Material for manufacturing hook and claw and manufacturing method thereof

Abstract

The application discloses a material and a manufacturing method for manufacturing a hook claw, which can improve the manufacturing efficiency and product quality. The material comprises a base part as a hook claw base, and further comprises a wear-resistant ring which is in a cylindrical shape and is made of wear-resistant material. The base part is in a cylindrical structure and is provided with a center hole in the center. The wear-resistant ring can be embedded into the center hole from the end of the base part. The wear-resistant ring is connected to the base part by welding after being embedded into the base part. After the welding is completed, the wear-resistant ring serves as a base material for subsequent processing of a tooth shape on the hook claw. The method is a manufacturing method for manufacturing the hook claw by using the material. By using the material and the manufacturing method, the tendency of intergranular corrosion near a surfacing fusion line can be effectively controlled, the safety hidden danger can be eliminated, the manufacturing quality of the hook claw can be improved, and the manufacturing efficiency of the hook claw can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nuclear reactor control rod drive mechanism parts, in particular to a claw manufacturing material and manufacturing method capable of improving processing efficiency and product quality. BACKGROUND

[0002] The control rod drive mechanism (CRDM) of a pressurized water reactor is one of the key equipment of a nuclear power plant. The principle of the CRDM is to drive the claw component to produce corresponding action through the control of the electromagnetic field, so as to drive the drive rod component and further drive the control rod assembly to move up and down in the reactor core, thereby realizing a series of important functions such as starting and stopping the reactor, adjusting or maintaining the power of the reactor core, and quickly stopping the reactor in the event of an accident.

[0003] The CRDM of the pressurized water reactor in service contains six independent claws. The claw is the most critical part of the CRDM. The claw has single or double tooth-shaped parts, which need to have properties such as wear resistance, impact resistance, corrosion resistance, and high temperature resistance. This is crucial to the service life and operation reliability of the CRDM, so the manufacturing requirements and inspection standards for the tooth-shaped parts of the claw are very strict.

[0004] At present, the tooth-shaped parts of the CRDM claw in the pressurized water reactor in service are mostly made by directly depositing Stellite6 alloy on the base material of austenitic stainless steel. This technology is simple to operate, mature in process, and widely used. Currently, 90% of the claws used in nuclear power in China are made by this process, that is, Stellite6 wear-resistant alloy welding material is fused on the preformed part of the claw by manual oxyacetylene welding to form the embryo of the tooth-shaped part of the claw, and then the tooth shape required on the claw is obtained through subsequent forming processing.

[0005] Further optimizing the preparation process of the nuclear reactor control rod drive mechanism claw to ensure the manufacturing quality and service life of the claw is an important direction for the skilled person in the art to optimize the claw manufacturing technology. SUMMARY

[0006] In view of the technical problem of further optimizing the preparation process of the nuclear reactor control rod drive mechanism claw to ensure the manufacturing quality and service life of the claw, which is an important direction for the skilled person in the art to optimize the claw manufacturing technology, the present application provides a claw manufacturing material and manufacturing method capable of improving processing efficiency and product quality. The claw manufacturing material and manufacturing method provided by the present application can not only effectively control the intergranular corrosion tendency near the deposited fusion line, thereby eliminating safety hazards and improving the manufacturing quality of the claw, but also has the characteristics of improving the manufacturing efficiency of the claw.

[0007] In view of the above problems, the hook manufacturing material and manufacturing method capable of improving processing efficiency and product quality provided by the present application solve the problems through the following technical points: the hook manufacturing material and manufacturing method capable of improving processing efficiency and product quality, the material comprises a base body as a hook base body, and further comprises a wear-resistant ring with wear-resistant material and in a cylindrical shape, the base body is in a cylindrical structure with a central hole in the center, the wear-resistant ring can be embedded in the central hole by the end of the base body, and the wear-resistant ring is connected to the base body by welding after being embedded in the base body; and after the welding is completed, the wear-resistant ring serves as the base material for machining the tooth shape on the subsequent hook.

[0008] In the existing control rod drive mechanism manufacturing process, the base material is generally austenitic stainless steel, and regarding the tooth shape on the hook, the existing technology generally obtains a wear-resistant alloy layer on the hook base body by means of surfacing, and then processes the required tooth shape on the wear-resistant alloy layer. Taking the surfacing layer material Stellite alloy as an example, during the surfacing of the Stellite alloy on the hook, due to the continuous heat input and long heat input time (the surfacing time of a single tooth shape is more than 1.5 hours, and if the base body part provided by the present application is used, the wear-resistant layer in a cylindrical shape needs to be surfaced on the central hole of the base body part, and the required time is several times of 1.5 hours), the base body temperature is relatively high (more than 450℃), and the austenitic stainless steel material generally used in the base body is in the sensitization temperature range of the austenitic stainless steel for a long time, so that the base body itself inevitably causes the precipitation of carbides at the austenitic grain boundary, which causes the obvious intergranular corrosion tendency of the carburized layer near the welding fusion line position. Therefore, the hook products of the surfacing type at home and abroad all have the intergranular corrosion tendency near the junction between the surfacing layer and the base material, and the metallographic graph of a specific embodiment is shown in Figure 1 .

[0009] During the service of the control rod drive mechanism, the tooth shape part on the hook needs to withstand more than 6 million times of strong impact and wear and tear in a 60-year service life, so the intergranular corrosion tendency near the welding fusion line will substantially affect the quality and service life of the hook.

[0010] In the scheme, the base part and the wear-resistant ring are welded on the base part, and the wear-resistant ring is used as the base material for processing the tooth shape on the hook claw. The whole welding part is the hook claw blank, and the hook claw blank can be obtained by cutting the hook claw blank. The base part is used as the hook base, and the wear-resistant ring is used as the base material for tooth forming. In the specific hook manufacturing process, the wear-resistant ring is connected to the base part by welding. That is, the tooth forming base material on the hook claw blank can be obtained by welding the wear-resistant ring on the base part. Since the welding has a connection effect different from the cladding layer obtained by surfacing, the heat introduction duration determined by the surfacing method is no longer present, and the tendency of intergranular corrosion near the welding fusion line is completely eliminated or effectively reduced, thereby improving the overall quality of the hook claw, eliminating safety hazards, and effectively ensuring the reliability and service life of the CRDM.

[0011] Meanwhile, after the welding is completed, the obtained hook claw blank can be clamped on a lathe or a grinding machine, the hook claw blank is driven to rotate around its axis, and the corresponding tool is driven to move in the radial direction and the axial direction of the hook claw blank. The inner wall of the wear-resistant ring is processed into a stepped hole with an annular protrusion. In the stepped hole, the larger diameter hole section is used to remove the excess material on the wear-resistant ring that affects the tooth formation, and the annular protrusion is used as the smaller diameter hole section in the stepped hole. The material of the annular protrusion itself is used as the material for subsequent tooth processing. For example, for a hook claw with one tooth shape, one annular protrusion is obtained, and for a hook claw with two tooth shapes, two annular protrusions are obtained. After the hole wall of the wear-resistant ring is processed, the hook claw blank is cut evenly, and the cutting surface is parallel to the axis of the hook claw blank. A plurality of arc-shaped hook claw blanks are obtained, each of which is used as the base material for processing a hook claw. For example, considering the size and application of the existing hook claw, the hook claw blank is preferably divided into four hook claw blanks. When the tooth shape is processed, the hole inner wall of the wear-resistant ring is processed to remove material. The annular protrusion obtained after cutting can be directly used as the tooth shape, or the annular protrusion obtained after cutting can be reprocessed with less material removal amount. Therefore, the manufacturing efficiency of the hook claw can be effectively improved.

[0012] In specific applications, the above welding connection can be achieved by using an electron beam welding in the prior art, which has good economic efficiency and can completely avoid the tendency of intergranular corrosion near the welding fusion line. Laser welding can also achieve the purpose of completely avoiding the tendency of intergranular corrosion near the welding fusion line.

[0013] Further technical solutions are as follows:

[0014] As a form of material implementation of the ideal material for manufacturing the hook claw, the material of the base part is austenitic stainless steel, and the wear-resistant ring is made of wear-resistant alloy material, such as Stellite alloy block.

[0015] In order to make the gap between the base part and the wear-resistant ring after the cooperation of the base part and the wear-resistant ring, the quality of the welding connection between the two is facilitated, and the hole diameter of the hole segment for cooperating with the wear-resistant ring on the center hole is greater than or equal to the outer diameter of the wear-resistant ring. In the specific welding, for the case that the hole diameter of the hole segment is greater than the outer diameter of the wear-resistant ring, the gap is filled with molten metal by means of hot melting welding, filling welding and the like, and thus the ideal welding quality can be obtained; for the case that the hole diameter of the hole segment is equal to the outer diameter of the wear-resistant ring, the electron beam welding is preferably used for welding, and the welding is efficiently completed by the characteristics of the strong penetration of the electron beam welding and the mutual cooperation of the two cooperating surfaces, and a completely intergranular corrosion-free welding fusion line can be obtained.

[0016] In order to reduce the positioning difficulty and improve the positioning accuracy of the base part and the wear-resistant ring during the welding of the base part and the wear-resistant ring, the center hole is provided in a stepped hole shape, and the depth of the wear-resistant ring embedded in the center hole is limited to the contact between the end of the wear-resistant ring deeply embedded in the center hole and the shaft shoulder on the center hole.

[0017] As a form of wear-resistant ring with better performance, the wear-resistant ring is a cylindrical structure made of nickel-based alloy by using oxygen-acetylene surfacing process on a core rod.

[0018] The manufacturing method of the hook claw can improve the processing efficiency and product quality, and the method comprises a hook claw blank forming step. The hook claw blank forming step is to obtain a base material for manufacturing a tooth shape on a base part as a hook claw base. The raw material of the base material is a wear-resistant ring with a wear-resistant material and a cylindrical structure. The base part is a cylindrical structure with a center hole in the center. The wear-resistant ring can be embedded in the center hole from the end of the base part. The wear-resistant ring is fixedly connected to the base part by welding after being embedded in the base part to obtain the hook claw blank. The wear-resistant ring is used as the base material for processing the tooth shape of the hook claw.

[0019] In the manufacturing method of the hook claw, the wear-resistant ring is connected to the base part by welding, that is, the base material for tooth shape forming on the hook claw blank only needs to weld the wear-resistant ring on the base part. Since the welding plays a connecting role different from the cladding layer obtained by surfacing, the heat introduction duration determined by the surfacing mode is no longer present, and the intergranular corrosion tendency near the welding fusion line is completely eliminated or effectively reduced, so that the overall quality of the hook claw is improved, the safety hidden danger is eliminated, and the reliability and service life of the CRDM are effectively guaranteed.

[0020] Meanwhile, after the welding is completed, the hook claw embryo in a ring shape is obtained, and the hook claw embryo can be clamped on a lathe or a grinding machine. The hook claw embryo is driven to rotate around its own axis, and a corresponding turning tool is driven to move in the radial direction and the axial direction of the hook claw embryo. The inner wall of the wear-resistant ring is processed into a stepped hole with a ring-shaped protrusion. In the stepped hole, the larger hole section is used to remove the excess material on the wear-resistant ring that affects the formation of the teeth. The ring-shaped protrusion is used as the smaller hole section in the stepped hole, and the material of the ring-shaped protrusion itself is used as the material for subsequent tooth shape processing. For example, for a hook claw with one tooth shape, one ring-shaped protrusion is obtained. For a hook claw with two tooth shapes, two ring-shaped protrusions are obtained. After the processing of the hole wall of the wear-resistant ring is completed, the hook claw embryo is evenly cut, and the cutting surface is parallel to the axis of the hook claw embryo. A plurality of arc-shaped hook claw blanks are obtained. Each hook claw blank is used as the base material for processing a hook claw. Considering the size and application of the existing hook claw, the hook claw embryo is preferably divided into four hook claw blanks. During the tooth shape processing, the inner wall of the wear-resistant ring is processed by, for example, material removal ring cutting and grinding. The inner side of the wear-resistant ring is processed into a wall structure with a ring groove before cutting. After cutting, the ring-shaped protrusion can be directly used as a tooth shape. Alternatively, the ring-shaped protrusion after cutting requires less material removal processing. Therefore, the manufacturing efficiency of the hook claw can be effectively improved.

[0021] To completely avoid the tendency of intergranular corrosion near the welding fusion line and facilitate complete penetration, the welding connection is made by using a high-energy-density beam welding method.

[0022] After the wear-resistant ring is embedded in the base part, each point on the side surface of the wear-resistant ring is completely attached to the hole wall of the center hole, or each point on the side surface has a gap with the hole wall. In the case of having the gap, the welding is completed by filling the gap with molten metal fluid during welding. In the case of complete attachment, the welding is completed by electron beam welding. The molten metal fluid can come from hot melting welding or filling welding.

[0023] As described above, to realize the synchronous material removal processing of the hook claw embryo for forming a plurality of hook claws before the final forming, and to improve the processing efficiency of the hook claw by using a synchronous processing method with high material removal efficiency, the hook claw embryo forming step is followed by a hook claw blank forming step. The hook claw blank forming step includes a machining process and a cutting process.

[0024] The machining process is to machine the inner side of the wear-resistant ring by turning and / or grinding to process the inner wall of the wear-resistant ring into a stepped hole with a ring-shaped protrusion. The ring-shaped protrusion is used as the material for obtaining the tooth shape.

[0025] The cutting processing procedure is after the machining procedure, the cutting processing procedure is: cutting the hook claw embryo, and the hook claw embryo is divided into a plurality of arc blocks, each arc block is as a hook claw blank, and each hook claw blank is used for processing a hook claw.

[0026] As a kind of excellent performance material selection scheme, it is provided that the material of the base portion is austenitic stainless steel, and the wear-resistant ring is wear-resistant alloy material, such as Stellite alloy block.

[0027] In order to make the wear-resistant ring have ideal wear-resistant performance and impact resistance, it is provided that it further includes a preparation step for obtaining the wear-resistant ring, the preparation step is that, using oxygen-acetylene surfacing process, the surfacing layer obtained by surfacing on the mandrel is nickel-based alloy, and then the wear-resistant ring is stripped from the surfacing layer by machining.

[0028] The present application has the following beneficial effects:

[0029] The material and manufacturing method provided by the present application are used for manufacturing hook claws, the wear-resistant ring is connected to the base portion by welding, that is, only the wear-resistant ring needs to be welded on the base portion to obtain the tooth forming type base material on the hook claw embryo, since the welding plays a connecting role different from the surfacing layer, by not appearing the heat introduction duration determined by the surfacing mode, the tendency of intergranular corrosion near the welding fusion line is completely eliminated or effectively reduced, so that the overall quality of the hook claw can be improved, the safety hidden danger can be eliminated, the reliability and service life of the CRDM can be effectively guaranteed.

[0030] Meanwhile, by adopting the scheme, after the welding is completed, the hook claw embryo in a ring shape is obtained, the obtained hook claw embryo can be clamped on a lathe or a grinding machine, the hook claw embryo is driven to rotate around its own axis, a corresponding turning tool is driven to move in the feeding motion along the radial direction and the axial direction of the hook claw embryo, and the inner wall of the wear-resistant ring is processed into a stepped hole with a ring-shaped protrusion, in the stepped hole, the hole section with a larger diameter is used for removing the excess material on the wear-resistant ring which affects the tooth formation, the ring-shaped protrusion is used as the hole section with a smaller diameter in the stepped hole, and the material of the ring-shaped protrusion itself is used as the material for subsequent tooth shape processing, for example, for a hook claw with one tooth shape, one ring-shaped protrusion is obtained, and for a hook claw with two tooth shapes, two ring-shaped protrusions are obtained. After the processing of the hole wall of the wear-resistant ring is completed, the hook claw embryo is evenly cut, the cutting surface is parallel to the axis of the hook claw embryo, a plurality of arc-shaped block-shaped hook claw blanks are obtained, each hook claw blank is used as the base material for processing a hook claw, preferably, the hook claw embryo is evenly divided into four hook claw blanks, in this way, during the tooth shape processing, the inner wall of the hole of the wear-resistant ring is processed by removing the material, the ring-shaped protrusion obtained after the cutting can be directly used as the tooth shape, or the amount of material removal during the reprocessing of the ring-shaped protrusion after the cutting is smaller, therefore, by adopting the scheme, the manufacturing efficiency of the hook claw can be effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 In a specific embodiment of the prior art, a metallographic diagram of the obtained surfacing part is obtained, in the metallographic diagram, the upper left part corresponds to the base material, and the lower right part corresponds to the surfacing layer, and it can be clearly seen from the metallographic diagram that a decarburized layer appears near the junction of the two parts;

[0032] Figure 2 In a specific embodiment of the hook claw manufacturing material and manufacturing method provided by the application, after the base body part and the wear-resistant ring are welded by adopting the electron beam welding mode, a metallographic diagram of the obtained hook claw embryo is obtained, in the metallographic diagram, the left part corresponds to the base material, and the right part corresponds to the welding seam;

[0033] Figure 3 In a specific embodiment of the hook claw manufacturing material provided by the application, the structure diagram of the surfacing structure of the wear-resistant ring on the core rod is shown;

[0034] Figure 4 In a specific embodiment of the hook claw manufacturing material provided by the application, the structure diagram of the cooperation relationship between the wear-resistant ring and the base body part is shown, the diagram is a sectional view, and in the diagram, the tooth shape mark position and the different section lines on the wear-resistant ring are only used for indicating the tooth shape position;

[0035] Figure 5 For Figure 4 a side view of the structure shown.

[0036] In the figure, the marks are respectively: 1, mandrel, 2, wear ring, 3, tooth shape, 4, base part. DETAILED DESCRIPTION

[0037] The application will be further described in detail below in conjunction with examples, but the application is not limited to the following examples:

[0038] Example 1:

[0039] As Figures 1 to 5 shown, the material for manufacturing the hook claw capable of improving the processing efficiency and product quality, the material includes a base part 4 as a hook claw base, and further includes a wear ring 2 made of wear-resistant material and in a cylindrical shape, the base part 4 is in a cylindrical structure with a central hole in the center, the wear ring 2 can be inserted into the central hole from the end of the base part 4, and the wear ring 2 is used to be connected to the base part 4 by welding after being inserted into the base part 4; and after the welding is completed, the wear ring 2 serves as the base material for subsequent processing of the tooth shape 3 on the hook claw.

[0040] In the existing control rod drive mechanism manufacturing process, the base material is generally austenitic stainless steel, and for obtaining the tooth shape 3 on the hook claw, the existing technology generally obtains a wear-resistant alloy layer on the hook claw base by means of surfacing, and then processes the required tooth shape 3 on the wear-resistant alloy layer. Taking the surfacing layer material Stellite alloy as an example, during the surfacing of the Stellite alloy on the hook claw, due to the continuous heat input and the long heat input time (the surfacing time of a single tooth shape 3 is about 1.5 hours, and if the base part 4 provided by the present application is used, a cylindrical wear-resistant layer needs to be surfaced on the central hole of the base part 4, and the required time is several times of 1.5 hours), the base temperature is relatively high (above 450°C), which inevitably causes the carbide to precipitate at the austenite grain boundary of the base itself, resulting in a clear intergranular corrosion tendency in the carburized layer near the welding fusion line position. Therefore, the existing hook claw products at home and abroad all have the intergranular corrosion tendency near the junction between the surfacing layer and the base material, and the metallographic image of a specific example is shown in Figure 1 .

[0041] During the service of the control rod drive mechanism, the tooth shape 3 on the hook claw needs to withstand more than 6 million times of strong impact and wear within a 60-year service life, so the intergranular corrosion tendency near the welding fusion line will substantially affect the quality and service life of the hook claw.

[0042] In the scheme, the base part 4 and the wear-resistant ring 2 are welded together, and the wear-resistant ring 2 is used as the base material for forming the tooth shape 3 on the hook claw. After the welding, the hook claw blank can be obtained by cutting the hook claw blank along the axial direction of the hook claw blank. The base part 4 is used as the base of the hook claw, and the wear-resistant ring 2 is used as the base material for forming the tooth shape 3. In the specific manufacturing of the hook claw, the wear-resistant ring 2 is connected to the base part 4 by welding. That is, the base material for forming the tooth shape 3 on the hook claw blank is obtained by welding the wear-resistant ring 2 on the base part 4. Since the welding is different from the cladding layer obtained by surfacing, the heat introduction duration determined by the surfacing method is no longer present, and the intergranular corrosion tendency near the welding fusion line is completely eliminated or effectively reduced, thereby improving the overall quality of the hook claw, eliminating safety hazards, and effectively ensuring the reliability and service life of the CRDM.

[0043] At the same time, after the welding is completed, the obtained hook claw blank can be clamped on a lathe or a grinding machine, and the hook claw blank is driven to rotate around its own axis. The corresponding tool is driven to move in the radial direction and the axial direction of the hook claw blank, and the inner wall of the wear-resistant ring 2 is processed into a stepped hole with an annular protrusion. The larger diameter hole section in the stepped hole is used to remove the excess material on the wear-resistant ring 2 that affects the formation of the tooth shape 3. The annular protrusion is used as the smaller diameter hole section in the stepped hole, and the material of the annular protrusion itself is used as the material for subsequent processing of the tooth shape 3. For example, for a hook claw with one tooth shape 3, one annular protrusion is obtained, and for a hook claw with two tooth shapes 3, two annular protrusions are obtained. After the hole wall processing of the wear-resistant ring 2 is completed, the hook claw blank is cut evenly, and the cutting surface is parallel to the axis of the hook claw blank, thereby obtaining several arc-shaped hook claw blanks. Each hook claw blank is used as the base material for processing a hook claw. Considering the size and application of the existing hook claw, the hook claw blank is preferably divided into four hook claw blanks. During the processing of the tooth shape 3, the inner wall of the hole of the wear-resistant ring 2 is processed to remove the material. The annular protrusion obtained after cutting can be directly used as the tooth shape 3, or the amount of material removed during reprocessing of the annular protrusion after cutting is reduced. Therefore, the manufacturing efficiency of the hook claw is effectively improved.

[0044] In the specific application of the scheme, the above welding connection can be realized by using the existing electron beam welding technology, which has good economic efficiency and can completely avoid the intergranular corrosion tendency near the welding fusion line. Laser welding can also achieve the purpose of completely avoiding the intergranular corrosion tendency near the welding fusion line.

[0045] Example 2:

[0046] The embodiment is further limited based on embodiment 1, and the further technical solution is:

[0047] As a material implementation form for manufacturing the hook claw, the material of the base body 4 is austenitic stainless steel, and the wear-resistant ring 2 is a Stellite alloy block.

[0048] In order to have a gap between the base body 4 and the wear-resistant ring 2 after they are matched, so as to facilitate the welding connection quality between them, it is provided that the hole diameter of the hole segment on the center hole for matching with the wear-resistant ring 2 is greater than or equal to the outer diameter of the wear-resistant ring 2. In the specific welding, for the case that the hole diameter of the hole segment is greater than the outer diameter of the wear-resistant ring, the gap is filled with molten metal by means of hot melting welding, filling welding and the like, and thus an ideal welding quality can be obtained.

[0049] In order to reduce the positioning difficulty and improve the positioning accuracy of the base body 4 and the wear-resistant ring 2 during welding, it is provided that the center hole is a stepped hole, and the depth of embedding the wear-resistant ring 2 into the center hole is limited to be achieved by the contact between the end of the wear-resistant ring 2 deeply penetrating into the center hole and the shaft shoulder on the center hole.

[0050] As a form of the wear-resistant ring 2 with better performance, it is provided that the wear-resistant ring 2 is a cylindrical structure made of nickel-based alloy by using oxygen-acetylene surfacing process to perform surfacing on the mandrel 1.

[0051] Embodiment 3:

[0052] The embodiment discloses a hook claw manufacturing method capable of improving processing efficiency and product quality, which comprises a hook claw embryo forming step. In the hook claw embryo forming step, a base material for manufacturing a tooth shape 3 is obtained on a base body 4 serving as a hook claw base body. The base material is made of a wear-resistant ring 2 which is a wear-resistant material and has a cylindrical structure. The base body 4 has a central hole. The wear-resistant ring 2 can be embedded into the central hole from the end of the base body 4. After being embedded into the base body 4, the wear-resistant ring 2 is fixedly connected with the base body 4 by welding to obtain the hook claw embryo. The wear-resistant ring 2 serves as a base material for subsequent processing of the tooth shape 3 on the hook claw.

[0053] In the manufacturing method provided in the embodiment, the wear-resistant ring 2 is connected to the base body 4 by welding. That is, the base material for tooth shape 3 forming on the hook claw embryo can be obtained only by welding the wear-resistant ring 2 to the base body 4. Since the welding has a connection effect different from that of the cladding layer obtained by surfacing, the heat introduction duration determined by the surfacing method no longer exists, and the tendency of intergranular corrosion near the welding fusion line is completely eliminated or effectively reduced, so that the overall quality of the hook claw is improved, the safety hidden danger is eliminated, and the reliability and service life of the CRDM are effectively guaranteed.

[0054] Meanwhile, by adopting the scheme, after the welding is completed, the hook claw embryo in a ring shape is obtained, the obtained hook claw embryo can be clamped on a lathe or a grinding machine, the hook claw embryo is driven to rotate around its own axis, a corresponding turning tool is driven to move in the feeding direction along the radial direction and the axial direction of the hook claw embryo, and the inner wall of the wear-resistant ring 2 is processed into a stepped hole with a ring-shaped protrusion. In the stepped hole, the hole section with a larger diameter is used to remove the excess material on the wear-resistant ring 2 that affects the formation of the tooth profile 3, and the ring-shaped protrusion is used as the hole section with a smaller diameter in the stepped hole. The material of the ring-shaped protrusion itself is used as the material for subsequent processing of the tooth profile 3. For example, for a hook claw of a tooth profile 3, one ring-shaped protrusion is obtained. For hook claws of two tooth profiles 3, two ring-shaped protrusions are obtained. After the hole wall processing of the wear-resistant ring 2 is completed, the hook claw embryo is evenly cut, and the cutting surface is parallel to the axis of the hook claw embryo, so as to obtain a plurality of hook claw blanks in the shape of an arc block. Each hook claw blank is used as the base material for processing a hook claw. For example, considering the size and application of the existing hook claw, the hook claw embryo is preferably divided into four hook claw blanks. In this way, during the processing of the tooth profile 3, the inner wall of the hole of the wear-resistant ring 2 is processed to remove the material. The ring-shaped protrusion after cutting can be directly used as the tooth profile 3, or the ring-shaped protrusion after cutting can be reprocessed with less material removal processing. Therefore, by adopting the scheme, the manufacturing efficiency of the hook claw can be effectively improved.

[0055] Embodiment 4

[0056] In order to completely avoid the tendency of intergranular corrosion near the welding fusion line and facilitate complete penetration, the welding connection adopts a high-energy-density beam welding method.

[0057] After the wear-resistant ring 2 is embedded in the base body 4, each point on the side surface of the wear-resistant ring 2 is completely attached to the hole wall of the center hole or each point on the side surface has a gap with the hole wall. In the case of the gap, the welding is completed by filling the gap with molten metal fluid during welding. In the case of complete attachment, the welding is completed by electron beam welding. The molten metal fluid can come from hot melting welding or filling welding.

[0058] As described above, in order to realize the synchronous material removal processing of the hook claw embryo for forming a plurality of hook claws before the plurality of hook claws are finally formed, and improve the processing efficiency of the hook claw by using the synchronous processing method with high material removal efficiency, the scheme is further limited as follows: a hook claw blank forming step is arranged after the hook claw embryo forming step. The hook claw blank forming step includes a machining process and a cutting process.

[0059] The machining process is as follows: the inner side of the wear-resistant ring 2 is machined by turning and / or grinding to process the inner wall of the wear-resistant ring 2 into a stepped hole with an annular protrusion, and the annular protrusion is used as the material to obtain the tooth shape 3.

[0060] The cutting process follows the machining process. The cutting process involves cutting the hook claw blank into multiple arc-shaped blocks, each arc-shaped block serving as a hook claw blank, and each hook claw blank being used to process a hook claw. As described above, it is preferable to use an equal-division method to divide the hook claw blank into four hook claw blanks.

[0061] As a high-performance material selection option, the base part 4 is made of austenitic stainless steel, and the wear-resistant ring 2 is a Stellite alloy block.

[0062] To ensure that the wear-resistant ring 2 has ideal wear resistance and impact resistance, the method includes a step for obtaining the wear-resistant ring 2. The step involves using an oxy-acetylene welding process to weld a nickel-based alloy layer onto a mandrel 1, and then machining the wear-resistant ring 2 off the weld layer.

[0063] Example 5:

[0064] This embodiment provides a specific implementation of the material and manufacturing method for the hook-making process provided in this solution:

[0065] In the manufacturing method:

[0066] S1. A small annular wear-resistant alloy ring with a size matching the design dimensions of the hook claw is used as wear-resistant ring 2, and wear-resistant ring 2 is placed at one end of the inner hole of the large annular base material that serves as the base part 4 (e.g., ...). Figure 4 (As shown), but the two are not in complete contact and there is a gap between them. The wear-resistant alloy ring described here is made of Stellite alloy, but other hard wear-resistant alloy materials can also be used; the base material is austenitic stainless steel.

[0067] S2. High-energy-density beam welding methods, such as electron beam welding and laser welding, are used to completely fill the gap between the wear-resistant alloy ring and the base material and form a weld, resulting in a... Figure 4 , Figure 5 The complete hook-claw embryo shown ( Figure 5 yes Figure 4 The left view shows that a circular base material can be processed into 4 hooks. The weld in this case is a weld fusion layer formed by high-energy-density beam welding. High-energy-density beam welding is usually self-fusion, that is, without the addition of filler material, although filler solder can be added.

[0068] S3, using mechanical cutting method, cutting the annular body into four separate hook claw embryos as hook claw blanks, and further processing into hook claw finished products. Figure 5 S3, using mechanical cutting method, cutting the annular body into four separate hook claw embryos as hook claw blanks, and further processing into hook claw finished products.

[0069] In order to ensure the product qualification rate and optimize the preparation cost, the small annular wear-resistant alloy ring described in S1 can also be realized according to the following method:

[0070] 1. A sufficient thickness of annular wear-resistant alloy cladding layer is stacked on the core rod as the core rod 1. The core rod is made of austenitic stainless steel round rod, the cladding method is oxyacetylene welding, and the wear-resistant alloy cladding material is Stellite alloy, such as Figure 3 .

[0071] 2. After the above cladding layer is machined by external circle, it becomes a wear-resistant alloy ring, and hardness detection and flaw detection can be performed to eliminate defective products. The flaw detection method can use one or a combination of UT, PT, and RT.

[0072] The technical scheme provided by the embodiment has the following beneficial effects:

[0073] The embodiment uses high-energy density beam welding method to replace the oxyacetylene cladding method in the prior art to realize reliable connection between the hook claw base body and the tooth-shaped 3 part wear-resistant alloy, completely eliminates the inevitable intergranular corrosion tendency of the cladding fusion line in the prior art, thereby ensuring the welding quality between the base body and the wear-resistant layer, improving the overall quality of the hook claw, eliminating quality risks, and effectively ensuring the reliability of the CRDM. At the same time, the method has high qualification rate, high processing efficiency (4 can be made at one time), and low comprehensive cost.

[0074] The above content is a further detailed description of the present application in combination with specific preferred embodiments, and cannot be considered as limiting the specific embodiments of the present application to these descriptions. For ordinary skilled persons in the technical field to which the present application belongs, other embodiments obtained without departing from the technical scheme of the present application should be included in the protection scope of the present application.

Claims

1. A hook manufacturing part capable of improving processing efficiency and product quality, comprising a base portion (4) as a hook base, characterized in that, Further comprising a wear-resistant ring (2) made of wear-resistant material and in the shape of a cylinder, the size of the wear-resistant ring (2) matching the design size of the hook claw, the base body (4) being in the shape of a cylinder with a central hole, the wear-resistant ring (2) being embedded in the central hole by the end of the base body (4), the wear-resistant ring (2) being connected to the base body (4) by welding after being embedded in the base body (4), and the wear-resistant ring (2) being the base material for machining the tooth shape (3) of the hook claw after the welding is completed, the wear-resistant ring (2) being made of wear-resistant alloy material; The central hole is in the shape of a stepped hole, and the depth of the wear-resistant ring (2) embedded in the central hole is limited by the contact between the end of the wear-resistant ring (2) deeply inserted into the central hole and the shaft shoulder on the central hole; The hole diameter of the hole section for cooperating with the wear-resistant ring (2) is equal to the outer diameter of the wear-resistant ring (2); and the base body (4) is made of austenitic stainless steel.

2. The hook manufacturing part according to claim 1, wherein The wear-resistant ring (2) is obtained by using the oxygen-acetylene surfacing process to perform surfacing on the core rod (1), and the surfacing layer made of nickel-based alloy is obtained, and then the wear-resistant ring (2) is stripped from the surfacing layer by mechanical processing.

3. A hook manufacturing method capable of improving the processing efficiency and the product quality, the method comprising a hook blank forming step of obtaining a base material for making a tooth shape (3) on a base portion (4) as a hook base, characterized by, The central hole is in the shape of a stepped hole, and the depth of the wear-resistant ring (2) embedded in the central hole is limited by the contact between the end of the wear-resistant ring (2) deeply inserted into the central hole and the shaft shoulder on the central hole; The hole diameter of the hole section for cooperating with the wear-resistant ring (2) is equal to the outer diameter of the wear-resistant ring (2); The welding is performed by using the electron beam welding; The base body (4) is made of austenitic stainless steel, and the wear-resistant ring (2) is made of wear-resistant alloy material.

4. The hook manufacturing method of claim 3, wherein the hook manufacturing method is characterized by, Further comprising a hook claw blank forming step after the hook claw blank forming step, the hook claw blank forming step comprising a machining process and a cutting process; The machining process is to perform turning and / or grinding on the inner side of the wear-resistant ring (2) by machining to process the inner side wall of the wear-resistant ring (2) into a stepped hole with an annular protrusion, the annular protrusion being the material for obtaining the tooth shape (3); The cutting process is performed after the machining process, and the cutting process is to cut the hook claw blank to divide the hook claw blank into a plurality of arc-shaped blocks, each arc-shaped block being a hook claw blank, and each hook claw blank being used to process a hook claw.

5. The hook manufacturing method of claim 3, wherein the hook manufacturing method is a method of manufacturing a hook for a hook and loop fastener. Further comprising a preparation step for obtaining the wear-resistant ring (2), the preparation step being to use the oxygen-acetylene surfacing process to perform surfacing on the core rod (1) to obtain a surfacing layer made of nickel-based alloy, and then stripping the wear-resistant ring (2) from the surfacing layer by mechanical processing.

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