阅读说明：本技术 一种压水堆环形燃料组件骨架焊接电极 (Welding electrode for pressurized water reactor annular fuel assembly framework ) 是由 赵婷 刘杰 赵常昆 郝新贵 刘宝桐 耿坤峰 张坤 高博 纪思倩 赵一霖 崔振波 于 2020-04-30 设计创作，主要内容包括：本发明涉及环形燃料组件制造技术领域,具体公开了一种压水堆环形燃料组件骨架焊接电极,为三棱柱体,其中一侧棱加工为弧形接触面,作为电极头部；在所述焊接电极的下方工作面、靠近电极头部处加工有圆柱体凸台A,作为电极工作部位。本发明电极结构设计合理,可满足不同位置焊点的焊接定位需求。(The invention relates to the technical field of annular fuel assembly manufacturing, and particularly discloses a skeleton welding electrode of a pressurized water reactor annular fuel assembly, which is a triangular prism, wherein one side edge is processed into an arc-shaped contact surface and is used as an electrode head; and a cylindrical boss A is processed on the working surface below the welding electrode and close to the head of the electrode to serve as an electrode working part. The electrode has reasonable structural design and can meet the welding positioning requirements of welding spots at different positions.)

1. The utility model provides a PWR annular fuel assembly skeleton welding electrode which characterized in that: the welding electrode is a triangular prism, wherein one side edge is processed into an arc contact surface and used as an electrode head;

the welding electrode is provided with a screw hole which penetrates through the upper working surface and the lower working surface of the welding electrode and is used for fixing the welding electrode on a welding gun by using a screw;

a cylindrical boss A is processed on the working surface below the welding electrode and close to the electrode head part, and is used as an electrode working part with the diameter d;

and a cylindrical boss B with the diameter D is processed on the upper working surface of the welding electrode and close to the electrode head, wherein D is larger than D.

2. The PWR annular fuel assembly skeleton welding electrode of claim 1, wherein: what is needed isDiameter of the electrode working partWherein F is the shearing force of a single welding point, and sigma is the shearing strength of the single welding point.

3. The PWR annular fuel assembly skeleton welding electrode of claim 2, wherein: arc of the electrode headWherein h is the indentation depth;

h is less than or equal to (h1+ h2) × (1-80%) +/2, h1 is the thickness of the welding lug wall, and h2 is the thickness of the guide tube wall.

4. The PWR annular fuel assembly skeleton welding electrode of claim 3, wherein: the screw hole on the welding electrode is a counter bore.

5. The PWR annular fuel assembly skeleton welding electrode of claim 4, wherein: the cylindrical boss A and the cylindrical boss B are coaxial.

6. The PWR annular fuel assembly skeleton welding electrode of claim 5, wherein: the axis of the cylindrical boss A is perpendicular to the lower working surface of the welding electrode.

7. The annular fuel assembly skeleton welding electrode of a pressurized water reactor as claimed in any one of claims 1 to 6, wherein: the welding electrode is made of beryllium cobalt copper.

Technical Field

The invention belongs to the technical field of annular fuel assembly manufacturing, and particularly relates to a skeleton welding electrode of a pressurized water reactor annular fuel assembly.

Background

The annular fuel assembly of the pressurized water reactor is firstly developed at home at present, and the requirements that the electrode structure is reasonable in design, can be in perfect contact with a workpiece, and has no defects of splashing and the like need to be met. The annular fuel assembly framework has larger difference with the existing pressurized water reactor fuel assembly framework, the pressurized water reactor fuel assembly framework only has one strip plug-in type grid, the spot welding position is positioned at the welding tongue of the whole protruding grid, and the electrode welding positioning is convenient; the annular fuel assembly framework is provided with strip plug-in type and grid cell type grillworks, welding points of the grid cell type grillworks are located in the middle of grid cells in the grillworks, and electrodes are required to enter the grid cells for positioning welding.

At present, no reference example exists in China for welding electrodes compatible with two forms of grid welding.

Disclosure of Invention

The invention aims to provide a welding electrode for a pressurized water reactor annular fuel assembly framework, which meets the requirement of welding the annular fuel assembly framework.

The technical scheme of the invention is as follows:

a pressurized water reactor annular fuel assembly skeleton welding electrode is a triangular prism, wherein one side edge is processed into an arc-shaped contact surface to serve as an electrode head;

the welding electrode is provided with a screw hole which penetrates through the upper working surface and the lower working surface of the welding electrode and is used for fixing the welding electrode on a welding gun by using a screw;

a cylindrical boss A is processed on the working surface below the welding electrode and close to the electrode head part, and is used as an electrode working part with the diameter d;

and a cylindrical boss B with the diameter D is processed on the upper working surface of the welding electrode and close to the electrode head, wherein D is larger than D.

Diameter of the working part of the electrodeWherein F is the shearing force of a single welding point, and sigma is the shearing strength of the single welding point.

Arc of the electrode headWherein h is the indentation depth;

h is less than or equal to (h1+ h2) × (1-80%) +/2, h1 is the thickness of the welding lug wall, and h2 is the thickness of the guide tube wall.

The screw hole on the welding electrode is a counter bore.

The cylindrical boss A and the cylindrical boss B are coaxial.

The axis of the cylindrical boss A is perpendicular to the lower working surface of the welding electrode.

The welding electrode is made of beryllium cobalt copper.

The invention has the following remarkable effects:

(1) the beryllium-cobalt-copper material and the zirconium material adopted by the invention have small alloying tendency, and the phenomenon of copper adhesion can not occur; the heat conductivity is good, and the excessive melting caused by heat accumulation can be avoided during continuous welding; the high-temperature strength and the hardness are high, and the material cannot deform obviously after long-term use; the resistivity is low, and the self resistance does not influence the contact resistance at the contact part of the grid welding tongue and the guide pipe to generate heat during welding.

(2) The electrode structure has proper size selection, and ensures that the strength of a welding spot meets the technical requirements while the welding spot has no defects of oxidation color, splashing, copper adhesion and the like.

(3) The electrode has reasonable structural design and can meet the welding positioning requirements of welding spots at different positions. When welding the welding tongue and the welding spot of the guide pipe, the grid frame can be conveniently positioned to the welding tongue; when welding spots in the grid cells are welded, the welding spots can penetrate into the grid cells for welding.

Drawings

FIG. 1 is a schematic view of a welding electrode.

FIG. 2 is a schematic cross-sectional view of a welding electrode;

FIG. 3 is a schematic view of a solder joint indentation;

Detailed Description

The invention is described in further detail below with reference to the figures and the embodiments.

A welding electrode for a pressurized water reactor annular fuel assembly framework is made of beryllium-cobalt-copper, has small alloying tendency with zirconium materials, does not have the phenomenon of copper adhesion, and has the advantages of good heat conductivity, high-temperature strength and hardness and low resistivity.

As shown in fig. 1-2, the welding electrode is a triangular prism, wherein one side edge is processed into an arc-shaped contact surface as an electrode head, and the arc of the electrode head is R. The arc contact surface can ensure good contact between the welding electrode and a workpiece under the condition that the welding electrode is slightly inclined, and avoids the defects of welding spot splashing, oxidation color and the like.

And counterbores are processed on the welding electrodes, penetrate through the upper working surface and the lower working surface of the welding electrodes and are used for fixing the welding electrodes on a welding gun by using screws.

And a cylindrical boss A is processed on the working surface below the welding electrode and close to the head of the electrode, and is used as an electrode working part with a diameter d. The axis of the cylindrical boss A is perpendicular to the lower working surface of the welding electrode.

And a cylindrical boss B with a diameter D is processed on the upper working surface of the welding electrode and close to the head part of the electrode. D is larger than D, and the boss A is coaxial with the boss B, so that the electrode and the welding gun are ensured to be installed and fastened, and wrong assembly is avoided.

Diameter of the working part of the electrodeWherein F is the shearing force of a single welding point, and sigma is the shearing strength of the single welding point.

The electrode head radian R is calculated in the following way:

the technical conditions require that the reduction of the wall thickness of the welding tongue and the wall thickness of the guide pipe is not less than 80 percent of the original workpiece, so that:

h≤(h1+h2)×(1-80％)÷2 (1)

wherein h is the indentation depth, h1 is the weld tongue wall thickness, and h2 is the guide tube wall thickness;

as shown in fig. 3, according to the law of collusion strands:

the available R value is calculated:

and selecting a proper electrode diameter d and an appropriate electrode head arc angle R according to the calculation result and considering the machining difficulty.