58results about How to "Ensure brazing quality" patented technology

The production method of austenitic stainless steel plate fin heat exchanger includes the following steps: part preparation: partition, sealing strip, fin, sealing head and connecting pipe preparation; cleaning before welding; acid pickling to remove oil, dirt and oxide, and using high-pressure water to wash; element assembling and holding; vacuum braze welding, adopting argon arc welding to weldscaling head and connecting pipe, making general assembly; test and inspection, making x-ray inspection, helium leak detection, flow resistance test, pressure test, TUV, ASME and other test and inspection. Said invented process raise the production quality of said stainless steel plate fin heat exchanger, tensile-strength of connector and its service life.

The invention discloses a vacuum brazing process of a stainless steel plate-fin structure, comprising: firstly placing a fin on a baffle and then placing a baffle thereon, placing a solder foil between the fin and the baffles, and then sealing the two sides by edge sealing tapes to form an elementary unit; stacking up a plurality of elementary units according to the design requirements, then using a special jig to clamp and firm the units and exerting pressure on the units, and placing the units in a vacuum brazing furnace; vacuumizing the brazing furnace firstly; then heating the stainless steel plate-fin structure to 850 to 870DEG C and then preserving the heat; and again heating the stainless steel plate-fin structure to the brazing temperature of 1070 to 1100DEG C and then preserving the heat; and then self-cooling the structure slowly in vacuum from the brazing temperature of 1070 to 1100DEG C to 620 to 640DEG C, then filling nitrogen into the furnace, starting up a fan to cool the structure to 40 to 60DEG C so as to take out the structure, and finally obtaining the stainless steel plate-fin structure. The stainless steel plate-fin structure acquired through the brazing process has excellent microstructures and rather high strength.

The invention relates to a method for brazing a compact efficient titanium alloy plate-fin heat exchanger, which adopts an amorphous titanium based brazing filler metal brazing titanium alloy with lower melting point which is between 820 and 840 DEG C, wherein the optimum clearance of the amorphous titanium based brazing filler metal brazing titanium alloy is between 20 and 90 microns, the optimum brazing temperature is between 850 and 900 DEG C, the optimum brazing time is between 10 and 15 minutes, the heating rate before soaking a workpiece is between 10 and 15 DEG C per minute, the heating rate for brazing after the soaking is 15 DEG C per minute, the cooling rate for the brazing filler metal to become solid from liquid is not less than 15 DEG C per minute, and a vacuum system only can be closed when the temperature is below 150 DEG C. Through strict selection and purchase of materials, precise part machining, careful part cleaning, brazing filler metal arrangement according to a process, precise assembling and clamping, and performing brazing according to a stated brazing process, a helium gas leakage test shows that the integral leakage of the product is 9*10<-8>PaM<3> / S which is in accordance with the standard requirement.

The invention relates to a vacuum furnace, in particular to a horizontal type vacuum furnace for diamond particle brazing. A structure of a round horizontal type vacuum shell is adopted, a furnace door is arranged on one side, an inner-outer dual-layer design structure is adopted, water is led into the position between the two layers to achieve cooling, and a heating chamber is of a cylindrical structure and is installed in the vacuum shell; a structure of a graphite-pipe-shaped heater is adopted, upper-lower two-zone heating is adopted, the front end and the back end are provided with temperature compensation structures, a cylindrical hard carbon felt is made of thermal insulation materials at a time to serve as an inner container, and the cylindrical hard carbon felt is wrapped with a soft carbon felt; door screens of same structures are arranged at the two ends of the cylindrical heating chamber, meanwhile, four air openings are arranged, and insulation structures for preventing temperature losses are arranged at the portions of the air openings; a furnace door side door screen is installed on the furnace door, the heating chamber is opened or closed along with opening and closing of the furnace door, an air cooling system is of an internal circulation cooling structure, and a forced air cooling motor is of a frequency conversion structure and placed at the back end of a furnace body; and a high-pressure impeller is assembled on the forced air cooling motor, air is blown into the heating chamber through furnace door side door screen openings, and the production efficiency is improved.

The invention discloses a production method of cutting picks of a coal mining machine. The production method comprises the following steps of: enabling the cutting picks which are well matched to sequentially enter a heating area of an inductor, and controlling the automatic feeding meter at 12 seconds-14 seconds; enabling the cutting picks to enter a welding area, firstly supplementing borax at the upper part of an alloy gear head, tightly shaking an alloy for a plurality of times after melting of copper, performing heat treatment when the temperature of an isothermobath is not less than 230 DEG C, gradually clamping out the well welded cutting picks, arranging into a hanging hook, rapidly lifting the hanging hook with the hand, immersing the cutting picks into a saline solution of the isothermobath, swinging left and right for 3 times, then hanging a cross rod, totally immersing the gear head alloy in the saline solution, and rapidly starting to supply water for cooling when temperature achieves 265 DEG C during feed-discharge balance; staying the cutting picks for not less than 30 minutes under the state that the variation in the isothermobath does not exceed a 20-DEG C constant temperature zone; and lifting out the cutting picks, performing salt leaching, and then washing and cooling. The difference between the production method disclosed by the invention and the prior art is that two times of heating are combined into a whole and can be completed once, thus the brazing quality is ensured, and the heat treatment quenching quality is also improved.

The invention discloses a process method for reducing vacuum brazing defects of a 6061 aluminum alloy and a clamp. The clamp comprises an upper cover plate (2) and a lower cover plate (1) connected through a vertical rod (7); an upper stainless steel plate (4), a spring (5) and a gasket (3) are successively arranged below the upper cover plate (2); and a lower stainless steel plate (6) is arrangedabove the lower cover plate (1). According to the process method and clamp disclosed by the invention, curves of temperature-raising, insulating and cooling processes are adjusted during brazing. Thecold plates can be domesticated by adopting the processing method and the clamp, the vacuum brazing defects of the 6061 aluminum alloy are reduced greatly, the product quality is improved, and meanwhile the international image of an enterprise is enhanced.

The invention discloses a brazing method for a cable shielding layer and a shell, wherein wire branching holes are formed in two ends of the shell; a cable passes through the wire branching holes; and the brazing method comprises the following steps of: winding, namely winding brazing wires on parts, opposite to the wire branching holes, of the cable shielding layer; fixing, namely fixing the cable, the shell and the brazing wires by a clamp; heating, namely, putting a brazing part into an induction coil and heating the brazing part by induction heating equipment; and cooling, namely stopping heating until the brazing part is cooled. By the brazing method, one-time molding of joints at two ends of the shell can be realized, the shape of the shell is uniform and stable, the brazing quality is easy to guarantee, and efficient and automatic production requirements can be met.

The invention provides an induction heating coil and a heating method thereof. The induction heating coil and heating method have the advantages that on the basis that the heating efficiency is guaranteed, the uniform heating is realized, the production period is short, and the quality of braze welding is guaranteed. In the provided induction heating coil (100), high frequency I generated through electromagnetic induction. In the heating object part (100a), a braze material (103) is arranged on the joint part between the end part of a first metal pipe (102) and the end part of a second metal pipe (104), wherein the external diameter of the first metal pipe is greater than that of the second metal pipe. Braze welding is carried out through high frequency heating. Reeling parts (105a, 105b) with at least two coils are formed on two sides of the first metal pipe and the second metal pipe respectively in opposite directions. Moreover, the join part (106) that connects all reeling parts is arranged on a side more close to the second metal pipe relative to the first metal pipe.

Provided is a small multi-assembly brazing clamping device. The small multi-assembly brazing clamping device comprises cores, wherein an upper supporting board is installed on a cover board at the tops of the cores, a lower supporting board is installed on a cover board at the bottoms of the cores, an upper base board is installed at the top of the upper supporting board, a lower base board is installed at the bottom of the lower supporting board, the two sides of the upper base board and the two sides of the lower base board are respectively provided with a plurality of through holes, and screws are installed in the through holes and are perpendicular to the upper base board and the lower base board respectively; the head portions of the screws are fixed on the top of the upper base board through first nuts, the bottoms of the screws are fixed at the upper end of the lower base board through second nuts, and the bottoms of the screws are fixed at the lower end of the lower base board through third nuts. The cores are installed between the upper base board and the lower base board, and the screws which are perpendicular to the cores are installed, so that the phenomenon of dislocation of the cores when thermal expansion stress occurs in the brazing process is prevented; the head portions and the root portions of the screws are respectively fixed on the base boards through the nuts, so that the structure is firm, the shifting phenomenon does not happen, the perpendicularity of the cores is guaranteed, and accordingly the brazing quality of the cores is ensured.

The invention discloses a punching device. The punching device comprises a pipe mold inserted into a pipe cavity of a to-be-punched pipe, a punch is arranged at a through hole formed in the pipe wallof the pipe mold, the punch does stretching and retracting movement perpendicular to the pipe core direction of the pipe mold in the through hole, the end part of the portion, located outside the pipemold, of the punch is a concave arc-shaped punching surface which is of an oval columnar shape with the long axis consistent with the direction of the pipe core of the pipe mold, the end face of theportion is a concave arc-shaped punching surface, and the curvature center line of the concave arc-shaped punching surface is perpendicular to the pipe core of the pipe mold. Under the matching actionof an oval columnar column body of the end part of the punch and the concave arc-shaped punching surface, a notch in the pipe wall of the to-be-punched pipe is oval after the to-be-punched pipe is punched, and the long axis of the oval is consistent with the direction of the pipe core of the to-be-punched pipe, so that the size of the notch in the pipe wall of the to-be-punched pipe in the circumferential direction is smaller than the size in the axial direction, and therefore it is guaranteed that the height of the edge of a hole port of a flanging hole is basically consistent after flanging, the flatness of the hole port of the flanging hole of the to-be-punched pipe is improved, and the brazing quality is guaranteed.

The invention discloses a seamless welding process of a copper tube, which aims at solving the problem of low brazing yield of the copper tube; the key points of the technical scheme are (1) pre-welding treatment; (2) inspection; (3) cutting; (4) installation of socket-and-spigot joint; (5) brazing clearance; (6) axial deviation of the copper tube; (7) selection of a welding torch and a welding nozzle; (8) selection of combustible gas; (9) flame regulation; (10) preheating and heating; (11) brazing connection; (12) heating and maintaining; (13) cooling operation; (14) post-welding treatment. The seamless welding process of the copper tube provided by the invention can improve the finished product rate of seamless welding, so that the copper tube has long service life and high stability after brazing.

The invention discloses a brazing method for radiating pipes and a middle diaphragm of a tubular radiator. The brazing method comprises the steps that 1, a plurality of layers of BNi82CrSiB amorphousbrazing filler metal with the thickness of 0.03 mm are laid on the surface of a stainless steel plate, and the amorphous brazing filler metal are slightly melted in a vacuum brazing furnace with the brazing parameters in which the temperature is 980 DEG C and the insulation time is 5 min; 2, a composite plate formed by slight-melting brazing is machined through a perforating machine to form the middle diaphragm, wherein it is guaranteed that the pore diameter of the middle diaphragm is larger than the outer diameter of the radiating pipes, that is, the brazing gap is within the range of 0.04 mm to 0.08 mm; 3, the radiating pipes are assembled into holes of the middle diaphragm; and 4, an assembly part is placed in the vacuum brazing furnace, and re-melting brazing is conducted for 10 min at the temperature of 1070 DEG C. According to the brazing method, the problem that after the multiple radiating pipes and the diaphragm are assembled, paste brazing filler metal is difficult to coat is solved.

The invention discloses a vacuum brazing method for a slender weld joint of a hole-shaft matched part. The method comprises the following steps of assembling the part, and spraying brazing filler metal, specifically, spot-welding a sheared nickel sheet to a conical surface part of a shaft-shaped part, and uniformly distributing the nickel sheet at 3-5 parts along the circumferential direction of the conical surface part; assembling, specifically, putting the shaft-shaped part in a hole-shaped part and assembling to the bottom, and enabling a clamping part to be in close fit with the inner wall of the hole-shaped part; coating and injecting the brazing filler metal, specifically, uniformly coating and injecting the prepared paste brazing filler metal on the edge of a gap formed by the shaft-shaped part and the hole-shaped part for a circle by using an injector; drying, specifically, cleaning the part, putting the part into a drying oven at (80+ / -10) DEG C, and keeping the temperature for (40+ / -10) minutes; and conducting brazing in a furnace. According to the vacuum brazing method, the front end of the hole-shaft matched part is in close fit, and the nickel sheets with the same thickness are uniformly distributed on the conical surface along the circumference for spot welding, so that the welding clearance is doubly ensured, the conical surface is prevented from being stuck in the assembling process, and the brazing quality of the slender weld joint is better ensured; and the process is easy to operate, parts are easy to assemble, and part assembly is not affected after the nickel sheets are preset on the conical surface.

The invention discloses a manufacturing method of a wear-resistance part for a concrete pump suitable for large-batch automation production. The method comprises following steps that S1, a wear-resisting part body is manufactured, and a hard alloy block is prepared; S2, the wear-resisting part body and the hard alloy block are cleaned; S3, the hard alloy block is assembled in a hard alloy mountinggroove to be brazed and fixed; S4, after brazing, discharge annealing treatment is carried out; S5, an overlaying wear-resisting layer is formed on the wear-resisting part body; S6, annealing treatment is carried out after overlaying; S7, the surface of the hard alloy is subjected to grinding machining; and S8, subsequent finish machining and checkout are carried out. Continuous atmosphere protection brazing is adopted, oxidation of the wear-resisting part body and the hard alloy in the brazing process is avoided, overlaying after brazing is carried out, the problems that due to secondary heating of the overlaying wear-resisting layer, the structure property becomes bad, and the wear-resisting property is suddenly reduced are solved, the original structure and properties of an overlayinglayer are ensured, the protection effect of the overlaying wear-resisting layer on the body and the hard alloy is improved, product quality is improved, and the service life is prolonged.

The invention discloses a method and device for conducting silver or silver alloy contact hard soldering through an alternating current welding machine. A metal reed (3) is disposed on a lower electrode (2) and provided with a soldering material (4). The soldering material (4) and the metal reed (3) are tightly pressed through a pressing rod (5), then a power source is switched on, an upper electrode (1) and the lower electrode (2) are made to communicate, heat is generated when a current flows through the lower electrode (2), and is conducted to the metal reed (3), a contact (6) and the soldering material (4), the metal reed (3) and the contact (6) are welded into a whole after the soldering material (4) reaches the melting temperature and is melted, and operation is completed. By means of the method, the current direction of the upper electrode is changed, and accordingly the influences of the addition amount of soldering flux on soldering and soldering quality are eliminated.

The invention relates to a composite material bearing pad and a manufacturing method thereof. The metal plastic composite bearing pad comprises a tile surface and a tile base, wherein the thickness of the tile surface is 3-6mm, the metal plastic composite bearing pad comprises a metal wire cushion layer and a polytetrafluoroethylene plastic surface layer, the thickness of the metal wire cushion layer is 2.5-5 mm, the metal wire cushion layer is made of a metal wire the diameter of which is 0.2-0.3mm, and the thickness of the polytetrafluoroethylene plastic surface layer is 0.5-1.5 mm. According to the composite material bearing pad provided by the invention, the metal wire cushion layer is manufactured through adopting the metal wire the diameter of which is 0.2-0.3 mm, the thickness of the metal wire cushion layer is notably reduced, and meanwhile, the void content of the metal wire cushion layer is notably reduced, so that the thin-reducing tile surface and the metal plastic composite bearing pad comprising the same are obtained, thereby achieving the technical effects that the material cost is saved, the applied range of the composite bearing pad is expanded, the brazing quality is guaranteed and the surface uniformity is improved.

The invention provides a dissimilar material brazing gap control method and system. The dissimilar material brazing gap control method comprises the steps of: presetting assembly gap values according to the actual structures of all workpieces to be assembled; determining performance parameters of all the workpieces; according to the brazing structures of all the workpieces and the brazing filler metal joint filling requirements, determining the positions of brazing seams and the boundary conditions of thermal structure analysis; according to the boundary conditions of thermal structure analysis and the performance parameters of all the workpieces, analyzing thermal displacement changes of all the workpieces, and working out brazing gap values among all the workpieces; performing comparison and re-calculation according to the brazing gap values among all the workpieces and a preset brazing gap range of a brazing material to obtain an optimal assembly gap range among the workpieces; and performing a process test according to the optimal assembly gap range to determine the actual assembly gap among the workpieces. According to the method, the initial assembly gap of the workpieces and the brazing gap are linked through simulation analysis, so that numerical control over the brazing gap of the dissimilar materials is achieved, and the brazing quality of products is guaranteed.

The invention discloses a slender object brazing coaxial positioning device capable of preventing brazing filler metal from flowing. The device comprises a supporting chassis, a vertical rod, a fixedbody and a coaxial positioning mechanism. The device can calibrate a central axis between two slender objects to be brazed through the coaxial positioning mechanism arranged up and down when brazing the slender objects, so that the center lines of the two slender objects are located on the same straight line, so that a weld joint is in a straight and uniform state during brazing work, the flowingof brazing filler metal during brazing work is avoided, the coaxiality of brazing is guaranteed, the brazing quality is guaranteed, and economic benefits are guaranteed. Through the arrangement of a positioning round tank, a movable frame and the fixed body on the vertical rod, the positions of the coaxial positioning mechanism arranged up and down can be adjusted, so that different welding positions can be adapted, and the working efficiency is improved.

The invention relates to the field of spacecraft machining, and discloses a machining method of an injector partition plate cavity. The machining method of the injector partition plate cavity comprises the following steps that A1, a fan-shaped groove and a wedge-shaped vertical groove are cutted on the inner circumference of an annular body; an upper cover plate, a lower cover plate and a wedge-shaped insert are machined, the upper cover plate and the lower cover plate is assembled at the fan-shaped groove, finish machining is carried out on the wedge-shaped insert, the wedge-shaped insert is assembled at a vertical groove, and vacuum brazing is carried out to obtain a partition plate cavity body assembly: A2, a ring groove piece is assembled at the inner circumference of the partition plate cavity body assembly, and fixing and brazing are achieved; wire cutting, assembling and brazing are performed on a hollow plate and a corrugated plate to obtain a partition plate; an adapter is wire cutted and assembled with the partition plate to obtain a honeycomb assembly: A3, the upper end of the wedge-shaped insert and the upper end of the annular groove piece are milled to form a sinking table surface, and a compensation block is finish-milled; a square groove is milled in the middle of a reinforcing plate, and brazing filler metal grooves are milled in the two sides of the square groove and the outer end face of the reinforcing plate; the partition plate cavity body assembly, the reinforcing plate, the honeycomb assembly and the compensation block are assembled, fixed and brazed; and finish machining is carried out after discharging, and argon arc welding is carried out on a water connector at a water inlet hole to obtain an injector partition plate cavity.

The present invention refers to brazing sheet type heat exchanger to make three kinds media. It contains Each heat exchange plate having six angle of aperture peripheral tight surface structure and having zero to six angle of aperture, wherein having single layer sealing surface, all angle of aperture open calibre size and vertical distance being same, plate heat exchanger periphery four angle of aperture channel heat transfer medium inlet and outlet adopting opposite angle flow mode, such structure being benefit weak intensity material such as aluminium product to make sweat seal.

The invention discloses a muffle-free brazing furnace special for a power battery liquid cooling plate of a new energy automobile. The muffle-free brazing furnace is low in manufacturing cost and good in brazing effect and comprises a rack, a workpiece feeding area, a brazing area, an air cooling area and a workpiece discharging area are sequentially arranged on the rack from front to back, a chain circulating conveying device is arranged on the rack, the chain circulation conveying device penetrates through the workpiece feeding area, the brazing area, the air cooling area and the workpiece discharging area; and the brazing area structurally comprises a furnace body, a hearth and a heating device, the hearth and the heating device are arranged in the furnace body, the front end of the hearth communicates with the workpiece feeding area, the rear end of the hearth communicates with the air cooling area, nanometer heat preservation materials are arranged in the periphery of the furnace body, nitrogen cavities are formed in the left side and the right side of the exterior of the furnace body correspondingly, a brazing area nitrogen pipe is arranged at the upper end of each nitrogen cavity, a nitrogen inlet is formed in the bottom of each nitrogen cavity, and the nitrogen cavities communicate with the hearth through a nitrogen inlet.

The production method of austenitic stainless steel plate fin heat exchanger includes the following steps: part preparation: partition, sealing strip, fin, sealing head and connecting pipe preparation; cleaning before welding; acid pickling to remove oil, dirt and oxide, and using high-pressure water to wash; element assembling and holding; vacuum braze welding, adopting argon arc welding to weld scaling head and connecting pipe, making general assembly; test and inspection, making x-ray inspection, helium leak detection, flow resistance test, pressure test, TUV, ASME and other test and inspection. Said invented process raise the production quality of said stainless steel plate fin heat exchanger, tensile-strength of connector and its service life.

The invention discloses a brazing method for a water load isolating square ceramic chip. The brazing method comprises the following steps: step 1, the square ceramic chip (4) is placed into a square waveguide tube (3); step 2, bow blocks (1) are fixed on the outer lateral wall of the square waveguide tube (3); step 3, brazing solder is used for brazing the square ceramic chip (4) and the square waveguide (3), wherein the bow blocks (1) are expansion alloy blocks and wound with metal wires, so that the bow blocks (1) can be tightly attached to the outer lateral wall of the square waveguide tube (3), the expansion coefficient of the metal wires is smaller than 6*10<-6> / DEG C and the melting point is not lower than 2,000 DEG C. By means of the brazing method, the square waveguide tube in a water load is welded with the square ceramic chip more tightly, and the vacuum tightness of brazing of the isolating ceramic chip is improved.

The invention discloses a braze welding system and a working method thereof. The braze welding system comprises a gas exchanging segment, an electric heating segment, a cooling segment, a vacuum-pumping system, a gas storage system, a constant temperature system, a heat recovering circulation system and a cooling system. The vacuum-pumping system comprises a vacuum tank and a vacuum pump unit. Onebranch of a gas outlet of the heat exchanging segment is connected with a gas inlet of the vacuum tank, and the other branch of the gas outlet of the heat exchanging segment is connected with the vacuum pump unit. The gas storage system feeds protective gas to the heat exchanging segment, the electric heating segment and the cooling segment. The cooling system comprises a water cooling system andan air cooling system. The constant temperature system is used for guaranteeing that the temperature of the heating segment is kept to be constant all the time when the heating segment is in a working state. The heat recovering circulation system is connected with the heat exchanging segment. The invention further discloses the working method of the braze welding system. According to the braze welding system and the working method of the braze welding system, on one hand, it can be guaranteed that workpieces to be welded can be welded in an assembly line manner, the braze welding process is carried out under the vacuum environment all the time, and the braze welding quality is effectively guaranteed; and on the other hand, the utilization efficiency of heat energy, the water resource andthe like can be greatly improved, and the production cost is reduced.

The invention discloses a vacuum brazing method for a slender weld of a hole-shaft matching part, which comprises the following steps: assembling the part, spraying brazing material; The cone surface is evenly distributed at 3-5 places in the circumferential direction; assembly: put the shaft-shaped part into the hole-shaped part, assemble to the bottom, and the clamping part and the inner wall of the hole-shaped part are tightly fitted; coating and injecting solder: use a syringe on the shaft-shaped part and the hole-shaped part The edge of the gap formed by the parts is evenly coated with the prepared paste solder for a week; drying: clean the parts and put them in an oven at (80±10) °C, keep warm for (40±10) min; put them into the furnace for brazing. In this vacuum brazing method, the front end of the hole-shaft matching part is tightly fitted, and nickel sheets of the same thickness are evenly distributed along the circumference of the cone surface for spot welding, which double guarantees the welding gap and prevents the cone surface from sticking to death during the assembly process. Good brazing quality of slender welds is ensured; the process is easy to operate, the parts are easy to assemble, and the pre-installed nickel sheet on the cone surface does not affect the assembly of parts.

A pipe end brazing method of an elongated embedded sleeve comprises guarantee measures of a brazing gap, brazing filler metal selection and thermal cycle, design of a brazing filler metal coating scheme and process control of vacuum brazing. The guarantee measures of the brazing gap includes guaranteeing that the brazing gap between the pipe end of a bellows and an outer sleeve after part assembly is 0.06-0.1 mm and utilizing a fixture to control the assembly dimension in the part assembly; the brazing filler metal selection and thermal cycle includes controlling the diameter Phi of the paste AMS4786 brazing filler metal with a brazing filler metal proportion of 92%-94% to be 1.0-1.6 mm when presetting the paste AMS4786 brazing filler metal with the brazing filler metal proportion of 92%-94% before brazing, and presetting brazing foils with a thickness of 0.1mm; the design of the brazing filler metal coating scheme includes performing welding by presetting brazing filler metal at two ends, and presetting the paste AMS4786 brazing filler metal with a diameter Phi of 1.0-1.6 mm; the process control of vacuum brazing includes guaranteeing various sizes of the part after vacuum brazing through control of the in-furnace fixture. According to the pipe end brazing method of the elongated embedded sleeve, the brazing gap of the part can be guaranteed, full penetration welding of the pipe end can be achieved, and the brazing quality can be guaranteed.

The invention relates to a temperature control method adopting high-frequency heating. According to actual production conditions and the self characteristics of intermediate and high-frequency equipment, the problem of incapability of precise control of a temperature control and time control method over the heating temperature is solved. According to the temperature control method, the advantages of two temperature control methods are combined, the defects of the two temperature control methods are avoided to the maximum, the temperature control accuracy of a production process is greatly increased, and conditions are provided for the realization of high-standard products.