326 results about "Weld pool" patented technology

The invention provides an intelligent real-time detection method and system for PCCP welding quality, and relates to the technical field of online detection and intelligent evaluation of pipeline welding quality through machine learning. Light energy data and multi-light-source images of a spiral weld pool are collected, exposure parameters are dynamically adjusted through the energy difference of visible light near-infrared bands, and the real-time detection of the PCCP welding quality is achieved. Inhibiting strong light interference and generating a weld surface image; a stress concentration area is positioned by scanning a welding seam thermal deformation area and combining speckle pattern change, sound frequency change and the elastic characteristic of the thin-wall steel cylinder; inputting the surface image and the deformation data into a space-time convolutional neural network, fusing light energy change, image details and spatial features to construct a weld joint space structure diagram, and adaptively correcting the position of a sensor; and comparing the sinking depth of the three-dimensional point cloud reconstruction, analyzing the correlation between the sinking degree and the stress, and generating a probability thermodynamic diagram to output the pressure-bearing failure risk level, so that the probabilistic early warning of the pressure-bearing failure risk can be realized.

The invention discloses a welding method for heterogeneous multi-wire in-situ metallurgy of a submerged arc pipe of a hydrogen conveying pipeline, and aims to solve the problem of hydrogen-induced failure caused by the problems of coarse weld structure, secondary phase particle aggregation, low-temperature impact toughness and the like caused by a traditional multi-wire submerged arc welding method. The welding method comprises the steps that firstly, the to-be-welded face of the hydrogen conveying pipeline is polished and cleaned; and secondly, the cleaned hydrogen conveying pipeline to be welded is welded through three-wire submerged arc welding, H08MnMoTiB is adopted as a first welding wire, BH60GX-III is adopted as a second welding wire, H08Mn2NiA is adopted as a third welding wire, the components of the three welding wires are optimized, and the technological parameters such as the wire feeding speed, the current and the voltage of the three welding wires are optimized and adjusted. According to the method, the idea of in-situ metallurgy and multi-wire submerged arc welding are fused, the alloy component proportion of transition metal of a welding pool is achieved by changing the wire feeding speed of different welding wires, and different welding process parameters are supplemented, so that quantitative adjustment of the cladding metallurgy performance of a welding seam is achieved, and the hydrogen-induced corrosion resistance is improved.

The invention discloses a full-position welding penetration online detection method based on cooperation of an electric signal and a molten pool image. A pipeline is subjected to full-position welding under cooperation of double robots; preliminary segmentation is conducted on the basis of the welding position, segmentation is conducted again at the angle of 5-10 degrees, a laser scanner is adopted to scan a pipeline groove to obtain the groove size of each segment, and self-adaptive setting of welding process parameters is achieved on the basis of a process knowledge base and a welding parameter adjusting model; fusing the molten pool image and the electric signal time domain characteristic value, and performing discrimination through a neural network prediction model; and obtaining weld pool size characteristics based on the weld pool image, calculating a reference weld pool oscillation frequency based on a reference weld pool oscillation frequency model, performing spectral analysis on an upper envelope signal of the voltage signal, calculating an actual weld pool oscillation frequency, and comparing the actual weld pool oscillation frequency with the reference weld pool oscillation frequency to judge whether the weld is penetrated or not. According to the invention, all-position welding forming defect monitoring of the robot is realized.

The invention belongs to the technical field of welding, and discloses a dissimilar metal power modulation galvanometer laser welding method which comprises the following steps: finely cleaning a 6061 aluminum alloy and a 304 stainless steel plate by using acetone, and then airing for more than 20 minutes; the aluminum steel sheet is assembled, pressed and fixed on a welding test platform in a steel-up-aluminum-down mode; the position of the welding test platform is adjusted, argon serves as welding protection gas, and a protection gas nozzle is arranged to be aligned with a welding pool area; laser welding parameters are set, a laser power modulation mode is set to be a gradient power mode, and the gradient power mode is to regulate and control phase point laser power in a circular scanning track in the advancing direction of a welding seam; a welding test is carried out in the mode that a galvanometer laser head is fixed and a welding test platform is moved, and a laser and the welding test platform are synchronously started and stopped; and the protective gas is started 5 seconds before the laser is started, and after the laser is stopped, the protective gas is stopped lagging for 10 seconds so as to continuously protect the welding seam and prevent oxidation.

The invention discloses a heat exchanger welding seam image enhancement processing method, and belongs to the technical field of image processing, and the method comprises the steps: S1, collecting a heat exchanger welding seam original image through a preset collection module, and converting the original image into a grayscale image; s2, a processing module is preset, the gray level image is segmented based on a preset dynamic threshold value, and a welding seam area image and a base metal area image are generated; s3, in the welding seam area image, generating a first enhanced image, a second enhanced image and a third enhanced image through a preset generation module; and S4, extracting a reference edge contour of the weld joint area image from the base metal area image, performing pixel-level fusion on the first enhanced image, the second enhanced image and the third enhanced image, and outputting a weld joint image. According to the method, the weld joint area is divided into the highlight area, the dark area and the middle area to be processed respectively, weld pool texture loss caused by strong reflection is effectively restrained, and the problem that details are lost in a highlight scene in an existing method is solved.

The invention discloses a coaxial composite laser welding method and a welding method of a flat wire motor winding, and relates to the technical field of laser welding, coaxial composite laser beams are adopted to act on the surface of a high-reflection material to form a welding pool, the coaxial composite laser beams comprise an outer ring laser beam and a core laser beam, the outer ring laser beam is a pulse laser beam, and the core laser beam is a core laser beam; the core laser beam is a continuous laser beam, the continuous laser beam forms a main molten pool, the pulse laser beam forms an auxiliary molten pool, and the main molten pool and the auxiliary molten pool have overlapped parts. The continuous laser and the pulse laser are combined, the main molten pool formed by the continuous laser and the auxiliary molten pool formed by the pulse laser are communicated in an overlapped mode, the pulse laser disturbs molten metal in the auxiliary molten pool and drives the molten metal in the main molten pool to achieve the oscillation stirring effect, and the laser energy absorption efficiency of the high-reflection material can be improved; and the energy distribution of the heat source can be optimized by adjusting the energy proportion and the focus point position, the energy state of the heat source is accurately controlled, and zero splashing is achieved.

The invention provides a narrow gap swing laser welding pool wettability prediction method based on CFD simulation. The method comprises the following steps that an interaction platform is constructed through Python + PyQt5, and geometric modeling, UDF compiling and a material library module are integrated; the groove parameters and the swing track are dynamically loaded to a Fluent solver, and a full-coupling transient model of a steam recoil pressure-buoyancy-molten drop mass source item is established; in CFD-POST, the widest section of the molten pool is positioned on the basis of the contour surface with the volume fraction being 0.5, and Z-direction displacement-flow velocity data are extracted along the two side wall surfaces; fusing defects are predicted through double criteria of a bilateral average flow velocity difference threshold value and F test variance homogeneity; according to the method, dynamic quantitative evaluation of wetting behaviors can be achieved, the process development period is shortened, the defect detection rate is increased, and the method is suitable for aerospace thick plate welding quality control.

A welding system configured to eliminate effects of arc blow in a welding operation. The welding system comprises welding circuitry, preheat circuitry, a drive roller, and control circuitry configured to perform a reciprocation cycle. The reciprocation cycle may include the steps of: advancing a filler material toward the welding work piece until the filler material is electrically connected to the weld pool; supplying the preheat power to heat the filler material while the filler material is electrically connected to the weld pool; retracting the filler material away from the welding work piece until the filler material is not electrically connected to the weld pool; and terminating supply of the preheat power to the filler material while the filler material is not electrically connected to the weld pool.

A method of blind welding thermoplastic composite components is provided that includes: providing a first thermoplastic composite having a FTPC bonding surface, a second thermoplastic composite having a STPC bonding surface, and an interface layer; disposing the interface layer between the FTPC STPC bonding surfaces; applying a normal force to the outer surface of the first thermoplastic composite component; applying an electromagnetic field to at least portions of the first and second thermoplastic composite components and the interface layer while the normal force is applied, and maintaining the application of the electromagnetic field until the first and second thermoplastic composite components and the interface layer create a weld pool; and removing the application of the electromagnetic field after the weld pool is created.

The steel wire rod for the low-carbon welding wire comprises the following chemical components in percentage by weight: 0.06 to 0.08 percent of C, 0.81 to 0.87 percent of Si, 1.41 to 1.47 percent of Mn, less than or equal to 0.023 percent of P, 0.008 to 0.015 percent of S, less than or equal to 0.010 percent of Al, more than or equal to 1.67 percent of Mn / Si and the balance of Fe and inevitable impurities. The invention further provides a production method of the steel wire rod for the low-carbon welding wire, and the steel wire rod for the low-carbon welding wire is prepared through a molten steel smelting procedure, a refining procedure, a casting procedure, a heating procedure, a temperature control rolling procedure and a slow cooling procedure which are sequentially carried out. The tensile strength of the wire rod is smaller than or equal to 550 Mpa, the percentage elongation after fracture is larger than or equal to 35%, the drawing performance is good, and the gas shielded welding wire with the diameter ranging from 0.8 mm to 1.2 mm can be produced; welding wire seam metal provided by the product is good in mobility, a welding pool is fast to solidify, and welding seam formability is good. In addition, the unique slow cooling process enables metallographic phase transformation to be sufficient, the use aging period of the product is shortened by half, and therefore the production cost of a manufacturer is reduced.

The invention discloses a welding device for steel structure installation, and relates to the technical field of steel structure welding. Comprising a welding handheld part, and a swing suction part is installed on the welding handheld part and used for overhead welding suction; a cover buckle suction piece is mounted on the swinging suction piece; the cover buckle suction piece is of an expandable structure. The cover buckle suction part is used for being attached to the inner side of a welding seam. An in-place test piece is mounted on the cover buckle suction piece; the problems that an existing welding device for steel structure installation is inconvenient to expand and surround a welding seam, a molten pool is prone to being damaged, and a worker is inconvenient to remind to reserve a cable are solved. By the adoption of the stop protection piece, it can be guaranteed that when a worker uses the welding gun, the problem that the length of a cable is still insufficient in the subsequent welding work process due to the fact that the worker forgets to reserve the reserved length of the cable on the welding gun body is solved, and self-inspection work is completed before welding work is conducted.

The invention relates to the technical field of valve welding, in particular to a welding tool for manufacturing a large marine valve. Workpiece positioning structures used for clamping and positioning valve workpieces are symmetrically assembled at the upper end of the welding tool frame along the middle portion. A welding seam bottom sealing structure for sealing the position of a welding seam in a valve workpiece is detachably assembled on the inner side of each workpiece positioning structure. According to the design of the welding seam bottom sealing structure, the inner space of the inner edge of the welding seam can be automatically sealed through the synergistic effect of the oblique angle groove plate, the assembly frame plate, the arc-shaped plate and other components, and in the process, the assembly frame plate moves on the oblique angle groove plate, so that a sealed metal circular ring is formed; according to the design, welding fluid is effectively prevented from leaking into the valve workpiece in the welding process, the wall thickness welding quality of the valve for the large ship is ensured, and therefore welding defects are avoided.

The invention provides a welding pool monitoring system and method, and the system comprises an input module which is used for obtaining a to-be-processed welding image according to a selected welding image input source; the processing module is used for selecting a matched welding information identification model, inputting the to-be-processed welding image into the welding information identification model, obtaining a welding pool identification result, and processing the welding pool identification result by adopting a preset parameter algorithm to obtain welding pool detection parameters; and the output module is used for pushing the molten pool detection parameters to a user. According to the method, the welding image to be processed can be obtained from the selected welding image input source, the matched welding information recognition model is selected for image recognition, processing is conducted according to the image recognition result to obtain the weld pool detection parameters so as to monitor the welding effect, and better applicability and deployment convenience are achieved.

An MIG welding parameter optimization method based on a composite heat source simulation model comprises the steps that firstly, a geometric model and a physical model for simulation are determined, then grid division work is carried out on the simulation model, reasonable boundary conditions are designed for the simulation model, and then a Gaussian heat source model and a cylinder heat source model are imported into the models; the method comprises the following steps of: setting a time step, starting a simulation process, monitoring, comparing a simulation result with an actual experiment result, verifying, and continuously and repeatedly optimizing the model until the simulation result and the actual experiment result have good consistency. A composite welding heat source model is embedded in a traditional heat source simulation model, so that real data such as the shape and the forming size of a welding pool under the welding wire filling condition can be more accurately simulated, the simulation precision is high, the data are reliable, and the size of the actual welding sample pool can be well fit.

According to the pipeline all-position robot intelligent welding system and method based on the AI algorithm, a laser vision scanning system is adopted for scanning a pipeline welding seam / groove, and an AI intelligent model generating system generates a pipeline all-position welding seam three-dimensional model diagram based on scanning data; the AI intelligent process generation system intelligently reads welding seam size information based on the model diagram, generates a welding gun path of all-position welding, optimizes the welding gun path, matches initial welding parameters and distributes the initial welding parameters to the intelligent welding robot, and the AI intelligent process optimization system predicts a welding seam molten pool in the welding execution process and judges whether the process is qualified or not. And if the process is unqualified, welding parameter adjustment is repeated, and if the process is qualified, process parameter optimization values are output. The welding quality of all-position welding of small and medium-diameter pipelines is accurately controlled, and the all-position welding quality of the pipelines is improved; and the system intelligently adapts to the complex environment of all-position welding of small and medium-diameter pipelines, and can cope with complex welding process changes in real time.

The invention discloses laser positioning / welding and laser cleaning synchronous integrated equipment and a laser positioning / welding and laser cleaning synchronous integrated method. The equipment realizes real-time positioning and automatic focusing based on welding seam tracking and optical signal processing, links two lasers to synchronously emit welding and cleaning light beams, acts on a welding pool at the same time, and is matched with shielding gas pre-injection, smoke discharge and slag removal and a special clamp to remove impurities in the welding pool in real time, generate micro-vibration stirring and promote grain refinement in the welding process. According to the equipment, key links such as workpiece clamping and positioning, automatic focusing, welding and cleaning are combined, the technological process is greatly simplified, and the compactness and the mechanical property of a welding seam of a plated part are improved.

The invention relates to an automatic and semi-automatic electric arc technology, in particular to a hollow guide rail quick positioning and welding device and a positioning method.The hollow guide rail quick positioning and welding device comprises a base, a rolling conveying piece installed on the base and a hollow guide rail body arranged on the rolling conveying piece in a transmission mode; the positioning piece is arranged on the base and is used for lifting and positioning the welding seam of the hollow guide rail main body. Through the integral matching design, intermittent lifting action of the ejector rod can be realized, and when the ejector rod performs lifting motion, the positioning piece connected with the ejector rod performs lifting action synchronously, so that the welding seam of the hollow guide rail main body is accurately lifted and positioned, the wave fluctuation height difference caused by sinking is weakened, and the welding quality of the hollow guide rail main body is improved. The height difference between the wave crest and the wave trough which fluctuate is controlled within the range that a welding pool can melt along flow as much as possible, the lifting action of the ejector rod and the positioning piece is driven by the driving piece, the phenomenon can be effectively avoided, the flatness of a welding seam is ensured, and a good foundation is provided for welding operation.

The invention provides a pipe fitting laser welding machine and a using method thereof, and relates to the technical field of laser welding, the pipe fitting laser welding machine comprises a base, two side fixing plates are symmetrically and vertically fixed to the two sides of the top of the base, a motor is fixed to the outer sides of the side fixing plates through mounting supports, and the axial part of an output shaft of the motor is located in the side fixing plates and rotationally mounted; an auxiliary structure is coaxially fixed at the end part of an output shaft of the motor; the auxiliary structure comprises a long shaft, by arranging the auxiliary structure, when a worker starts the motor to drive the pipeline to rotate and convey inert gas, the gas conveying pipe can stably convey gas to the four-way converging pipe, then the gas is conveyed to a welding area through the stretchable flexible exhaust pipe, and meanwhile the gas conveying pipe is matched with rotation of the turbulent flow main shaft; therefore, uniform distribution of the inert gas in the welding area can be achieved, a stable protection atmosphere is provided for welding, the diffusion mode is that the inert gas diffuses from the interior of the pipeline to the weld joint and can directly act on a welding pool and a nearby high-temperature area, and the stability of welding quality is ensured.

The invention provides an observation device for a welding pool in a vacuum environment, which comprises a pressure-resistant cavity device, a camera shooting mechanism and a mobile platform, the pressure-resistant cavity device is internally provided with an accommodating cavity, the welding pool in the vacuum environment is arranged outside the pressure-resistant cavity device, the accommodating cavity is internally provided with the camera shooting mechanism, and the camera shooting mechanism can shoot an image of the welding pool; and the moving platform is arranged in the containing cavity and connected with the camera shooting mechanism, and the moving platform can drive the camera shooting mechanism to move in the containing cavity so as to adjust the distance between the camera shooting mechanism and a welding pool outside the pressure-resistant cavity device, so that the camera shooting mechanism completes automatic focusing shooting. According to the invention, the problem that a welding pool observation high-speed camera in the prior art cannot automatically focus in a vacuum environment can be solved, so that the observation precision is improved; according to the invention, whether to filter light or not can be automatically switched in a strong light or normal light environment, the cooling and heat dissipation performance is good, and the observation precision and quality of a welding pool are greatly improved.

The invention relates to the technical field of attitude planning, in particular to a mechanical arm attitude planning method and system. The method comprises the following steps that a product welding structure diagram and basic setting parameters of a mechanical arm welding gun are obtained, the morphological difference between welding spot sequences is analyzed, and morphological difference data of the welding spot sequences are obtained; secondly, based on basic setting parameters of a mechanical arm welding gun, simulating and analyzing the form deviation of a welding pool, and carrying out strength loss posture association mining to obtain strength loss posture association data; and finally, joint angle space limiting matching is conducted according to the strength loss posture correlation feature data, joint angle space limiting matching data are generated, mechanical arm welding gun posture planning design is conducted through the data, and final posture planning data are obtained. According to the invention, the attitude planning technology is optimized, so that the attitude planning technology is more accurate.

The present invention belongs to the field of image processing technology, and discloses a welding pool visual monitoring method based on multimodal semi-supervised semantic segmentation, firstly constructing a semantic segmentation network; training the semantic segmentation network based on a semi-supervised semantic segmentation network training strategy; inputting the collected original image of the welding pool into the trained semantic segmentation network to obtain a segmented welding pool image. The present invention utilizes a multimodal semi-supervised learning strategy combining supervised learning based on a small amount of labeled data and unsupervised learning of pseudo-labeled data of different modalities to achieve effective training of the semantic segmentation network, while improving the training efficiency of the semantic segmentation network, ensuring the accuracy of welding pool detection.

According to the filler wire welding method based on the composite laser, the first laser beam and the second laser beam which are different in wavelength can be irradiated to the welding seam of the to-be-welded aluminum alloy workpiece through the composite laser welding head, and light spots, acting on the to-be-welded aluminum alloy workpiece, of the two laser beams partially coincide or do not coincide; the two light spots are distributed front and back in the welding direction. When the light spot of the first laser beam is in the front and the light spot of the second laser beam is in the rear, the first laser beam can be used for preheating, so that the welding wire melting efficiency can be improved, the reflectivity of aluminum alloy to the second laser beam is reduced, and welding seam forming is improved. When the light spot of the first laser beam is in the rear and the light spot of the second laser beam is in the front, the first laser beam can be used for slowly cooling a welding pool / performing post-heat treatment on a welding seam, so that welding defects are reduced. It can be seen that the welding quality of the to-be-welded aluminum alloy workpiece is improved by means of characteristic cooperation and function complementation between the two kinds of lasers of different wave bands.

The invention discloses high-strength steel laser wire filling welding equipment and method based on AI intelligent identification, and belongs to the field of laser welding and artificial intelligence. Comprising a laser wire filling welding system, a robot control system loaded with a laser wire filling welding head, an element analysis and vision and distance measurement system integrated on the laser wire filling welding head, an online detection system loaded with a CNN training model and a PLC real-time feedback system. Laser wire filling welding is carried out through the laser wire filling welding system and the robot control system, meanwhile, whether an AlSi coating exists on the surface of a high-strength steel plate or not and the appearance of a plate butt joint gap and a welding pool are obtained through the element analysis and vision and distance measurement system, and data are transmitted to the on-line detection system to be analyzed; and then an analysis result is fed back to a laser wire filling welding system through a real-time feedback system, so that the wire feeding type and the wire feeding speed of a wire feeding system are changed, and wire feeding parameters are modified in situ.

The invention provides an aluminum-silicon coating thermal forming door ring welding assembly and method.The assembly comprises a plurality of door ring material pieces and limiting bosses, the door ring material pieces are made of steel plates with aluminum-silicon coatings, the door ring material pieces are connected end to end to form a door ring shape in a surrounding mode, the limiting bosses are arranged in pairs, and the limiting bosses are connected with the door ring material pieces in an end-to-end mode. The limiting bosses are formed in the end portions of the door ring material pieces and protrude towards the outer sides of the door ring material pieces, gaps are reserved between the limiting bosses, the tail ends of the limiting bosses are spliced with the end portions of the adjacent door ring material pieces, and welding gaps are defined between the door ring material pieces and the limiting bosses; when the welding method is adopted for splicing and welding door ring welding object workpieces and ultrahigh-frequency swing laser welding is adopted, a strong convective stirring effect can be formed in a welding pool, various element components in the welding pool can be uniformly diffused, the adverse effect of non-uniform element components on the overall strength of a welding seam is reduced, and the welding quality of the door ring welding object workpieces is improved. And head-to-tail rapid positioning of multiple plates can be achieved, the welding efficiency and quality of door ring products are effectively improved, and the cost of a tool positioning device is greatly reduced.

The invention relates to the technical field of nuclear materials. The invention discloses a welding method of a metal hafnium plate, which comprises the following steps of: pretreating a to-be-welded surface of the to-be-welded metal hafnium plate to obtain the treated to-be-welded metal hafnium plate; aligning the two treated metal hafnium plates to be welded in a first plane, and performing spot welding and fixing to obtain a test piece to be welded; and the to-be-welded test piece is fixed to a welding platform, and high-frequency oscillation scanning electron beam welding is conducted on the to-be-welded test piece in a vacuum electron beam welding machine. During vacuum electron beam welding, the electron beam high-frequency oscillation scanning process is added, stirring oscillation of a welding pool is achieved, effective overflow of internal gas is promoted, welding defects are reduced, a certain inhibiting effect on growth of crystal grains in a welding seam is achieved, and the mechanical property of the welding seam is improved.

The invention relates to the technical field of girth welding, in particular to a girth welding method, system and device for bicycle parts. The method comprises the following steps: acquiring a thermal imaging image of a bicycle part in a welding process, and carrying out graying processing to obtain a grayscale image; according to the gray level distribution characteristics of the gray level image, a welding pool area, a heat influence area and a splashing hot spot are determined; radiating outwards from the central point of the welding pool area, and determining a gradient characteristic sequence of temperature change of the heat affected area in different edge pixel point directions; determining the deviation degree of the pipe diameter of the workpiece according to the length difference and the gray scale distribution of the gradient feature sequence; analyzing gray level change characteristics of welding pool areas in the gray level images of the current frame and the previous frame, and evaluating a stability index in combination with the area and distribution characteristics of splashing hot spots of the current frame; and according to the stability index and the workpiece pipe diameter deviation degree, parameters of the current welding process are adjusted in real time. Real-time regulation and control of the welding process can be effectively achieved, and the welding stability is improved.

The invention relates to the field of molten pool monitoring, in particular to a welding molten pool fusion monitoring method and system. Comprising the steps of obtaining ultrasonic scanning data of a welding pool through a single-point scanning method; according to the size parameter information of the welding pool, first reflection time and second reflection time are determined; determining other maximum value points from the ultrasonic scanning data according to the first reflection time and the second reflection time; determining real defect points from other maximum value points; and echo signal features of the real defect points are input into the trained long-short-term memory network, the defect types and the fusion state are output through the trained long-short-term memory network, and fusion parameters and optimization algorithms of a welding pool are adjusted through the defect types and the fusion state. According to the method, the defect type and the fusion state of the welding pool can be identified, and the welding process of the welding pool can be adjusted and optimized in time.

This application provides an end cover (12), a battery cell (600), a battery (100), and an electric apparatus. The battery cell (600) includes a shell (11), an electrode assembly (20), and an end cover (12), and an opening (K) is provided at an end of the shell (11) in a first direction (X), and the electrode assembly (20) is accommodated in the shell (11). The end cover (12) is configured to cover the opening (K). The end cover (12) includes an end cover body (121) located in a projection of the opening (K) in the first direction (X). The end cover (12) is welded to the shell (11) to form a weld pool structure (R). In a radial direction (Y) of the opening (K), the weld pool structure (R) is exposed on an outer surface of the shell (11) and penetrates deep into the end cover body (121). In an embodiment of this application, a laser needs to be irradiated from an outer peripheral side of the shell (11) to the vicinity of a boundary position between the shell (11) and a protrusion (122) along the radial direction (Y) of the shell (11), so that the formed weld pool structure (R) can include most or even the entire structure of the protrusion (122), a partial structure of the shell (11), and a partial structure of the end cover body (121). This helps to increase an overall size of the weld pool structure (R) and improve the welding strength between the shell (11) and the end cover (12).

To accurately acquire the state of a molten pool.SOLUTION: A welded state analysis method comprises the steps of: acquiring a molten pool shape which is a three-dimensional shape of a molten pool having been subjected to welding (step S11); acquiring a virtual bead shape which is a three-dimensional shape of a bead at a position corresponding to the molten pool of when it is assumed that a pushing pressure due to a weld phenomenon is not applied to the molten pool (step S12); and determining a weld pressure distribution, which is a distribution of pushing pressures to the molten pool by a weld phenomenon, or a weld force, which is a pushing force to the molten pool by the weld phenomenon, on the basis of a difference between the molten pool shape and the virtual bead shape (step S13). Thereby, the welded state analysis method can accurately determine the state of a molten pool.SELECTED DRAWING: Figure 5

The invention relates to a laser welding method. According to the welding method, a first welding wire and a second welding wire are used for conducting laser welding at the same time, the first welding wire is a gas shielded welding wire, and the second welding wire is a gas shielded welding wire or a NiCr alloy welding wire. According to the welding method for laser double-wire welding, under the action of high-energy-density laser, molten metal is rapidly melted into a gap to form a welding seam molten pool, meanwhile, molten metal in a welding seam can be rapidly cooled and solidified, thermal deformation is small, the welding seam is uniform and compact, the surface quality is good, and the risk of cracking caused by stress concentration can be reduced.