332 results about "Heat-affected zone" patented technology

The application discloses a kind of thick gauge 430 ferritic stainless steel laser weld low-temperature rollability processing method, comprising: using-1~‑2mm negative defocusing+8~10kW low-power laser welding, the grain of heat-affected zone is refined;NiCr-3 welding wire is preheated to 300~400℃ and carried out hot wire laser welding, reduces cooling rate;Weld is implemented 700 DEG C / 10-12 seconds short time induction annealing, decomposes martensite and releases residual stress;Weld is inducted to ≥50 DEG C before rolling and restores plasticity;Optimize five rack continuous rolling parameter, and the reduction of first rack is reduced to 15%-20%.The application is by welding-heat treatment-rolling whole process synergic control, makes weld low-temperature cracking rate from 2.6 times / month reduce to 1 times below, and-10 DEG C impact toughness is promoted to 22J, cup convexity qualification rate reaches 95%, and annual economic benefit is greatly improved, applicable to the thickness 3.0~8.0mm 430 stainless steel cold rolling production, solves the technical problem that thick gauge 430 stainless steel weld is easy to crack under low-temperature environment.

The invention discloses a heat-treatment-free control method for inhibiting hydrogen-induced cracks in ultrahigh-strength steel welding, which belongs to the technical field of welding, and enables weld metal to obtain a low-phase-transition-temperature characteristic and a double-phase structure containing retained austenite under a specific dilution rate window by cooperatively regulating and controlling components of a welding material and welding process parameters. Therefore, preheating-free and post-heat-treatment-free efficient welding of the ultrahigh-strength steel is achieved. According to the method, the volume expansion effect generated by low-temperature martensite phase transformation of weld metal is utilized to actively counteract restrained tensile stress formed by welding cooling shrinkage; on the other hand, the effect of the retained austenite serving as an efficient'hydrogen trap 'is fully played, migration and enrichment of hydrogen to crack sensitive areas such as a heat affected zone or a fusion line are effectively blocked, and finally effective inhibition of hydrogen-induced cracks in ultrahigh-strength steel welding is achieved; the obtained welding joint is free of hydrogen-induced cracks and has the mechanical property level well matched with base metal.

The invention discloses a dynamic regulation and control device and method for aluminum alloy electron beam welding residual stress, and belongs to the technical field of electron beam machining, and the device integrates a multi-sensing information acquisition system, a vibration system and a control system. The sensing information acquisition system measures the surface residual stress of a welding seam and a heat affected zone in real time and in situ in the welding process through a vacuum compatible X-ray probe and a detector, compares the predicted stress with a target value, and generates a regulation and control instruction of electron beam welding parameters through the control system; the electron beam welding behavior is adjusted in real time to dynamically control stress, and the vibration system is used for applying high-frequency micro-amplitude vibration to a local high-stress area of a weldment to promote residual stress release. The device integrates monitoring, regulation and stress release functions in a vacuum environment, can remarkably reduce welding residual stress and improve welding seam quality, and is particularly suitable for electron beam welding of large thin-wall aluminum alloy structural parts.

The invention discloses a back contact solar cell, a preparation method thereof and a photovoltaic module, and relates to the field of photovoltaic technology. According to the preparation method of the back contact solar cell provided by the invention, the grid line groove is formed in the first passivation layer by using the deep ultraviolet laser, and the deep ultraviolet laser has relatively high photon energy which is higher than chemical bond energy of a passivation layer material, so that chemical bonds can be broken through a photochemical effect instead of depending on a thermal effect to melt the material. The heat affected zone of deep ultraviolet laser grooving is small, generated thermal stress is small, and edge warping of the first passivation layer caused by thermal expansion difference can be restrained. The metal seed layer formed through subsequent deposition can be well attached to the inner surface of the grid line groove and the outer surface of the first passivation layer in the grid line area, the metal seed layer is good in integrity and has good adhesive force, and the manufactured back contact solar cell has good reliability and cell performance.

The invention discloses an ultrasonic-annular water cooling synergetic thermosetting composite material repairing method and equipment, on the basis of coaxial annular water cooling, an annular cooling cavity with a variable contour and a structural design of a closed ring with a plane contour which can be circular, elliptical, waist-circular or polygonal are introduced, so that the inner side contour of a cooling ring can be more attached to a welding area. For a large-size or irregularly-shaped thermosetting matrix component repaired by adopting ultrasonic local fusion welding, the cooling zone can be tightly attached to the outline of a welding interface in the circumferential direction through the design, heat is effectively prevented from overflowing along a complex boundary, compared with a fixed circular or linear cooling structure, the range of a heat affected zone can be further narrowed, and the service life of the component is prolonged. And a high-temperature area in the thermosetting matrix is more limited near a welding interface, so that the overall temperature of the thermosetting matrix is always lower than the glass-transition temperature while sufficient melting and flowing of the thermoplastic patch are ensured, and resin degradation and interface strength attenuation caused by local overheating are avoided.

High-toughness, low yield ratio and low longitudinal-transverse strength anisotropy YP460MPa grade weathering steel plate and its manufacturing method, the component weight percentage is: C 0.04~0.08%, Si≤0.20%, Mn1.10~1.50%, P≤0.018%, S≤0.003%, Cu 0.25~0.40%, Ni 0.15~0.45%, Cr0.35~0.65%, Nb 0.015~0.040%, Ti 0.008~0.016%, Als 0.040~0.070%, N≤0.0050%, Mg 0.0010~0.0040%, the balance includes Fe and other inevitable inclusions.The application obtains high strength, excellent low temperature toughness, low yield ratio, high weather resistance and low longitudinal-transverse strength anisotropy of the base material weathering steel plate, and the low temperature toughness of HAZ is also excellent when large heat input welding, that is, the base material weathering steel plate-40℃ impact toughness KV2≥120J, the welding heat affected zone-40℃ Akv≥60J, and it is particularly suitable for the steel structure of ocean platform, cross-sea bridge, water and electricity metal structure component, port machinery and engineering machinery in cold regions.

The invention discloses a selective melting beam shaping and residual stress regulation cooperation method and system, and belongs to the technical field of selective melting additive manufacturing. The method comprises the steps that slicing data of a to-be-formed part are obtained, and characteristic parameters of all areas are analyzed; light beam spot parameters are adjusted in real time through a dynamic light beam shaping module based on the characteristic parameters; in the forming process, stress associated data of a molten pool and a heat affected zone are collected through a multi-dimensional stress monitoring module; the cooperative control unit analyzes the data based on a preset correlation model and judges stress abnormity; if yes, light spot parameter adjustment and stress regulation and control operation are synchronously controlled; and subsequent forming parameters are corrected through a closed-loop algorithm. The system comprises corresponding function modules and a process database. According to the method, light beam shaping and residual stress regulation are coordinated, the residual stress of parts is effectively reduced, deformation and cracking are reduced, the forming precision and the production efficiency are both considered, the process stability is improved, and the adaptation range of materials and complex structures is widened.

A flashbutt joint member having excellent processability of a joint portion and a welding method thereof are provided. The present disclosure relates to a joint member having excellent processability and a manufacturing method thereof, and in a joint member having a joint portion obtained by flashbutt welding a butt joint portion of a steel sheet using an electrode, an average hardness difference between a coarse grain heat-affected zone and a fine grain heat-affected zone formed on any one of left and right sides of the joint portion, based on a joint line (joint interface) is within 50 in Vickers hardness.

This invention relates to the field of new energy technology and discloses a battery cell and an electrical device. The battery cell includes: a shell having an opening along a first direction; a top surface of the shell formed at the end face of the opening along the first direction; a cover plate disposed at the opening of the shell, the cover plate including a body portion and an overlapping portion, the overlapping portion abutting against the top surface of the shell along the first direction; and a welding portion adapted to weld the shell and the cover plate together, the welding portion forming a molten first end and a molten second end, the direction from the molten first end to the molten second end being the welding direction; in a plane perpendicular to the welding direction, the projected area of ​​the molten first end is larger than the projected area of ​​the molten second end; along the welding direction, the molten second end is located within the body portion area. The battery cell provided by this invention allows the heat-affected zone during welding to penetrate deep into the interior of the cover plate along a direction perpendicular to the first direction, reducing the impact of the heat-affected zone on the thickness direction of the shell and improving the strength of the shell.

The application discloses a 75-60kg / m U75VH online heat treatment special-shaped rail for heavy haul railway and a heel end heat treatment method, wherein the heel end heat treatment method is provided for the 75kg / m forged 60kg / m U75VH heat treatment special-shaped rail, and the heat treatment cooling process of the heel end is controlled by controlling the heating temperature of the forged special-shaped rail at the heel end and controlling the air pressure, cooling speed and final cooling temperature of the rail head side at different positions (a forming section, a transition section and a heat affected zone), so that the structure and performance difference between the high-temperature forged heel end of the 75-60kg / m U75VH special-shaped rail and the base material can be effectively improved.

The application discloses a joint structure of high-energy beam welding and a processing and welding method thereof, and aims at solving the problems of stress concentration, gas residue, heat affected zone and difficult control of welding quality in the prior art. The joint structure comprises coaxially assembled base material I and base material II; a first annular groove is arranged on a welding surface of the base material I, a second annular groove is arranged on a welding surface of the base material II, the groove widths of the first annular groove and the second annular groove are consistent and the positions of the first annular groove and the second annular groove correspond; the first annular groove and the second annular groove form an annular stress relief channel after the base material I and the base material II are assembled; at least one exhaust channel is arranged on the base material I and / or the base material II, one end of the exhaust channel is communicated with the annular stress relief channel, and the other end is used for communicating with an external environment; and the maximum radial dimension of the communicated position of the exhaust channel and the annular stress relief channel is smaller than the groove width of the annular stress relief channel. The structure can eliminate stress concentration during welding, and prevent the initiation and expansion of cracks after welding.

The invention discloses a non-oriented high-silicon steel plate machining method and a non-oriented high-silicon steel plate. The non-oriented high-silicon steel plate machining method comprises the steps that the non-oriented high-silicon steel plate is provided; a laser beam of a laser is guided by water jet, and the non-oriented high-silicon steel plate is cut into a preset size; permanent magnets are symmetrically arranged on the two sides or the rear portion of the laser and used for stabilizing magnetic domains under the action of external magnetic field energy, and the magnetic domains are arranged in the easy magnetization direction. And the cut non-oriented high-silicon steel plate is cooled through water jet, the width of a heat affected zone is reduced, and the machined non-oriented high-silicon steel plate is obtained. According to the method, the high-silicon steel plate with low surface roughness, small residual stress and excellent magnetic performance can be obtained.

The invention discloses a machining method for a laser quenching cutter point, and belongs to the technical field of metal surface treatment and cutter machining. According to the method, efficient and uniform quenching of the cutter point is achieved through multi-beam laser composite scanning and artificial intelligence real-time feedback control; the method comprises the steps of workpiece pretreatment, multi-beam laser scanning, real-time monitoring and feedback control, post-treatment and quality evaluation. The method has the effects of reducing heat affected zones, improving hardening uniformity and reducing energy consumption.

The utility model discloses a coating gasket and a die head, the coating gasket comprises a gasket main body, the gasket main body comprises a main body part, connecting parts and a thinning area, two ends of the thinning area are connected with the main body part through the corresponding connecting parts, the thickness of the thinning area is smaller than that of the connecting parts, and a groove strip is arranged in the thinning area. According to the utility model, the thinning area is arranged on the coating gasket, and the groove strips are arranged in the thinning area, so that a groove structure can be directly formed in a wet film coating stage, the technical effect which is the same as that of the existing laser or mechanical grooving process is realized, and the phenomenon that a heat affected zone and dust are easily generated through laser or mechanical grooving is avoided; meanwhile, the structure of an electrode material is possibly damaged, and the performance of the battery is reduced.

The application discloses a gluing thickness determination method, a laser processing method, a device, a storage medium, equipment and a system. A plurality of processing images of a target material processed by laser under different gluing thicknesses are obtained; pixel features and heat affected zones of a cutting line in each processing image are identified. The cutting line is a linear mark formed by laser processing; the heat affected zone is a zone representing the influence of heat generated by laser processing on the periphery of the cutting line. A target image is determined from the plurality of processing images based on heat affected control conditions and grayscale screening conditions. Finally, based on the correspondence between the processing image and the gluing thickness, the gluing thickness corresponding to the target image is determined as a target gluing thickness matched with the target material. By comparing the processing images of the target material processed by laser under different gluing thicknesses, the gluing thickness ensuring and improving the material processing yield is automatically determined, so that the intelligent level of material gluing and material processing is improved.

The application provides an automatic welding system and method for liquefied natural gas ship pipe manufacturing, wherein the welding area of the liquefied natural gas ship pipe is divided into multiple welding sub-areas through surface topography data of the welding area of the liquefied natural gas ship pipe; the posture reachable space of the arc welding gun end effector in the Cartesian space is determined, and multiple process control points of the ship pipe welding area are calibrated according to the feature correlation relationship between the weld geometric features of each welding sub-area in combination with the posture reachable space, and then the heat affected zone of each process control point under the thermal state is predicted; the preheating regulation and control parameters when the welding area of the ship pipe is welded are determined through the interaction relationship of the heat affected zones between adjacent process control points; the welding area is guided by heat energy according to the preheating regulation and control parameters, and then the weld fusion work of the welding area after the heat energy guidance is completed. The above scheme can avoid local thermal burn-through of the weld during welding based on the preheating regulation and control parameters.

The invention relates to the technical field of pressure vessel manufacturing, and discloses a spherical tank welding stress reduction process with coupling preheating and interlayer temperature control, which comprises the following steps: preheating a to-be-welded area of a spherical shell plate before welding; multi-layer and multi-pass welding is conducted through a small heat input welding method, in the welding process, self-adaptive heat input control is executed based on geometrical characteristics of a standard linear area, a T-shaped intersection area and the like of a weld joint path, and meanwhile the interlayer temperature between all welding passes is strictly controlled; a symmetric welding method and a segmented back welding method are adopted to balance deformation; and finally, a tempering welding bead with low linear energy is welded on the cover surface layer. According to the method, through in-situ, zoning and multi-stage coordinated regulation and control of welding heat input, formation of hard and brittle structures is effectively restrained, the performance of a heat affected zone is optimized, the residual stress peak value of a welding joint, especially a geometric discontinuous region, is remarkably reduced, and the process does not need overall heat treatment after welding, so that the production cost is reduced. The manufacturing period is shortened; and the production cost is reduced.

The invention discloses a device capable of being continuously used for pipeline welding seam detection and a detection method thereof, and relates to the technical field of pipeline welding seam detection.The device comprises a guide rail, the top of the guide rail is connected with a precision control box in a clamped mode, three first magnetic attraction devices are further installed at the bottom of the guide rail, and rotating buttons are arranged on the outer sides of the three first magnetic attraction devices; a rotary positioner is installed on the outer side wall of the precision control box and used for adjusting the position of a pressure head, continuous monitoring of different areas of a weld joint is achieved, and a to-be-detected weld joint pipeline is further adsorbed to the bottom end of the first magnetic attraction device and used for detection; by arranging the flexible guide rail and the magnetic attraction device, the device can be stably attracted to the surfaces of pipelines with different pipe diameters, and continuous and automatic movement and accurate positioning in the circumferential direction of the circumferential weld are achieved in combination with the precise control box and the rotary positioner. And rapid and continuous indentation testing and data acquisition can be performed on a plurality of key areas such as a base metal area, a heat affected area and a weld center area.

The present invention provides a steel sheet comprising, by wt%, carbon (C): 0.11% - 0.14%, silicon (Si): 0.1% - 0.3%, manganese (Mn): 0.9% - 1.3%, soluble aluminum (Sol. Al): 0.015% - 0.055%, phosphorus (P): 0 (exclusive) - 0.015% (inclusive), sulfur (S): 0 (exclusive) - 0.003% (inclusive), nickel (Ni): 1.7% - 2.2%, chromium (Cr): 0.2% - 0.6%, and molybdenum (Mo): 0.2% - 0.6%, with the balance being iron and inevitable impurities, wherein the microstructure of the heat-affected zone in welding has a maximum size of effective grain of 50 μm or less with a grain boundary misorientation angle of 15° or more, and comprises, by area fraction, 90–98% of lower bainite and upper bainite in total, and less than 5% of martensite-austenite constituent.

The present application relates to the technical field of diamond saw blade, in particular to a laser welded diamond saw blade for ultra-narrow slit cutting and a preparation method thereof.The laser welded diamond saw blade comprises the following raw materials: copper-cobalt-tin alloy powder, tungsten carbide powder, titanium aluminum nitride, spherical cobalt powder, rare earth yttrium powder, phosphorus iron powder and diamond abrasive particles.The core of the preparation method is the combination of powder metallurgy pre-preparation of the cutter head and precise laser welding process, especially the innovative laser welding process.The prepared diamond saw blade has high weld strength, narrow heat affected zone and minimal substrate deformation, solves the problems of substrate deformation, insufficient weld strength and short service life of traditional saw blades in ultra-narrow slit cutting, and is perfectly suitable for ultra-narrow slit cutting scenarios with extremely high requirements for precision and stability.

This disclosure provides a battery, a battery pack, and an electrical device. The battery includes a casing and a cover. The cover is welded to an opening in the casing. The casing includes a short sidewall with a short flange and a long sidewall with a long flange. The short flange and the long flange form at least a portion of the opening. A first protrusion protrudes from the inner surface of the short sidewall toward the battery cell. The cover includes a short side and a long side. The long side is welded to the long flange, and the short side is welded to the short flange. The first protrusion has a dimension a1 along a second direction, the short sidewall has a dimension a2 along the second direction, the short side has a length b1, the long side has a length b2, and the hardness of the heat-affected zone is c. The formula is selected with values ​​in the range of 10 × 10⁻⁶. ‑4 HV ‑1 Up to 4500×10 ‑4 HV ‑1 Within this range, the battery not only has a lower risk of cracking at the short wall edge and short side weld, but also a lower risk of the explosion-proof valve opening unexpectedly.

This invention discloses an optimized method for stator and rotor welding processes in the field of motor manufacturing, comprising the following steps: improving welding quality through pretreatment, coating with modified composite materials, and optimizing laser welding parameters. During pretreatment, the stator and rotor areas to be welded are sanded with 800-1200 grit sandpaper, followed by ultrasonic cleaning with acetone or alcohol for 10-15 minutes to achieve a surface roughness Ra ≤ 1.6 μm; a 0.1-0.3 mm thick layer of modified composite material is coated onto one surface and dried at 80-120°C for 1-2 hours; laser welding is employed, with the molten pool temperature monitored at 1800-2200°C during welding; immediately after welding, the welded parts are placed in a holding furnace at 200-300°C for slow cooling for 2-4 hours, and then cooled to room temperature at a rate of 5-10°C / min. This method effectively improves the strength, toughness, and crack resistance of the welded joint, reduces the heat-affected zone, and minimizes deformation.

The present application belongs to the technical field of rare metal material modification, and particularly relates to a production method for refining coarse grains of a titanium material welding seam, selects TA1 titanium plate as a research object, processes an X-shaped groove on the titanium plate, adopts manual tungsten argon arc welding to perform multi-pass welding on the TA1 titanium plate, adopts multi-pass cold pressing to perform deformation treatment on the titanium plate after butt welding, and finally performs annealing heat treatment, so as to obtain a welding seam structure similar to a base material structure. The method is beneficial to refining grains in a welding seam area and a heat affected zone, and reducing differences between grains in each area of the welding seam and base material grains.

The process comprises the following steps: S1, crack detection: scanning the surface of a casting blank by adopting an infrared thermal imager, setting a temperature difference threshold value to be greater than or equal to 10 DEG C so as to identify the crack, generating a three-dimensional thermal field distribution diagram, and marking the depth, length and distribution density of the crack; s2, laser micro-melting repair is conducted, specifically, a mechanical arm is adopted to control a laser head, and according to path planning, spiral scanning or a Z-shaped track is adopted to conduct remelting on a crack area according to set parameters; s3, post-treatment and quality inspection are conducted, specifically, a repairing area is air-cooled to 200 DEG C or below, and residual stress accumulation is avoided; and then ultrasonic flaw detection and metallographic detection are conducted, the crack elimination rate and the structure uniformity are verified, it is ensured that the crack elimination rate is larger than or equal to 98%, and the depth of a heat affected zone is smaller than or equal to 0.2 mm. Subcutaneous cracks are accurately positioned through the thermal infrared imager, micro-area remelting is carried out on a defect area in combination with the movable optical fiber laser head, the cracks can be efficiently eliminated, meanwhile, the original structure performance of a casting blank is kept, and the yield of the continuous casting blank is remarkably increased.

The invention relates to an underground energy storage chamber adapting to alternating high internal pressure conditions and a deformable connecting structure thereof, and the deformable connecting structure comprises two connecting steel plates which are respectively and vertically fixed to the end parts of two annularly adjacent chamber body steel plates; longitudinal channels are formed in the outer side faces of the connecting steel plates, and when the two connecting steel plates are in annular butt joint, the channels in the two sides are in butt joint, and the whole space is filled with rubber sealing strips. Bolt holes perpendicular to the connecting steel plates are formed in the positions, located on the two sides of the cave body steel plate, of the connecting steel plates, the connecting bolts are inserted to connect the two connecting steel plates, the rubber sealing strip is compressed, and the two connecting steel plates are spaced by a specified interval in the annular direction. Self-adaptive deformation can be achieved under the high-pressure alternating load, stress concentration of a heat affected zone is effectively relieved, microcrack propagation is prevented, and therefore long-term stable sealing performance is ensured, expansion and shrinkage caused by temperature fluctuation are absorbed through an elastic compensation mechanism, and the reliability and durability of the whole structure in a severe environment are improved.

The invention discloses a pressure pipeline welding arc-shaped gasket device in the technical field of pipeline welding, which comprises a machine body frame, a mechanical arm and a reducing mechanism, and further comprises a retainer detachably connected with the machine body frame, a plurality of sections of gasket brackets are uniformly distributed on the periphery of the retainer in the circumferential direction, and the sections of gasket brackets can be sequentially spliced end to end to form a ring; each section of gasket support is provided with a gasket assembly capable of being in butt joint through a quick release structure, a driving piece and a limiting piece are installed on the retainer, the driving piece can control all the gasket supports to synchronously rotate around the radial axes of the gasket supports, and the limiting piece assists the gasket supports in synchronous radial displacement in the rotating process. According to the method, the problems that in existing large pressure pipeline circular seam root welding, workers still need to enter the pipe for manual lining attaching, and consequently oxygen deficit poisoning radioactive high-risk operation is caused, the back face forming defect is caused by gasket circumference dislocation, and after-welding heat affected zone adhesion is difficult to detach are solved, so that limited space operation is thoroughly eliminated, and the welding seam quality and the construction efficiency are synchronously improved are solved.

The present invention provides a battery case with suppressed thermal deformation, a battery, and a method for manufacturing a battery case. [Solution] A battery case according to one aspect of the present disclosure comprises a cylindrical body made of a bent metal plate and a pair of lids that seal the openings at both ends of the body, wherein the first end of the metal plate has one or more folded portions extending from one lid to the other lid and provided on the outer surface of the body, and a base portion which is a region overlapping with the folded portions, the second end of the metal plate overlapping the folded portions on the outer surface of the body, the body has a weld metal that extends from one lid to the other lid and joins the folded portions and the second end to each other, and the base portion has a heat-affected zone.

The present invention provides a welded structure having excellent heat-affected zone (HAZ) toughness and suppressed strength inhomogeneity in the HAZ, and a steel plate from which such a welded structure can be obtained. [Solution] The steel sheet according to this disclosure has the chemical composition described in the specification, wherein f1 as defined by formula (1) satisfies 0.35 to 0.47, f2 as defined by formula (2) satisfies 0.21 or less, and in the central part of the thickness of the steel sheet, the microstructure consists of 28.0 to 45.0% ferrite, 0 to 15.0% pearlite, 0.01 to 5.00% MA structure, and the remainder being bainite, with a dislocation density of 0.7 × 10 14 ~3.0×10 14 m -2 It satisfies the condition. f1=C+Mn / 6+Si / 24+Ni / 40+Cr / 5+Mo / 4+V / 14 (1) f2=C+Si / 30+Mn / 20+Cu / 20+Ni / 60+Cr / 20+Mo / 15+V / 10+5B (2)

The application belongs to the technical field of X-ray tubes, and discloses an anode assembly and a processing method thereof. The anode assembly comprises a molybdenum reflector, a molybdenum rotor assembly and an intermediate layer. The intermediate layer is made of metal material and is arranged between the molybdenum reflector and the molybdenum rotor assembly by using the processing method. In the heating process, the intermediate layer can effectively absorb and buffer thermal stress and shrinkage stress generated from the molybdenum components on both sides due to heating and cooling through plastic deformation of the intermediate layer, thereby greatly reducing the risk of micro-cracks caused by stress concentration. Moreover, since the chemical affinity of the intermediate layer to impurity atoms is higher than that of molybdenum material, in a protective atmosphere or a vacuum environment, the intermediate layer can be ensured to preferentially react with the harmful impurities in the interface area during the welding process to form stable compounds, thereby preventing the impurities from segregating at the grain boundaries of molybdenum, significantly improving the microstructure and toughness of the molybdenum heat-affected zone, and enhancing the anti-grain boundary cracking ability.

The application discloses an underwater magnetic field coupling magnetostrictive backfill type friction spot welding device, which comprises a stirring needle, a compression ring, welding material, a compression ring chuck, a top end clamp, a top rod, a cap, an electromagnetic transducer, a magnetic conducting ring, a fixed connecting rod and a water tank; the top end clamp is fixed on the compression ring chuck and cooperates with the internal top rod to fix the welding material at the bottom end of the electric spindle; the fixed connecting rod is sequentially sleeved with the electromagnetic transducer and the cap, and the three are concentrically matched and located at the bottom of the welding point center; the magnetic field energy is converted into electric energy and mechanical energy to the welding point through the electromagnetic transducer. The stirring needle is opposite to the surface of the welding material; the welding material is submerged in the pool of the water tank, and the pool water flow in the water tank is adjusted according to the temperature change; the electronic converter is added at the bottom to improve the temperature distribution of the welding point and the material flow; the underwater welding reduces the heat input and the heat affected zone structure area, and ensures the effective implementation of electromagnetic induction.