CN113462880A - Method and structure for reducing full-field residual stress of weld joint by local heating and water jet - Google Patents

Abstract

The application relates to a method for reducing the full-field residual stress of a welding line by local heating and water jet, which comprises the steps of defining an external heating area on the outer side of a welding connector and defining an internal jet injection area on the inner side; the external heating area and the internal jet flow spraying area cover the welding seam on the welding connector; heating the external heating area to a heat treatment temperature T; the inner jet spray zone is sprayed with a waterjet fluid at a predetermined pressure P. The structure comprises a plurality of heating sheets, wherein each heating sheet is correspondingly connected to one heating belt on the welding connector so as to heat an external heating area on the welding connector and heat the external heating area to a heat treatment temperature T; the heat insulation cotton is connected to the welding connector and covers the external heat insulation area; and a nozzle provided inside the welded connection body to be able to spray a fluid of a predetermined pressure P toward an inner jet spray area on the welded connection body.

Description

Method and structure of localized heating and water jet to reduce residual stress in welding seam

technical field

The present application belongs to the technical field of welding residual stress treatment, and in particular relates to a method and a structure for reducing the residual stress in the welding seam by local heating and water jet.

Background technique

In petrochemical projects, the barrels of the towers mostly rely on welding to achieve butt joints, and rely on welding to achieve butt joints. After the welding is completed, residual stress will inevitably occur in the weld area, and the existence of residual stress will affect the stability and safety of the tower. The above-mentioned problems are more prominent in the case of large-scale development of petrochemical projects and larger and larger towers.

At present, the method of local heat treatment is mostly used in engineering to deal with the residual stress generated in the weld area. However, due to the lack of corresponding specifications, this method is mostly implemented based on experience, and it is difficult to effectively eliminate the residual stress in the weld area. This problem is particularly prominent when the wall thickness of the welded connection is relatively large.

SUMMARY OF THE INVENTION

Based on the above-mentioned background technology, the purpose of the present application is to provide a method and structure for localized heating and water jet to reduce the residual stress in the welding seam, so as to overcome or alleviate the known technical defects in at least one aspect.

The technical solution of this application is:

On the one hand, a method for localized heating and water jet to reduce the residual stress in the welding seam is provided, including:

An external heating area is defined on the outside of the welded connection body, and an internal jet injection area is defined on the inside; wherein, the external heating area and the internal jet injection area cover the weld on the welded connection body;

Heating the external heating area to the heat treatment temperature T;

The inner jet ejection area is ejected with a water jet fluid of a predetermined pressure P.

According to at least one embodiment of the present application, in the above-mentioned method for reducing the overall residual stress of a welding seam by local heating and water jet, the external heating area is obtained by offsetting both sides of the welding seam on the welded connection body by more than 300 mm outward.

其中，According to at least one embodiment of the present application, in the above-mentioned method for reducing the full-field residual stress of a welded joint by local heating and water jet, when the welded joint is a cylindrical body welded butt joint, the internal jet injection area is within the width of the welded joint of the welded joint. size in direction

in,

W is the size of the external heating area in the width direction of the welded joint;

R is the radial dimension of the welded connection cylinder;

t is the equivalent thickness of the welded connection cylinder.

According to at least one embodiment of the present application, the above-mentioned method for reducing the full-field residual stress of a weld by local heating and water jet further includes:

A number of heating strips are divided along the width of the weld joint in the external heating area, where:

A heating belt covers the welding seam on the welding connection body, and the heating belt is the first heating belt;

The two heating belts located outside the first heating belt are the second heating belts;

The two heating belts located outside the two second heating belts are the third heating belts;

The two heating belts located outside the two third heating belts are the fourth heating belts;

The external heating area is heated to the heat treatment temperature T, specifically:

Heating the first heating belt to T-5°C;

Heating the two second heating belts to T°C;

Heating the two third heating belts to T+2°C;

The two fourth heating belts were heated to T+5°C.

According to at least one embodiment of the present application, in the above-mentioned method for reducing the residual stress of the welding seam by local heating and water jet, the size of each heating belt in the width direction of the welding seam of the welded joint is 100 mm;

The spacing of each heating belt in the width direction of the welded joint is 20 mm.

According to at least one embodiment of the present application, the above-mentioned method for reducing the full-field residual stress of a weld by local heating and water jet further includes:

An external thermal insulation area is constructed on the outside of the welded joint, and the external thermal insulation area covers the external heating area.

According to at least one embodiment of the present application, in the above-mentioned method for reducing the full-field residual stress of the weld by local heating and water jet, the dimension of the external heat preservation area in the width direction of the weld of the welded joint is 1000 mm.

According to at least one embodiment of the present application, in the above-mentioned method for reducing the residual stress of the welding seam by local heating and water jet, the injection of the fluid with a predetermined pressure P to the inner jet injection area is specifically:

On the outside of the welded connection body, from the position away from the upper welding seam to the position close to the upper welding seam, the fluid with a predetermined pressure P is sprayed on the inner jet spraying area.

According to at least one embodiment of the present application, in the above-mentioned method for reducing the full-field residual stress of a weld by local heating and water jet, P=0.6-0.8σ;

in,

σ is the equivalent yield strength of the welded joint material.

Another aspect provides a structure for localized heating and water jet to reduce the residual stress of the weld, including:

a plurality of heating pieces, each of which is connected to a heating belt on the welding connection body, so as to be able to heat the external heating area on the welding connection body, and heat the external heating area to the heat treatment temperature T;

Insulation cotton, connected to the welded connector, covering the external insulation area;

A nozzle is provided inside the welded connection so as to be able to spray water jet fluid of a predetermined pressure P to the internal jet injection area on the welded connection.

According to at least one embodiment of the present application, in the above-mentioned structure in which local heating and water jets reduce the overall residual stress of the weld, H=5b, wherein,

H is the distance from the nozzle to the inside of the welded connection;

b is the diameter of the nozzle.

This application has at least the following beneficial technical effects:

In one aspect, there is provided a method for localized heating and water jet reduction of full-field residual stress in a weld, which heats an externally heated area outside a welded connection to locally heat treat the weld area of the welded connection, and, in a predetermined manner. The fluid with pressure P sprays the internal jet injection area inside the welded connection body, and performs jet peening treatment on the weld area on the welded connection body, that is, the welding connection body is realized in the form of local heat treatment and jet peening treatment. Residual stress treatment in the weld area, based on this method, the full-field residual stress generated in the weld area can be effectively eliminated.

On the other hand, a structure for reducing the overall residual stress of the weld by local heating and water jet is provided, which is used to realize the above disclosed method for reducing the residual stress of the weld by local heating and water jet, which can be treated by local heat treatment and jet peening The form of coupling realizes the treatment of residual stress in the weld area of the welded joint, and effectively eliminates the full-field residual stress generated in the weld area.

Description of drawings

FIG. 1 is a flow chart of a method for reducing the residual stress in the welding seam by local heating and water jet provided in an embodiment of the present application;

FIG. 2 is a schematic diagram of a structure for reducing the residual stress in the welding seam by local heating and water jet provided in an embodiment of the present application;

FIG. 3 is a partial schematic diagram of a structure for reducing the residual stress in the weld seam by local heating and water jet provided in an embodiment of the present application;

FIG. 4 shows the results of processing the residual stress in the weld area of the welded connection body formed by the butt welding of the cylinder body by the method and its structure for reducing the residual stress of the welding seam by local heating and water jet provided in the embodiment of the present application. The comparison diagram of the residual stress treatment results of the welded joint formed by the heat treatment method on the welded joint formed by the butt welding of the cylinder along the wall thickness direction of the welded joint;

FIG. 5 shows the results of processing the residual stress in the weld area of the welded connection body formed by the butt welding of the cylinder body by the method and its structure for reducing the residual stress in the welding seam by local heating and water jet provided in the embodiment of the present application. The results of the heat treatment method on the residual stress in the weld area of the welded joint formed by the butt welding of the cylinder body, and the comparison diagram along the axial direction of the welded joint;

FIG. 6 is the temperature distribution of heating the external heating area of the welded connection body formed by the butt welding of the cylinders by the method of local heating and water jet for reducing the residual stress in the welding seam provided by the embodiment of the present application and the structure thereof. Comparison of the temperature distribution of the external heating area of the welded connection body formed by the welding and butt joint of the cylinder body by the local heat treatment method;

in:

1-welding connector; 2-heating sheet; 3-insulation cotton; 4-nozzle.

In order to better illustrate the present embodiment, some parts of the drawings are omitted, enlarged or reduced, which do not represent the size of the actual product; in addition, the drawings are used for exemplary illustration, and the terms describing the positional relationship are only limited to the exemplary illustration. , and cannot be construed as a limitation on this patent.

Detailed ways

In order to make the technical solution of the present application and its advantages more clear, the technical solution of the present application will be further described in detail and completely with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only part of the present application. The examples are only used to explain the present application, but not to limit the present application. It should be noted that, for the convenience of description, only the parts related to the present application are shown in the drawings, and other related parts may refer to the general design. If there is no conflict, the embodiments in the present application and the techniques in the embodiments Features can be combined with each other to obtain new embodiments.

Also, unless otherwise defined, technical or scientific terms used in the description of this application shall have the ordinary meaning as understood by those of ordinary skill in the art to which this application belongs. The words "upper", "lower", "left", "right", "center", "vertical", "horizontal", "inner", "outer", etc. used in the description of this application to indicate orientation are only used To indicate the relative direction or positional relationship, rather than implying that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and when the absolute position of the described object changes, its relative positional relationship may also change accordingly , so it cannot be construed as a limitation on this application. The terms "first", "second", "third" and similar terms used in the description of this application are only used for the purpose of description, to distinguish different components, and cannot be construed as indicating or implying relative importance. Words like "a," "an," or "the" and the like used in the description of this application should not be construed as an absolute limitation on the quantity, but should be construed as the presence of at least one. As used in the description of this application, "comprises" or "comprises" and similar words mean that the elements or things appearing before the word encompass the elements or things listed after the word and their equivalents, but do not exclude other elements or things.

In addition, it should be noted that, unless otherwise expressly specified and limited, the words "installed", "connected", "connected" and the like used in the description of this application should be understood in a broad sense, for example, the connection may be a fixed The connection can also be a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be an internal connection between two components. A skilled person can understand its specific meaning in this application according to specific circumstances.

The present application will be further described in detail below with reference to FIGS. 1 to 6 .

On the one hand, a method for localized heating and water jet to reduce the residual stress in the welding seam is provided, including:

An external heating area is defined on the outside of the welded connection body 1, and an internal jet injection area is defined on the inner side; wherein, the external heating area and the internal jet injection area cover the welding seam on the welded connection body 1;

Heating the external heating area to the heat treatment temperature T to perform local heat treatment on the welding seam area on the welded connection body 1;

The inner jet spray area is sprayed with a water jet fluid of a predetermined pressure P to perform jet peening treatment on the weld seam area on the welded connection body 1 .

As for the method for reducing the residual stress of the welding seam by local heating and water jet disclosed in the above embodiments, those skilled in the art can understand that the method heats the external heating area outside the welded connection body 1 to heat the welded connection body 1 . Local heat treatment is performed on the weld area of the welded joint 1, and the internal jet spray area inside the welded joint 1 is sprayed with a fluid with a predetermined pressure P, and the weld area on the welded joint 1 is subjected to jet peening treatment, that is, local heat treatment The residual stress in the weld area of the welded connection body 1 can be treated in the form of coupling with the jet peening treatment. Based on this method, the residual stress generated in the weld area can be effectively eliminated.

As for the method for reducing the residual stress of the welding seam by local heating and water jet disclosed in the above embodiments, those skilled in the art can also understand that the external heating area is heated to the heat treatment temperature T, and the specific heat treatment temperature T is The numerical value can be determined by those skilled in the art according to existing experience or specifications when applying the technical solutions disclosed in the present application.

Those skilled in the art can also understand that the method for reducing the residual stress of the welding seam by local heating and water jet disclosed in the above embodiments can be applied to the residual stress generated in the welding seam area between the barrels of the towers. Treatment, when applied to the treatment of residual stress in the welding seam area between the column bodies, the welded connection body 1 is formed by the welding and butt joint of the column body, which can effectively eliminate the generation of the welding seam area between the column bodies. residual stress.

For the methods for local heating and water jet reduction of the full-field residual stress of the weld disclosed in the above embodiments, those skilled in the art can also understand that the internal jet spray area is sprayed with a fluid of a predetermined pressure P, which may be a predetermined The water flow of pressure P sprays the inner jet spray area.

In some optional embodiments, in the above-mentioned method for reducing the residual stress of the welding seam by local heating and water jet, the external heating area is obtained by offsetting the two sides of the welding seam on the welded connector 1 outward by more than 300 mm, In order to ensure the effective coverage of the welding seam area on the welded connection body 1, the effect of eliminating residual stress in the welding seam area of the welded connection body 1 is ensured.

其中，In some optional embodiments, in the above-mentioned method of local heating and water jet to reduce the residual stress of the welding seam, when the welded connection body 1 is a cylindrical body welded butt joint, the internal jet injection area is welded on the welded connection body 1. Dimensions in seam width direction

in,

W is the dimension of the external heating area in the width direction of the welding seam of the welded connector 1;

R is the radial dimension of the welded connection cylinder;

t is the equivalent thickness of the welded connection cylinder.

可保证对焊接连接体1上焊缝区域的有效覆盖，以将外部加热区域涵盖在内，以此可保证对焊接连接体1焊缝区域残余应力的消除效果。As for the method of local heating and water jet for reducing the residual stress in the welding seam disclosed in the above embodiments, those skilled in the art can understand that when the welded connection body 1 is a cylindrical welded butt joint, the internal jet injection area is designed to be in the welding position. Dimensions in the width direction of the weld seam of connector 1

Effective coverage of the welding seam area on the welded connection body 1 can be ensured to cover the external heating area, thereby ensuring the effect of eliminating residual stress in the welding seam area of the welded connection body 1 .

In some optional embodiments, the above-mentioned method for reducing the full-field residual stress of a weld by local heating and water jet further includes:

In the external heating area, a plurality of heating strips are divided along the width of the welding seam of the welded joint 1, wherein:

A heating belt covers the welding seam on the welding connection body 1, and the heating belt is the first heating belt;

The two heating belts located outside the first heating belt are the second heating belts;

The two heating belts located outside the two second heating belts are the third heating belts;

The two heating belts located outside the two third heating belts are the fourth heating belts;

The external heating area is heated to the heat treatment temperature T, specifically:

Heating the first heating belt to T-5°C;

Heating the two second heating belts to T°C;

Heating the two third heating belts to T+2°C;

The two fourth heating belts were heated to T+5°C.

As for the method for reducing the residual stress of the welding seam by local heating and water jet disclosed in the above embodiments, those skilled in the art can understand that the external heating area is heated to the heat treatment temperature T, and the heating to the heat treatment temperature The temperature T does not mean that the external heating area is absolutely heated to the heat treatment temperature T, but refers to the heating of the external heating area approximately to the heat treatment temperature T, and the specific value is close to T.

For the methods for reducing the residual stress of the welding seam by local heating and water jet disclosed in the above embodiments, those skilled in the art can also understand that, in the case that the outer area of the welded connection body 1 is too large, the external heating When the area is heated, it is difficult to ensure the uniformity of the heating of the external heating area, which is not conducive to the effective elimination of residual stress in the weld area on the welded connection body 1. In the above embodiment, the external heating area is designed to be welded along the welded connection body 1. A plurality of heating belts are divided in the width direction of the slit. When heating the external heating area, each heating belt is heated independently, which can avoid the uneven heating of the external heating area to a certain extent, and there will be no serious middle part. When the temperature of the part is high and the temperature of the edge part is low, the residual stress in the welding seam area on the welded connection body 1 can be effectively eliminated.

As for the method for reducing the residual stress of the welding seam by local heating and water jet disclosed in the above embodiments, those skilled in the art can also understand that the design is that when the external heating area is heated, it is designed to synchronously heat the first heating belt. Heating to T-5°C, heating two second heating belts to T°C, heating two third heating belts to T+2°C, heating two fourth heating belts to T+5°C, Based on this, it can be ensured that when the external heating area is heated, the temperature difference around the external heating area will not exceed 10°C, so that the secondary thermal stress caused by the local heat treatment temperature can be reduced, and the welding seam of the welded connection body 1 can be guaranteed. Sufficient relief of regional residual stress.

As for the method for reducing the residual stress of the welding seam by local heating and water jet disclosed in the above embodiments, those skilled in the art can also understand that the design is that when the external heating area is heated, it is designed to synchronously heat the first heating belt. Heating to T-5°C, heating two second heating belts to T°C, heating two third heating belts to T+2°C, heating two fourth heating belts to T+5°C, Among them, 5°C and 2°C can be other values, and the specific values can be selected by the relevant technical personnel according to the actual situation when applying the technical solutions disclosed in the present application.

In some optional embodiments, in the above-mentioned method for reducing the residual stress of the welding seam by local heating and water jet, the size of each heating belt in the width direction of the welding seam of the welded connection body 1 is 100 mm;

The spacing of each heating belt in the width direction of the welding seam of the welded connection body 1 is 20 mm.

In some optional embodiments, the above-mentioned method for reducing the full-field residual stress of a weld by local heating and water jet further includes:

An external heat preservation area is constructed on the outside of the welded connection body 1, and the external heat preservation area covers the external heating area to ensure the effect of local heat treatment of the welding seam area of the connection body 1. The temperature is uniform throughout the heating area.

In some optional embodiments, in the above-mentioned method for reducing the residual stress of the welding seam by local heating and water jet, the dimension of the external heat preservation area in the width direction of the welding seam of the welded connection body 1 is 1000 mm.

In some optional embodiments, in the above-mentioned method for localized heating and water jet to reduce the residual stress of the weld seam, the injection of the fluid with a predetermined pressure P to the internal jet injection area is specifically:

On the outside of the welded connection body 1, from the position away from the upper welding seam to the position close to the upper welding seam, the fluid with a predetermined pressure P is sprayed on the inner jet spraying area.

As for the methods for local heating and water jet reduction of the full-field residual stress of the weld disclosed in the above-mentioned embodiments, those skilled in the art can understand that the design is that when the fluid with a predetermined pressure P is sprayed on the internal jet spray area, according to the automatic The part far from the welding seam is gradually carried out to the part close to the welding seam. In this way, the internal jet spraying area is sprayed to ensure that the welded joint 1 has a sufficiently large compressive stress at the bottom of the welding seam after the jet peening treatment.

In some optional embodiments, in the above-mentioned method for reducing the full-field residual stress of a weld by local heating and water jet, P=0.6-0.8σ;

in,

σ is the equivalent yield strength of the welded joint 1 material.

For the methods for local heating and water jet reduction in the welding seam full-field residual stress disclosed in the above embodiments, those skilled in the art can understand that the design of the method to spray the internal jet spray area with a fluid with a pressure of 0.6-0.8σ can avoid Cracks are generated inside the welded connection body 1 .

Another aspect provides a structure for localized heating and water jet to reduce the residual stress of the weld, including:

a plurality of heating sheets 2, each of which is connected to a heating belt on the welding connection body 1, so as to be able to heat the external heating area on the welding connection body 1, and heat the external heating area to the heat treatment temperature T;

The thermal insulation cotton 3 is connected to the welding connector 1 and covers the external thermal insulation area;

The nozzle 4 is arranged inside the welded connection 1 so as to be able to spray the fluid of the predetermined pressure P to the internal jet injection area on the welded connection 1 .

In some optional embodiments, in the above-mentioned structure in which local heating and water jets reduce the residual stress of the welding seam, H=5b, wherein,

H is the distance from the nozzle 4 to the inner side of the welded connection body 1;

b is the diameter of the nozzle 4 .

For the structure of the local heating and the water jet to reduce the residual stress of the welding seam disclosed in the above embodiments, those skilled in the art can understand that the distance from the designed nozzle 4 to the inner side of the welded connection body 1 is 5 times the diameter of the nozzle 4, In this way, it can be ensured that when the nozzle 4 sprays the jet jet area inside the welding connection body 1, the single action area is large, and the effect of jet peening on the residual stress in the welding seam area of the welding connection body 1 can be guaranteed, and the welding connection body 1. 1 Cracks on the inside.

For the method and structure for reducing the full-field residual stress of a weld by local heating and water jet disclosed in the above embodiments, those skilled in the art can understand that the inner side and outer side of the welded connection body 1 can be welded connection body 1. 1 Distinguish the inner and outer sides of the weld.

Those skilled in the art can understand that the structure of the local heating and water jets disclosed in the above embodiments to reduce the overall residual stress of the welding seam is used to realize the local heating and water jets disclosed in the above embodiments to reduce the overall residual stress of the welding seam For the method of stress, the technical effect that can be obtained can be referred to the technical effect of the relevant part of the method of local heating and water jet to reduce the residual stress of the weld in the whole field, and will not be repeated here.

In a specific embodiment, a cylinder with an inner diameter of 1 m made of 2205 duplex stainless steel with a thickness of 100 mm is welded to form a welded joint 1, and the current local heat treatment method is used to treat the residual stress generated in the weld area. . A comparison of the effects of the method and its structure for reducing the residual stress in the welding seam area by using the local heating and water jet disclosed in this application are shown in Figures 4-6.

It can be seen from Figure 4 that the residual stress distribution along the wall thickness direction treated by the existing local heat treatment method is extremely uneven. From the inner wall to the outer wall, the hoop stress changes from about 400MPa tensile stress to -200MPa compressive stress, and the axial stress is about -90MPa. The compressive stress changes to the tensile stress of about 400MPa, and the existing local heat treatment method cannot reduce the full-field residual stress along the wall thickness direction. The pure water jet treatment can not reduce the residual stress in the whole field, but can only reduce the residual stress in the surface layer and the superficial layer. However, after the method of the present application is adopted, the full-field residual stress along the wall thickness direction is reduced, the hoop stress is maintained below 100 MPa, and the axial stress is maintained below 130 MPa.

It can be seen from FIG. 5 that the residual stress of the inner wall after the existing local heat treatment method is still a relatively high tensile stress, but after the method of the present application, the residual stress of the inner wall is reduced to a compressive stress.

It can be seen from Figure 6 that the temperature distribution along the axial direction by the existing local heat treatment method is extremely uneven, showing the distribution law of high in the middle and low on both sides, while the axial temperature uniformity of the method of the present application is greatly improved, and the maximum temperature difference in the heating area is less than 50 ° C. .

The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other.

For the device disclosed in the above-mentioned embodiment, since it corresponds to the method disclosed in the above-mentioned embodiment, the description is relatively simple. For the specific related parts, please refer to the description of the method part, and the technical effect can also refer to the technical effect of the method part. This will not be repeated here.

So far, the technical solutions of the present invention have been described with reference to the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the protection scope of the present invention is obviously not limited to these specific embodiments, without departing from the principles of the present invention. Under the premise of the present invention, those skilled in the art can make equivalent changes or replacements to the relevant technical features, and the technical solutions after these changes or replacements will fall within the protection scope of the present invention.

Claims (10)

1. a method for local heating and water jet reduction of welding seam full field residual stress, is characterized in that, comprising: An external heating area is defined on the outside of the welded connection body (1), and an internal jet jet area is defined on the inner side; wherein, the external heating area and the internal jet injection area cover the welding seam on the welded connection body (1); Heating the external heating area to the heat treatment temperature T; The inner jet ejection area is ejected with a water jet fluid of a predetermined pressure P. 2. The method for reducing the residual stress of the welding seam by local heating and water jet according to claim 1, wherein the external heating area is offset by 300mm on both sides of the welding seam on the welding connector (1). obtained above. 3. The method for reducing the residual stress of the welding seam by local heating and water jet according to claim 1, characterized in that, when the welded connection body (1) is a cylindrical body welded butt joint, the internal jet jet area is in the welded connection. Body (1) Dimensions in the width direction of the weld

in, W is the dimension of the external heating area in the width direction of the welded joint (1); R is the radial dimension of the welded connection cylinder; t is the equivalent thickness of the welded connection cylinder. 4. The method for reducing the full-field residual stress of the weld by local heating and water jet according to claim 1, further comprising: In the external heating area, a plurality of heating strips are divided along the width of the welded joint (1), wherein: A heating belt covers the welding seam on the welding connection body (1), and the heating belt is the first heating belt; The two heating belts located outside the first heating belt are the second heating belts; The two heating belts located outside the two second heating belts are the third heating belts; The two heating belts located outside the two third heating belts are the fourth heating belts; The external heating area is heated to the heat treatment temperature T, specifically: Heating the first heating belt to T-5°C; Heating the two second heating belts to T°C; Heating the two third heating belts to T+2°C; The two fourth heating belts were heated to T+5°C. 5. The method for reducing the full field residual stress of the weld by local heating and water jet according to claim 4, wherein, The size of each heating belt in the width direction of the welding seam of the welding connector (1) is 100 mm; The interval of each heating belt in the width direction of the welding seam of the welded connection body (1) is 20 mm. 6. The method for reducing the full-field residual stress of the weld by local heating and water jet according to claim 1, further comprising: An external thermal insulation area is constructed on the outside of the welded connection body (1), and the external thermal insulation area covers the external heating area. 7 . The method for reducing the residual stress in the welding seam by local heating and water jet according to claim 6 , wherein the dimension of the external heat preservation area in the width direction of the welding seam of the welded joint (1 ) is 1000 mm. 8 . 8. The method for reducing the full-field residual stress of the weld by local heating and water jet according to claim 1, wherein the fluid with a predetermined pressure P is sprayed to the internal jet spray area, specifically: On the outside of the welded connection body (1), from the position away from the upper welding seam to the position close to the upper welding seam, the fluid with a predetermined pressure P is sprayed on the inner jet spraying area. 9. The method for reducing the full-field residual stress of the weld by local heating and water jet according to claim 1, wherein, P=0.6-0.8σ; in, σ is the equivalent yield strength of the material of the welded joint (1). 10. A structure for localized heating and water jet to reduce the residual stress in the welding seam, characterized in that it comprises: A plurality of heating pieces (2), each heating piece (2) is correspondingly connected to a heating belt on the welding connection body (1), so as to be able to heat the external heating area on the welding connection body (1), and heat the external heating strip (1). The heating area is heated to the heat treatment temperature T; The thermal insulation cotton (3) is connected to the welded connection body (1) and covers the external thermal insulation area; A nozzle (4) is provided inside the welded connection (1) to be able to spray water jet fluid of a predetermined pressure P to the internal jet injection area on the welded connection (1).

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