289 results about "Flash welding" patented technology

The present invention generally relates to methods of connecting two expandable tubulars. In one aspect, the method includes flash welding the ends of the expandable tubulars together. Thereafter, the connected tubulars are lowered into the wellbore for expansion. The flash welding process provides a highly reliable joint for expansion. In another aspect, the present invention provides a method for expanding a non-uniform tubular. In one embodiment, the non-uniform tubular is formed by connecting two misaligned tubulars.

The invention discloses a heat treatment method of a steel rail flash welding head, and belongs to the technical field of steel rail welding. The invention aims to solve the technical problems of saddle type abrasion and early-stage fatigue fracture of a steel rail welding head due to the fact that the hardness of a welding area is lower or the welding head microstructure is abnormal in the line service process of the steel rail, the heat treatment method of the steel rail flash welding head is provided, the steel rail welding head is sequentially subjected to a first cooling stage, a second cooling stage and a third cooling stage, the cooling speed and the temperature of each stage are controlled, so that abnormal tissues such as martensite, bainite and the like are not exist in the metallographic structure of the steel rail welding head. The heat treatment method of steel rail flash welding head has the beneficial effects that saddle type abrasion and early-stage fatigue fracture ofthe steel rail welding head due to the fact that the hardness of the welding area is lower or the welding head microstructure is abnormal in the line service process of the steel rail are improved, and the safety of railway operation is guaranteed.

The invention discloses a 60 kg / m R260 hot-rolled rail moving flash welding method, which comprises five stages of flash, flash, accelerated firing, upset and holding pressure. The total heat input during welding is 3.0-4.8 MJ, the total welding duration is 110-135s, and the welding upset is 12.4-16.7 mm. The invention improves the welding quality of the rail by controlling the total welding heatinput, the total welding time and the upset forging amount in the moving flash welding process, and controlling the welding heat input and the duration time of each of the five stages of flash, flash,accelerated firing, upset forging and holding pressure; 60 kg / m R260 hot-rolled rail can be successfully move for flash welding by that invention, The total width of HAZ of the whole 60kg / m R260 hot-rolled rail moving flash welding joint is controlled within 32mm, and the difference between the maximum and minimum of the total width is less than 8.2 mm. The internal defects of the rail joint areless, and the welding quality is stable.

A rail repair method and insert therefor enables repair of rails and rail-like structures. A rail defect is initially identified and removed as contained within a volumetric material portion so as to form a contoured void while maintaining continuity of the rail opposite the void. A pre-formed insert is then placed into the void thereby effecting a rail-to-insert interface. Current is driven through the interface as force directs the insert against the rail. Resistance heat and pressure weld the insert to the rail. The flash welding aspects remove oxides and other impurities from the interface, and the forge welding aspects create a robust solid state weld. Excess material, whether flash, rail, or insert-based, is removed during the finishing processes to provide a virtually seamless rail repair. The solid state weld repair insert and underlying methodology enabled thereby may be used to repair any number of targeted metallic rail-like structures.

The invention discloses a steel rail flash welding machine, which comprises a first pair of box body, a second pair of box body, a central shaft, a clamping oil cylinder, an upsetting oil cylinder, a knob removing device and a welding transformer, wherein the clamping oil cylinder comprises a cylinder body, a piston, a piston rod, a piston rod end connecting piece and an end cover; the cylinder body is divided into a first cavity and a second cavity; the inside of the piston rod is provided with a supercharged piston; the inner cavity of the piston rod is divided into a third cavity and a fourth cavity; the end part of the cylinder body is provided with a first oil line and a second oil line and is connected with a hydraulic integrated block provided with an electromagnetic reversing valve, a pilot reducing valve and a hydraulic control one-way valve; and the periphery of an oil conduit at least forms a segment of sliding fit with the through hole of the supercharged piston. The steel rail flash welding machine is large in clamping force, simple and reasonable in structure, facilitates the control of the output clamping force and is suitable for welding steel rails with different lengths and weights.

A method for welding a bainite steel frog and a carbon steel rail is characterized in that CrNi series austenite-ferrite dual phase steel is adopted as a connecting material; the technological process is as follows: (1) the carbon steel rail is preheated to 300-500 DEG C; (2) the carbon steel rail and the connecting material are butt-welded together; (3) the connecting material is cut and retained at the length of 20-30mm; (4) the bainite steel frog is preheated to 300-500 DEG C; (5) the retained connecting material and the bainite steel frog are flash welded; and (6) the temperature of a welding joint is preserved between 900-1,000 DEG C for 10-20 minutes, and then the welding joint is air cooled. The connecting material has the following composition (weight %): C is equal to or less than 0.2; Cr is 15-17; Ni is 7-9; Si is equal to or less than 0.3; S+P is equal to or less than 0.04; and iron is in balancing amount. The connecting material is heated to 1,050 DEG C, and then solution treatment is performed to obtain austenite-ferrite dual phase tissue, wherein the content of ferrite is 10-20%; the flash speed of flash welding is 2-3mm / s; the upset forging speed is 80-100mm / s; the upset forging pressure intensity is 40-50MPa; and the extension elongations of the material are equal during the welding process.

The invention discloses an automatic-clamping and precise-positioning mechanism of a pipeline in flash butt welding. The automatic-clamping and precise-positioning mechanism comprises a bottom platform, a traveling mechanism A, a traveling mechanism B, a holding mechanism A, a supporting frame A, a holding mechanism B and a supporting frame B, wherein the traveling mechanism A and the traveling mechanism B are arranged on the bottom platform and consist of two sliding platforms respectively; the holding mechanism A is arranged on one sliding platform of the traveling mechanism A; the supporting frame A is arranged on the other sliding platform of the traveling mechanism A and is connected with the holding mechanism A; the holding mechanism B is arranged on one sliding platform of the traveling mechanism B; the supporting frame B is arranged on the other sliding platform of the traveling mechanism B and is connected with the holding mechanism B; a screw-rod driving mechanism is arranged between the traveling mechanism A and the bottom platform; the supporting frame A is provided with a distance fixing column; the supporting frame B is provided with a longitudinal positioning mechanism. The automatic-clamping and precise-positioning mechanism disclosed by the invention has the advantages that the structure is simple and the operation is convenient; by matching with pipeline flash welding equipment for use, the pipeline can be automatically arranged on the pipeline welding equipment by high efficiency, the positioning accuracy is higher, the difficulty that the installing accuracy cannot be ensured in the manual installation process of the pipeline in flash butt welding is effectively solved, and the labor intensity of operators is reduced.

The invention relates to the field of a compressor, in particular to a compressor exhaust pipe and a manufacturing method and application of the compressor exhaust pipe. The compressor exhaust pipe is arranged on an upper cover of the compressor and comprises a copper pipe section and an iron pipe section, the copper pipe section and the iron pipe section are in butt welding through flash welding, and the iron pipe section is connected with the upper cover of the compressor through electric resistance welding. The manufacturing method of the compressor exhaust pipe comprises preheating and upset-forging. The compressor exhaust pipe can be applied to an air conditioning compressor, a refrigerator compressor and a scroll compressor. The connection between the copper pipe section and the iron pipe section of the compressor exhaust pipe and the connection between the iron pipe section and the upper cover of the compressor adopt a welding method without welding materials, the use of the welding materials is completely eradicated, thus the environment cannot be polluted by waste gases such as carbon dioxide generated during a production process, the technology is simplified while the green production is realized, and the manufacturing cost is lowered; and the compressor exhaust pipe has the advantages that the welding quality is good, the welding strength is more reliable, the welding quality is increased, and the service life is prolonged.

The invention discloses a movable flash welding and heat treatment technology for a 60kg / mU75V+U75VG steel rail, in particular to a movable flash welding and heat treatment technology for a 60kg / mU75V+U75VG steel rail in the technical field of steel rail welding. The movable flash welding and heat treatment technology for the 60kg / mU75V+U75VG steel rail comprises a flash flattening stage, a pulsation stage, an accelerated incineration stage, an upsetting stage and a pressure maintaining stage. In the welding process, the total welding heat input is 8.2MJ-8.7MJ, the total welding duration timeis 111s-121s, and the welding upsetting length is 16.0mm-16.6mm. By the adoption of the method, the 60kg / mU75V+U75VG steel rail can be successfully subjected to movable flash welding, few internal defects are produced inside a steel rail connector, welding quality is stable, and the steel rail connector can pass various mechanical property tests such as a fatigue test, a tensile test and a staticbending test; and the steel rail connector can continuously pass the test of 15 flash welding connector drop hammers, and has good stability.

The invention discloses a copper-aluminum socket connector for the electric conduction, the preparation method thereof and the application thereof. The socket connector comprises an aluminum body and a copper plug integrated into a whole by welding. The preparation method comprises the following steps: (1) manufacturing the molded aluminum body and the copper plug, and cleaning the welding surfaces of both the aluminum body and the copper plug; and (2) welding the aluminum body and the copper plug into an integrated part by adopting a flash welder or a spin friction welder to obtain the copper-aluminum socket connector semi-product for the electric conduction. The socket connector is mainly applied to a moving contact, a static contact or a conductive contact arm in a high and low voltage switch cabinet or a vacuum circuit breaker. The socket connector has the advantages of non-contact resistance, no galvanic corrosion, smaller resistance, less current conveyance loss, improved current transmission efficiency and reduced power transmission and transformation loss.

The invention relate to the field of welding of steel rails, and discloses a method for movable flash welding of a 75 kg / m hypereutectoid steel rail and a pearlite steel rail, and the steel rails obtained through welding according to the method. The method comprises the steps of flash flattening, pulsing, accelerated burning, upsetting and pressure maintaining, and is characterized in that the total heat input for welding in the movable flash welding process is controlled to 10-13 MJ, the total duration for welding is 143-162 s, and the upsetting amount for welding is 15.5-18.5 mm. By adoption of the method, movable flash welding of the 75 kg / m hypereutectoid steel rail and the pearlite steel rail can be achieved, internal defects of joints of dissimilar steel rails are few, and the welding quality is stable; and the joints of the dissimilar steel rails can be checked continuously through 15 splash welding joint drop hammers, and the stability is good.

The invention relates to a stationary rail flash welder, comprising main frame and two primary rail racks 40 and 41. The main frame rack 42 is equipped with moving rack 16, static rack 17 and centering rack 22. The moving and static rack are connected with moving rack rail clamping cylinder 6 and static rack rail clamping cylinder 7 on the upper side respectively, static rack rail clamping cylinder 7 is connected with potential transformer cover 37, and the lower part of potential transformer is connected to rail electrode 38. The moving rack 16 is connected with cradle 42vthrough supporting axis 18 and lower supporting axis 19, and the insulated heading cylinder 3 is connected with cradle 42 and moving rack 16. The horizontal centering cylinder I on right of centering rack 22 is connected with static rack 17, and vertical centering cylinder 2 is connected with cradle 42. The moving and static rack is equipped with a unit of horizontal adjusting and locating device respectively. The horizontal clamping device of primary rail racks 40 and 41 on rail bottom is drove by cylinder 21 through rack bar 30, and rack bar 30 drives two gears to rotate and locate rail in horizontal direction. The vertical location for rail is finished by lifting gearing. The invention can obviously improve welder working condition and increases welding quality.

The invention discloses a flash welding technological method for the head and the tail of a non-oriented electrical steel used in cold-rolling pickling line and tandem cold mill to enhance the quality of the weld joint. The technological method can be described as follows: a low-carbon steel material with the same thickness and width is inserted between a front roll of non-oriented electric steel and a back roll of non-oriented electric steel; the head of the low-carbon steel material is welded with the tail of the back roll of non-oriented electric steel and the tail of low-carbon steel material is welded with the head of the back roll of the non-oriented electric steel. The flash welding technological method for the head and the tail of a non-oriented electrical steel used in cold-rolling pickling line and tandem cold mill has the advantages that due to good plasticity and toughness, the quality of the weld joint of the non-oriented steel after welding is greatly enhanced without lap joint and tested qualified in the on-site cupping test, avoiding thrust belt of the joint; the weld joint can not only pass through the acid, but also normally through the miller for rolling, without need of reducing pressure, tension or speed, therefore, popularization in band steel manufacturing of cold-rolling pickling line and tandem cold mill is particularly suitable.

The invention discloses a flash welding forming method of an alpha-beta two-phase titanium alloy thin-wall ring piece. The method includes the steps that a D-shaped ring blank with an opening is filled in a welding machine, the welding machine is started to close the opening of the ring blank, and 7V-18V voltage is applied between two poles of the welding machine so that a left end surface and a right end surface at the position of the opening of the ring blank is heated and melt through flash current with density of 20A / mm<2>-180A / mm<2> to form a lintel and then blasted to form a flash; the burning loss speed of the flash of the ring blank is 3.0mm / s-6.0mm / s, and the right end surface of the ring blank is driven to perform accelerating feed movement toward the left end surface with the initial speed of 2.0mm / s-3.0mm / s and the accelerated speed of 0.5mm / s<2>-1.0mm / s<2> so that the distance between the left end surface and the right end surface is smaller than 10mm; and after the flash is finished, a right side straight edge of the ring blank is driven to perform high speed movement toward a left side straight edge, the left end surface and the right end surface are hit against each other under the action of upsetting forces of 10kN-15kN to form the flash welding thin-wall ring piece, and pressure maintaining is performed for 20s-30s under the action of the upsetting forces. According to the method, flashing process can be continuously performed to improve welding quality.

The invention provides a flash welding process of a high-strength low-magnetic anchor chain. The flash welding process is characterized in that the burn-off degree reaches 7-9 mm, the upset forging length reaches 6-8 mm, the burn-off speed reaches 1.8-2.0 mm / s, the secondary no-load voltage reaches 4.7 V, and the system pressure reaches 14-16 MPa. Compared with a conventional technological process, the flash welding process has the advantages that a pre-flash process is added, so that the problems about the rapid heat dissipation of a material and the heating of welds during low-temperature welding can be solved, the heat-affected area can be effectively enlarged, the upset forging effect can be guaranteed, and the relatively consistent shapes of welding joints can be guaranteed; sufficient upset forging pressure is exerted on welding end surfaces, gaps among the joints are rapidly reduced, the lintel blasting is stopped, liquid metal and oxide inclusion on the end surfaces are extruded, and joint areas are subjected to certain plastic deformation, so that the progress of recrystallization can be promoted, common crystal grains can be formed, and firm butt joints can be acquired; and after the upset forging is finished, the pressure of electrodes and the pressure of an upset forging oil cylinder are maintained for a certain time, and then the electrodes and the upset forging oil cylinder are cooled, so that the deformation resistance of the joints can be sufficient and welding end ports can be protected against cracking caused by ring-shaped springback.

The invention discloses a medium frequency induction welding method of a rail. The medium frequency induction welding method is characterized by comprising the following steps: 1. a rail to be welded is clamped by utilizing a gas pressure welding clamping machine; the end surface area to be welded of the rail to be welded is heated by a medium frequency inductor; in the heating process, an infrared thermometer is used for detecting whether the heating temperature of the end surface area to be welded reaches a welding upsetting initial temperature or not; and the medium frequency inductor is connected with a medium frequency power source and a water cooling system; and 2. the welding upsetting of the rail to be welded is realized. Through the medium frequency induction welding method disclosed by the invention, in a welding process, the welding upsetting temperature is accurately controlled; the interference of anthropic factors on the welding quality is eliminated to a maximum extent; the stability is high; foundry defects and flash welding ash spots are not generated; and when the welding quality is guaranteed, the automatic flow line production is conveniently realized and the welding production efficiency is favorably improved.

An energy absorbing assembly for a vehicle including an elongated crash box having ends with circular cross sections. One end of the crash box is received in a bumper beam and is friction welded to an inside surface of the beam. The other end of the crash box is friction welded to a bracket assembly.

The invention relates to a welding production technology for an R4-level anchor chain. The welding production technology includes the processes of material preparing, heating, ring bending, flash butt welding, deburring, gear pressing and inspecting. In the ring bending process, round steel is bent into a small opening with the end faces relatively forming a V shape. In the flash butt welding step, roughing processing is conducted on the end faces, to be welded, of a bent ring before welding, during welding, extrusion force in different directions is applied to the bent ring, and welding of the bent ring is achieved. According to technology parameters of flash welding, the flash speed is 1.2-1.6 mm / s, the flash time is 5-8 s, the maximum value of maximum current is 90 kA, the upsetting speed is 100-120 mm / s, and the upsetting force is 40-55 kN.

The invention provides a steel rail flash welding machine which comprises fulcrums arranged thereon, at least two steel rail clamping mechanisms arranged on the corresponding fulcrums, a flash welding transformer and an upset forging actuating mechanism. Each steel rail clamping mechanism comprises an operating mechanism, two lever structures and two connecting rod pieces, wherein the operating mechanism is provided with an operating rod capable of vertically applying force or actuating; the two lever structures can pivot around the fulcrums, and the lower end of each lever structure can loosen or clamp a steel rail; and one end of each connecting rod piece is pivotally connected with a common first pivot point on the operating rod, and the other end of the connecting rod piece is pivotally connected with one of second and third pivot points lower than the first pivot point on the corresponding lever structure, and the operating rod vertically applies the force to or actuates the connecting rod pieces, so that the lower ends of the lever structures loosen or clamp the steel rails. The invention also provides container type steel rail flash welding equipment with the steel rail flash welding machine.

The invention discloses a rail welding method which is characterized in that the method can achieve the purpose of laying rails of corresponding strength grade in different sections on the line by carrying out mixed welding on rails with marks of U71Mn, U75V and U76CrRe and rails with mark of U75V in different delivery states. According to the invention, rails in different steel types or different delivery states are welded together by utilizing a fixed flash welding manner, and then truck loading and laying of long rails can be carried out according to the conditions of the railway line. By adopting the rail welding method, rails of corresponding strength grade can be laid in different sections on the line, a welding joint is a high-strength flash welding joint, and the overall level of the seamless line of the railway can be improved by improving the use level of the rails.

The invention relates to the field of a compressor, in particular to a liquid reservoir air inlet and outlet pipe and application thereof. The liquid reservoir air inlet and outlet pipe comprises an air inlet pipe and an air outlet pipe, wherein the air inlet pipe is arranged on the upper part of a liquid reservoir; the air outlet pipe is arranged on the lower part of the liquid reservoir; the air inlet pipe comprises a first air inlet pipe and a second air inlet pipe; the first air inlet pipe and the second air inlet pipe are butt-welded through flash welding; the air outlet pipe comprises a first air outlet pipe and a second air outlet pipe; and the first air outlet pipe and the second air outlet pipe are butt-welded through flash welding. By using the liquid reservoir air inlet and outlet pipe of the structure, the using amount of copper is saved, and the manufacturing cost is reduced; and the second air inlet pipe and the second air outlet pipe are all connected to a housing of the liquid reservoir through the electric resistance welding free of solder. The technology of the invention is simple, the solder is saved, further the manufacture cost is reduced, meanwhile in the manufacture process exhaust gas such as carbon dioxide or the like is not generated to pollute the environment.

The invention relates to a shell, and a manufacturing method and the application of the shell. The shell refers to a liquid accumulator shell for a compressor, a muffler shell for an air conditioner, a gas-liquid separator shell for a central air conditioner or an oil-gas separator shell. The shell is formed by butt welding of at least two parts. A self-fluxing annular weld pass welding process of argon arc welding, plasma welding, positive ion welding, high frequency welding or laser welding is adopted to carry out synchronization self-fluxing butt welding on connector parts. During welding, heat of butt-joint parts of parts of the liquid accumulator shell or the muffler shell is stable and controllable, both sides reach the melting temperature at the same time, so good fusion is realized, the welding quality is improved, welding junctions are smooth and bright, the welding strength can be improved by more than 1.5 times in comparison with that of the traditional stove passing welding, and the production efficiency is improved by 3-6 times in comparison with that of the traditional stove passing welding, and 2-3 times in comparison with that of flashing welding. The force used for removing a pipe section is small during welding, and the clamping force is very small, so the clamping damage to the surface of the pipe section is not caused, and the equipment cost is only 1 / 5 to 1 / 3 that of the flash welding.

The invention discloses a manufacturing technology of an R4 grade mooring cable used on a deep sea drilling platform. The manufacturing technology comprises steps as follows: blanking, heating, ring making, flash welding, burr removing, ledge pressing, quenching and tempering, tension testing, surface polishing, non-destructive flaw testing, packing, dip coating and shipping, wherein during heating, the fine grain steel granularity is required to be maintained to be higher than three grades; the temperature difference is controlled to be plus or minus 2 DEG C; during ring making, welded junctions are spaced for 1-3 mm, the angle is 3-4 degrees, and the alignment tolerance is 0.3 mm; the burr removing precision is smaller than 3%; the difference of the reshaping size of a pressed ledge is controlled to be plus or minus 0.2 mm; a ledge is strengthened and not symmetric; and the ledge length difference is plus or minus 0.2 mm. The marine mooring cable manufactured with the manufacturing technology method has the effects of high strength and toughness, corrosion resistance and fatigue resistance.

The invention discloses a heat treatment method of a steel rail welding joint, and belongs to the technical field of steel rail welding. The heat treatment method of the steel rail flash welding jointaims at solving the technical problems of saddle-shaped abrasion and early fatigue fracture of the steel rail welding joint of a steel rail caused by low hardness of a welding area or abnormal microstructure of the joint in the line service process. According to the method, the steel rail welding joint is sequentially subjected to a first cooling stage, a second cooling stage and a third coolingstage, the cooling speed and temperature of each stage are controlled, so that no martensite structure exists in the metallographic structure of the steel rail welding joint, saddle-shaped abrasion and early fatigue fracture of the steel rail welding joint of the steel rail caused by low hardness of the welding area or abnormal microstructure of the joint in the line service process are avoided, and it is ensured that the fatigue life of the steel rail welding joint reaches 3 million times or more.

The invention relates to the field of a compressor, in particular to the compressor, a manufacturing method and application of the compressor. The compressor comprises a compressor shell and a liquid reservoir shell, wherein the compressor shell is formed by welding at least two parts, and butt-joint ends of constituent parts of the compressor shell are subjected to flash welding butt welding; and the liquid reservoir shell is formed by welding at least two parts, and butt joint ends of constituent parts of the liquid reservoir shell are subjected to flash welding butt welding. The manufacturing method of the compressor shell and the liquid reservoir shell comprises preheating and upset-forging. The compressor is applied to optional one of an air conditioning compressor, a refrigerator compressor and a scroll compressor. According to the compressor disclosed by the invention, not only is the welding performance of welding parts of the compressor shell and the liquid reservoir shell excellent, but also the structural design is simpler, a flange is not needed to be additionally arranged for assisting the welding, the material is saved, and the cost is reduced.

The invention relates to a heat treatment method for a U71MnH steel rail flash welding joint, and belongs to the technical field of steel rail welding. The problem that harmful structures such as martensites are generated to influence the joint hardness due to the fact that the local cooling speed is higher than the critical transition temperature when an existing steel rail welding joint is cooled in the heat treatment process is solved. The heat treatment method for the U71MnH steel rail flash welding joint comprises the steps that a U71MnH steel rail welding joint welding seam area which iscooled to 300 DEG C or below after being welded is heated to 870-930 DEG C, then heating is stopped, air spraying cooling is adopted and stopped after the steel rail joint tread temperature is lowered to 420-470 DEG C, and natural cooling is conducted till the room temperature is achieved. By adopting the method, it is guaranteed that the joint structure is normal while the hardness of the U71MnHsteel rail flash welding joint is effectively controlled.

The invention relates to a post-welding thermal treatment method for a channel type steel rail flash welding head, belongs to the technical field of railway steel rail welding, and aims to solve the technical problems that the channel type steel rail flash welding head is low in impact toughness through air-cooling, and the hardness of the longitudinal section of the post-welded thermally-treatedrail head is low. According to the technical scheme adopted by the invention, the post-welding thermal treatment method comprises the following steps of: performing first-time cooling on a channel type steel rail welding joint until a temperature lower than 200 DEG C, stopping heating while heating the joint to a temperature of 850-920 DEG C, performing second-time cooling, stopping second-time cooling while cooling to a temperature of 430-520 DEG C, and performing third-time cooling to a temperature of 10-30 DEG C. The rail head longitudinal section hardness of the post-welded thermally treated channel type rail welding joint is 90% or more of average hardness of a steel rail base material, a joint softening region width is within 20 mm, and abnormal structures such as martensite and bainite are avoided. The post-welded thermally treated channel type steel rail all-section welding seam impact power Aku is higher than or equal to 15 J.

The invention relates to a production process for a welded chain cable. The production process includes the procedures of material preparation, heating, ring bending, flash butt welding, deburring, pressing and inspection, wherein in the ring bending procedure, round steel is bent to form a small opening with the opposite end faces in a V shape; in the flash butt welding procedure, extrusion force in different directions is exerted on a bent ring to achieve welding of the bent ring, and according to process parameters of the flash butt welding, the flash speed is 1.4-1.8 mm / s, the flash time is 5-8 s, the maximum current value is 80 kA, the upsetting speed is 90-120 mm / s, and the upsetting pressure is 30-50 kN. Through modification of the bent ring structure, the opening with the end faces being at a certain angle is formed, extrusion is exerted on the lateral ends of the bent ring and the two ends of the opening of the bent ring, stress concentration of the lateral ends of the bent ring and deformation of the ends of the opening are reduced, and welding is achieved through one-time flash; end face dislocation is effectively controlled, the upsetting distance is reduced, and in addition, the flash welding efficiency and the welding quality are further improved through the proper welding process parameters.

The invention discloses a flash welding forming method of a constructional steel thin-wall ring member, which comprises the steps of: loading a D type ring blank with an opening in a welder, starting the welder to close the opening of the preheated ring blank, applying a 7-18V voltage between two poles of the welder to ensure that the left end face and the right end face of the opening of the ring blank are heated and molten through a flash current with the current density of 15A / mm<2>-220A / mm<2> to form a lintel, exploding to form a flash, wherein the flash burning loss speed of the ring blank is 3.6mm-7.2mm / s; driving the right end face of the ring blank to make an accelerated feeding movement towards the left end face at an initial speed of 2.5mm / s-4.0mm / s and an acceleration of 1.0mm / s<2>-2.0mm / s<2> so as to ensure that the distance between the left end face and the right end face is not more than 7mm; and after the flash is completed, driving a right straight side of the ring blank to move at a high speed towards a left straight side of the ring blank to ensure that the left end face and the right end face collide with each other under the action of an upsetting force of 9kN-15kN to form the flash welding thin-wall ring member, and keeping the pressure for 10s-30s under the action of the upsetting force. The method can ensure that the flash process is continuously and stably carried out, thereby improving the weld quality.