condensed and scanned is the backside laser light that is condensed immediately after that. Since it is heated to a temperature not lower than the melting temperature of the above-mentioned supplementary cladding material by scanning, the total heat input amount of the phase-transforming base material is further reduced. For this reason, the influence on the dilution of the supplementary cladding material to the phase transformation base material is suppressed, and the hardness of the supplementary cladding material is prevented from being lowered.

  In the overlay welding method of the present invention, the powdered supplementary overlay material is supplied to the surface overlay position of the phase transformation base material. Therefore, in the overlay welding method of the present invention, the supplementary cladding material that has been improved in heat absorption by being powdered is overlay welded to the phase transformation base material by heating with a reduced total heat input.

  In the overlay welding method of the present invention, the supplementary overlay material is made of an alloy containing cobalt as a main component and about 30% chromium and about 4 to 15% tungsten. Therefore, in the overlay welding method of the present invention, the supplementary overlay material that is overlay welded to the phase transformation base material generates good wear resistance and corrosion resistance.

  In the overlay welding method of the present invention, the phase transformation base material is made of a chromium alloy that undergoes phase transformation at about 900 to 1000 ° C. Therefore, in the overlay welding method of the present invention, the phase transformation base material easily undergoes phase transformation even by heating with laser light.

  In the overlay welding method of the present invention, the phase transformation base material is composed of a turbine blade of a steam turbine, and the surface overlay position is composed of a surface of an edge portion of the turbine blade. Therefore, in the overlay welding method of the present invention, the overlay cladding material is overlay welded to the surface of the edge of the turbine blade.

  The build-up welding apparatus of the present invention is a build-up that builds up and welds a supplementary build-up material on at least a part of the surface of the base material of the phase transformation base material formed in a shape having a base material surface and a base material back surface. A welding apparatus, a surface side welding mechanism for overlay welding the above-described supplementary cladding material on the surface overlay position of the above-mentioned phase transformation base material, and a portion where the above-mentioned supplementary cladding material of the above-mentioned phase transformation base material is overlay welded And a back side welding mechanism for heating from the back surface of the base metal to a temperature not lower than the phase transformation temperature and not higher than the melting temperature of the supplementary cladding material.

  Therefore, in the overlay welding method using the overlay welding apparatus according to the present invention, welding deformation such as longitudinal shrinkage and longitudinal bending deformation and shrinkage distortion are applied to the surface overlay position of the filling overlay material and the welded phase transformation base material. Even if the above occurs, the phase-transformation base metal is welded to the portion where the build-up overlay material is welded to a temperature not lower than the phase transformation temperature and not higher than the melting temperature of the fill-up overlay material. Due to the expansion strain due to the phase transformation on the back surface side of the base material of the material, welding deformation, shrinkage strain, etc. are offset and alleviated. In addition, since the heating with the phase transformation base material as the phase transformation temperature is performed on the back surface of the base material, this heating does not affect the filling overlay material that has been welded to the surface overlay position.

  In the overlay welding method of the present invention, even if welding deformation such as longitudinal shrinkage or longitudinal bending deformation or shrinkage distortion occurs in the surface overlay position of the overlay overlay or the phase transformation base material welded, The portion of the phase change base material on which the overlaying material is overlay welded is heated to a temperature that is higher than the phase transformation temperature and lower than the melting temperature of the additional material. For this reason, the expansion distortion due to the phase transformation on the back surface side of the base material of the phase transformation base material can cancel and alleviate welding deformation, shrinkage strain, etc. The material can be formed into a good shape. And since the heating which uses this phase transformation base material as a phase transformation temperature is performed on a base material back surface, it can prevent that this heating influences the filling overlay material welded to the surface overlay position.

  In the overlay welding apparatus of the present invention, even if welding deformation such as longitudinal shrinkage or longitudinal bending deformation or shrinkage distortion occurs in the surface overlay position of the overlay overlay and the phase transformation base material that has been overlay welded, The portion of the phase change base material on which the overlaying material is overlay welded is heated to a temperature that is higher than the phase transformation temperature and lower than the melting temperature of the additional material. For this reason, the expansion distortion due to the phase transformation on the back surface side of the base material of the phase transformation base material can cancel and alleviate welding deformation, shrinkage strain, etc. The material can be formed into a good shape. And since the heating which uses this phase transformation base material as a phase transformation temperature is performed on a base material back surface, it can prevent that this heating influences the filling overlay material welded to the surface overlay position.

It is a typical side view which shows the overlay welding method of embodiment of this invention. It is a typical side view which shows the overlay welding method by the overlay welding apparatus of embodiment of this invention. It is a typical top view which shows the turbine blade which is a phase transformation base material. It is AA sectional drawing of FIG. 3 which shows the phase-transformation base material and the filling cladding material which the overlay welding was completed. It is a typical side view which shows the overlay welding method by the overlay welding apparatus of the modification of embodiment of this invention.

  Next, an embodiment of the present invention will be described below with reference to the drawings. In the present embodiment, description will be made by defining the front-rear, left-right, up-down directions as shown. However, this is provided for the sake of convenience in order to briefly explain the relative relationship between the components. Therefore, the direction at the time of manufacture and use of the product which implements the present invention is not limited.

  As shown in FIG. 1, the overlay welding apparatus 100 according to the present embodiment of the invention includes a base material surface 210 of a phase transformation base material 200 formed into a shape having a base material surface 210 and a base material back surface 220. The build-up overlay 300 is at least partially welded.

  For this reason, as shown in FIG. 2, the overlay welding apparatus 100 of the present embodiment includes a front side welding mechanism 110, a back side welding mechanism 120, a buildup material supply mechanism 130, a base material holding mechanism 140, and a base material holding mechanism 140. It has a material moving mechanism 150, a welding apparatus frame 160, and an operation control circuit 170.

  The front-side welding mechanism 110 includes a laser oscillator, and heat-up welds the fill-up build-up material 300 to the surface build-up position 211 of the phase transformation base material 200 with a front-side laser beam URL having a predetermined wavelength and a predetermined output.

  The back side welding mechanism 120 is also composed of a laser oscillator, and the phase transformation temperature of the portion of the phase transformation base material 200 where the fill-up buildup material 300 is build-up welded from the base material back side 220 with the back side laser beam DRL having a predetermined wavelength and a predetermined output. As described above, the material is heated to a temperature equal to or lower than the melting temperature of the filling overlay 300.

  As will be described in detail later, the front side welding mechanism 110 collects and scans the front side laser beam URL at the surface build-up position 211 of the phase transformation base material 200, and the back side welding mechanism 120 compensates for the phase transformation base material 200. The back side laser beam DRL is condensed on the base material back surface 220 of the portion where the build-up material 300 is build-up welded, and scanning is performed so as to follow the scanning of the front side laser beam URL.

  The phase transformation base material 200 as described above is made of a chromium alloy that undergoes phase transformation at about 900 to 1000 ° C. More specifically, as shown in FIG. 3, the phase transformation base material 200 is composed of turbine blades of a steam turbine, and a base material surface 210 at the right edge portion where the surface build-up position 211 is a flow leading edge of the turbine blades. Consists of.

  The build-up material supply mechanism 130 supplies the supplementary build-up material 300 pulverized to a predetermined particle size by a predetermined capacity to a position heated by the front side laser beam URL at the surface build-up position 211 of the phase transformation base material 200. .

  The supplementary cladding material 300 supplied in this way is made of, for example, an alloy having about 30% chromium and about 4 to 15% tungsten containing cobalt as a main component, and is made of so-called Stellite (registered trademark).

  Base material holding mechanism 140 includes a so-called chuck mechanism and the like, and holds the rear end of phase transformation base material 200. The base material moving mechanism 150 includes a so-called solenoid or the like, and moves the phase transformation base material 200 held by the base material holding mechanism 140 backward at a predetermined speed.

  The welding device frame 160 holds the front-side welding mechanism 110, the back-side welding mechanism 120, the build-up material supply mechanism 130, and the base material moving mechanism 150 as described above at respective predetermined positions. More specifically, the welding apparatus frame 160 supplies the supplementary buildup material 300 to the surface buildup position 211 of the phase transformation base material 200 that is held by the base material holding mechanism 140 and moved by the base material moving mechanism 150. The build-up material supply mechanism 130 is arranged at a position to be used.

  Furthermore, the welding apparatus frame 160 arrange | positions the front side welding mechanism 110 in the position which condenses front side laser beam URL in the surface overlay position 211 of the phase transformation base material 200 to which the supplementary cladding material 300 is supplied as mentioned above. doing.

  Then, the welding apparatus frame 160 is positioned so as to follow the scanning of the front side laser beam URL that precedes the base material back surface 220 of the portion where the overlaying material 300 of the phase change base material 200 is build-up welded. A back side welding mechanism 120 is arranged. For this reason, the back side welding mechanism 120 is arranged behind the front side welding mechanism 110 by a predetermined distance.

  The operation control circuit 170 includes, for example, a microcomputer on which an appropriate computer program and parameters are mounted, and controls the operations of the front side welding mechanism 110, the back side welding mechanism 120, the build-up material supply mechanism 130, and the base material moving mechanism 150. To do.

  Such a computer program of the operation control circuit 170, for example, causes the base material moving mechanism 150 to move the phase transformation base material 200 held by the base material holding mechanism 140 backward at a predetermined speed, and this phase to be moved. By supplying the build-up material supply mechanism 130 to the surface build-up material supply mechanism 130 at the surface build-up position 211 of the transformation base material 200, the supply supplied to the surface build-up position 211 of the phase change base material 200 The build-up material 300 is heated by the front-side welding mechanism 110 with the front-side laser beam URL for build-up welding, and the portion of the phase transformation base material 200 on which the build-up build-up material 300 is build-up welded is connected to the back-side welding mechanism 120. Heating from the base material back surface 220 to the temperature not lower than the phase transformation temperature and not higher than the melting temperature of the filling overlay 300 with the back side laser beam DRL. It is described so as to perform to the timber supply mechanism 130 and the base material moving mechanism 150.

  In the construction as described above, in the overlay welding method by the overlay welding apparatus 100 of the present embodiment, for example, as shown in FIG. 3, a turbine of a steam turbine made of a chromium alloy that undergoes a phase transformation at about 900 to 1000 ° C. The wing is a phase transformation base material 200.

  Then, for example, about 30% chromium and about 4 to 15% of cobalt as a main component are formed on the surface buildup position 211 formed by the base material surface 210 of the right edge portion which is the flow leading edge of the phase transformation base material 200. The build-up overlay 300 made of an alloy having tungsten is overlay welded.

  More specifically, first, the rear end of the phase transformation base material 200 is held by the base material holding mechanism 140, and the held front surface laser light URL of the front side welding mechanism 110 is used to hold the held phase transformation base material 200. The base material moving mechanism 150 is arranged at a position where the rear end of the surface build-up position 211 is irradiated.

  In such a state, the base material moving mechanism 150 moves the phase transformation base material 200 backward, and at the same time, the build-up material supply mechanism 130 moves to the surface build-up position 211 of the phase transformation base material 200 to be moved. The powdered filling overlay 300 is supplied.

  Further, the overlaying material 300 supplied to the surface overlaying position 211 of the moving phase transformation base material 200 is overlay welded with the focused front side laser beam URL of the front side welding mechanism 110, and this phase transformation base material. The portion of the material 200 on which the overlaying material 300 is overlay welded is not less than the phase transformation temperature from the base material back surface 220 by the focused backside laser beam DRL of the backside welding mechanism 120 and below the melting temperature of the compensation building material 300. Heat to the temperature of.

  In the build-up welding method using the build-up welding apparatus 100 of the present embodiment, the build-up build-up material 300 is build-up welded to the surface build-up position 211 of the phase change base material 200 as described above, and the phase change base material 200 is formed. The portion where the overlaying material 300 is overlay welded is heated from the base material back surface 220 to the phase transformation temperature.

  For this reason, as described above, the front side welding mechanism 110 collects and scans the front side laser beam URL at the surface build-up position 211 of the phase transformation base material 200, and the back side welding mechanism 120 performs the phase transformation base material. The back side laser beam DRL is condensed on the base material back surface 220 of the portion where the 200 build-up buildup materials 300 are build-up welded, and scanning is performed so as to follow the scanning of the preceding front side laser beam URL.

  Then, when the base material moving mechanism 150 moves backward to the position where the front side laser beam URL of the front side welding mechanism 110 is irradiated to the front end of the surface buildup position 211, the buildup material 300 of the supplementary buildup material 300 by the buildup material supply mechanism 130 Supply and irradiation of the front side laser beam URL by the front side welding mechanism 110 are stopped.

  Further, when the base material moving mechanism 150 moves backward to a position where the condensed back side laser beam DRL of the back side welding mechanism 120 is irradiated to the front end of the surface build-up position 211, the back side laser beam DRL by the back side welding mechanism 120 is moved. Irradiation is also stopped and the work is completed.

  In the build-up welding method using the build-up welding apparatus 100 of the present embodiment, the build-up build-up material 300 is build-up welded to the surface build-up position 211 of the phase transformation base material 200 as described above. However, the portion of the phase transformation base material 200 where the overlaying material 300 is build-up welded is heated from the base material back surface 220 to the phase transformation temperature.

  Therefore, as shown in FIG. 4 which is a cross-sectional view taken along the line AA of FIG. 3, the surface build-up position 211 of the filling build-up material 300 or the phase transformation base material 200 that has been welded welded is subjected to longitudinal shrinkage, longitudinal bending deformation, Even if welding deformation, shrinkage distortion, or the like occurs, the portion of the phase change base material 200 on which the overlaying material 300 is overlay welded is heated to the phase transformation temperature, whereby the base material of the phase transformation base material 200 is obtained. Due to the expansion strain due to the phase transformation on the back surface 220 side, welding deformation, shrinkage strain, and the like are offset and alleviated.

  Further, since the heating with the phase transformation base material 200 as the phase transformation temperature is performed on the base material back surface 220, this heating may affect the supplementary cladding material 300 welded to the surface cladding position 211. Can be prevented.

  Moreover, in the build-up welding method using the build-up welding apparatus 100 of the present embodiment, the build-up build-up material 300 is heated at the surface build-up position 211 of the phase transformation base material 200 with the front side laser beam URL and build-up welding is performed.

  Therefore, compared with a gas burner, the total heat input of the supplementary cladding material 300 and the phase transformation base material 200 can be reduced. For this reason, since welding deformation such as longitudinal shrinkage and longitudinal bending deformation can be suppressed, it is possible to form the phase transformation base material 200 in which the build-up buildup material 300 is welded in a better shape.

  In particular, since the heating for overlay welding the supplementary cladding material 300 is performed by scanning the focused front-side laser beam URL, the total heat input between the supplementary cladding material 300 and the phase transformation base material 200 is further reduced. can do.

  Furthermore, in the overlay welding method using the overlay welding apparatus 100 according to the present embodiment, the phase transformation base material 200 is subjected to phase transformation from the base material back surface 220 to the back side laser beam DRL from the base material back surface 220. Heat to temperature. Therefore, the portion where the build-up build-up material 300 of the phase change base material 200 is build-up welded by the front side laser beam URL can be set to the phase change temperature without excess or deficiency.

  Moreover, in the overlay welding method by the overlay welding apparatus 100 of the present embodiment, the portion of the phase transformation base material 200 in which the supplementary overlay material 300 is overlay welded by the front side laser beam URL and heated from the base material surface 210. However, immediately after that, it is heated from the base material back surface 220 to the phase transformation temperature by the back side laser beam DRL.

  Accordingly, the portion of the phase transformation base material 200 on which the overlaying material 300 is overlay welded can be heated to the phase transformation temperature before being cooled. For this reason, the output of the back side laser beam DRL can be minimized, and overlay welding can be completed quickly.

  In particular, in the overlay welding method using the overlay welding apparatus 100 according to the present embodiment, the heating for overlay welding the supplementary cladding material 300 is performed by scanning the focused front-side laser beam URL, and the supplementary cladding material. Heating to the phase transformation temperature of the portion where the 300 is overlay welded is performed by scanning the condensed back side laser beam DRL. For this reason, it is possible to further reduce the total heat input amount of the supplementary cladding material 300 and the phase transformation base material 200, and it is possible to quickly complete the overlay welding.

  Moreover, in the overlay welding method using the overlay welding apparatus 100 of the present embodiment, the powdered supplementary overlay material 300 is supplied to the surface overlay position 211 of the phase transformation base material 200. For this reason, the endothermic property of the filling cladding material 300 can be improved by pulverization. Therefore, the total heat input amount of the supplementary cladding material 300 and the phase transformation base material 200 can be further reduced.

  In addition, in the overlay welding method by the overlay welding apparatus 100 of the present embodiment, the filling overlay material 300 that is overlay welded to the phase transformation base material 200 generates good wear resistance and corrosion resistance. A turbine blade or the like of a steam turbine having good wear and corrosion resistance can be manufactured.

  Furthermore, in the overlay welding apparatus 100 of the present embodiment, the front-side welding mechanism 110 and the back-side welding mechanism 120 are composed of individual laser oscillators. For this reason, the front side welding mechanism 110 can irradiate the phase transformation base material 200 with the front side laser beam URL having an appropriate output for overlay welding the supplementary cladding material 300, and the back side welding mechanism 120 performs the phase transformation. It is possible to irradiate the back side laser beam DRL with an appropriate output at an appropriate wavelength, which heats the base material 200 to a temperature not lower than the phase transformation temperature and not higher than the melting temperature of the filling cladding 300.

  Further, in the overlay welding apparatus 100 of the present embodiment, the front side welding mechanism 110, the back side welding mechanism 120, and the overlay material supply mechanism 130 are fixed at predetermined positions by the welding apparatus frame 160, and the base material moving mechanism 150 is provided. Then, the phase transformation base material 200 is moved.

  Therefore, the relative positions of the front-side welding mechanism 110, the back-side welding mechanism 120, and the build-up material supply mechanism 130 do not change, and only by moving one base material moving mechanism 150, the base material moving mechanism 150 is moved. The front-side welding mechanism 110, the back-side welding mechanism 120, and the build-up material supply mechanism 130 can be moved.

  The present invention is not limited to the present embodiment, and various modifications are allowed without departing from the scope of the present invention. For example, in the said form, it illustrated that the front side welding mechanism 110 and the back side welding mechanism 120 had a laser oscillator separately.

  However, like the overlay welding apparatus 400 illustrated in FIG. 5, the front side welding mechanism 410 and the back side welding mechanism 420 share one laser oscillator 401, and the laser beam is an optical path 411, 421 such as an optical fiber. Thus, the front side welding mechanism 410 and the back side welding mechanism 420 may be optically separated (not shown).

  In this case, the front side welding mechanism 410 and the back side welding mechanism 420 may be formed as a condensing laser head. In this build-up welding apparatus 400, since the number of laser oscillators 401 can be one, the number of parts can be reduced and the apparatus structure can be simplified.

  Further, in the above embodiment, the front side welding mechanism 110, the back side welding mechanism 120, and the build-up material supply mechanism 130 are fixed at predetermined positions by the welding apparatus frame 160, and the base material moving mechanism 150 moves the phase transformation base material 200. Exemplified that

  However, as in the overlay welding apparatus 400 illustrated in FIG. 5, the phase transformation base material 200 is fixed, and the front side welding mechanism 110, the back side welding mechanism 120, and the overlay material are placed by the position control robots 412, 422, and 131. The supply mechanism 130 may be moved.

  Furthermore, in the said form, it heated up the surface build-up position 211 of the phase-transformation base material 200, and it heat-up by the front side laser beam URL, and carried out overlay welding. However, build-up welding of the fill-up material 300 at the surface build-up position 211 of the phase transformation base material 200 may be performed with a gas burner or plasma.

  Similarly, in the above-described embodiment, the portion where the build-up overlay 300 of the phase-transform base material 200 is welded by overlay welding is heated from the base-material back surface 220 to the phase transformation temperature using the back-side laser beam DRL. However, such heating may be performed with a gas burner or plasma.

  Furthermore, in the above embodiment, the overlaying material 300 is heated and welded to the surface overlaying position 211 of the phase transformation base material 200 with the front side laser beam URL, and the supplementary cladding material 300 of the phase transformation base material 200 is made of meat. An example of heating the welded portion from the base material back surface 220 to the phase transformation temperature with the back side laser beam DRL was exemplified.

  However, the surface overlay position 211 of the phase change base material 200 is heated to build up the overlay material 300, and the portion of the phase change base material 200 where the build up material 300 is overlay welded is the base. The heating from the material back surface 220 to the phase transformation temperature may be performed at completely separate timings.

  Further, in the above embodiment, the powdered filling overlay 300 is supplied to the surface overlay position 211 of the phase transformation base material 200. However, a plate-shaped supplementary cladding material (not shown) may be disposed at the surface cladding position 211 of the phase transformation base material 200 for overlay welding.

  Moreover, in the said form, it illustrated that the filling cladding material 300 consists of an alloy which has about 30% chromium and about 4-15% tungsten which has cobalt as a main component. However, various metals that satisfy the necessary conditions can be used as the filling cladding material 300.

  Furthermore, in the said form, it illustrated that the phase transformation base material 200 consists of a chromium alloy which carries out a phase transformation at about 900-1000 degreeC. However, as the phase transformation base material 200, various metals satisfying necessary conditions can be used.

  As such a metal, for example, SUS630 or nickel heat-resistant alloy can be used. As such a nickel heat-resistant alloy, for example, C: 0.05 to 0.25%, Cr: 18 to 25%, Co: 15 to 25%, Mo ≦ 3.5%, W: 5 to 10%, W + 1 / 2Mo: 5-10%, Ti: 1.0-5.0%, Al: 1.0-4.0%, Ta: 0.5-4.5%, Nb: 0.2-3. An alloy of 0%, Zr: 0.005 to 0.10%, B: 0.001 to 0.01%, and remaining Ni can be used.

  Moreover, in the said form, the front side welding mechanism 110, the back side welding mechanism 120, and the build-up material supply mechanism 130 were being fixed, and moving the phase change base material 200 by the base material moving mechanism 150 was illustrated. However, the phase transformation base material 200 is fixed, and the front side welding mechanism 110, the back side welding mechanism 120, and the build-up material supply mechanism 130 may move, or both may move (not shown).

  Furthermore, in the said form, it illustrated that the phase transformation base material 200 consisted of the turbine blade of a steam turbine, and the surface build-up position 211 consisted of the base material surface 210 of the edge of a turbine blade. However, the build-up welding method using the build-up welding apparatus 100 according to the present embodiment can be used for build-up welding of the filling build-up material 300 to various phase transformation base materials 200.

  In the present embodiment, the operation control circuit 170 is exemplified as a microcomputer having a computer program mounted thereon. However, such an operation control circuit 170 can also be formed as hardware including a logic circuit.

  Needless to say, the above-described embodiment and a plurality of modifications can be combined within a range in which the contents do not conflict with each other. Further, in the above-described embodiments and modifications, the structure of each part has been specifically described, but the structure and the like can be changed in various ways within a range that satisfies the present invention.

DESCRIPTION OF SYMBOLS 100 Overlay welding apparatus 110 Front side welding mechanism 120 Back side welding mechanism 200 Phase transformation base material 210 Base material surface 220 Base material back surface 300 Supplementary overlay material DRL Back side laser beam URL Front side laser beam

Claims (10)

A build-up welding method for overlay welding a supplementary build-up material on at least a part of the base material surface of the phase-transform base material formed in a shape having a base material surface and a base material back surface,
Overlay welding the supplementary cladding material on the surface cladding position of the phase transformation base material,
Heating the portion of the phase change base metal on which the build-up overlay has been welded from the back of the base material to a temperature not lower than the phase transformation temperature and below the melting temperature of the fill overlay,
Overlay welding method. While heating and welding the supplementary cladding material at the surface cladding position of the phase transformation base material,
Heating the portion of the phase change base metal on which the build-up overlay has been welded from the back of the base material to a temperature not lower than the phase transformation temperature and below the melting temperature of the fill overlay,
The overlay welding method according to claim 1.   The build-up welding method according to claim 1 or 2, wherein the fill-up build-up material is heated and welded to the surface build-up position of the phase transformation base material with a front side laser beam.   2. The portion of the phase change base material on which the overlaying material is build-up welded is heated from the back surface of the base material to a temperature not lower than the phase transformation temperature and not higher than the melting temperature of the supplementary cladding material by a back side laser beam. The overlay welding method as described in any one of thru | or 3. Condensing and scanning the front side laser light at the surface build-up position of the phase transformation base material,
The back side laser beam is condensed on the back surface of the base material of the portion of the phase change base material where the fill-up build-up material has been welded and welded so as to follow the scanning of the front side laser light,
The overlay welding method according to claim 1.   The overlay welding method according to any one of claims 1 to 5, wherein the pulverized filling overlay material is supplied to a surface overlay position of the phase transformation base material.   The overlay welding method according to any one of claims 1 to 6, wherein the supplementary cladding material is made of an alloy containing cobalt as a main component and approximately 30% chromium and approximately 4 to 15% tungsten.   The overlay welding method according to any one of claims 1 to 7, wherein the phase transformation base material is made of a chromium alloy that undergoes phase transformation at about 900 to 1000 ° C. The phase transformation base material consists of turbine blades of a steam turbine,
The surface build-up position consists of the surface of the edge of the turbine blade;
The build-up welding method as described in any one of Claims 1 thru | or 8. A build-up welding apparatus that builds up and welds a supplementary build-up material on at least a part of the surface of the base material of the phase transformation base material formed in a shape having a base material surface and a base material back surface,
A front-side welding mechanism for overlay welding the supplementary cladding material on the surface cladding position of the phase transformation base material;
A back side welding mechanism that heats the portion of the phase change base metal that has been welded from the back surface of the base metal to the temperature above the phase transformation temperature and below the melting temperature of the base material,
The overlay welding apparatus which has.

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