CN210254945U

CN210254945U - Bar for preparing wear-resistant layer on inner wall of hole capable of improving product yield

Info

Publication number: CN210254945U
Application number: CN201921338490.0U
Authority: CN
Inventors: 喻杰
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-08-16
Filing date: 2019-08-16
Publication date: 2020-04-07
Anticipated expiration: 2029-08-16

Abstract

The utility model discloses a can improve hole inner wall wearing layer preparation of product percent of pass and use rod, including the rod body, the rod body includes surrounding layer and middle plug, the surrounding layer cladding is in the outside of middle plug, and the surrounding layer is whole to be cylindricly, the surrounding layer is through carrying out the build-up welding on middle plug and obtaining, the material of surrounding layer is the same with the material of wearing layer. The bar is adopted to realize the processing of the wear-resistant layer on the inner wall of the hole, so that the product percent of pass can be effectively improved; meanwhile, the structural design of the bar is convenient to prepare.

Description

Bar for preparing wear-resistant layer on inner wall of hole capable of improving product yield

Technical Field

The utility model relates to a part spot facing work technical field especially relates to a rod is used in preparation of downthehole wall wearing layer that can improve the product percent of pass.

Background

The reactor Control Rod Drive Mechanism (CRDM) is one of the key devices of a nuclear power plant, and its principle may be: the hook claw component is driven to generate corresponding action by controlling the regular change of the electromagnetic field, so that the driving rod component is driven to drive the control rod component to move up and down in the reactor core, and a series of important functions such as reactor core power regulation or maintenance and rapid reactor shutdown under accident conditions in the process of reactor start and stop and normal operation are realized.

Aiming at the CRDM for the nuclear power station which comprises the hooks in active service, each set of the CRDM comprises an upper hook group and a lower hook group, and each set of the hook groups consists of 3 sets of hooks, pin shafts and connecting rods. The finger is a key feature in CRDM and is shaped as shown in fig. 1 with two holes of diameter D for insertion of the pin. Since the properties of wear resistance, impact resistance, corrosion resistance, high temperature resistance, etc. of the fingers are critical to the life and operational reliability of the CRDM, the manufacturing requirements and inspection standards for the fingers are very stringent.

At present, the forming process of the claw mainly comprises three types: surfacing welding type hooks, integrally casting type hooks and forming the hooks by an additive method. The overlaying welding type claw is characterized in that an abrasion-resistant alloy layer (such as an overlaying welding layer on the inner side of a hole in a picture 1 and a claw tooth overlaying welding layer on the outer surface of the claw) is overlaid on a moving contact surface of the overlaying welding type claw, the claw is good in comprehensive performance, the practical application is wide, the operation experience in the overlaying welding process is rich, and the existing overlaying welding process is poor in controllability, low in qualification rate, low in production efficiency and high in manufacturing cost. The integrally cast claw is integrally cast by Stellite6 alloy, the forming process is simple, the batch production is easy, but the impact resistance of the cobalt alloy is poor, the cobalt alloy is integrally cobalt alloy, and the content of cobalt element in the pile is increased. The additive method forming claw is still in a conceptual stage, the technology is not fully verified, and no practical application experience exists.

Therefore, in the existing and newly-built nuclear power stations in future, the surfacing type claw still accounts for the vast majority, and the claw in the form has the largest manufacturing difficulty and the lowest manufacturing process qualification rate: the main reason is that the holes with the wear-resistant alloy layer need to be obtained by build-up welding, whereas the specific value of the hole diameter D is typically 9.5 mm. At present, the existing mature small-hole surfacing welding technology for the hook claw, such as patent with application number of CN201410154226.7, namely 'a forming process for a bottom hole of a hook claw part of a pressurized water reactor control rod driving mechanism', and the like, melts and covers the Stellite6 wear-resistant alloy welding material on the inner wall of a prefabricated hole in a manual oxyacetylene welding mode to form a hook claw blank body shown in figure 2. In fig. 2, the hatching line is the base body of the hook claw by oblique lines, the material is usually austenitic stainless steel, and the part with the hatching line is the overlay welding cladding layer of the wear-resistant alloy. However, the aperture of the prefabricated hole is small, the difficulty of oxyacetylene surfacing operation is high, and meanwhile, the final qualified rate of the surfacing layer is low due to the high flaw detection requirement of the claw abrasion-resistant surfacing layer and the narrow hardness control range of the surfacing layer, which becomes a well-known technical bottleneck in the CRDM manufacturing industry.

SUMMERY OF THE UTILITY MODEL

To the current pile-up welding formula hook that above-mentioned provided, the technical problem that the qualification rate is low of existence when preparing, the utility model provides a can improve the rod for the preparation of downthehole wall wearing layer of product percent of pass. The bar is adopted to realize the processing of the wear-resistant layer on the inner wall of the hole, so that the product percent of pass can be effectively improved; meanwhile, the structural design of the bar is convenient to prepare.

To the above problem, the utility model provides a pair of can improve hole inner wall wearing layer preparation of product percent of pass and use rod solves the problem through following technical essential: the utility model provides a can improve hole inner wall wearing layer preparation of product percent of pass and use rod, includes the rod body, the rod body includes surrounding layer and middle plug, the surrounding layer cladding is in the outside of middle plug, and the surrounding layer is whole to be cylindricly, the surrounding layer is through carrying out the surfacing on middle plug and obtaining, the material of surrounding layer is the same with the material of wearing layer.

This rod is when specifically using for prepare the hole that has inner wall wearing layer on corresponding part, if: finally, a hole with the inner diameter D and a wear-resistant layer on the hole wall is obtained on the part, and the method can be set to comprise the following steps:

s1, drilling a prefabricated hole with the inner diameter of D1 on the part, wherein D1 is larger than D; obtaining the bar, wherein the outer diameter of the outer cladding layer on the bar is smaller than D1 and larger than D, and the outer diameter of the middle core rod is smaller than or equal to D;

s2, embedding the bar into the prefabricated hole, and filling the gap between the bar and the prefabricated hole through filling welding or self-fluxing welding;

s3, obtaining holes with the diameter D on the bar, providing all hole walls for the holes with the diameter D by the outer cladding, and taking the outer cladding as the wear-resistant layer material.

In the scheme, the step S1 is a preparation step, and a prefabricated hole and a bar for filling the prefabricated hole are obtained; step S2 is a welding step, and welding of the bar in the prefabricated hole is completed; step S3 is used for the hole final molding that the diameter is D, and the hole final molding that the diameter is D back, this rod material is as the pore wall in hole, and original this rod can be whole material and wearing layer material the same promptly, also can be local material and wearing layer material the same, and is the same for this original rod is local material and wearing layer material, accomplishes step S3 back, utilizes drilling processing, reaming processing etc. to get rid of after other materials, can make on this rod material and the unanimous part of wearing layer material conduct wearing layer material.

The rod that this scheme provided can be used to the hole preparation that has the inner wall wearing layer on the part, for the direct build-up welding wearing layer on the inner wall in prefabricated hole among the prior art, owing to weld again after inserting prefabricated hole through this rod, like this, provides the boundary for the weld bath in other words: the outer side is the hole wall of the prefabricated hole, and the inner side is the outer wall of the bar, so that the surfacing welding of the inner wall of the prefabricated hole which is difficult to operate is changed into gap filling welding which is easy to operate at present, and the purpose of improving the product percent of pass by being beneficial to the welding quality is achieved by greatly reducing the difficulty of the welding operation; simultaneously, compare in prefabricated downthehole wall build-up welding, to above filling welding and hot melt welding, the usable automatic weld of clearance packing between prefabricated hole and this rod is accomplished, so not only can further guarantee product quality, be convenient for simultaneously improve the preparation efficiency of the hole that has the inner wall wearing layer, do benefit to and realize mass production.

In the scheme, the outer cladding layer consistent with the wear-resistant layer is obtained by performing surfacing on the middle core rod, namely the scheme provides a realization scheme that the rod can be conveniently obtained. And the outer side of the middle core rod is subjected to surfacing to obtain the outer cladding layer, so that the surfacing can be realized by utilizing automatic welding equipment or manually because of convenient operation, and manufacturers for preparing the holes generally have the characteristic of the capability of preparing the bar, so that the bar is easy to prepare, and the preparation quality and the preparation efficiency can be ensured.

As the technical personnel in the field, after the final hole is formed, the used material is only the outer cladding layer material, and the intermediate core rod is only used as the base body of the overlaying cladding layer, so the technical personnel in the field can set the intermediate core rod to be the material with good drilling processing performance and good combination quality with the outer cladding layer so as to remove the intermediate core rod in the subsequent process.

The further technical scheme is as follows:

as a specific implementation mode of the middle core rod, the middle core rod is a hollow tube. This scheme of adoption utilizes the inside boundary of the outside restraint surrounding layer of hollow tube, and the convenient follow-up middle plug of getting rid of the lectotype of middle plug.

The middle core rod is a solid rod. The solid rod is adopted as the middle core rod, compared with a pipe which is a hollow pipe and is used as the middle core rod, when overlaying is carried out to obtain an outer cladding layer, the solid middle core rod is more difficult to deform, so that the shape of the inner side boundary of the outer cladding layer can be accurately wrapped, and therefore when the middle core rod is selected, the diameter of the middle core rod can be closer to the value D, and if the diameter of the middle core rod is equal to D or slightly smaller than D, the middle core rod can be obtained. For the case that the diameter of the middle core rod is smaller than D, the D is set to be larger than the diameter of the middle core rod by 0.3-3 mm. Since the wear layer itself is difficult to machine, the step S3 is facilitated by the smaller thickness of the outer cladding layer that needs to be processed in the step S3 for obtaining the hole with the diameter D.

As a specific application mode, the method comprises the following steps: the holes are pin holes in a connecting rod or a claw on the CRDM, and the outer cladding is made of Stellite6 alloy. The scheme provides a part preparation method which is easy to prepare a hook claw or a connecting rod and can improve the product percent of pass: the surfacing process is completed at the outer side of the hole, the obtained wear-resistant layer of the inner wall of the hole is obtained by filling welding and subsequent hole processing, the product percent of pass can be effectively improved, and the processing quality of the connecting rod and the claw is ensured. The subsequent hole machining can be to remove the material on the inner side of the outer cladding layer in a grinding and hole expanding mode after removing the middle core rod through drilling so as to finally form a hole with a space D. In order to facilitate the surfacing quality, the outer cladding layer made of Stellite6 alloy is formed by adopting an oxyacetylene surfacing mode; and the subsequent welding between the outer cladding layer and the prefabricated hole adopts a high-energy-density beam welding mode, such as electron beam welding and laser welding.

In order to facilitate the surfacing quality, the middle core rod is a ferrite stainless steel pipe or bar.

As a concrete scheme of the middle core rod which is easy to obtain materials, the method is characterized in that: the middle core rod is a 304 stainless steel pipe or rod.

As a specific form of the bar, provided are: the outer diameter of the middle core rod is smaller than 9mm, and the outer diameter of the outer cladding layer is larger than 10 mm.

Furthermore, to increase the minimum thickness of the resulting wear layer, the following settings are made: the outer diameter of the middle core rod is smaller than 8mm, and the outer diameter of the outer cladding layer is larger than 11.5 mm.

The utility model discloses following beneficial effect has:

Drawings

FIG. 1 is a schematic perspective view of an embodiment of a conventional claw for a control rod drive mechanism;

FIG. 2 is a sectional view showing the structure of one embodiment of a conventional hook for a control rod drive mechanism, in which a hole on the upper side is a long hole and two coaxial holes on the lower side are short holes;

FIG. 3 is a top view of the bar for preparing the wear-resistant layer on the inner wall of the hole according to the embodiment of the present invention, which is obtained by overlaying an outer cladding layer on the hollow tube or the solid rod;

FIG. 4 is a cross-sectional view of the rod for preparing the wear-resistant layer on the inner wall of the hole, which is obtained by overlaying an outer cladding layer on the solid rod, according to an embodiment of the rod for preparing the wear-resistant layer on the inner wall of the hole, which can improve the product yield;

fig. 5 is a sectional view of a part after a prefabricated hole is formed on the part according to an embodiment of the rod for manufacturing the wear-resistant layer on the inner wall of the hole, which can improve the product yield of the present invention;

fig. 6 is a sectional view of a part obtained after welding the bar and a prefabricated hole of the part is completed in a specific embodiment of the bar for preparing the wear-resistant layer of the inner wall of the hole capable of improving the product yield, in the sectional view, the diameter of the prefabricated hole is continuously reduced from one end of the prefabricated hole to the other end and then continuously increased, and the scheme is suitable for gap filling welding of a gap between the bar and a long hole on a claw;

fig. 7 is a concrete example of a hole inner wall wearing layer preparation that can improve the product percent of pass in order to use rod, accomplish the part cross-sectional view that obtains after this rod and the prefabricated hole welding of part, in this cross-sectional view, the diameter in prefabricated hole diminishes or grow in succession earlier by prefabricated hole one end to the other end, this scheme is applicable to the clearance filling welding in clearance between the short hole on this rod and the hook.

The reference numbers in the drawings are respectively: 1. the bar comprises a bar body, 2 parts, a hollow pipe, 3 parts, an outer cladding, 4 parts, a solid rod, 5 parts, 6 parts, prefabricated holes, 7 parts and gaps.

Detailed Description

The present invention will be described in further detail with reference to the following examples, but the present invention is not limited to the following examples:

example 1:

as shown in fig. 3 to 7, a can improve hole inner wall wearing layer preparation rod of product percent of pass is with rod, including rod body 1, rod body 1 includes surrounding layer 3 and middle plug, the outside of surrounding layer 3 cladding in middle plug, and surrounding layer 3 is whole to be cylindricly, surrounding layer 3 obtains through carrying out the build-up welding on middle plug, the material of surrounding layer 3 is the same with the material of wearing layer.

This rod is used for preparing the hole that has inner wall wearing layer on corresponding part 5 when specifically using, if: finally, a hole with an inner diameter D and a wear resistant layer on the wall of the hole is obtained on the part 5, and the method can be set to comprise the following steps:

s1, drilling a prefabricated hole 6 with the inner diameter of D1 on the part 5, wherein D1 is larger than D; obtaining the bar, wherein the outer diameter of the outer cladding layer 3 on the bar is smaller than D1 and larger than D, and the outer diameter of the middle core rod is smaller than or equal to D;

s2, embedding the bar into the prefabricated hole 6, and filling the gap 7 between the bar and the prefabricated hole 6 through filling welding or self-fluxing welding;

s3, obtaining holes with the diameter D on the bar, providing all hole walls for the holes with the diameter D by the outer cladding 3, and taking the outer cladding 3 as the wear-resistant layer material.

In this scheme, step S1 is a preparation step, and a prefabricated hole 6 and a bar for filling the prefabricated hole 6 are obtained; step S2 is a welding step, and welding of the rod in the prefabricated hole 6 is completed; step S3 is used for the hole final molding that the diameter is D, and the hole final molding that the diameter is D back, this rod material is as the pore wall in hole, and original this rod can be whole material and wearing layer material the same promptly, also can be local material and wearing layer material the same, and is the same for this original rod is local material and wearing layer material, accomplishes step S3 back, utilizes drilling processing, reaming processing etc. to get rid of after other materials, can make on this rod material and the unanimous part of wearing layer material conduct wearing layer material.

The rod that this scheme provided can be used to the hole preparation that has the inner wall wearing layer on the part 5, for directly build-up welding wearing layer on the inner wall in prefabricated hole 6 among the prior art, owing to insert again and weld behind the prefabricated hole 6 through this rod, like this, provides the boundary for the weld bath in other words: the outer side is the hole wall of the prefabricated hole 6, the inner side is the outer wall of the bar, the build-up welding of the inner wall of the prefabricated hole 6 which is difficult to operate is changed into the gap 7 filling welding which is easy to operate at present, and the purpose of improving the product percent of pass by being beneficial to the welding quality is achieved by greatly reducing the difficulty of the welding operation; meanwhile, compared with the build-up welding of the inner wall of the prefabricated hole 6, the gap 7 between the prefabricated hole 6 and the bar is filled by utilizing automatic welding to complete filling welding and hot-melt welding, so that the product quality can be further ensured, meanwhile, the preparation efficiency of the hole with the inner wall wear-resistant layer is convenient to improve, and the mass production is favorably realized.

In the scheme, the outer cladding layer 3 consistent with the wear-resistant layer is obtained by performing surfacing on the middle core rod, namely the scheme provides a realization scheme that the rod can be conveniently obtained. And the outer cladding layer 3 is obtained by surfacing on the outer side of the middle core rod, and because the operation is convenient, the surfacing can be realized by utilizing automatic welding equipment or manually, and manufacturers for preparing the holes generally have the characteristic of the capability of preparing the bar, so that the bar is easy to prepare, and the preparation quality and the preparation efficiency can be ensured.

As the technicians in the field, after the final hole is formed, the used material is only the outer cladding layer 3 material, and the middle core rod is only used as the base body of the overlaying cladding layer 3, so the technicians in the field can conveniently remove the middle core rod, and the middle core rod is set to be the material with good drilling processing performance and good bonding quality with the outer cladding layer 3.

Example 2:

the present embodiment is further limited by the embodiment 1, and as a specific implementation manner of the intermediate core rod, the intermediate core rod is a hollow tube 2. By adopting the scheme, the inner side boundary of the outer cladding layer 3 is restrained by the outer side of the hollow tube 2, and the middle core rod is convenient to remove in the follow-up process.

Example 3:

this embodiment is further defined on the basis of embodiment 1, said intermediate core rod being a solid rod 4. Adopt solid 4 as middle plug, compare in middle plug adoption for the tubular product of hollow tube 2, when implementing the build-up welding in order to obtain outer cladding 3, solid middle plug is difficult warp so can the inside border shape of accurate outer cladding 3, like this, when choosing middle plug, can make the diameter of middle plug more be close to with above D value, if the diameter of middle plug equals D or slightly is less than D can. For the case that the diameter of the middle core rod is smaller than D, the D is set to be larger than the diameter of the middle core rod by 0.3-3 mm. Since the wear layer itself is difficult to process, the outer cladding 3 to be processed in step S3 for the hole having the diameter D has a smaller thickness, which facilitates the implementation of step S3.

Example 4:

the embodiment is further limited on the basis of embodiment 1, and as a specific application mode, the following is set: the holes are pin holes on a connecting rod or a claw on the CRDM, and the outer cladding 3 is made of Stellite6 alloy. The scheme provides a part 5 preparation method which is easy to prepare a hook claw or a connecting rod and can improve the product percent of pass: the surfacing process is completed at the outer side of the hole, the obtained wear-resistant layer of the inner wall of the hole is obtained by filling welding and subsequent hole processing, the product percent of pass can be effectively improved, and the processing quality of the connecting rod and the claw is ensured. The subsequent hole machining can be to remove the material on the inner side of the outer cladding 3 in a grinding and reaming mode after removing the middle core rod through drilling so as to finally form a hole with a space D.

As a specific form of the bar, provided are: the outer diameter of the middle core rod is less than 9mm, and the outer diameter of the outer cladding layer 3 is greater than 10 mm.

Furthermore, to increase the minimum thickness of the resulting wear layer, the following settings are made: the outer diameter of the middle core rod is smaller than 8mm, and the outer diameter of the outer cladding layer 3 is larger than 11.5 mm.

Example 5:

this example is further defined on the basis of example 4, and a specific method for preparing the wear-resistant layer on the claw is provided below, so as to further explain the present invention in detail:

1. firstly, a wear-resistant alloy layer with enough thickness is formed on the outer circle surface of a section of round steel in a surfacing mode to serve as an outer cladding layer 3, and the bar is obtained as shown in fig. 3 or fig. 4. Wherein, the diameter of the round steel is 7.5 mm, and the final size D of the small hole of the claw is 9.5 mm; the round steel material is 304 stainless steel, the overlaying layer is Stellite6 alloy, and an oxyacetylene overlaying mode is adopted.

2. Machining the surface of the outermost layer of the bar subjected to surfacing in the last step, turning and cylindrical grinding to obtain the outer surface of the surfacing layer with high quality, and then discovering defects in the surfacing layer in a UT + PT flaw detection mode and identifying the defects.

3. And (3) shortening the qualified bar subjected to flaw detection in the previous step to a proper length, wherein the length is not less than the length of the long hole of the claw when aiming at the long hole on the claw and is not less than the length of the short hole when aiming at the short hole on the claw according to the object to be filled by the bar.

4. On the hook claw, a prefabricated hole 6 (also can be in the form of the prefabricated hole 6 shown in fig. 7) is processed as shown in fig. 5; the rod shown in fig. 4 is then placed in the preformed hole 6 to obtain the fitting relationship of the part 5 and the rod as provided in fig. 6.

5. Performing vacuum electron beam welding at the position of the gap 7 shown in fig. 6, filling Stellite6 powder welding material in the welding process, completely filling the gap 7 on one side of the prefabricated hole 6, turning over the part 5, and completely filling the gap 7 on the other side of the prefabricated hole 6; for the prefabricated hole 6 form shown in fig. 7, vacuum electron beam welding is performed from the wider side of the gap 7, and the gap 7 is completely filled. The method is particularly suitable for welding short holes of the claw and is also particularly suitable for manufacturing overlaying layers of connecting rods of CRDM parts 5 of the same type.

6. And (3) machining the claw which is welded with the part 5 and the bar material through the steps to obtain the qualified claw shown in the figures 1 and 2.

Compared with the prior art, the embodiment has the following beneficial effects:

1. the method for manufacturing the small hole overlaying layer on the claw of the control rod driving mechanism changes the previous small hole inner wall overlaying which is difficult to operate into the existing round steel outer circle overlaying which is easy to operate, greatly reduces the overlaying operation difficulty, has the characteristics of reliable overlaying quality, realization of automatic overlaying, low bar preparation cost, high yield and the like, and is favorable for batch production.

2. The method provided by the embodiment can be suitable for the surfacing layer manufacturing of the connecting rod of the CRDM part 5 of the same type.

3. The method provided by the embodiment can be used for carrying out comprehensive flaw detection on the surfacing layer on the excircle of the round steel, so that the qualification rate of the final finished product of the hook claw and the connecting rod is greatly improved, and the comprehensive manufacturing cost of the finished product is reduced.

The foregoing is a more detailed description of the present invention, taken in conjunction with the specific preferred embodiments thereof, and it is not intended that the invention be limited to the specific embodiments thereof. To the utility model belongs to the technical field of the ordinary skilled person say, do not deviate from the utility model discloses a other embodiments that reach under the technical scheme all should be contained the utility model discloses a within the scope of protection.

Claims

1. The utility model provides a can improve hole inner wall wearing layer preparation of product percent of pass and use rod, includes rod body (1), its characterized in that, rod body (1) includes surrounding layer (3) and middle plug, surrounding layer (3) cladding is in the outside of middle plug, and surrounding layer (3) are whole cylindricly, surrounding layer (3) are obtained through build-up welding on middle plug, the material of surrounding layer (3) is the same with the material of wearing layer.

2. The rod material for producing a wear-resistant layer on the inner wall of a hole, which can improve the yield of products, according to claim 1, wherein the central core rod is a hollow tube (2).

3. The rod material for preparing the wear-resistant layer on the inner wall of the hole, which can improve the product yield, according to claim 1, wherein the intermediate core rod is a solid rod (4).

4. The rod material for preparing wear-resistant layer on inner wall of hole for increasing the product yield of claim 1, wherein the hole is a pin hole on a connecting rod or a claw on CRDM, and the material of the outer cladding (3) is Stellite6 alloy.

5. The rod material for preparing a wear-resistant layer on the inner wall of a hole, which can improve the product yield according to claim 4, wherein the intermediate core rod is a ferritic stainless steel tube or rod material.

6. The rod material for preparing the wear-resistant layer on the inner wall of the hole, which can improve the product yield according to claim 5, wherein the middle core rod is a 304 stainless steel pipe or rod material.

7. Bar for producing wear-resistant layer on the inner wall of hole capable of increasing the product yield according to claim 4, characterized in that the outer diameter of the central core rod is less than 9mm and the outer diameter of the outer cladding (3) is more than 10 mm.

8. Bar for the preparation of wear layer of inner wall of hole capable of increasing the product yield according to claim 7, characterized in that the outer diameter of the central core rod is less than 8mm and the outer diameter of the outer cladding (3) is more than 11.5 mm.