JP2010229894A - Impeller and method for manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impeller having a new structure of which surface is coated with high corrosion resistant material, which has a complicated shape and high corrosion resistance, and which is used in a pump and a centrifugal compressor, and a new method for manufacturing the impeller. <P>SOLUTION: Alloy containing iron as the main component is used as base material for a structure member of the impeller and surface of the structure member is coated by nickel base alloy. The impeller is manufactured by providing a prescribed groove on the abutment surface of the structure member abutted on a coated blade, and welding the blade and the structure member after inserting the blade in the groove. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an impeller such as a centrifugal compressor used for conveying various gases and air, an axial flow pump used for various liquid conveying devices, and a manufacturing method thereof, and more particularly to an impeller having a complicated shape and It relates to the manufacturing method.

  Among the impellers used in centrifugal compressors and the like, in the manufacture of the impeller 10 composed of the core plate 2, the side plate 3, and the vanes 1 shown in FIG. Turn into. As shown in FIG. 13, the impeller is welded with the blade 1, the core plate 2, and the side plate 3 processed as individual members and coated with a corrosion-resistant corrosion-resistant coating layer 4 made of a nickel-based alloy or the like on the surface. There is a method of overlay welding by forming the overlay beads 6 in the welded portion by an arc welding method such as welding, MIG welding, or TIG welding. Further, as shown in FIG. 14, the blade 1 formed integrally with the core plate 2 by precision casting and machining or the like is overlapped with the side plate 3 having a groove (groove) where the blade is welded. A method of joining the blade end portion and the side plate by forming the filling overlay bead 7 by the arc welding method and overlay welding is often used.

  However, the former requires alignment of a large number of members, and there is a problem that sufficient accuracy is difficult to obtain and a predetermined performance cannot be obtained. Moreover, when the space | gap between the core plate 2 and the side plate 3 is narrow, there exists a problem that welding becomes difficult without a welding rod or a welding torch entering a welding part. Furthermore, when a component having a corrosion-resistant coating layer is welded, there is a problem that the chemical composition in the filled overlay bead 7 portion of the welded portion is greatly changed, and predetermined strength and corrosion resistance cannot be obtained.

  The latter has the advantage that it can be applied even when the gap between the core plate 2 and the side plate 3 is narrow in order to weld from the outside of the side plate, but because of the large amount of heat input during welding, the deformation after welding is large, Further, there is a problem that the shape and chemical composition of the built-up bead formed at the joint between the blade 1 and the side plate 3 are likely to be non-uniform due to non-uniform welding arc.

  As a method for solving such a problem, for example, as seen in Patent Document 1, a core plate is formed by forging and cutting, and a blade is formed by precision casting, and a plurality of blades and a core plate are combined to form a blade. After the position is set, a technique is disclosed in which a plurality of blades and a core plate are welded, given a predetermined mechanical property by heat treatment, and then subjected to precision finishing to finish to a predetermined shape and size.

  On the other hand, as materials used for centrifugal compressors, axial pumps, and the like, alloys mainly composed of iron from carbon steel to stainless steel are usually used. Among gases to be transferred, there are gases that are corrosive to metals such as hydrogen sulfide, and therefore metal materials to be used are selected according to the corrosivity of the gas to be transferred. In particular, a nickel-base alloy containing nickel as a main component may be used in a compressor or the like that transports a highly corrosive gas. However, many nickel-based alloys have lower material strength than iron-based alloys, and may limit the design of compressors and pumps.

  As a method for solving this problem, for example, as seen in Patent Document 2, by coating the base material surface of a pump component made of stainless steel with a nickel-based alloy, the strength of an alloy containing iron as a main component, A technique for providing a covering member having the corrosion resistance and wear resistance of a nickel-based alloy has been disclosed.

Japanese Patent Laid-Open No. 9-239484 Japanese Patent No. 3886394

  In the above-described known technology, it is difficult to uniformly coat the impeller surface with a highly corrosion-resistant material after manufacturing the impeller having a complicated shape, or the surface covering member is subjected to precision finishing to obtain a predetermined shape and size. There are technical problems such as difficulty in finishing. In addition, when a centrifugal compressor or the like is manufactured by welding a member previously coated with a nickel-base alloy, it is difficult to finish to a predetermined shape and size, and in the vicinity of the welded portion of the member coated with a nickel-base alloy However, there are technical problems such as inability to obtain predetermined strength and corrosion resistance.

  An object of the present invention is to provide an impeller that reduces design restrictions on material strength, is inexpensive, and has excellent corrosion resistance, and a method for manufacturing the impeller.

  The present invention has an impeller having a blade, a core plate, and a side plate, and is formed by welding and joining at least two of the blade, the core plate, and the side plate. And the surfaces of the blade, core plate, and side plate are coated with a nickel-based alloy corrosion-resistant coating layer containing nickel as a main component, and the welded portion of the blade, core plate, and side plate is the nickel-based alloy. It is comprised from the alloy which has a component corresponded to this corrosion-resistant coating layer.

  The blade and the core plate are integrally formed in advance.

  Further, at least one of the core plate and the side plate to which the blade is welded is provided with a groove that accommodates the blade tip and positions the welded portion.

  Further, the tip of the blade is protruded into the groove.

  Further, in an impeller having a blade, a core plate, and a side plate, and formed by welding and joining at least two of the blade, the core plate, and the side plate, a corrosion-resistant alloy is used for the blade, and the core plate and the side plate are used. An iron-based alloy is used, and the surface of the core plate and the side plate is coated with a nickel-based alloy corrosion-resistant coating layer containing nickel as a main component, and the welded portion of the blade, the core plate, and the side plate is It is characterized by comprising an alloy having a component corresponding to a corrosion-resistant coating layer of a nickel-based alloy.

  Moreover, as a corrosion-resistant alloy which comprises the said blade | wing, a nickel base alloy is good. For example, a nickel-base alloy having a composition of 54 mass% Ni-19 mass% Cr-5 mass% Nb-3 mass% Mo or a nickel-base alloy having a composition of 42 mass% Ni-32 mass% Fe-21 mass% Cr-3 mass% Mo is preferable. .

  Further, at least one of the core plate and the side plate to which the blade is welded is provided with a groove that accommodates the blade tip and positions the welded portion.

  Further, the tip of the blade is protruded into the groove.

  Further, the impeller has a blade, a core plate, and a side plate, and is formed by welding and joining at least two of the blade, the core plate, and the side plate, and the blade, the core plate, and the side plate mainly include iron. And the surfaces of the blade, core plate, and side plate are coated with a nickel-based alloy corrosion-resistant coating layer containing nickel as a main component, and the welded portion of the blade, core plate, and side plate is the nickel-based alloy. In the impeller composed of an alloy having a component corresponding to the corrosion-resistant coating layer, a step of forming the blade, the core plate, and the side plate with an iron-based alloy, and the surfaces of the blade, the core plate, and the side plate A step of forming a corrosion-resistant coating layer by coating with a nickel-based alloy, a step of positioning at least one of the blade, the core plate and the side plate on which the corrosion-resistant coating layer is formed, and the bonded blade Weld at least one of core plate and side plate And having a that step.

  Further, the impeller has a blade, a core plate, and a side plate, and is formed by welding and joining at least two of the blade, the core plate, and the side plate, using a nickel-based alloy for the blade, An iron-based alloy is used as the side plate, and the surface of the core plate and the side plate is coated with a nickel-based alloy corrosion-resistant coating layer containing nickel as a main component, and the welded portion between the blade, the core plate, and the side plate In the impeller composed of an alloy having a component corresponding to the corrosion-resistant coating layer of the nickel base alloy, the step of forming the blades with a nickel base alloy, and the core plate and the side plate with an alloy mainly composed of iron A step of forming a corrosion-resistant coating layer by coating the surfaces of the core plate and the side plate with a nickel-based alloy, and a step of positioning at least one of the blade, the core plate and the side plate, and positioning the blade position; Jointed feather and mandrel and Characterized in that a step of welding at least one plate.

  Furthermore, a groove is provided on at least one abutting surface of the core plate and the side plate joined to the blade, and at least one of the blade, the core plate, and the side plate is welded after the blade is inserted into the groove. And

  Furthermore, a step of providing a groove having a predetermined cross-sectional shape and depth toward the blade on a joint surface of at least one of a core plate and a side plate to be bonded to the blade, and a bottom portion of the groove and the blade And a process of supplying a filler metal to the groove bottom and filling and welding the groove.

  In the impeller of the present invention, a high-strength material is used as the base material of the constituent member, and the base material surface is coated with a nickel-based alloy mainly composed of nickel, which has excellent corrosion resistance. Therefore, centrifugal compression combines strength and corrosion resistance. There is an effect that a machine, an axial flow pump and the like can be provided. Moreover, since the usage-amount of nickel can be reduced, compared with the impeller manufactured entirely with the nickel base alloy, there exists an effect which can provide an inexpensive impeller.

  Moreover, durability of an impeller can further be improved by using a nickel base alloy for the blade | wing of a structural member.

The schematic diagram of the impeller of Example 1 of this invention. The schematic diagram of the modification of Example 1 of this invention. The schematic diagram of the other modification of Example 1 of this invention. The schematic diagram of the impeller of Example 2 of this invention. The schematic diagram of the modification of Example 2 of this invention. The schematic diagram of the other modification of Example 2 of this invention. The schematic diagram of the impeller of Example 3 of this invention. The schematic diagram of the modification of Example 3 of this invention. The schematic diagram of the other modification of Example 3 of this invention. The schematic diagram of the impeller of Example 4 of this invention. Sectional drawing of the impeller of Example 4 of this invention. The perspective view which shows the external appearance of the general impeller for centrifugal compressors. The schematic diagram which shows an example of the conventional impeller welding method. The schematic diagram which shows the other example of the conventional impeller welding method.

  Hereinafter, details of the present invention will be described using examples.

  In FIG. 1, the schematic diagram of the impeller 110 of Example 1 is shown. The impeller 110 has a structure in which a groove G into which a blade end portion is inserted is provided at a welded portion of a core plate 102 or a side plate 103 provided above and below the blade 101, and the blade 101, the core plate 102, and the side plate 103 are welded. Have Here, each of the blade 101, the core plate 102, and the side plate 103 is made of a low alloy steel to which about 2 mass% of Cr is added as a base material, and the surface thereof is covered with a corrosion-resistant coating layer 4 made of a nickel-based alloy. .

  Next, a method for manufacturing the impeller 110 will be described. First, the constituent members of the blade 101, the core plate 102, and the side plate 103 constituting the impeller were processed into a predetermined shape and size by combining low alloy steel casting or forging and cutting. Next, a nickel-based alloy was sprayed and deposited on the surface of each component using an arc spraying method to form a corrosion-resistant coating layer 4. Next, a groove G for positioning the welding position of the blade 101 was formed on the core plate 102 and the side plate 103 to which the corrosion-resistant coating layer 4 was adhered.

  The impeller was manufactured by combining the components of the impeller according to the following procedure. First, after the blade 101 is inserted into the groove G formed on the core plate 102 and positioned, the nickel base of the corrosion-resistant coating layer 4 is formed on the blade side of the wedge-shaped gap formed between the blade 101 and the core plate 102. A welding alloy having a chemical composition equivalent to the alloy was supplied and melted by the TIG welding method to form the back bead 5 on the blade side of the core plate 102. The back wave bead is a wavy bead formed on the back surface of the welded portion having a complete welded state in one-side welding.

  Next, an alloy having a chemical composition equivalent to the nickel-based alloy of the corrosion-resistant coating layer 4, that is, an alloy having a composition close to that of the corrosion-resistant coating layer 4 and corrosion resistance is supplied as a filler material into the gap between the blade 101 and the core plate 102. Overlay welding was performed on the groove G to form a filled overlaid bead 7, and the gap between the blade 101 and the core plate 102 was filled to form a predetermined shape. Furthermore, after positioning the welding position by combining the welded body to which the blade 101 and the core plate 102 are welded and the side plate 3, the blade 101 and the side plate 103 are welded in the same manner in the same procedure, and then filling is performed by overlay welding. An impeller 110 was manufactured by filling the gap between the blade 101 and the side plate 103 with the bead 7.

  As shown in the above embodiment, since the low alloy steel is used as the base material of the member constituting the impeller, the strength of the low alloy steel can be used as it is. In addition, the surface of the base material is coated with a nickel-base alloy, and a nickel-base alloy is also exposed on the outer surface of the welded portion by using a weld alloy corresponding to the nickel-base alloy of the corrosion-resistant coating layer 4 as a filler for the constituent members. Therefore, since the impeller has the same corrosion resistance as the corrosion-resistant coating layer and can reduce the amount of nickel used, it is possible to provide an impeller that is less expensive than an impeller manufactured from a nickel-based alloy.

  Furthermore, according to the above configuration, since the end portion of the blade 101 protrudes into the groove G of the core plate 102 and the side plate 103 and is welded, an impeller having strong joint strength and high dimensional accuracy can be obtained. .

  In the above embodiment, the groove for positioning the blades 101 is formed on both the core plate 102 and the side plate 103 forming the exterior body, but as in the modification shown in FIG. 2 and the other modification shown in FIG. The groove G for positioning is formed only in one of the core plate 2 and the side plate 3, and one end of the blade 111 or 121 is inserted into the groove G to determine the position, and the blade and the core plate or side plate are formed by overlay welding. The impeller may be manufactured by a similar welding procedure by filling the gap and joining the other end to the other end by a normal overlay welding method. In this case, the dimensional accuracy and strength are slightly inferior to those of the embodiment of FIG. 1, but the process is simplified and practically sufficient performance is obtained.

  FIG. 4 is a schematic diagram of an impeller 210 according to the second embodiment of the present invention. The impeller 210 has a structure in which a groove G into which a blade end portion is inserted is provided in the core plate 202 or the side plate 203 at both ends of the blade 201 and the blade 201 and the core plate 202 or the side plate 203 are welded.

  Here, the blade 201 is made by processing a nickel-base alloy having a composition of 54 mass% Ni-19 mass% Cr-5 mass% Nb-3 mass% Mo having corrosion resistance, and the core plate 202 and the side plate 203 are both 13 mass. % Cr martensitic stainless steel is used as a substrate, and its surface is covered with a corrosion-resistant coating layer 4 made of a nickel-based alloy.

  Next, the manufacturing method of this impeller is shown. First, each of the constituent members of the blade 201, the core plate 202, and the side plate 203 constituting the impeller 210 was processed into a predetermined shape and size by a combination of casting or forging of a raw metal and cutting. Here, a groove G for determining the welding position of the blade 201 was formed on the core plate 202 and the side plate 203 in advance. Next, the corrosion-resistant coating layer 4 made of a nickel-based alloy was adhered to the entire surface of the core plate 202 and the side plate 203 using an arc spraying method.

  Thus, after providing a groove | channel, it coat | covers with a nickel base alloy, and a weldability with the weld metal part in a groove | channel improves by providing an alloy layer in the groove | channel. Moreover, since the steel material is not exposed in the groove, a mixed layer of iron and nickel that lowers the corrosion resistance is unlikely to occur. On the other hand, providing the groove after providing the coating layer is preferable because the working process is easy.

  The impeller was manufactured by combining the core plate 202, the side plate 203, and the blades 201, which were respectively surface-coated, in the following procedure. First, a slightly weld metal having a chemical composition equivalent to the nickel-based alloy of the corrosion-resistant coating layer 4 is deposited on the blade side of the gap between the blade 201 and the core plate 202 and on the blade side of the gap between the blade 201 and the side plate 203. I let you. Next, the blades 201 welded with the weld metal were inserted into the groove G formed on the core plate 202 for positioning.

  First, the weld metal welded to the blade 201 was redissolved by the TIG welding method, and the back bead 5 was formed on the blade surface side of the core plate 2. Next, an alloy having a chemical composition equivalent to the nickel-based alloy of the corrosion-resistant coating layer 4 is supplied as a filler material into the gap between the blade 201 and the core plate 202 to form the filled cladding bead 7 in the groove, A predetermined shape was formed by filling the gap of the core plate 202.

  Further, the blade 201 and the side plate 203 are joined in the same procedure as the joining method of the blade 201 and the core plate 202 by combining the welded body in which the blade 201 and the core plate 202 are welded, and the side plate 203 to manufacture the impeller 210. did.

  As the second embodiment shows, since martensitic stainless steel is used as a constituent member of the impeller core plate 202 and the side plate 203, the strength can be utilized. In addition, since the base material surfaces of the core plate 202 and the side plate 203 are coated with the nickel base alloy, and the nickel base alloy is also exposed on the outer surface of the welded portion of the core plate 202 and the side plate 203 and the blade 201, The impeller 201 has a corrosion resistance equivalent to that of the corrosion-resistant coating layer. Furthermore, since the base material of the core plate 202 and the side plate 203 is martensitic stainless steel and the amount of nickel used for the impeller can be reduced, the impeller is less expensive than an impeller manufactured from a nickel-based alloy. Can provide a car.

  Since the second embodiment uses a corrosion-resistant nickel-based alloy having a composition of 54 mass% Ni-19 mass% Cr-5 mass% Nb-3 mass% Mo for the vane 201, the vane is most easily damaged although it is more expensive than the first embodiment. The durability of the part is greatly improved.

  In the above embodiment, the groove G for positioning the blade 201 is formed on both the core plate 2 and the side plate 3, but as in the modification shown in FIG. 5 and the other modification shown in FIG. A blade 221 is prepared, a positioning groove G is formed on at least one of the core plate 202 and the side plate 203 and welded, and the other is joined by a normal overlay welding method. A car may be manufactured. In this case as well, the dimensional accuracy and strength are slightly inferior to those of Example 2 in FIG. 4, but the process is simplified and practically sufficient performance is obtained.

  FIG. 7 is a schematic diagram of an impeller according to a third embodiment of the present invention. The impeller 310 has a groove G for welding the blades at both ends of the blade 301, and has a structure in which the blade 301 and the core plate 302 or the side plate 303 are welded. Here, the blade 301 is made by processing a nickel-based alloy having a composition of 42 mass% Ni-32 mass% Fe-21 mass% Cr-3 mass% Mo having corrosion resistance, and the core plate 302 and the side plate 303 are all about A low alloy steel to which 9 mass% Ni is added is used as a substrate, and the surface thereof is covered with a corrosion-resistant coating layer 4 made of a nickel-based alloy.

  Next, the manufacturing method of this impeller is shown. First, the constituent members of the blade 301, the core plate 302, and the side plate 303 constituting the impeller were processed into a predetermined shape and size by combining raw metal casting or forging and cutting. Here, a groove G for welding the blade 301 to the core plate 302 and the side plate 303 was formed in advance. Next, the corrosion-resistant coating layer 4 of the nickel base alloy was adhered to the entire surface of the core plate 302 and the side plate 303 by using an arc spraying method.

  Next, the impeller 310 was manufactured by combining the core plate 302, the side plate 303, and the blades 301, which were surface-coated with a nickel-based alloy, in the following procedure. First, after positioning the blade 301 and the core plate 302, an alloy having a chemical composition equivalent to the nickel-based alloy used for the blade 301 is supplied to the gap between the blade 301 and the core plate 302, and the alloy inserted by laser welding is used. By melting, the back bead 5 was formed on the blade surface side of the core plate 302. Next, an alloy having a chemical composition equivalent to the nickel-based alloy used for the blade 301 is supplied as a filler material to the space between the blade 301 and the core plate 302 to form the fill-up bead 7 in the groove G. A wide gap between 301 and the core plate 302 was filled to form a predetermined shape.

  Furthermore, the blade 301 and the side plate 303 are back welded in the same procedure as the method of joining the blade 301 and the core plate 302 by combining the welded body in which the blade 301 and the core plate 302 are welded and the side plate 303, and overlay welding. Thus, the impeller 310 was manufactured by filling the gap between the blade 301 and the side plate 303.

  Since Example 3 uses a nickel-base alloy having a composition of 42 mass% Ni-32 mass% Fe-21 mass% Cr-3 mass% Mo for the blade, although it is more expensive than Example 1, the durability of the blade portion that is most susceptible to damage The characteristics are greatly improved.

  In the above embodiment, the groove for positioning the blades 301 is formed on both the core plate 302 and the side plate 303 forming the exterior body. However, as in the modification shown in FIG. 8 and the other modification shown in FIG. The blade 311 and the blade 321 are prepared, the groove G for positioning is formed only in at least one of the core plate 302 and the side plate 303 to form the filled overlay bead 7, and the other is joined by a normal overlay welding method. A member may be manufactured and an impeller may be manufactured with the same welding procedure. In this case as well, the dimensional accuracy and strength are slightly inferior to those of Example 3 in FIG. 7, but the process is simplified and practically sufficient performance is obtained.

  FIG. 10 shows a schematic diagram of the fourth embodiment. The fourth embodiment shows an impeller 410 used in an axial flow pump including a blade 401, a core plate 402, and a side plate 403. FIG. 11 is a sectional view thereof. In order to obtain a predetermined performance, the impeller 410 has a three-dimensional curved surface in which the blade 401 and the core plate 402 are integrally formed as shown in FIG. 10B, and accurate dimensional accuracy is obtained by machining after precision casting. Have gained.

  In the manufacturing method of the impeller 410, first, a groove G is formed in a portion of the side plate 403 where the blade 401 is welded, and the tip of the blade 401 is inserted into the groove G and abutted. As shown in FIG. 10 (a), the impeller is integrally manufactured by the method.

  As the configurations of the blade 401, the core plate 402, and the side plate 403, various composite metal materials similar to those described in the first to third embodiments are used.

  In Example 4, since the blades 401 and the core plate 402 are integrally formed in advance, an impeller excellent in dimensional accuracy and strength can be obtained, and the processing steps can be greatly shortened.

101, 111, 121, 201, 211, 221, 301, 311, 321: blades 102, 202, 302: core plate 103, 203, 303: side plate 4: corrosion-resistant coating layer 5: reverse bead 6: overlay bead Part 7: Filled overlay bead part G: Groove

Claims (15)

In an impeller having a blade, a core plate, and a side plate, and formed by welding and joining at least two of the blade, the core plate, and the side plate,
An alloy containing iron as a main component is used for the blade, core plate, and side plate, and the surface of the blade, core plate, and side plate is coated with a nickel-based alloy corrosion-resistant coating layer containing nickel as a main component, An impeller characterized in that the welded portion between the core plate and the side plate is made of an alloy having a component corresponding to the corrosion-resistant coating layer of the nickel-based alloy.   2. The impeller according to claim 1, wherein the blade and the core plate are integrally formed in advance.   3. The impeller according to claim 1, wherein at least one of a core plate and a side plate to which the blade is welded is provided with a groove for receiving the blade tip and positioning the welded portion. car.   4. The impeller according to claim 3, wherein a tip of the blade is protruded into the groove. In an impeller having a blade, a core plate, and a side plate, and formed by welding and joining at least two of the blade, the core plate, and the side plate,
A nickel-based alloy is used for the blades, an alloy mainly composed of iron is used for the core plate and the side plate, and the surface of the core plate and the side plate is a corrosion-resistant coating layer of a nickel-based alloy mainly composed of nickel. An impeller characterized in that the welded portion of the blade, the core plate, and the side plate is made of an alloy having a component corresponding to the corrosion-resistant coating layer of the nickel-based alloy.   6. The impeller according to claim 5, wherein a groove for accommodating the tip of the blade and positioning the welded portion is provided in at least one of the core plate and the side plate to which the blade is welded.   The impeller according to claim 6, wherein a tip of the blade protrudes into the groove.   A centrifugal compressor having the impeller according to any one of claims 1 to 7.   The axial flow pump which has an impeller of any one of Claims 1 thru | or 7. An impeller having a blade, a core plate, and a side plate, and formed by welding and joining at least two of the blade, the core plate, and the side plate, and an alloy mainly composed of iron in the blade, the core plate, and the side plate And the surfaces of the blade, core plate, and side plate are coated with a nickel-based alloy corrosion-resistant coating layer containing nickel as a main component, and the welded portion of the blade, core plate, and side plate is corrosion-resistant of the nickel-based alloy. In an impeller composed of an alloy having a component corresponding to the coating layer,
Forming the blade, the core plate, and the side plate from an alloy containing iron as a main component; coating the surfaces of the blade, the core plate, and the side plate with a nickel-based alloy to form a corrosion-resistant coating layer; and the corrosion-resistant coating. And a step of positioning at least one of the blade, the core plate, and the side plate on which the layer is formed, and a step of welding at least one of the bonded blade, the core plate, and the side plate. The manufacturing method of an impeller. An impeller having a blade, a core plate, and a side plate, formed by welding and joining at least two of the blade, the core plate, and the side plate, and using a nickel-based alloy for the blade, An iron-based alloy is used, and the surface of the core plate and the side plate is coated with a nickel-based alloy corrosion-resistant coating layer containing nickel as a main component, and the welded portion of the blade, the core plate, and the side plate is In an impeller composed of an alloy having a component corresponding to a corrosion-resistant coating layer of a nickel-based alloy,
Forming the blades with a nickel-based alloy; forming the core plate and the side plate with an iron-based alloy; and coating the surface of the core plate and the side plate with a nickel-based alloy to form a corrosion-resistant coating layer. A step of forming, a step of positioning at least one of the blade, the core plate, and the side plate by positioning the blade, and a step of welding at least one of the bonded blade, the core plate, and the side plate. Manufacturing method of impeller.   The impeller manufacturing method according to claim 10 or 11, wherein a groove is provided on at least one abutting surface of a core plate and a side plate to be joined to the blade, and the blade is inserted into the groove after the blade is inserted into the groove. An impeller manufacturing method comprising welding at least one of the core plate and the side plate.   The impeller manufacturing method according to claim 10 or 11, wherein a predetermined cross-sectional shape and depth are formed toward the blade on a joint surface of at least one of a core plate and a side plate joined to the blade. A step of providing a groove, a step of welding the bottom of the groove and the end of the blade, and a step of supplying a filler material to the groove bottom and filling and welding the groove. The manufacturing method of the impeller characterized by the above-mentioned.   A centrifugal compressor having an impeller manufactured by the manufacturing method according to claim 10.   An axial flow pump having an impeller manufactured by the manufacturing method according to any one of claims 10 to 13.

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