CN114473151A

CN114473151A - Full-automatic electric pulse joint segmented welding device and process for butt joint of different metal pipes

Info

Publication number: CN114473151A
Application number: CN202210036105.7A
Authority: CN
Inventors: 姜雁斌; 谭騛; 李周; 徐国富; 龙佳慧
Original assignee: Central South University
Current assignee: Central South University
Priority date: 2022-01-12
Filing date: 2022-01-12
Publication date: 2022-05-13

Abstract

The invention discloses a device and a process for full-automatic electric pulse combined segmented welding of butt joint of different metal pipes, wherein the device comprises a heating system and a welding system, the electric pulse system and the heating system comprise eddy current coils and are used for carrying out eddy current heating pretreatment on a workpiece to be welded; the welding system comprises a Tig welding gun, a Mag welding gun, a Mig welding gun and a bearing rotating device, wherein the Tig welding gun, the Mag welding gun and the Mig welding gun are arranged on the bearing rotating device, the bearing rotating device is used for automatically rotating and selecting the welding gun to weld a workpiece to be welded, the electric pulse system comprises a high-frequency pulse power supply and a graphite electric brush rod, and the graphite electric brush rod is connected with the high-frequency pulse power supply to provide electric pulse current for a welding part; the device can be used for the welding process among the same or different metals of steel, cast iron and nonferrous metal, prevents the phenomena of coarsening and segregation of crystal grains, improves the mechanical property of a welding structure and has simple operation.

Description

Full-automatic electric pulse joint segmented welding device and process for butt joint of different metal pipes

Technical Field

The invention relates to the technical field of welding and forming of metal pipes, in particular to a full-automatic electric pulse joint segmented welding device and process for butt joint of different metal pipes.

Background

Along with the development, industries such as mines, machinery and metallurgy put forward higher and higher requirements on the service performance and the mechanical property of materials, and as industries such as mines, machinery and metallurgy, the materials have certain requirements on the hardness, strength and plastic toughness of the materials, however, the strength, hardness and plastic toughness of the materials have a mutual exclusion relationship, so that the strength and hardness of the materials can not meet the toughness of the materials when the strength and hardness of the materials are improved, and otherwise, the strength and hardness of the materials can not be ensured. In order to ensure the service life of the equipment, welding of dissimilar metals, that is, welding of a material with high strength and hardness and a material with high ductility and toughness is generally adopted.

Although the mechanical properties of a single material have been greatly developed under the efforts of researchers, the research progress of welding different materials is slow, and the influence of a post-welding heat treatment process on the tissues and the properties of the welding materials is researched more. This is because the weld structure has a large amount of thermal stress in the weld region due to the thermal influence during welding, and the weld structure has relatively coarse grains. Although the structure is regulated and controlled through certain postweld heat treatment, a large amount of heat preservation time is needed in the process, so that the cost is greatly improved, the efficiency is reduced, and a reticular structure and segregation still exist, so that the improvement range of the plasticity and toughness of the material is not large.

The existing welding method for dissimilar steel mainly adopts Mag welding, wherein a flame spray gun is used for heating a pipe to be welded to a certain temperature, a Mag welding gun is used for priming and filling, and air cooling is carried out after filling is completed; and (4) performing subsequent heat treatment processes, such as annealing, tempering, normalizing and the like, by using the heat treatment furnace to perform tissue regulation. This process has certain disadvantages, such as: a. a large amount of manpower is needed to operate each process, the efficiency of the whole welding process is reduced, and the labor cost is increased; b. heating by a flame spray gun leads to formation of a large amount of oxide skin in a to-be-welded area, seriously influences the fusion process of a weld joint structure and reduces the mechanical property of a material, and is easy to crack and the like; c. since the workpiece needs to be subjected to post-weld heat treatment, the size of the workpiece is limited, the size is too large, the heat treatment process cannot be carried out, and the heat treatment process can affect the microstructure of the whole workpiece and change the performance of the whole workpiece. d. The Mag welding process has high requirements on welding speed, and when the welding speed is high, phenomena of undercut, overburning and the like often occur in a welding area, so that a welding wire cannot completely fill a V-shaped groove, the mechanical property of molten metal between passes is poor, and the welding wire is easy to crack. When the welding speed exceeds a critical value, periodic fluctuation occurs on the surface of the welding seam, the strength and the performance of the welding joint are damaged, and the continuity of the welding seam metal is low.

Under the requirement of the industry, not only higher requirements are put on welding organizations, but also more importantly higher requirements are put on welding equipment.

As a new process capable of effectively improving the organization and performance of materials at high speed, the high-energy electric pulse technology focuses on the following three aspects:

1) the high-energy electric pulse treatment is carried out on the solid metal, so that the aspects of microstructure evolution, performance and the like of the material can be controlled;

2) the high-energy electric pulse treatment is carried out on the liquid metal in the solidification process, when the metal material is in a solid-liquid two-phase region, the high-energy electric pulse treatment can obviously improve the as-cast structure of the material, can accelerate the formation of crystal nuclei, and simultaneously inhibit the growth of crystal grains to obtain uniform and refined crystal grains;

3) and the high-energy electric pulse treatment is carried out on the molten metal, so that the crystal grains can be effectively refined, the segregation is reduced, and the microstructure morphology is changed.

The working principle is that high-energy pulse current is applied to two sides of a metal material, namely, the pulse current is input to an electrifying area section of the metal material moving between two electrodes by a pulse power supply through the two electrodes, and the pulse current generates the coupling effect of joule heating effect and non-heating effect in the electrifying area section of the metal material. The pulse current is utilized to remarkably promote atomic diffusion in the material and strong interaction on defects (vacancies, dislocations and crystal boundaries), the organizational structure of the material can be improved by rapidly inducing actions such as recovery, recrystallization and phase change, the solidification structure of the metal material is controlled, grains are refined, the diffusion capacity of elements is improved, and the uniform distribution of hard phases in the metal material is promoted; meanwhile, high-energy electric pulses are transmitted by pulse current between the two electrodes, so that the mechanical property and the processing property of the material in the target area can be adjusted and controlled.

The Tig welding is a welding method with simple operation and higher flexibility, and a welding arc is generated to fill the welding line area when the welding line area is contacted with a welding wire under the protection of pure argon gas in the welding process. The welding process has a wide application range and can be used for welding a complicated part; meanwhile, the heat source energy density generated in the welding process is low, so that the heat affected zone is large, and the base metal crystal grains on the two sides of the welding line are large in size due to the influence of heat circulation in the welding process, so that the mechanical property of a welding joint is reduced.

At present, many process methods for welding the same metal material exist, and few researches are made on the welding method of the different metal material. Patent application document CN103521887A discloses a welding process of 45 steel and 35CrMo cast steel, which adopts a single Mag welding process, and uses a wind shovel to impact each welding seam during welding to primarily eliminate stress generated during welding, and finally further eliminates stress generated in a welding machine area during welding by heat preservation after welding. The patent application with the patent number of CN109396695B discloses a fastener and a workpiece for MIG brazing and flame brazing and a manufacturing method thereof, and the process provides a welding process for realizing MAG welding, TIG welding, MIG welding and the like by continuously replacing a welding power supply and a welding gun corresponding to the welding power supply to realize the same welding equipment. The process methods are complicated to operate, labor is consumed for replacing the welding gun heads manually, and the process methods are not greatly different from a plurality of welding guns.

However, for dissimilar alloy steels, the structure and performance of the weld joint region cannot be well guaranteed by a single welding method, and a large amount of heat preservation time is consumed by combining subsequent heat preservation treatment, so that the labor cost is increased, and the weld joint structure cannot achieve the optimal result. Therefore, how to solve the problems of the existing dissimilar metal pipe welding process equipment, improve the microstructure appearance and mechanical property of a welding seam area, reduce the cracking tendency of materials caused by the phenomena of particle coarsening, segregation, inclusion and the like, and develop an efficient, rapid and intelligent welding device for butt joint of the same or dissimilar metal pipes is particularly important.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a full-automatic electric pulse joint segmented welding device and a full-automatic electric pulse joint segmented welding process for butt joint of different metal pipes based on the aims of energy conservation, efficiency improvement and carbon neutralization; the method solves the problems of undercut, overburning and the like caused by the instability of the welding speed of Mag welding, Mig welding and Tig welding, reduces the cracking tendency of the material caused by the phenomena of coarsening, segregation, inclusion and the like of particles, and improves the working efficiency of the existing welding process and equipment in the welding process.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention relates to a full-automatic electric pulse combined segmented welding device for intelligently butting different metal pipes, which comprises 2 spinning machine tools, a heating system, a welding system, an electric pulse system and a quenching system; the spinning machine tool is used for fixing a workpiece to be welded; the heating system comprises an eddy current coil and is used for carrying out eddy current heating pretreatment on the workpiece to be welded; the welding system comprises a Tig welding gun, a Mag welding gun, a Mig welding gun and a bearing rotating device, wherein the Tig welding gun, the Mag welding gun and the Mig welding gun are arranged on the bearing rotating device, the bearing rotating device is used for automatically rotating and selecting the welding gun to weld a workpiece to be welded, the electric pulse system comprises a high-frequency pulse power supply and a graphite electric brush rod, and the graphite electric brush rod is connected with the high-frequency pulse power supply to provide electric pulse current for the welded part; the quenching system is used for quenching the welding parts after the electric pulse treatment.

The full-automatic electric pulse combined segmented welding provided by the invention mainly integrates a welding system and an electric pulse system, so that after a workpiece to be welded is welded, electric pulse heat treatment can be directly carried out, and the phenomena of coarsening and segregation of crystal grains in the welding process of Mag welding, Mig welding and Tig welding are improved by utilizing the Joule thermal effect of high-energy electric pulses.

The heating system comprises the eddy current coil, and the surface of the material to be welded is high in heating uniformity; and the temperature rise speed and the heat preservation time in the heating process are monitored by an infrared temperature measuring gun, and the temperature-time curve is transmitted to a PC control system in real time through electric signals. After preheating is completed, the PC control system is used for controlling the eddy current induction heating coil to perform translational motion under the self-control, and the eddy current induction heating coil returns to an initial position, so that interference with a subsequent welding process and an electric pulse process is prevented.

Preferably, the device further comprises a PC control system, and the PC control system is used for sending instructions for controlling other systems.

In a preferred scheme, the device further comprises an electric cabinet, wherein the electric cabinet comprises a direct-current power supply, an alternating-current power supply and a transformer, and the electric cabinet is used for supplying power to the device.

In the actual operation process of the invention, an electric cabinet is used for supplying power to a PC control system, a spinning machine tool, an electric pulse system, a welding system, a supporting transmission system, a quenching system, a heating system, a temperature measuring system and a rotary clamping fixed supporting seat, so that an instruction sent by the PC control system is transmitted to a corresponding part to control the rotation angular speed of the spinning machine tool; providing corresponding signals such as pulse current frequency, current density, electrifying time, heating speed, heating time and the like for an electric pulse system; selecting a corresponding welding gun mouth and mixed gas according to a command program, determining a welding stroke according to the electrifying time, and controlling welding current and welding voltage; selecting corresponding quenching medium and spray cooling time according to the instruction program; and controlling the voltage and the current of an eddy current coil in the heating system according to the instruction program, controlling the heating temperature, the heating speed and the heat preservation time, and simultaneously sending an instruction to enable the temperature measurement system to carry out real-time temperature monitoring on the welding track.

Preferred embodiment, 2 spinningSpinning machine tool 1 with machine tool divided into left end^#And a spinning machine 2 at the right end^#The spinning machine 1^#For fixing a workpiece 1 to be welded^# Spinning machine tool 2^#For fixing a workpiece 2 to be welded^#(ii) a Any one spinning machine tool comprises a main shaft, a chuck, a spinning core mold, a pressing device and a spinning handle; the chuck is arranged on the main shaft, and the clamping rotary core mold is combined with the pressing device and the spinning handle to press and fix the workpiece to be welded.

Preferably, the device also comprises a supporting transmission system and a base; the supporting transmission system comprises a supporting pulley positioned at the top, a guide pulley positioned at the bottom and a supporting rod, the supporting pulley positioned at the top and the guide pulley positioned at the bottom are fixed at the two ends of the top and the bottom of the supporting rod and are placed in a guide groove of the base, the workpiece is rotated for 360 degrees by the cooperation of the top supporting pulley and the spinning machine tool, and the guide pulley at the bottom is used for controlling the workpiece to be welded to be fixed on the spinning machine tool.

According to the preferable scheme, the device further comprises a temperature measuring system, wherein the temperature measuring system comprises an external temperature measuring instrument, the external temperature measuring instrument is a bidirectional gun head, and the external temperature measuring instrument faces towards the graphite brush rod of the electric pulse system and the composite welding gun head in the welding system respectively.

In the actual operation process, the guide pulley in the heating system is controlled to advance to the area to be heated and then electrified according to the instruction sent by the PC control system, eddy current heating is carried out according to the set temperature, and the welding bead and the 30mm of the periphery are monitored in real time by using an infrared thermometer.

Preferably, the welding system further comprises a mixed gas guiding device and a tungsten electrode.

The welding system adopts 'one electrode, three gun mouths and three spray heads' to be annularly wrapped, integrates a Mag welding gun, a Mig welding gun, a Tig welding gun and corresponding protective gas thereof by using a bearing rotating device, and selects the corresponding welding gun to carry out welding work according to a corresponding instruction sent by a PC control system.

And in the welding process, the corresponding protective gas is sprayed out by matching with the mixed gas guiding device according to the welding gun, so that the welding process is protected.

Preferably, the device further comprises a rotary clamping fixed support seat, wherein the rotary clamping fixed support seat is used for clamping and fixing a graphite electric brush rod of an electric pulse system, a composite welding gun of a welding system, an infrared temperature measuring gun of a temperature measuring system and a quenching nozzle rotating device of a quenching system, the electric pulse system and the welding system are in 180-degree reverse distribution, and the infrared temperature measuring gun of the temperature measuring system is fixed at the central position of the rotary clamping fixed support seat; the quenching system is fixed in the middle of the rotary clamping fixed supporting seat.

In the actual operation process, the electric pulse system starts to work after welding is finished, the connection process of the high-energy electric pulse electrode is that a PC control system sends an instruction to the rotating clamping support, when the graphite brush rod is in contact with the pipe to be welded, the rotation is stopped, the pulse power supply is immediately connected, and the pipe electrifying area works according to signals such as pulse current frequency, current density, pulse width, electrifying time, temperature rising speed and the like set by the PC control system.

Preferably, the quenching system comprises a liquid guide pipe, a distributing spray nozzle, a control valve and a spray nozzle rotating device, wherein the liquid guide pipe, the distributing spray nozzle and the control valve are fixed in the spray nozzle rotating device, the rotating device is fixed in the middle of a rotary clamping fixed supporting seat, and the distributing spray nozzle is a single-phase spray nozzle and faces towards a graphite electric brush rod of the electric pulse system.

In the actual operation process, the spray heads filled with the corresponding quenching media are automatically selected for quenching according to the instruction sent by the PC control system.

The invention relates to a full-automatic electric pulse combined segmented welding process for intelligently butting different metal pipes, which comprises the following steps of:

a workpiece 1 to be welded^#To be welded 2^#Pre-grooving, fixing the groove on a spinning machine, placing and positioning the groove to form a region to be welded, carrying out eddy current heating pretreatment on the region to be welded to obtain a welding region, and finally carrying out electric pulse treatment and quenching treatment on the welding region to obtain a welding finished product; the welding mode is selected from at least one of a Mag welding process, a Tig welding process and a Mig welding process.

In a preferred embodiment, the workpieces 1 to be welded^#With the work 2 to be welded^#Of different materials, the workpieces 1 to be welded^#With the work 2 to be welded^#Is selected from Q890 or 42CrMoA, wherein the workpiece 1 to be welded is^#With the work 2 to be welded^#The thicknesses of the components are less than or equal to 40mm, and preferably, the thicknesses of the components are less than or equal to 30 mm.

In a preferred embodiment, the workpieces 1 to be welded^#With the work 2 to be welded^#The grooves are all pre-arranged at 10-25 degrees, and preferably at 15-20 degrees.

In the preferred scheme, the lap is positioned to form the to-be-welded workpiece 1 with the groove^#With the work 2 to be welded^#The butt joints are butted in a V-groove mode, and the space clearance of the butt joint is controlled within 5mm, preferably within 3 mm.

In the preferable scheme, the temperature of the preheating treatment is 100-400 ℃, the time of the preheating treatment is 5-20 min, and the temperature rising rate is 30-70 ℃/min.

The inventor finds that the weldment is placed in the eddy current heating coil for preheating treatment, and the heating is carried out by adopting the procedure, so that the heating uniformity can be ensured, and the finally obtained welding finished product has the advantages of optimal microstructure and better performance. In the actual operation process, a temperature measuring gun is used for measuring the temperature of the welding groove in real time, and the temperature is kept after the temperature is stable, namely the preheating time.

Further preferably, the temperature of the preheating treatment is 150-280 ℃, the time of the preheating treatment is 10-15 min, and the rate of temperature rise is 50-70 ℃/min.

In a preferred scheme, when the welding mode adopts a Mag welding process in the whole process, the parameters of the Mag welding process are as follows: the welding voltage is controlled to be 10-30V, the welding current is controlled to be 10-400A, and the welding speed is controlled to be 0-5 m/min.

Further preferably, in the Mag welding process, the adopted protective atmosphere contains a mixed atmosphere of argon and oxygen, wherein in the mixed atmosphere, the volume ratio of argon to oxygen is 80: 20, the flow rate of the protective atmosphere is 16-18L/min.

In the actual operation process, the Mag welding adopts an HGS-80 welding wire, and the diameter of the HGS80 welding wire is 1.2 mm.

According to the preferable scheme, when the whole welding mode is a Tig welding process, the parameters of the Tig welding process are that the welding voltage is controlled to be 10-30V, the welding current is controlled to be 10-350A, and the welding speed is controlled to be 0-5 m/min.

Further preferably, during the Tig welding process, the adopted protective atmosphere is argon, and the flow of the argon is 16-18L/min.

In the actual operation process, the Tig welding adopts an HGS-80 welding wire, and the protective gas of the HGS80 welding wire with the diameter of 1.2mm is argon.

Preferably, the welding mode is that a Tig welding process is adopted for backing welding, and then a Mag welding process is adopted for filling the cover surface.

The inventor finds that for welding dissimilar alloys, the above welding method is preferred, and the performance of the final material is optimal, and a Tig welding process is firstly adopted for the workpieces 1 to be welded^#With the work 2 to be welded^#The groove is subjected to backing welding, and then a Mag welding process is adopted to weld the workpiece 1 to be welded^#With the work 2 to be welded^#The grooves are covered and filled along the same direction, and finally the tissue appearance is regulated and controlled at the grooves by a high-energy electric pulse and quenching device.

By adopting a sectional process combining the Tig welding and the Mag welding, the better air tightness in the Tig welding process is firstly utilized, so that air holes in a welding line in the welding process can be effectively reduced; and because the energy density of the heat source is low, the oxidation degree is low in the welding process, and oxides cannot be generated, the welding quality of the bottom welding seam can be ensured, and meanwhile, the cap surface is filled by Mag welding in the subsequent welding process. The welding method provided by the invention has the advantages that the cost is reduced, the problems that the welding wire cannot completely fill the V-shaped groove, the mechanical property of molten metal between passes is poor, and cracking is easy to occur can be solved, the welding quality of a welding seam is improved to a certain extent, the toughness of a welding joint is improved, and the cracking tendency is reduced.

According to the preferable scheme, during backing welding, the thickness of a backing welding bead is controlled to be 2-7 mm, and Tig welding technological parameters are as follows: the welding current is controlled to be 150-250A, the welding voltage is 15-30V, and the argon flow is 16-18L/min.

In the invention, when the sectional welding is adopted, the technological parameters of the backing welding are required to be controlled within the range, a backing weld bead with the thickness of 2-7 mm is obtained, the performance of the final material is optimal under the thickness, and if the backing welding is too thick, the welding strength is poor.

In addition, the inventors found that an excessive welding current not only causes an excessive thickness, but also causes a large amount of spattered particles generated during welding, which directly cause, as second phase impurities, a large brittleness of the weld pool region, thereby affecting the performance, and that an excessive current causes a large heat input amount to be transmitted to the weld pool at the same time, causing a large grain size of the entire fusion zone and the heat affected zone, which also deteriorates the mechanical properties of the material.

Further preferably, during backing welding, the thickness of a backing weld bead is controlled to be 2-5 mm, and Tig welding process parameters are as follows: the welding current is controlled to be 150-180A, and the welding voltage is 15-23V.

In the actual operation process, before the Tig backing welding is carried out, the tungsten pole of a welding gun is aligned to the V-shaped groove, meanwhile, pure argon is introduced into the area, arc striking is started after air in the V-shaped groove is removed, and an HGS-80 welding wire is adopted in the welding process.

According to the preferable scheme, when the cover surface is filled, the adopted protective atmosphere is a mixed atmosphere containing argon and oxygen, wherein in the mixed atmosphere, the volume ratio of the argon to the oxygen is 95-98: 2 to 5.

In the preferable scheme, the parameters of the Mag welding process are that the welding current is controlled to be 150-300A, the welding voltage is 18-30V, and the gas flow is 16-18L/min.

In the actual operation process, the surface welding slag and the end part bulges are immediately ground and removed after the backing welding is finished. After the polishing is finished, introducing protective gas to the V-shaped groove for about 10s by using a Mag welding gun, and beginning Mag welding to fill the cover surface after air in the welding area is removed. And an HGS-80 welding wire is adopted in the welding process.

According to the preferable scheme, the Mag welding adopts a multilayer multi-pass welding process, welding passes are overlapped, the width of a welding line at the overlapped part is larger than or equal to 1/3 of the width of a welding line at the previous pass, the welding direction of any pass is consistent, and the inter-pass temperature is kept at 140-280 ℃, preferably 160-220 ℃.

In the invention, the Mag welding adopts multilayer multi-pass welding until the complete capping is finished.

In the actual operation process, when a multilayer and multi-pass welding process is adopted, a temperature measuring gun is required to measure the temperature of the periphery of the welding groove within 10mm after each pass of filling.

Preferably, the process parameters of the electric pulse treatment are as follows: the pulse current frequency is controlled to be 200-800 Hz, and the current density is controlled to be 1 multiplied by 10⁴～6×10⁵A/cm²Heating the local area of the welding part to 800-1000 ℃ within 20-120 s, and treating the electric pulse for 1-10 min. In the invention, the local area refers to a welding area and an area with the periphery of 30-50 cm, and the heating time is controlled within 20-120 s.

In the present invention, the properties of the material finally obtained by the electric pulse treatment under the above process parameters are optimal because the electric current greatly affects the grain size of the machining region during the electric pulse treatment, and the excessive electric current easily causes coarsening of grains, while the insufficient electric current cannot eliminate segregation between grains.

Further preferably, the process parameters of the electric pulse treatment are as follows: the pulse current frequency is controlled to be 200-600 Hz, the heating temperature of a local area is controlled to be 800-900 ℃, and the electrifying time is about 1-5 min.

In the actual operation process, the power supply is cut off immediately after the electric pulse treatment is carried out for about 1-10 min, and quenching treatment is carried out to obtain fine grains with high solid solubility.

Preferably, the quenching treatment process comprises the steps of heating a welding area of a welding part to 800-900 ℃, preserving heat for 1-10 min, and then flushing the welding area with cooling liquid to cool the welding area to room temperature.

Compared with the prior art, the invention has the beneficial effects that:

1) compared with the traditional dissimilar metal welding process (single welding technology and postweld heat treatment), the invention provides a full-automatic electric pulse combined segmented welding device for intelligently butting different metal pipes, wherein a Mag welding gun, a Mig welding gun and a Tig welding gun are compounded into a comprehensive welding gun, and the phenomena of coarsening and segregation of crystal grains in the Mag welding, Mig welding and Tig welding processes are improved by using the joule heat effect of high-energy electric pulses; meanwhile, the PC control system is used for intelligently, digitally and automatically controlling the selection of a welding gun, the rotation angular velocity of a welding bead, the eddy current heating rate, the heat preservation time, the pulse current, the voltage, the frequency, the pulse width and other important parameters of the pipe in the welding process at a high speed, monitoring the welding process and the high-energy electric pulse process in real time, solving the phenomena of undercut, overburning and the like caused by the instability of the welding speed in the Mag welding process, Mig welding process and Tig welding process, improving the microstructure morphology and the mechanical property of a welding seam area, reducing the cracking tendency caused by the phenomena of particle coarsening, segregation, inclusion and the like caused by the thermal influence of welding on the material, improving the welding efficiency and reducing the welding cost on the premise of ensuring the welding yield.

2) In addition, the invention also provides a welding and electric pulse processing method suitable for dissimilar alloys, and the process adopted by the Tig welding, Mag welding and high-energy electric pulse combined segmented welding method is the electric pulse processing of two welding technologies. By adopting the segmentation process of Tig welding and Mag welding, the welding cost can be reduced on the premise of ensuring the welding quality. The Tig welding, Mag welding and high-energy electric pulse combined segmented welding method adopts high-energy electric pulse treatment to regulate and control the microstructure of the welding joint, and improves the mechanical property of the welding joint, improves the plastic toughness, the strength and the like of the welding joint, and reduces the cracking tendency of materials by refining crystal grains, eliminating segregation in the microstructure, crushing net-shaped carbide and eliminating welding thermal stress. Compared with the existing dissimilar metal welding process, the welding process does not need long-time heat treatment and heat preservation time after welding, and a large amount of welding cost is saved.

Drawings

Fig. 1 is a front view and a right view of a structural schematic diagram of a full-automatic electric pulse joint segmented welding device for intelligent butt joint of different metal pipes. Wherein 1 is a PC control system; 2, an electric cabinet; 3 is a spinning machine tool 1^#(ii) a 4 is a pipe 1 to be welded^#(ii) a 5 is an electric pulse system; 6 is a welding system; 7 is a pipe 2 to be welded^#(ii) a 8 is a spinning machine tool 2^#(ii) a 9 is a supporting transmission system; 10 is a quenching system; 11 is a heating system; 12 is a temperature measuring system; and 13 is a base.

Fig. 2 is a right side view of a schematic structural diagram of a full-automatic electric pulse joint welding device for intelligent butt joint of different metal pipes, and fig. 14 shows a rotary clamping fixed support seat.

FIG. 3 is a schematic diagram of a welding system, in which three mixed

gas conveying channels

61, 65 and 66 are provided; 62. 64 and 67 are welding gun lanes of three welding processes respectively; 63 is a tungsten electrode bar of a Tig welding process; and 68 is a bearing rotating device.

FIG. 4 is a schematic view of the installation of the rotary clamping fixed support seat, the quenching system, the temperature measuring system, the electric pulse system and the welding system, wherein 5 is the electric pulse system loaded with the graphite brush bar; 121 is an infrared temperature measuring gun in a temperature measuring system; 101 is a quenching spray gun in the quenching system; 141 is a connecting rod in a rotary clamping fixed support seat; 69 is a compound welding gun in the welding system; 142 is a support seat in the rotary clamping fixed support seat.

FIG. 5 is a metallographic structure diagram of a 42CrMoA base metal in example 3 at a distance of 30mm from the center;

FIG. 6 is a metallographic structure diagram of a Q890 base metal in example 3 at a distance of 30mm from the center;

FIG. 7 is a metallographic structure diagram of a backing weld in example 3;

FIG. 8 is a metallographic structure diagram of the backing weld in comparative example 1;

fig. 9 is a metallographic structure diagram of the backing weld in comparative example 2.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings.

As shown in fig. 1 and 2, the full-automatic electric pulse joint welding device for intelligently butting different metal pipes in the embodiment mainly comprises a PC control system 1, and

electric cabinets

2 and 1^#

Spinning machine tool

3, 1^#To-be-welded pipe 4, electric pulse system 5 and

welding systems

6 and 2^#

Pipes

7, 2 to be welded^#The rotary extrusion machine tool comprises a rotary extrusion machine tool 8, a supporting transmission system 9, a quenching system 10, a heating system 11, a temperature measuring system 12, a base 13, a rotary clamping fixed support seat 14 and the like.

The electric cabinet comprises a direct-current power supply, an alternating-current power supply, a transformer and the like (not shown in the figure), and the electric cabinet is used for supplying power to a PC control system, a spinning machine tool, an electric pulse system, a welding system, a supporting transmission system, a quenching system, a heating system, a temperature measuring system and a rotary clamping fixed supporting seat, so that an instruction sent by the PC control system is transmitted to a corresponding part, and the rotating angular speed (1-1000 r/min) of the spinning machine tool is controlled; providing corresponding pulse current frequency (10-8000 Hz), pulse width (10-30000 mu s) and current density (10-30000 mu s) for an electric pulse system³～10⁶A/cm²) Signals such as power-on time, heating-up speed (10-100 ℃/min), heating time and the like; selecting a corresponding welding muzzle and mixed gas according to a command program, determining a welding stroke according to the electrifying time, and controlling welding current (80-500A) and welding voltage (10-40V); selecting corresponding quenching media (cooling water and oil) and spraying cooling time according to a command program; and controlling the voltage and the current of an eddy current coil in the heating system according to the instruction program, controlling the heating temperature, the heating speed and the heat preservation time, and simultaneously sending an instruction to enable the temperature measurement system to carry out real-time temperature monitoring (1-999 ℃) on the welding track.

The specific operation comprises the following steps:

1) the two beveled pipes to be welded are hoisted and placed in a groove in the top of a supporting transmission system through a fixture, the height of a supporting rod is adjusted through a handle to enable the center line of the pipe to be aligned to the center line of a rotary core mold of a spinning machine tool, the end, which is not beveled, of the pipe is fixed on a chuck by moving a guide pulley at the bottom of the supporting transmission system, the distance between the butted pipes is adjusted to be generally controlled to be 30-50 mm, and the pipe is fixed through a pressing device through a spinning handle.

2) After the two pipes to be welded with the grooves are fixed on a spinning machine tool, the heating system receives an instruction of the PC control system and moves forward to the position near the corresponding welding area to start electrifying the eddy current coil, and eddy current heating is carried out according to the temperature rising speed, the heat preservation temperature and the heat preservation time set by the PC control system. And when the set heat preservation time is reached, electrifying is finished, heating is stopped, and the guide pulley at the bottom is retreated to the original position. The pipe to be welded does not need to move in the preheating process, and is realized by providing heat radiation through the eddy current coil.

3) After the preheating treatment of the pipe to be welded is finished, the PC control system immediately sends an instruction to control the welding system to start working, automatically rotates and selects a corresponding welding gun according to the selected welding process parameters, and matched with corresponding mixed gas to flow out of the flow guide device, corresponding protective gas is sprayed out of the welding bead, the welding process is protected, the process adopts a multilayer multi-pass welding process, the welding bead and the periphery of the welding bead are monitored in real time by an infrared thermometer in the temperature measurement system in each pass, the welding bead and the periphery temperature of each pass are required to be controlled within the set temperature range to be welded, and the welding process is stopped after the welding bead is completely covered. The control of the welding speed in the welding process is mainly provided by utilizing the rotation angular velocity of a main shaft in a spinning machine tool and is realized by conveying through a supporting pulley at the top of a supporting transmission device; and the temperature of the welding bead and the peripheral 30mm is monitored by an infrared thermometer in real time in the whole welding process.

4) After the pipe to be welded is welded in a segmented mode, the PC control system immediately sends an instruction to the electric pulse system to control the rotary clamping control support to perform three-dimensional rotary motion, the graphite brush rod is in contact with the pipe to be welded by using a rotary bearing at the center, a high-frequency pulse power supply is automatically switched on after a trigger point is controlled at a position 50mm around the pipe to be welded, and electric pulse tissue adjustment is performed on a pipe electrifying area according to signals such as pulse current frequency, current density, pulse width, electrifying time and temperature rising speed set by the PC control system.

5) And after the pipe to be welded is subjected to high-frequency electric pulse treatment, sending an instruction to control the rotary clamping control support to perform three-dimensional rotary motion through the PC control system, so that the graphite electrode rod returns to the initial position. And then sending an instruction to the quenching system, and controlling a spray head rotating device of the quenching system to quench according to the required quenching medium and cooling speed.

As shown in fig. 3, a schematic structural diagram of a welding system in a full-automatic electric pulse joint welding device for intelligent butt joint of different metal pipes according to the embodiment is mainly composed of a mixed gas conveying channel, a welding bead of a welding gun, a tungsten electrode bar and a bearing rotating device. Wherein 61, 65 and 66 are three mixed gas conveying channels respectively; 62. 64 and 67 are welding gun lanes of three welding processes respectively; 63 is a tungsten electrode bar of a Tig welding process; 68 is a bearing rotating device

In the figure, a component 61, a component 62, a component 63, a component 64, a component 65, a component 66 and a component 67 are installed in a component 68 in an annular mode by adopting a 'one electrode, three muzzles and three nozzles', the electrode and the top of the muzzle are connected with an electric cabinet, the center of the muzzle is a welding wire (not marked in the figure), the top of the nozzle is connected with a mixed gas pipeline and is provided with an electric control valve, and the selection of the muzzle and the mixed gas is carried out according to signals transmitted by a PC control system.

As shown in fig. 4, it is a schematic view of the installation of the rotary clamping system, the quenching system, the temperature measuring system, the electric pulse system and the welding system in the full-automatic electric pulse joint welding device for the intelligent butt joint of different metal pipes according to the present embodiment, wherein 5 is the electric pulse system loaded with the graphite brush bar; 121 is an infrared temperature measuring gun in a temperature measuring system; 101 is a quenching spray gun in the quenching system; 141 is a connecting rod in a rotary clamping system; 69 is a compound welding gun in the welding system; 142 is a support in a spin clamp system.

The invention also provides a process for welding and electric pulse processing of dissimilar alloys by using the device, which comprises the following steps: the following is a more detailed description of the embodiments with reference to the specific examples

Example 1

A Mag welding and high-energy electric pulse combined segmented welding method for Q890, 42CrMoA and other dissimilar alloys comprises the following steps:

a. preparing materials: opening grooves of 20 degrees on Q890 and 42CrMoA materials, wherein the corresponding alloy chemical element compositions and the mass fractions thereof are respectively as follows: q890: c: 0.15 percent; si: 0.28 percent; mn: 1.33 percent; p: 0.011 percent; s: 0.01 percent; al: 0.041 percent; cu: 0.02 percent; cr: 0.45 percent; ni: 0.325%; mo: 0.326 percent; v: 0.035%; ti: 0.02 percent. 42 CrMoA: c: 0.41 percent; si: 0.24 percent; mn: 0.62 percent; p: 0.015%; s: 0.006%; cr: 1.02 percent; ni: 0.1 percent; mo: 0.21 percent. The thickness of the alloy material is 30mm, and scrap iron, oil stains, oxides and other impurities which are 30mm on the surface and the periphery of the groove are polished to be removed completely and cleaned.

b. Placing and positioning: and (3) butting the Q890 with the groove and the 42CrMoA in a V-shaped groove mode, and controlling the space gap of the butt joint within 5 mm.

c. Preheating treatment: and (3) placing the butted materials in an eddy current heating coil, setting a heating speed of 60 ℃/min after electrifying, preheating the butted materials to 220 ℃, and preserving heat for 5 min.

d. Backing welding: and (3) butting the Q890 and 42CrMoA alloys with 10-25-degree single-side grooves in a V-shaped mode, and priming in the V-shaped groove by adopting a Mag welding process, wherein the thickness of a priming weld bead is 6 mm. Before backing welding, the tungsten pole of a welding gun is aligned to the V-shaped groove, protective gas is introduced into the area for about 10s, arc striking is started after air in the V-shaped groove is removed completely, and surface welding slag and end protrusions are immediately ground and removed after backing welding is finished. After the polishing is finished, introducing protective gas to the V-shaped groove for about 10s by using a Mag welding gun, and beginning Mag welding to fill the cover surface after air in the welding area is removed. In the welding process, an HGS-80 welding wire is adopted, and the volume fraction ratio of the protective gas is 80% Ar + 20% O₂The mixed gas of (1). Meanwhile, the Mag welding direction is required to be consistent with the previous welding direction. The process adopts a multilayer multi-pass welding process, a temperature measuring gun is required to measure the temperature of the periphery of the welding groove within 10mm after each pass of filling, the inter-pass temperature is required to be kept at 250 ℃, and HGS-80 welding wires are adopted in the welding process. The parameters in the welding process are as follows: the diameter of an HGS80 welding wire is 1.2mm, and the welding current is controlled to be 150-250A, the welding voltage is adjusted to be 25V, and the gas flow is 16L/min.

e. Electric pulse grain refinement treatment: after Mag welding is finished, the two ends of the welding part are clamped at the two ends of the electric pulse electrode, the power supply is switched on to enable high-density pulse current to pass through the welding part, the frequency of the pulse current is controlled to be 600Hz, and the current density is controlled to be 1 multiplied by 10⁴～6×10⁵A/cm²The local area of the weld was rapidly heated to 900 ℃. Immediately cutting off the power supply after the electric pulse treatment for about 10min, and quenching the outer 30mm of the two ends of the welding area to obtain fine grains with high solid solubility.

Through testing, the obtained welding area center and periphery performance is as follows:

(1) impact performance (impact temperature 233.15K):

1) and the impact energy at the welding seam: 32.4J

2) And the impact energy at the welding line at the Q890 side: 34.9J

3) And the impact energy at the 42CrMoA side fusion line: 40.7J

(2) Tensile strength: 916.3MPa

(3) Elongation percentage: 17.2 percent of

(4) Hardness: 296HV

Example 2

A Tig welding and high-energy electric pulse combined segmented welding method for Q890, 42CrMoA and other dissimilar alloys comprises the following steps:

a. preparing materials: opening grooves of 10-20 degrees on Q890 and 42CrMoA materials, wherein the corresponding alloy chemical element compositions and mass fractions thereof are respectively as follows: q890: c: 0.15 percent; si: 0.28 percent; mn: 1.33 percent; p: 0.011 percent; s: 0.01 percent; al: 0.041 percent; cu: 0.02 percent; cr: 0.45 percent; ni: 0.325%; mo: 0.326%; v: 0.035%; ti: 0.02 percent. 42 CrMoA: c: 0.41 percent; si: 0.24 percent; mn: 0.62 percent; p: 0.015 percent; s: 0.006%; cr: 1.02 percent; ni: 0.1 percent; mo: 0.21 percent. The thickness of the alloy material is 30mm, and scrap iron, oil stain, oxide and other impurities on the surface of the groove and at the periphery of the groove, which are 20-30 mm, are polished completely and cleaned.

b. Placing and positioning: and (3) butting the Q890 with the groove and the 42CrMoA in a V-shaped groove mode, and controlling the space gap of a butt joint within 3 mm.

c. Preheating treatment: and placing the butted materials in an eddy current heating coil, setting a heating speed of 60 ℃/min after electrifying, preheating the butted materials to 250 ℃, and preserving heat for 5 min.

d. Backing welding: and (3) butting the Q890 and 42CrMoA alloys with 20-degree single-side grooves in a V-shaped mode, and priming in the V-shaped groove by adopting a Tig welding process, wherein the thickness of a priming weld bead is 5 mm. Before the Tig backing welding is carried out, the tungsten pole of a welding gun is aligned to the V-shaped groove, meanwhile, pure argon protective gas is introduced into the area for about 10s, arc striking is started after air in the V-shaped groove is removed completely, and surface welding slag and end protrusions are immediately ground and removed after the backing welding is finished. And (5) after polishing, introducing protective gas to the V-shaped groove for about 10s by using a Tig welding gun, and after air in the welding area is removed completely, beginning to perform Tig welding to fill the cover surface. And an HGS-80 welding wire is adopted in the welding process, and meanwhile, the Tig welding direction is required to be consistent with the previous welding direction. The process adopts a multilayer multi-pass welding process, a temperature measuring gun is required to measure the temperature of the periphery of the welding groove within 10mm after each pass of filling, the inter-pass temperature is required to be maintained at 220 ℃, and HGS-80 welding wires are adopted in the welding process. The parameters in the welding process are as follows: the diameter of an HGS80 welding wire is 1.2mm, the welding current is controlled to be 150-230A, the welding voltage is adjusted to be 23V, and the gas flow is 16L/min.

e. Electric pulse grain refinement treatment: after the Tig welding cover surface is finished, clamping two ends of the welding piece at two ends of an electric pulse electrode, switching on a power supply to enable high-density pulse current to pass through the welding piece, controlling the frequency of the pulse current to be 500Hz and the current density to be 1 multiplied by 10⁴～6×10⁵A/cm²The local area of the weld was rapidly heated to 900 ℃. Immediately cutting off the power supply after the electric pulse treatment for about 7min, and quenching the outer 30mm of the two ends of the welding area to obtain fine grains with high solid solubility.

(1) impact performance (impact temperature 233.15K):

1) and impact work at the welding seam: 40.3J

2) And the impact energy at the welding line at the Q890 side: 52.4J

3) And the impact energy at the 42CrMoA side fusion line: 56.7J

(2) Tensile strength: 988.9MPa

(3) Elongation percentage: and (3) Tig weld bead: 20.7 percent

(4) Hardness: 317HV

Example 3

A Tig welding, Mag welding and high-energy electric pulse combined segmented welding method for Q890, 42CrMoA and other dissimilar alloys comprises the following steps:

a. preparing materials: opening grooves of 20 degrees on Q890 and 42CrMoA materials, wherein the corresponding alloy chemical element compositions and the mass fractions thereof are respectively as follows: q890: c: 0.15 percent; si: 0.28 percent; mn: 1.33 percent; p: 0.011 percent; s: 0.01 percent; al: 0.041 percent; cu: 0.02 percent; cr: 0.45 percent; ni: 0.325%; mo: 0.326%; v: 0.035%; ti: 0.02 percent. 42 CrMoA: c: 0.41 percent; si: 0.24 percent; mn: 0.62 percent; p: 0.015 percent; s: 0.006%; cr: 1.02 percent; ni: 0.1 percent; mo: 0.21 percent. The thickness of the alloy material is 30mm, and scrap iron, oil stain, oxide and other impurities of 30mm on the surface and the periphery of the groove are polished to be removed completely and cleaned.

c. Preheating treatment: and placing the butted materials in an eddy current heating coil, setting a heating speed of 60 ℃/min after electrifying, preheating the butted materials to 220 ℃, and preserving heat for 10 min.

d. Backing welding: and (3) butting the Q890 and 42CrMoA alloys with 20-degree single-side grooves in a V-shaped mode, and priming in the V-shaped groove by adopting a Tig welding process, wherein the thickness of a priming weld bead is 3 mm. Before the Tig backing welding is carried out, the tungsten pole of a welding gun is aligned to the V-shaped groove, meanwhile, pure argon protective gas is introduced into the area for about 10s, arc striking is started after air in the V-shaped groove is removed, and an HGS-80 welding wire is adopted in the welding process. The parameters in the welding process are as follows: the diameter of an HGS80 welding wire is 1.2mm, the welding current is controlled to be 150-180A, the welding voltage is adjusted to be 18V, and the gas flow is 16L/min.

e. Filling the cover surface: and immediately polishing and removing surface welding slag and end bulges after backing welding is finished. After the polishing is finished, introducing protective gas to the V-shaped groove for about 10s by using a Mag welding gun, and beginning Mag welding to fill the cover surface after air in the welding area is removed. An HGS-80 welding wire is adopted in the welding process, and the protective gas is 98% of argon and 2% of oxygen. Meanwhile, the Mag welding direction is required to be consistent with the previous welding direction. The parameters in the welding process are as follows: the diameter of an HGS80 welding wire is 1.2mm, the welding current is controlled to be 150-180A, and the welding voltage is adjusted to be 18V. The process adopts a multilayer multi-pass welding process, a temperature measuring gun is required to measure the temperature of the periphery of the welding groove within 10mm after each pass of filling, the temperature between passes is required to be kept at 200 ℃, and the gas flow is 16L/min.

f. Electric pulse grain refinement treatment: after Mag welding is finished, the two ends of the welding part are clamped at the two ends of the electric pulse electrode, the power supply is switched on to enable high-density pulse current to pass through the welding part, the frequency of the pulse current is controlled to be 450Hz, and the current density is controlled to be 1 multiplied by 10⁴～6×10⁵A/cm²The local area of the weld was rapidly heated to 850 ℃. Immediately cutting off the power supply after the electric pulse treatment for about 3min, and quenching the outer 30mm of the two ends of the welding area to obtain fine grains with high solid solubility.

FIGS. 5 to 7 are photographs of the corresponding structures of example 3.

Wherein FIG. 5 is a metallographic structure of the 42CrMoA base metal in example 3 at a distance of 30mm from the center, and the microstructure thereof was composed of uniform sorbite and a small amount of ferrite. FIG. 6 is a metallographic structure diagram of the base material Q890 in example 3 at a distance of 30mm from the center, the microstructure thereof consisting of martensite and particulate carbides. FIG. 7 is a metallographic structure of the backing weld in example 3, the microstructure of which consists of low carbon lath martensite and lath bainite.

(1) impact performance (impact temperature 233.15K):

1) and the impact energy at the welding seam: 49.7J

2) And the impact energy at the welding line at the Q890 side: 55.6J

3) And the impact energy at the 42CrMoA side fusion line: 58.8J

(2) Tensile strength:

1) and Tig weld bead: 996.1MPa

2) And Mag weld bead: 948.1MPa

(3) Elongation percentage:

1) and Tig weld bead: 21.4 percent

2) And Mag weld bead: 20.2 percent of

(4) Hardness: 327HV

Comparative example 1

The current common dissimilar metal used is a single Tig welding and tempering heat treatment welding method, which comprises the following steps:

a. preparing materials: opening grooves of 20 degrees on Q890 and 42CrMoA materials, wherein the corresponding alloy chemical element compositions and the mass fractions thereof are respectively as follows: q890: c: 0.15 percent; si: 0.28 percent; mn: 1.33 percent; p: 0.011 percent; s: 0.01 percent; al: 0.041 percent; cu: 0.02 percent; cr: 0.45 percent; ni: 0.325%; mo: 0.326 percent; v: 0.035%; ti: 0.02 percent. 42 CrMoA: c: 0.41 percent; si: 0.24 percent; mn: 0.62 percent; p: 0.015 percent; s: 0.006%; cr: 1.02 percent; ni: 0.1 percent; mo: 0.21 percent. The thickness of the alloy material is 40mm, and scrap iron, oil stain, oxide and other impurities of 30mm on the surface and the periphery of the groove are polished and cleaned completely.

c. Preheating treatment: the well butted material is heated by an acetylene oxygen open flame heater, preheated to 250 ℃, and the temperature is measured by a temperature measuring gun.

d. Welding: and (3) butting the Q890 and 42CrMoA alloy with a 20-degree single-side groove in a V-shaped mode, performing backing welding in the V-shaped groove by adopting a Tig welding process, and welding after introducing protective gas, wherein the thickness of a backing weld bead is 6 mm. And filling the cover surface along the same direction after the backing welding is finished. And an HGS-80 welding wire is adopted in the welding process, and the protective gas is argon. The parameters in the welding process are as follows: the diameter of an HGS80 welding wire is 1.2mm, the welding current is controlled to be 150-250A, the welding voltage is adjusted to be 23V, and the gas flow is 18L/min.

e. Postweld heat treatment: and air cooling is carried out after the filling is finished, and after the joint to be welded is completely cooled, the material is placed in a heat preservation furnace for tempering heat treatment. In the heat treatment process, the temperature of the hearth is raised to 350 ℃ at the heating rate of 5 ℃/min, the hearth is kept for 2h and then cooled to room temperature along with the furnace.

FIG. 8 is a metallographic structure diagram of the weld joint of the backing weld in comparative example 1, the microstructure of which consists of low carbon lath martensite and lath bainite. Comparing fig. 7 and 8, it can be seen that the low carbon lath martensite and lath bainite structures in fig. 8 are relatively coarse in size. This is because, during the electric pulse treatment, the welding zone is locally heated to the solid solution temperature, so that segregation occurs during the welding process, the second phase is re-austenitized, and the welding zone is rapidly cooled by quenching at the end to form fine grains with high solid solution.

(1) impact performance (impact temperature 233.15K):

1) and the impact energy at the welding seam: 27.7J

2) And the impact energy at the welding line at the Q890 side: 30.3J

3) And the impact energy at the 42CrMoA side fusion line: 34.7J

(2) Tensile strength: 894.1MPa

(3) Elongation percentage: 16.2 percent

(4) Hardness: 269 HV.

Comparative example 2

The single Mag welding and tempering heat treatment welding method commonly used for the dissimilar metals at present comprises the following steps:

a. preparing materials: opening grooves of 20 degrees on Q890 and 42CrMoA materials, wherein the corresponding alloy chemical element compositions and the mass fractions thereof are respectively as follows: q890: c: 0.15 percent; si: 0.28 percent; mn: 1.33 percent; p: 0.011 percent; s: 0.01 percent; al: 0.041 percent; cu: 0.02 percent; cr: 0.45 percent; ni: 0.325%; mo: 0.326 percent; v: 0.035%; ti: 0.02 percent. 42 CrMoA: c: 0.41 percent; si: 0.24 percent; mn: 0.62 percent; p: 0.015 percent; s: 0.006%; cr: 1.02 percent; ni: 0.1 percent; mo: 0.21 percent. The thickness of the alloy material is 30mm, and scrap iron, oil stain, oxide and other impurities of 30mm on the surface and the periphery of the groove are polished to be removed completely and cleaned.

d. Welding: and (3) butting the Q890 and 42CrMoA alloys with 20-degree single-side grooves in a V-shaped mode, performing backing welding in the V-shaped groove by adopting a Mag welding process, and welding after introducing protective gas, wherein the thickness of a backing weld bead is 5 mm. And filling the cover surface along the same direction after backing welding is finished. The HGS-80 welding wire is adopted in the welding process, and the protective gas is 80% of argon and 20% of oxygen. The parameters in the welding process are as follows: the diameter of an HGS80 welding wire is 1.2mm, the welding current is controlled to be 150-250A, the welding voltage is adjusted to be 23V, and the gas flow is 18L/min.

e. Postweld heat treatment: and air cooling is carried out after the filling is finished, and after the joint to be welded is completely cooled, the material is placed in a heat preservation furnace for tempering heat treatment. In the heat treatment process, the hearth is heated to 300 ℃ at the heating rate of 5 ℃/min, is kept warm for 2h and then is cooled to room temperature along with the furnace.

FIG. 9 is a metallographic structure diagram of the weld joint of the backing weld in comparative example 2, the microstructure of which consists of low carbon lath martensite and lath bainite.

(1) impact performance (impact temperature 233.15K):

1) and the impact energy at the welding seam: 25.4J

2) And the impact energy at the welding line at the Q890 side: 28.2J

3) And the impact energy at the 42CrMoA side fusion line: 32.5J

(2) Tensile strength: 883.2MPa

(3) Elongation percentage: 15.8 percent

(4) Hardness: 264 HV.

Claims

1. The utility model provides a device that segmentation welding is united to full-automatic electric pulse of intelligent butt joint of different metal tubular products which characterized in that: comprises 2 spinning machine tools, a heating system, a welding system, an electric pulse system and a quenching system; the spinning machine tool is used for fixing a workpiece to be welded; the heating system comprises an eddy current coil and is used for carrying out eddy current heating pretreatment on a workpiece to be welded; the welding system comprises a Tig welding gun, a Mag welding gun, a Mig welding gun and a bearing rotating device, wherein the Tig welding gun, the Mag welding gun and the Mig welding gun are arranged on the bearing rotating device, the bearing rotating device is used for automatically rotating and selecting the welding gun to weld a workpiece to be welded, the electric pulse system comprises a high-frequency pulse power supply and a graphite electric brush rod, and the graphite electric brush rod is connected with the high-frequency pulse power supply to provide electric pulse current for the welded part; the quenching system is used for quenching the welding parts after the electric pulse treatment.

2. The device for full-automatic electric pulse joint welding of different metal pipes in intelligent butt joint according to claim 1 is characterized in that:

the device also comprises a PC control system, wherein the PC control system is used for sending instructions to control other systems;

the device further comprises an electric cabinet, wherein the electric cabinet comprises a direct-current power supply, an alternating-current power supply and a transformer, and the electric cabinet is used for supplying power to the device.

3. The device for full-automatic electric pulse joint welding of different metal pipes in intelligent butt joint according to claim 1 is characterized in that:

2 spinning machine tool divided into left end spinning machine tool 1^#And a spinning machine 2 at the right end^#The spinning machine 1^#For fixing a workpiece 1 to be welded^#Spinning machine tool 2^#For fixing a workpiece 2 to be welded^#(ii) a Any one spinning machine tool comprises a main shaft, a chuck, a spinning core mold, a pressing device and a spinning handle; the chuck is arranged on the main shaft and is used for clamping the rotary core moldThe tightening device and the spinning handle are used for pressing and fixing the workpiece to be welded.

4. The device for full-automatic electric pulse joint welding of different metal pipes in intelligent butt joint according to claim 1 is characterized in that:

the device also comprises a supporting transmission system and a base; the supporting transmission system comprises a supporting pulley positioned at the top, a guide pulley positioned at the bottom and a supporting rod, the supporting pulley positioned at the top and the guide pulley positioned at the bottom are fixed at the two ends of the top and the bottom of the supporting rod and are placed in a guide groove of the base, the workpiece is rotated for 360 degrees by the cooperation of the supporting pulley at the top and a spinning machine tool, and the guide pulley at the bottom is used for controlling the workpiece to be welded to be fixed on the spinning machine tool;

the device also comprises a temperature measuring system, wherein the temperature measuring system comprises an external temperature measuring instrument, the external temperature measuring instrument is a bidirectional gun head and respectively faces the graphite brush rod of the electric pulse system and the composite welding gun head in the welding system;

the device also comprises a rotary clamping fixed supporting seat, wherein the rotary clamping fixed supporting seat is used for clamping and fixing a graphite electric brush rod of an electric pulse system, a composite welding gun of a welding system, an infrared temperature measuring gun of a temperature measuring system and a quenching nozzle rotating device of a quenching system, the electric pulse system and the welding system are in 180-degree reverse distribution, and the infrared temperature measuring gun of the temperature measuring system is fixed at the central position of the rotary clamping fixed supporting seat; the quenching system is fixed in the middle of the rotary clamping fixed supporting seat.

5. The device for full-automatic electric pulse joint welding of different metal pipes in intelligent butt joint according to claim 1 is characterized in that:

the welding system also comprises a mixed gas flow guiding device and a tungsten electrode;

the quenching system comprises a liquid guide pipe, a distributing and sprinkling nozzle, a control valve and a nozzle rotating device, wherein the liquid guide pipe, the distributing and sprinkling nozzle and the control valve are fixed in the nozzle rotating device, the rotating device is fixed in the middle of a rotary clamping and fixing supporting seat, and the distributing and sprinkling nozzle is a single-phase nozzle and faces a graphite electric brush rod of an electric pulse system.

6. A full-automatic electric pulse joint segmented welding process for intelligently butting different metal pipes is characterized in that: the method comprises the following steps: a workpiece 1 to be welded^#To be welded 2^#Pre-grooving, fixing the groove on a spinning machine, placing and positioning the groove to form a region to be welded, carrying out eddy current heating pretreatment on the region to be welded to obtain a welding region, and finally carrying out electric pulse treatment and quenching treatment on the welding region to obtain a welding finished product; the welding mode is at least one selected from the group consisting of Mag welding process, Tig welding process and Mig welding process in the whole process.

7. The full-automatic electric pulse joint segmented welding process for intelligent butt joint of different metal pipes according to claim 6, characterized in that: the workpiece 1 to be welded^#With the work 2 to be welded^#Of different materials, the workpieces 1 to be welded^#With the work 2 to be welded^#The materials of the welding material are all selected from Q890 or 42CrMoA, wherein the workpieces 1 to be welded^#With the work 2 to be welded^#The thickness of the steel wire is less than or equal to 40 mm;

the workpiece 1 to be welded^#With the work 2 to be welded^#A groove of 10-25 degrees is formed in advance;

the lap is positioned to form a to-be-welded workpiece 1 with a groove^#With the work 2 to be welded^#Butt joint is carried out in a V-shaped groove mode, and the space gap of a butt joint is controlled within 5 mm;

the temperature of the preheating treatment is 100-400 ℃, the time of the preheating treatment is 5-20 min, and the temperature rising rate is 30-70 ℃/min.

8. The full-automatic electric pulse joint segmented welding process for intelligent butt joint of different metal pipes according to claim 6, characterized in that:

when the welding mode adopts a Mag welding process in the whole process, the parameters of the Mag welding process are as follows: the welding voltage is controlled to be 10-30V, the welding current is controlled to be 10-400A, and the welding speed is controlled to be 0-5 m/min;

when the whole welding mode is the Tig welding process, the parameters of the Tig welding process are that the welding voltage is controlled to be 10-30V, the welding current is controlled to be 10-350A, and the welding speed is controlled to be 0-5 m/min.

9. The full-automatic electric pulse joint segmented welding process for intelligent butt joint of different metal pipes according to claim 6, characterized in that:

the welding mode is that a Tig welding process is adopted for backing welding, and then a Mag welding process is adopted for filling the cover surface;

during backing welding, the thickness of a backing welding bead is controlled to be 2-7 mm, and Tig welding technological parameters are as follows: controlling the welding current to be 150-250A, the welding voltage to be 15-30V, and the argon flow to be 16-18L/min;

when the cover surface is filled, the adopted protective atmosphere is a mixed atmosphere containing argon and oxygen, wherein in the mixed atmosphere, the volume ratio of the argon to the oxygen is 95-98: 2-5;

the parameters of the Mag welding process are that the welding current is controlled to be 150-300A, the welding voltage is 18-30V, and the gas flow is 16-18L/min;

the Mag welding adopts a multilayer multi-pass welding process, welding passes are overlapped, the width of a welding line at the overlapped part is more than or equal to 1/3 of the width of a welding line at the previous pass, the welding direction of any pass is consistent, and the temperature between passes is kept at 140-280 ℃.

10. The full-automatic electric pulse joint segmented welding process for intelligent butt joint of different metal pipes according to claim 6, characterized in that:

the electric pulse treatment process parameters are as follows: the pulse current frequency is controlled to be 200-800 Hz, and the current density is controlled to be 1 multiplied by 10⁴～6×10⁵A/cm²Heating the local area of the welding part to 800-1000 ℃ within 20-120 s, wherein the treatment time of the electric pulse is 1-10 min;

the quenching treatment process comprises the steps of heating a welding area of a welding part to 800-900 ℃, preserving heat for 1-10 min, and then flushing the welding area with cooling liquid to cool the welding area to room temperature.