Simple argon filling device and process for butt welding of stainless steel 90-degree bent pipe and conjoined flange

Abstract

The invention discloses a simple argon filling device for butt welding of a stainless steel 90-degree bent pipe and a connected flange. The simple argon filling device comprises a tool bottom plate, a connected flange steel plate, a first pipeline, a second pipeline, a pipe plug and an argon filling pipe. 45-degree pipe notches are formed in the first pipeline and the second pipeline respectively, the other end of the second pipeline serves as a pipeline inlet, the connected flange steel plate is rectangular, and a pipeline outlet is formed in the center of the connected flange steel plate; the two ends of the tool bottom plate are correspondingly provided with a first 7-shaped clamping block and a second 7-shaped clamping block in parallel at intervals, and the two ends of the one-piece flange steel plate are matched with the inner sides of the first 7-shaped clamping block and the second 7-shaped clamping block respectively and clamped between the first 7-shaped clamping block and the second 7-shaped clamping block. The lower end of the first pipeline is combined with the upper surface of an outlet of the one-piece flange steel plate pipeline, the second pipeline and the first pipeline are combined through respective 45-degree pipe notches, the pipe plug is matched with a pipeline inlet of the second pipeline and can be inserted into the inner side of the pipeline inlet, and an argon filling pipe is arranged on the pipe plug in a penetrating mode. By means of the argon filling device, the argon filling problem of butt welding of the stainless steel 90-degree bent pipe and the connected flange can be effectively solved.

Description

Technical Field

[0001] The invention belongs to the technical field of welding, and in particular relates to a simple argon filling device and process for butt welding of a stainless steel 90° elbow pipe and a one-piece flange, which is suitable for butt welding of various pipelines. Background Art

[0002] At present, when stainless steel pipes are butt-welded to each other or to plates, argon must be filled inside the pipes to ensure internal quality, so as to protect the bottom weld from being well-formed, prevent root oxidation, and eliminate welding defects. Generally, when pipes are welded to pipes or plates, operators perform argon filling protection in a conventional manner, that is, various sealing tapes, thermal insulation cotton and other materials are used to seal, which can basically meet the requirements. However, when a large number of stainless steel 90° elbows and one-piece flanges are butt-welded, there are the following argon filling problems: (1) The various argon filling materials used are easy to fall off during welding, and the leakage protection effect is poor, which directly affects the quality of the welds. Some of them are repaired due to excessive root welding defects. (2) The argon filling materials currently used are all disposable, wasting a lot of procurement costs. Therefore, for a large number of stainless steel 90° elbows and one-piece flanges, it is necessary to design a simple argon filling device that can be reused economically, safely, and reliably, and does not affect the precision installation and welding of normal pipe-to-pipe and pipe-to-plate butt assemblies. Summary of the invention

[0003] In view of the technical problems existing in the background technology, the present invention provides a simple argon filling device and process for butt welding of stainless steel 90° elbow pipes and one-piece flanges, which can effectively solve the problem of argon filling in butt welding of stainless steel 90° elbow pipes and one-piece flanges.

[0004] The technical solution of the present invention to solve the technical problem is as follows:

[0005] According to one aspect of the present invention, a simple argon filling device for butt welding of a stainless steel 90° elbow and a conjoined flange is provided, which comprises a tooling base plate, a conjoined flange steel plate, a first pipeline, a second pipeline, a pipe plug and an argon filling pipe; 45° pipe cutouts are respectively provided on opposite sides of the first pipeline and the second pipeline, the other end of the second pipeline serves as a pipeline inlet, the conjoined flange steel plate is rectangular, and a pipeline outlet matching the inner diameter of the first pipeline is provided at the center; first and second "7"-shaped clamping blocks are respectively and parallelly arranged at intervals at both ends of the tooling base plate, and the two ends of the conjoined flange steel plate are respectively matched with the inner sides of the first and second "7"-shaped clamping blocks and are clamped therebetween; the lower end of the first pipeline is combined with the upper surface of the pipeline outlet of the conjoined flange steel plate, the second pipeline and the first pipeline are combined to form a 90° elbow through their respective 45° pipe cutouts, the pipe plug is matched with the pipeline inlet of the second pipeline and can be inserted into the inner side of the pipeline inlet, and the argon filling pipe is penetrated through the pipe plug.

[0006] Furthermore, there is one first "7"-shaped card block, which is arranged at the center of one end of the tooling base plate, and there are two second "7"-shaped card blocks, which are respectively arranged at the front and rear sides of one end of the tooling base plate.

[0007] The number of the first "7"-shaped card block is one, which is arranged on the tooling base plate. The tooling base plate is cut and machined from 20mm steel plate; the first "7"-shaped card block and the second "7"-shaped card block are cut and machined from 60mm steel plate, and are welded and arranged at both ends of the tooling base plate; the pipe plug is cut and machined from Φ120mm round rod; the argon filling tube is cut and machined from Φ8mm seamless steel pipe.

[0008] According to another aspect of the present invention, a stainless steel 90° elbow and conjoined flange butt welding process is provided, which is performed by the simple argon filling device described in the above technology, and the steps are as follows:

[0009] S1. Production and installation of simple argon filling device;

[0010] 1.1) According to the specifications of the stainless steel 90° elbow and one-piece flange to be butt-welded, the tooling base plate, the first "7"-shaped block, the second "7"-shaped block, the pipe plug and the argon-filled pipe are manufactured by machining steel plates, round bars and seamless steel pipes;

[0011] 1.2) Weld the first "7"-shaped block and the second "7"-shaped block on both ends of the upper surface of the tooling bottom plate, respectively, penetrate and weld the argon filling tube to the pipe plug, insert the pipe plug into the pipe inlet of the second pipe, combine the second pipe, the first pipe and the one-piece flange steel plate, and insert the one-piece flange steel plate between the first "7"-shaped block and the second "7"-shaped block;

[0012] S2. Preparation before welding:

[0013] 2.1) Welding equipment: manual argon arc welding and arc welding combined welding machine, high-purity argon purity 9999.9%, welding materials: CHG-308L welding wire, argon arc welding wire φ2.5mm, φ3.0mm;

[0014] 2.2) Welding material: stainless steel 0Cr18Ni9;

[0015] 2.3) Welding position: 45° fixed welding;

[0016] 2.4) Auxiliary facilities: angle grinder, file, hammer, flat shovel, mask, sample, thermometer, magnifying glass, thermal insulation cotton;

[0017] 2.5) Requirements before welding: The welding position area and welding materials must be free of oil, oxide layer and moisture, and the metallic luster must be exposed;

[0018] 2.6) Welding technical requirements: single-sided welding and double-sided forming, the weld cladding layer fuses the parent material, the weld has no welding defects and meets the design dimensions;

[0019] 2.7) Welding process parameters: Welding parameters are determined according to welding equipment, welding materials and welding requirements;

[0020] S3, welding implementation;

[0021] 3.1) Clean the combined position of the first pipeline and the pipeline outlet on the one-piece flange steel plate and the combined position of the 45° pipe cutouts of the first pipeline and the second pipeline; connect the argon filling pipe to the argon gas source for gas supply, and then weld the base layer, the filling layer and the cover layer at the two combined positions in sequence, and form the first weld and the second weld respectively;

[0022] 3.2) When welding the bottom layer at two combinations, the welding machine uses CHG-308L welding wire, φ2.5mm, manual tungsten inert gas arc welding, crescent strip method, high-purity argon purity 9999.9%, and wet cloth is used on both sides of the weld. During the welding process, the cloth is continuously wetted with water to ensure rapid cooling and welding to avoid various welding defects of stainless steel due to excessive temperature, which affects the quality of the weld. The horizontal angle between the welding wire and the pipe is 30-45°, the horizontal angle between the welding gun and the pipe is 65-80°, the welding current is 90-110A, the pipe-to-tube and the pipe-to-steel plate flange welding are all symmetrically welded from the 6 o'clock position from bottom to top to the 12 o'clock position, the bottom layer is single-sided welded and double-sided formed, and the welding is complete. After completion, clean the weld surface, confirm that there are no welding defects and grind the weld. Use a temperature gun to measure the temperature of the weld and heat-affected zone to be less than 60°, and then weld the filling layer and cover layer; the welding process of the filling layer and cover layer is consistent with the base layer welding process, the welding wire is φ3.0mm, the welding current is 120-140A, the cover layer is higher than the parent material, and the two sides of the weld maintain a smooth transition with the parent material, and then quickly cool to room temperature, and perform X-ray inspection according to the pressure vessel non-destructive testing standard JB / T4730-2005, and then perform standard mechanical properties testing according to NB / T47016-2011. After the test results confirm that they meet the requirements, they are put into use.

[0023] Furthermore, the welding equipment is a YC-400TX4 manual argon arc welding and stick arc welding combined welding machine.

[0024] Furthermore, when welding the base layer, the welding current is 90-110A, the arc voltage is 15-20V, the welding speed is 2.0-3.2mm / s, the heat input is 0.4-0.61kJ / mm, the welding method is GTAW, and the polarity is DCEP; when welding the filling layer and the cover layer, the welding current is 120-140A, the arc voltage is 20-24V, the welding speed is 4.3-6.6mm / s, the heat input is 0.6-0.91kJ / mm, the welding method is GTAW, and the polarity is DCEP.

[0025] Furthermore, the cover layer weld is no higher than the base material by no more than 3 mm.

[0026] Furthermore, argon gas is supplied 2 minutes in advance before welding.

[0027] Compared with the prior art, the present invention discloses a simple argon filling device and process for butt welding of a stainless steel 90° elbow and a one-piece flange. The simple argon filling device is made of common materials, has low cost, good effect, and is reusable. Combined with its process, it can effectively solve the problem of filling argon during welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1It is a structural schematic diagram of the simple argon filling device of the present invention;

[0029] Figure 2 for Figure 1 Explosion diagram of

[0030] Figure 3 is a schematic diagram of the first pipeline or the second pipeline in the present invention;

[0031] In the figure: 1. tooling base plate; 21. first "7"-shaped block; 22. second "7"-shaped block; 4. one-piece flange steel plate; 5. first pipeline; 6. second pipeline; 7. pipe plug; 8. argon filling tube; 9. first weld; 10. pipeline outlet; 11. pipeline inlet; 12. second weld; 13. 45° pipe cut. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the usual meanings understood by people with general skills in the field to which the present disclosure belongs. "Up", "down", "left", "right", "front", "back" and the like used in the patent application specification and claims of the present disclosure are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship also changes accordingly; "connected" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The parts not described in detail in the present invention are all known technologies of technicians in the field of this technology.

[0033] Embodiment 1:

[0034] like Figure 1-3As shown, the present invention provides a simple argon filling device for butt welding of a stainless steel 90° elbow and a conjoined flange, which comprises a tooling base plate 1, a conjoined flange steel plate 4, a first pipeline 5, a second pipeline 6, a pipe plug 7 and an argon filling pipe 8; a 45° pipe cutout 13 is respectively provided on one side opposite to the first pipeline 5 and the second pipeline 6, and the other end of the second pipeline 6 serves as a pipeline inlet 11; the conjoined flange steel plate 4 is rectangular, and a pipeline outlet 10 adapted to the inner diameter of the first pipeline 5 is provided at the center; first "7"-shaped pipes are respectively provided at two ends of the tooling base plate 1 in parallel and spaced apart from each other. shaped block 21 and the second "7" shaped block 22, and both ends of the conjoined flange steel plate 4 are respectively matched with the inner sides of the first "7" shaped block 21 and the second "7" shaped block 22 and clamped therebetween; the lower end of the first pipeline 5 is combined with the upper surface of the pipeline outlet 10 of the conjoined flange steel plate 4 to form a welding flange, the second pipeline 6 and the first pipeline 5 are combined through their respective 45° pipe cuts 13 to form a 90° elbow, the pipe plug 7 is matched with the pipeline inlet 11 of the second pipeline 6 and can be inserted into the inner side of the pipeline inlet 11, and an argon filling tube 8 is penetrated through the pipe plug 7.

[0035] As a preferred embodiment, there is one first "7"-shaped block 21 disposed at the center of one end of the tooling base plate 1, and there are two second "7"-shaped blocks 22 disposed at the front and rear sides of one end of the tooling base plate 1, respectively.

[0036] As a preferred embodiment, the tooling base plate 1 is machined by cutting from a 20mm steel plate; the first "7"-shaped block 21 and the second "7"-shaped block 22 are machined by cutting from a 60mm steel plate, and are welded at both ends of the tooling base plate 1; the pipe plug 7 is machined by cutting from a Φ120mm round bar; the argon filling tube 8 is machined by cutting from a Φ8mm seamless steel pipe.

[0037] When in use, first make each component according to the specifications of the butt-welded stainless steel 90° elbow and the one-piece flange, weld and fix the first "7"-shaped block 21 and the second "7"-shaped block 2 to the two ends of the upper part of the tooling base plate 1 respectively, then penetrate and weld and fix the argon filling pipe 8 to the pipe plug 7, then insert the pipe plug 7 into the inner hole of the second pipeline 6 to prevent air leakage from the pipeline inlet 11, and then combine and fix the one-piece flange steel plate 4, the first pipeline 5, and the second pipeline 6 with the body. When the first pipeline 5 is respectively combined with the second pipeline 6 and the one-piece flange steel plate 4, the two combinations can be fixed by means of existing clamps or by bridging, point fixing, etc. Finally, insert the body flange steel plate 4 between the first "7"-shaped block 21 and the second "7"-shaped block 2 to prevent air leakage from the pipeline outlet 10, ensure that argon is transported from the argon filling pipe 8, ensure that the first weld 9 and the second weld 12 formed at the two combinations have good internal quality and ensure the welding quality.

[0038] Embodiment 2:

[0039] The present invention provides a stainless steel 90° elbow and conjoined flange butt welding process, which is performed by the simple argon filling device in Example 1, and the steps are as follows:

[0040] S1. Production and installation of simple argon filling device;

[0041] 1.1. According to the specifications of the stainless steel 90° elbow and the one-piece flange to be butt-welded, the tooling base plate 1, the first "7"-shaped clamp block 21, the second "7"-shaped clamp block 22, the pipe plug 7 and the argon filling pipe 8 are manufactured by machining steel plates, round bars and seamless steel pipes;

[0042] 1.2. Weld the first "7"-shaped block 21 and the second "7"-shaped block 22 at both ends of the upper surface of the tooling bottom plate 1, penetrate and weld the argon filling tube 8 to the pipe plug 7, insert the pipe plug 7 into the pipe inlet 11 of the second pipe 6, combine the second pipe 6, the first pipe 5 and the conjoined flange steel plate 4, and insert the conjoined flange steel plate 4 between the first "7"-shaped block 21 and the second "7"-shaped block 22;

[0043] S2. Preparation before welding:

[0044] 2.1. Welding equipment: Panasonic YC-400TX4 manual argon arc welding and electrode arc welding combined welding machine, high-purity argon purity 9999.9%, welding materials: CHG-308L welding wire, argon arc welding wire φ2.5mm, φ3.0mm;

[0045] 2.2. Welding material: stainless steel 0Cr18Ni9;

[0046] 2.3. Welding position: 45° fixed welding;

[0047] 2.4. Auxiliary facilities: angle grinder, file, hammer, flat shovel, mask, sample, thermometer, magnifying glass, thermal insulation cotton;

[0048] 2.5. Requirements before welding: The welding position area and welding materials must be free of oil, oxide layer and moisture, and the metallic luster must be exposed; oxyacetylene flame should be used to remove rust, grease and moisture, and then emery cloth or grinding wheel machine should be used to grind and remove rust;

[0049] 2.6. Welding technical requirements: single-sided welding and double-sided forming, the weld cladding layer fuses the parent material, the weld has no welding defects and meets the design dimensions;

[0050] 2.7. Welding process parameters: Welding parameters are determined according to welding equipment, welding materials and welding requirements;

[0051] Welding process parameters

[0052] Weldlayers Weldmethod Filler material filler metal Φ (mm) Amps Current (A) Volts Voltage (V) Polarity Travelspeed welding speed (mm / s) Weldingspeed wire feeding speed (mm / s) Heat input (kJ / mm) Bottom Layer GTAW CHG-308L Φ2.5 90-110 15-20 DCEP 2.0-3.2 -- 0.4-0.61 Filling, covering GTAW CHG-308L Φ3.0 120-140 20-24 DCEP 4.3-6.6 -- 0.6-0.91

[0053] S3, welding implementation;

[0054] 3.1. Clean the combination position of the first pipeline 5 and the pipeline outlet 10 on the one-piece flange steel plate 4 and the combination position of the 45° pipe cutout 13 of the first pipeline 5 and the second pipeline 6; connect the argon filling pipe 8 to the argon gas source for gas supply, preferably 2 minutes in advance, and then weld the base layer, the filling layer and the cover layer at the two combinations in sequence, and form the first weld 9 and the second weld 12 respectively;

[0055] 3.2. When welding the bottom layer at two combinations, the welding machine uses CHG-308L welding wire, φ2.5mm, manual tungsten inert gas arc welding, crescent strip method, high-purity argon purity 9999.9%, and wet cloth is used on both sides of the weld. During the welding process, the cloth is continuously wetted with water to ensure rapid cooling and welding to avoid various welding defects of stainless steel due to excessive temperature, which affects the quality of the weld. The horizontal angle between the welding wire and the pipe fitting is 30-45°, the horizontal angle between the welding gun and the pipe fitting is 65-80°, the welding current is 90-110A, and the pipe-to-tube and pipe-to-steel plate flange welding are all symmetrically welded from the 6 o'clock position from bottom to top to the 12 o'clock position. The bottom layer is single-sided welded and double-sided formed. After welding, the weld is cleaned and The surface of the seam is checked to ensure that there are no welding defects and the weld is repaired. The temperature of the weld and the heat-affected zone is measured by a temperature gun to be less than 60°, and then the filling layer and the cover layer are welded; the welding process of the filling layer and the cover layer is consistent with the welding process of the base layer, the welding wire is φ3.0mm, the welding current is 120-140A, the cover layer is higher than the parent material, but cannot be greater than 3mm, and the two sides of the weld are kept in a smooth transition with the parent material, and then quickly cooled to room temperature, and then X-ray flaw detection is carried out according to the pressure vessel non-destructive testing standard JB / T4730-2005, and then standard mechanical properties testing is carried out according to NB / T47016-2011. After the test results are confirmed to meet the requirements, it is delivered for use.

Claims

1. A simple argon filling device for butt welding of stainless steel 90° elbows and conjoined flanges, characterized in that: The utility model comprises a tooling base plate (1), a one-piece flange steel plate (4), a first pipeline (5), a second pipeline (6), a pipe plug (7) and an argon filling pipe (8); a 45° pipe cutout (13) is respectively provided on opposite sides of the first pipeline (5) and the second pipeline (6); the other end of the second pipeline (6) serves as a pipeline inlet (11); the one-piece flange steel plate (4) is rectangular in shape, and a pipeline outlet (10) matching the inner diameter of the first pipeline (5) is provided at the center thereof; a first "7"-shaped card block (21) and a second "7"-shaped card block (22) are respectively and parallelly arranged at opposite ends of the tooling base plate (1). The two ends of the one-piece flange steel plate (4) are respectively matched with the inner sides of the first "7"-shaped clamping block (21) and the second "7"-shaped clamping block (22) and are clamped therebetween; the lower end of the first pipe (5) is combined with the upper surface of the pipe outlet (10) of the one-piece flange steel plate (4); the second pipe (6) and the first pipe (5) are combined through respective 45° pipe cutouts (13) to form a 90° elbow; the pipe plug (7) is matched with the pipe inlet (11) of the second pipe (6) and can be inserted inside the pipe inlet (11); the argon filling pipe (8) is penetrated by the pipe plug (7).

2. A simple argon filling device for butt welding of stainless steel 90° elbow pipe and conjoined flange according to claim 1, characterized in that: The number of the first "7"-shaped card block (21) is one, which is arranged at the center of one end of the tooling base plate (1); the number of the second "7"-shaped card blocks (22) is two, which are arranged at the front and rear sides of one end of the tooling base plate (1), respectively.

3. A simple argon filling device for butt welding of stainless steel 90° elbow pipe and conjoined flange according to claim 1, characterized in that: The tooling base plate (1) is machined by cutting a 20 mm steel plate; the first "7"-shaped clamping block (21) and the second "7"-shaped clamping block (22) are machined by cutting a 60 mm steel plate and are welded to both ends of the tooling base plate (1); the pipe plug (7) is machined by cutting a Φ120 mm round bar; and the argon filling tube (8) is machined by cutting a Φ8 mm seamless steel tube.

4. A stainless steel 90° elbow and joint flange butt welding process, characterized in that: The simple argon filling device according to any one of claims 1 to 3 is used, and the steps are as follows: S1. Production and installation of simple argon filling device; 1.1) According to the specifications of the stainless steel 90° elbow and the one-piece flange to be butt-welded, the tooling base plate (1), the first "7"-shaped clamping block (21), the second "7"-shaped clamping block (22), the pipe plug (7) and the argon filling pipe (8) are manufactured by machining steel plates, round bars and seamless steel pipes; 1.2) Welding the first "7"-shaped block (21) and the second "7"-shaped block (22) at both ends of the upper surface of the tooling bottom plate (1), passing the argon filling tube (8) through the pipe plug (7) and fixing it by welding, inserting the pipe plug (7) into the pipe inlet (11) of the second pipe (6), assembling the second pipe (6), the first pipe (5) and the conjoined flange steel plate (4), and inserting the conjoined flange steel plate (4) between the first "7"-shaped block (21) and the second "7"-shaped block (22); S2. Preparation before welding: 2.1) Welding equipment: manual argon arc welding and arc welding combined welding machine, high-purity argon purity 9999.9%, welding materials: CHG-308L welding wire, argon arc welding wire φ2.5mm, φ3.0mm; 2.2) Welding material: stainless steel 0Cr18Ni9; 2.3) Welding position: 45° fixed welding; 2.4) Auxiliary facilities: angle grinder, file, hammer, flat shovel, mask, sample, thermometer, magnifying glass, thermal insulation cotton; 2.5) Requirements before welding: The welding area and welding materials must be free of oil, oxide layer and moisture, and the metallic luster must be exposed; 2.6) Welding technical requirements: single-sided welding and double-sided forming, the weld cladding layer fuses the parent material, the weld has no welding defects and meets the design dimensions; 2.7) Welding process parameters: Welding parameters are determined according to welding equipment, welding materials and welding requirements; S3, welding implementation; 3.1) Clean the combined position of the first pipeline (5) and the pipeline outlet (10) on the one-piece flange steel plate (4) and the combined position of the 45° pipe cutout (13) of the first pipeline (5) and the second pipeline (6); connect the argon filling pipe (8) to an argon gas source for gas supply, and then weld the base layer, the filling layer and the cover layer at the two combined positions in sequence, and form a first weld (9) and a second weld (12) respectively; 3.2) When welding the bottom layer at two combinations, the welding machine uses CHG-308L welding wire, φ2.5mm, manual tungsten inert gas arc welding, crescent strip method, high-purity argon purity 9999.9%, and wet cloth is used on both sides of the weld. During the welding process, the cloth is continuously wetted with water to ensure rapid cooling and welding to avoid various welding defects of stainless steel due to excessive temperature, which affects the quality of the weld. The horizontal angle between the welding wire and the pipe is 30-45°, the horizontal angle between the welding gun and the pipe is 65-80°, the welding current is 90-110A, the pipe-to-tube and the pipe-to-steel plate flange welding are all symmetrically welded from the 6 o'clock position from bottom to top to the 12 o'clock position, the bottom layer is single-sided welded and double-sided formed, and the welding is complete. After completion, clean the weld surface, confirm that there are no welding defects and grind the weld. Use a temperature gun to measure the temperature of the weld and heat-affected zone to be less than 60°, and then weld the filling layer and cover layer; the welding process of the filling layer and cover layer is consistent with the base layer welding process, the welding wire is φ3.0mm, the welding current is 120-140A, the cover layer is higher than the parent material, and the two sides of the weld maintain a smooth transition with the parent material, and then quickly cool to room temperature, and perform X-ray inspection according to the pressure vessel non-destructive testing standard JB / T4730-2005, and then perform standard mechanical properties testing according to NB / T47016-2011. After the test results confirm that they meet the requirements, they are put into use.

5. The process according to claim 6, characterized in that: The welding equipment is a YC-400TX4 manual argon arc welding and electrode arc welding combined welding machine.

6. The process according to claim 6, characterized in that: When welding the base layer, the welding current is 90-110A, the arc voltage is 15-20V, the welding speed is 2.0-3.2mm / s, the heat input is 0.4-0.61kJ / mm, the welding method is GTAW, and the polarity is DCEP; when welding the filling layer and the cover layer, the welding current is 120-140A, the arc voltage is 20-24V, the welding speed is 4.3-6.6mm / s, the heat input is 0.6-0.91kJ / mm, the welding method is GTAW, and the polarity is DCEP.

7. The process according to claim 6, characterized in that: The weld of the cover layer is no higher than the base material by no more than 3 mm.

8. The process according to claim 6, characterized in that: Supply argon gas 2 minutes in advance before welding.

Images