CN110170723A - A kind of double heat source synchronous wire feeds, powder feeding welding method - Google Patents

Abstract

The invention discloses a welding method for synchronous wire feeding and powder feeding with dual heat sources. The welding system is composed of a wire feeding device, a front heat source, a rear heat source, a powder feeding device, and a gas protection device. The wire feeding gun head and the front heat source are , the rear heat source, and the powder feeding nozzle are arranged in series in the welding direction, and the wire feeding device is matched with the front heat source to realize wire feeding welding, and the powder feeding device is matched with the rear heat source to realize powder feeding welding. The distance between the heat source and the rear heat source and the output power, the front heat source realizes wire feeding welding and forms a certain height of weld reinforcement, and the rear heat source forms a small molten pool at the end of the liquid metal pool formed by the front heat source , the melting width is 1/5~1/2 of the melting width produced by the front heat source, and the powder feeding welding is implemented, and the weld reinforcement is 1/10~1/2 of the welding seam reinforcement of the front heat source wire feeding welding, which promotes The flow of liquid metal at the end of the welding pool increases the filling of the weld metal, which is beneficial to the suppression of welding defects such as cracks and pores.

Description

A welding method for synchronous wire feeding and powder feeding with dual heat sources

technical field

The invention relates to the technical field of material processing engineering, in particular to a welding method for synchronous wire feeding and powder feeding with dual heat sources.

Background technique

Wire feeding fusion welding is a welding method that uses heat source heating to melt the welding joint and welding materials to form a liquid metal molten pool, and then solidifies and forms the joint connection after the heat source is removed. Due to the addition of filler materials (welding consumables), this method can obtain a certain reinforcement on the surface of the weldment, make the weld shape full, and is beneficial to the improvement of the mechanical properties of the welded joint, so it is widely used in engineering practice. However, when welding metal materials with a high tendency of welding hot cracking or welding under rigid restraint conditions, welding cracks are prone to appear at the position of the weld centerline. The appearance of these cracks is related to the lack of liquid phase metal in the later stage of weld solidification, It is closely related to the difficulty of filling pores and the effect of welding tensile stress. This defect seriously affects the mechanical properties of welded joints and the reliability of welded structures.

According to the principle of solidification and the mechanism of solidification thermal cracks, improving the liquid flow conditions at the end of solidification of welds and increasing the filling capacity of liquid metal to pores is an effective method to suppress thermal cracks. In addition, improving the stress distribution of welded joints and weakening the welding tensile stress can also suppress the occurrence of cracks. However, due to the small weld pool and fast solidification speed in the welding process, it is difficult to use the metal hot crack suppression methods commonly used in the casting process, such as stirring and feeding, which also leads to the suppression of welding cracks as one of the difficulties in welding.

Therefore, those skilled in the art are committed to developing a welding method with dual heat sources for synchronous wire feeding and powder feeding, so as to improve the flow ability of the molten pool metal produced by the main welding heat source at the end of solidification, and promote the flow of molten pool metal at the end of solidification. The micro-gap feeding caused by shrinkage can improve the stress distribution of the weld to suppress the appearance of cracks and improve the mechanical properties of the weld.

Contents of the invention

In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to improve the flow capacity of the molten pool metal produced by the main welding heat source at the end of solidification, and to promote the feeding of the tiny gaps produced by the shrinkage of the molten metal in the molten pool at the end of solidification. , and improve the stress distribution of the weld to suppress the appearance of cracks and improve the mechanical properties of the weld.

In order to achieve the above object, the present invention provides a welding method for synchronous wire feeding and powder feeding with dual heat sources, comprising the following steps:

(1) Grind the welding surface of the workpiece to be welded until smooth, clean to remove oxides and oil stains, and install the workpiece to be welded on the welding tool;

(2) Arrange the wire feed gun head, front heat source, rear heat source, and powder feeding nozzle in series above the weld along the welding seam, and install side-blowing protective gas pipes on both sides of the weld seam, and the axis of the side-blowing protective gas pipes points to The center of the front heat source, and the central axis of the side blowing shielding gas pipe is perpendicular to the welding direction;

(3) Adjust the position of the gun head of the wire feeding device so that the tip of the welding wire sent by the wire feeding device is coupled to the center of the front heat source, and the angle between the axis of the gun head and the axis of the front heat source is 30-60°; adjust the powder feeding The position of the nozzle of the device is such that the powder stream sent by the powder feeding device is focused on the center of the rear heat source, and the angle between the axis of the nozzle and the axis of the rear heat source is 10-30°; adjust the first side blowing protection gas pipe and the second The position of the protective air pipe on both sides is such that the angle between the direction of the airflow and the surface of the workpiece to be welded is 30-60°;

(4) Set welding parameters: set the heat input value of the front heat source according to the thickness of the workpiece to be welded, and set the heat input value of the rear heat source so that the width of the weld pool produced by the front heat source is 1/ 5～1/2 of the required energy, the wire feeding speed is set according to eliminating the undercut and the surface is not fully welded and forming defects, and the residual height can be obtained on the surface of the weldment, and the powder feeding speed is sent to the front heat source according to the obtained residual height Set between 1/10~1/2 of the excess height generated by wire welding, set the flow rate of powder feeding gas to 5~25L/min, and set the gas flow rate of side blowing protective gas pipe to 5~50L/min;

(5) Start the control system, start welding, make the wire feeding device, front heat source, rear heat source, powder feeding device and gas protection device work at the same time, and implement dual heat source synchronous wire feeding and powder feeding welding.

Further, the front heat source and the rear heat source simultaneously generate two molten pools, which are the front molten pool and the rear molten pool, the front molten pool and the rear molten pool partially overlap, and the center of the rear molten pool is located in the front molten pool At the tail, the width of the rear molten pool is 1/5 to 1/2 of the width of the front molten pool.

Further, the heat input value of the front heat source in step (4) is 60-200 J/mm, and the heat input value of the rear heat source is 30-60 J/mm.

Further, the residual height generated by the rear heat source is 1/10-1/2 of that generated by the front heat source.

The present invention also provides a welding device for synchronous wire feeding and powder feeding with dual heat sources, including a front heat source, a rear heat source, a wire feeding device, a powder feeding device and a gas protection device, a front heat source, and a rear heat source powder feeding device And the gas protection device is arranged in series above the welding seam along the welding direction, the gas protection device is installed on both sides of the welding seam, the front heat source and wire feeding device are set to cooperate with wire feeding welding, and the rear heat source and powder feeding device It is set to cooperate with the implementation of powder feeding welding, and the wire feeding device, front heat source, rear heat source, powder feeding device and gas protection device are set to start or stop at the same time.

Further, the wire feeding device includes a wire feed gun head, the angle between the center line of the wire feed gun head and the center line of the front heat source is 30-60°, and the tip of the wire feed gun head is coupled to the center of the front heat source.

Further, the powder feeding device includes a powder feeding nozzle, the angle between the powder feeding nozzle and the centerline of the rear heat source is 10-30°, and the powder stream of the powder feeding nozzle is set to be sent out through the coaxial powder feeding nozzle and focused to Center the heat source.

Further, the center of the rear molten pool generated by the rear heat source is at the tail of the front molten pool generated by the front heat source, and the width of the rear molten pool is 1/5-1/2 of the width of the front molten pool.

Further, the gas protection device is a side-blowing protective gas pipe, and the side-blowing protective gas pipe includes a first side-blowing protective gas pipe and a second side-blowing protective gas pipe, and the first side-blowing protective gas pipe and the second side-blowing protective gas pipe are respectively installed on sides.

Further, the central axis of the side-blowing shielding gas pipe is set to point to the position of the weldment surface where the front heat source acts, and the included angle with the plane where the weldment is located is 30-60°.

Compared with the prior art, the present invention has at least the following beneficial technical effects:

In the present invention, a rear heat source is installed at the end of the molten pool generated by the front heat source. During the welding process of metal workpieces, the front heat source is the main heat source for welding, which realizes welding with the maximum penetration depth and meets the engineering requirements of welding thickness, while the rear heat source improves The flow ability of the molten pool metal increases the filling capacity of the liquid metal at the end of the solidification of the molten pool, promotes the escape of pores in the welded molten pool, improves the forming and stress distribution, and inhibits the appearance of thermal cracks at the end of solidification.

The invention adds a rear heat source for powder feeding welding, effectively increases the healing ability of the liquid phase metal backflow, improves the liquid phase filling capacity of the pores generated by the solidification and shrinkage of the tail of the molten pool, reduces the pores generated by the solidification and shrinkage of the tail of the molten pool, and improves the weld structure. structure, inhibiting the appearance of cracks;

The present invention adds a rear heat source for powder feeding welding, and can also change the shape of the weld seam produced by the front heat source wire feeding welding, which can make the center of the weld seam have a slightly raised reinforcement and prevent the weld seam from having a concave surface, thereby effectively improving the weld seam shape. Stress state on the surface of the weld to suppress the appearance of cracks on the surface of the weld;

The rear heat source of the present invention adopts the powder feeding method for metal filling. Compared with the wire feeding method (the general accuracy is 0.4-1.0g/min), the control of the metal filling amount is effectively improved, and the control accuracy can reach 0.02g/min. Greater precision.

The idea, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings, so as to fully understand the purpose, features and effects of the present invention.

Description of drawings

Fig. 1 is a schematic diagram of a welding device of dual heat source synchronous wire feeding and powder feeding in a preferred embodiment of the present invention;

Fig. 2 is a schematic diagram of molten pool of dual heat source synchronous wire feeding and powder feeding plate surfacing welding of a preferred embodiment of the present invention;

Fig. 3 is a schematic diagram of the crack tendency of the pre-heat source wire feeding welding of a thick plate according to a preferred embodiment of the present invention;

Fig. 4 is a schematic diagram of stress state of dual heat source synchronous wire feeding and powder feeding welding of a thick plate according to a preferred embodiment of the present invention.

Among them, 1-front heat source, 2-rear heat source, 3-wire feeding device, 4-powder feeding device, 5-first side blowing protective gas pipe, 6-second side blowing protective gas pipe, 7-first welder to be welded piece, 8-the second workpiece to be welded, 9-weld seam, 10-pre molten pool, 11-post molten pool, 12-tensile stress, 13-compressive stress.

Detailed ways

The following describes several preferred embodiments of the present invention with reference to the accompanying drawings, so as to make the technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the protection scope of the present invention is not limited to the embodiments mentioned herein.

In the drawings, components with the same structure are denoted by the same numerals, and components with similar structures or functions are denoted by similar numerals. The size and thickness of each component shown in the drawings are shown arbitrarily, and the present invention does not limit the size and thickness of each component. In order to make the illustration clearer, the thickness of parts is appropriately exaggerated in some places in the drawings.

As shown in Figure 1, a dual heat source synchronous wire feeding and powder feeding welding device in a preferred embodiment of the present invention includes a front heat source 1, a rear heat source 2, a wire feeding device 3, a powder feeding device 4, a first side Blow the protective gas tube 5 and the second side blow the protective gas tube 6. Among them, the front heat source 1, the rear heat source 2, the gun head of the wire feeding device 3 and the nozzle of the powder feeding device 4 are arranged in series directly above the welding seam 9 according to an axis; the powder feeding device 4 includes a coaxial gas Protective device (not shown in the figure): the first side-blowing protective gas pipe 5 and the second side-blowing protective gas pipe 6 are symmetrically placed on both sides of the front heat source 1, and the axes all point to the center of the front heat source 1. The front heat source 1, the rear heat source 2, the wire feeding device 3, the powder feeding device 4, the first side blowing protection gas pipe 5 and the second side blowing protection gas pipe 6 are all simultaneously started or stop at the same time. The first side-blowing protective gas pipe 5, the second side-blowing protective gas pipe 6, and the coaxial gas protection device (not shown in the figure) are all equipped with pressure regulating valves, which are controlled by the control system to adjust the gas flow rate, and the protective gas used is an inert gas , including any one of argon, helium and xenon. In a preferred embodiment of the present invention, pure argon is used as the shielding gas. The specific operation steps for welding with the above welding device are as follows:

(1) The welding surfaces of the first workpiece 7 to be welded and the second workpiece 8 to be welded are polished to be smooth and smooth, and cleaned to remove oxides and oil stains, and the first workpiece 7 to be welded and the second workpiece 8 to be welded are installed on the on the welding tooling (not shown in the figure);

(2) Adjust the position of the gun head of the wire feeding device 3 so that the angle between the axis of the gun head and the axis of the front heat source 1 is 30-60°, and the tip of the welding wire sent by the wire feed device 3 is coupled to the center of the front heat source 1 ; Adjust the position of the nozzle of the powder feeding device 4 so that the angle between the axis of the nozzle and the axis of the rear heat source 2 is 10-30°, and the powder beam sent by the powder feeding device 4 is focused on the center of the rear heat source 2; The positions of the side-blowing shielding gas pipe 5 and the second side-blowing shielding gas pipe 6 are such that the angle between the airflow direction of the first side-blowing shielding gas pipe 5 and the surface of the first workpiece 7 to be welded is 30-60°, and the second side-blowing The angle between the gas flow direction of the shielding gas pipe 6 and the surface of the second workpiece 8 to be welded is 30-60°;

(3) According to the thickness of the first workpiece to be welded 7 and the thickness of the second workpiece to be welded 8, set the heat input value of the front heat source 1, the heat input value of the rear heat source 2, the wire feeding speed and powder feeding of the wire feeding device 3 The powder feeding speed of device 4;

(4) The gas flow rate of the coaxial gas protection device is set to 5-25 L/min, and the gas flow rate of the first side-blowing protective gas pipe 5 and the second side-blowing protective gas pipe 6 is set to 5-50 L/min;

(5) Start the control system and start welding.

In a preferred embodiment of the present invention, the wire feeding device 3 cooperates with the front heat source 1 to implement wire feeding welding, and the powder feeding device 4 cooperates with the rear heat source 2 to implement powder feeding welding.

Example 1

In this embodiment, a thin metal plate with a thickness of 2mm is selected as the first workpiece to be welded and the second workpiece to be welded, and the plate surfacing welding is carried out under the protection of argon gas. The specific welding steps are as follows:

(1) Grinding the welding surfaces of the first workpiece 7 to be welded and the second workpiece 8 to be welded to be smooth, cleaning to remove impurities such as oxides and oil stains, and installing the first workpiece 7 to be welded and the second workpiece 8 to be welded On the welding tool, metal plates are placed at both ends of the welding tool as the arc strike plate;

(2) Arrange the wire feed gun head, front heat source 1, rear heat source 2 and powder feeding nozzle in series along an axis along the forward direction of the welding heat source, and place the side blowing protective gas pipes respectively on the front heat source On both sides of 2, the axis of the trachea points to the center of the front heat source, and the central axis of the trachea is perpendicular to the welding direction; adjust the position of the gun head of the wire feeding device so that the tip of the welding wire is coupled to the center of the front heat source, and the axis of the welding wire and the front heat source The included angle is 60°; adjust the position of the nozzle of the powder feeding device to focus the powder beam to the center of the rear heat source, and the angle between the axis of the nozzle and the axis of the rear heat source is 20°; adjust the first side blowing protective gas pipe and the position of the second side blowing shielding gas pipe, so that the angle between the direction of the airflow and the surface of the first workpiece to be welded and the surface of the second workpiece to be welded is 40°;

(3) Set the heat input value of the front heat source 1 to 60J/mm, the heat input value of the rear heat source 2 to 30J/mm, the wire feeding speed of the wire feeding device 3 to 1m/min, and the powder feeding device 4 The speed is 3g/min;

(4) The coaxial gas protection device, the gas flow rate of the first workpiece 7 to be welded and the second workpiece 8 to be welded are set to 15L/min;

(5) Start the control system to make the front heat source 1, the rear heat source 2, the wire feeding device 3, the powder feeding device 4, the first side blowing protection gas pipe 5 and the second side blowing protection gas pipe 6 run simultaneously, and implement double heat source synchronization Wire feeding, powder feeding welding.

In this embodiment, the setting of the wire feeding speed in step (4) is to make the wire feeding welding appear on the welding seam 9 with a bulge of 0.1 to 0.3mm as the degree of excess height, and the setting of the powder feeding speed is to make the powder feeding welding in the The reinforcement produced on the weld seam 9 is 1/10 to 1/2 of the reinforcement produced by wire feeding welding. As shown in FIG. 2 , the front heat source 1 produces a front molten pool 10 , and the rear heat source 2 produces a rear molten pool 11 , and the center of the rear molten pool 11 is at the tail of the front molten pool 10 . The input value of the rear heat source is set so that the width of the rear molten pool 11 is 1/5-1/2 of the width of the front molten pool 10 in degrees. The introduction of the rear heat source 2 assists powder feeding welding. On the one hand, it effectively increases the healing ability of the liquid phase metal backflow, reduces the pores at the tail of the front molten pool 10 due to solidification and shrinkage, improves the organizational structure of the weld 9, and suppresses the occurrence of cracks. To improve the mechanical properties of the weld 9, further, the present invention uses dual heat sources to feed wire and powder simultaneously for welding, so that the center of the weld 9 finally has a convex reinforcement of <0.5mm, avoiding the appearance of the weld 9 The surface is concave, which changes the shape of the weld seam produced by the simple wire feeding welding method, thereby improving the stress state of the weld seam surface and suppressing the appearance of cracks on the weld seam surface; on the other hand, powder feeding welding can achieve accurate metal filling Control, the filling accuracy can reach 0.02g/min, compared with the general powder feeding welding method with a filling accuracy of 0.4-1.0g/min, the filling accuracy is higher, and it can ensure the precise adjustment ability under the condition of small filler metal.

This embodiment describes the plate surfacing welding process of dual heat source synchronous wire feeding and powder feeding. The energy density of the front heat source is greater than that of the rear heat source, resulting in a larger weld pool of the front heat source, and the center of the rear heat source acts on the final solidification point at the end of the weld pool of the front heat source, resulting in a smaller weld pool of the rear heat source. The rear heat source heats the welding pool of the front heat source, which effectively improves the flow capacity of the molten pool metal at the end of solidification, so that the precipitation ability of the pores caused by the welding keyhole of the deep penetration welding reduces the pore defects of the weld; secondly, the alloy The filling of the welding pool by the powder improves the reflow healing ability of the metal liquid phase during the solidification process, and reduces the tendency of solidification shrinkage to cause welding cracks.

Example 2

In this embodiment, a thick metal plate with a thickness of 10mm is selected as the first workpiece to be welded and the second workpiece to be welded, and the thick plate is butt welded under the protection of argon gas. The specific welding steps are as follows:

(1) Open a V-shaped groove on the side of the first workpiece 7 to be welded and the second workpiece 8 to be welded as the welding surface, the groove angle is 20°, the groove depth is 5mm, and the groove is ground to smooth with a grinder Smooth, carry out chemical cleaning to remove impurities such as oxides and oil stains, install the first workpiece to be welded and the second workpiece to be welded on the welding tool, and place metal plates at both ends of the welding tool as arc strike plates;

(2) Arrange the wire feed gun head, front heat source 1, rear heat source 2 and powder feeding nozzle in series along an axis along the forward direction of the welding heat source, and place the side blowing protective gas pipes respectively on the front heat source 1, the axis of the trachea points to the center of the front heat source, and the central axis of the trachea is perpendicular to the welding direction. The included angle is 30°; adjust the position of the nozzle of the powder feeding device 4 so that the powder stream is focused on the center of the rear heat source, and the angle between the axis of the nozzle and the axis of the rear heat source is 20°; adjust the first side blowing protection gas pipe 5 and the position of the second side blowing shielding gas pipe 6, so that the angle between the direction of the airflow and the surface of the first workpiece 7 to be welded and the surface of the second workpiece 8 to be welded is 40°;

(3) And set the heat input of the front heat source 1 to 200J/mm, the heat input of the rear heat source 2 to 60J/mm, the wire feeding speed of the wire feeding device 3 to 5m/min, and the powder feeding speed of the powder feeding device 4 15g/min;

(4) Set the coaxial gas protection device, the gas flow rate of the first workpiece to be welded and the second workpiece to be welded is 15L/min;

(5) Start the control system, so that the front heat source 1, the rear heat source 2, the wire feeding device 3, the powder feeding device 4, the first side blowing protective gas pipe 5 and the second side blowing protective gas pipe 6 operate simultaneously, implementing dual heat sources Synchronous wire feeding and powder feeding welding.

In this embodiment, a relatively large heat input is used for welding. As shown in FIG. 3, the front molten pool 10 is in contact with the inner wall of the groove, and the phenomenon of liquid metal wetting occurs, so that a concave weld shape appears after cooling, and the weld 9 The central position of the center is subjected to the tensile stress 12 directed to the inner wall of the groove, which causes the weld 9 to have a tendency to crack. As shown in Figure 4, the rear heat source 2 produces weld reinforcement through powder feeding welding, which is 1/5 to 1/2 of the maximum reinforcement produced by the front heat source 1, and the weld width is 1/5-1/2 of the width of the weld seam generated by the heat source 1 changes the shape of the weld seam from concave to convex, thereby introducing compressive stress 13 at the center of the weld seam 9 and suppressing the appearance of cracks.

The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make many modifications and changes according to the concept of the present invention without creative efforts. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art shall be within the scope of protection defined by the claims.

Claims (10)

1. A welding method for synchronous wire feeding and powder feeding with dual heat sources, characterized in that, comprising the steps: (1) grinding the welding surface of the workpiece to be welded to smooth and smooth, cleaning to remove oxides and oil stains, and installing the workpiece to be welded on the welding tool; (2) Arrange the wire feeding device, the front heat source, the rear heat source, and the powder feeding device in series above the welding seam along the welding direction, and install side-blowing protective gas pipes on both sides of the weld seam, and the axis of the side-blowing protective gas pipe Pointing to the center of the front heat source, and the central axis of the side blowing shielding gas pipe is perpendicular to the welding direction; (3) Adjust the position of the gun head of the wire feeding device so that the tip of the welding wire sent by the wire feeding device is coupled to the center of the front heat source, and the angle between the axis of the gun head and the axis of the front heat source is 30-60° ; Adjust the position of the nozzle of the powder feeding device so that the powder stream sent by the powder feeding device is focused on the center of the rear heat source, and the angle between the axis of the nozzle and the axis of the rear heat source is 10-30° ; Adjusting the positions of the first side-blowing shielding gas pipe and the second side-blowing shielding gas pipe so that the angle between the direction of the airflow and the surface of the workpiece to be welded is 30-60°; (4) Set welding parameters: set the heat input value of the front heat source according to the thickness of the workpiece to be welded, and set the heat input value of the rear heat source so that the width of the weld pool produced is that produced by the front heat source The energy required for welding molten pool width 1/5 ~ 1/2, the wire feeding speed is set according to the elimination of undercut and the surface is not fully welded and formed defects, and the residual height can be obtained on the surface of the weldment, the powder feeding speed is based on the obtained residual height The height is set between 1/10 and 1/2 of the residual height generated by the wire feeding welding of the front heat source, the flow rate of the powder feeding gas is set to 5-25L/min, and the gas flow rate of the side blowing protective gas pipe is set to 5-50L/min ; (5) Start the control system, start welding, make the wire feeding device, front heat source, rear heat source, powder feeding device and gas protection device work at the same time, and implement dual heat source synchronous wire feeding and powder feeding welding. 2. The welding method according to claim 1, wherein the front heat source generates a front molten pool, the rear heat source generates a rear molten pool, and the front molten pool and the rear molten pool part overlapping, the center of the rear molten pool is at the tail of the front molten pool, and the width of the rear molten pool is 1/5 to 1/2 of the width of the front molten pool. 3. The welding method according to claim 2, wherein the heat input value of the front heat source in step (4) is 60 to 200 J/mm, and the heat input value of the rear heat source is 30 to 60 J/mm . 4. The welding method according to claim 3, wherein the residual height generated by the rear heat source is 1/10-1/2 of the residual height generated by the front heat source. 5. A welding device for synchronous wire feeding and powder feeding with dual heat sources, characterized in that it includes a front heat source, a rear heat source, a wire feeding device, a powder feeding device and a gas protection device, and the front heat source and the rear heat source The powder feeding device and the gas shielding device are arranged in series above the weld seam along the welding direction. The gas shielding device includes two side-blowing shielding gas pipes installed on both sides of the weld seam. The front heat source The wire feeding device is set to cooperate with the implementation of wire feeding welding, the rear heat source and the powder feeding device are set to cooperate with the implementation of powder feeding welding, the wire feeding device, the front heat source, the rear heat source, the feeding The powder device and the gas protection device are set to start or stop at the same time. 6. The welding device for synchronous wire feeding and powder feeding with dual heat sources as claimed in claim 5, wherein the wire feeding device comprises a wire feed gun head, and the center line of the wire feed gun head is in line with the front heat source. The included angle of the center line is 30-60°, and the tip of the wire feed gun head is coupled with the center of the front heat source. 7. The welding device for synchronous wire feeding and powder feeding with dual heat sources as claimed in claim 5, wherein the powder feeding device comprises a powder feeding nozzle, and the included angle between the powder feeding nozzle and the center line of the rear heat source is 10-30°, the powder stream of the powder feeding nozzle is set to be sent out through the coaxial powder feeding nozzle and focused to the center of the rear heat source. 8. The welding device for synchronous wire feeding and powder feeding with dual heat sources as claimed in claim 5, wherein the center of the rear molten pool generated by the rear heat source is at the tail of the front molten pool generated by the front heat source, The width of the rear molten pool is 1/5˜1/2 of the width of the preceding molten pool. 9. The welding device for synchronous wire feeding and powder feeding with dual heat sources as claimed in claim 5, wherein the two side-blowing shielding gas pipes comprise a first side-blowing shielding gas pipe and a second side-blowing shielding gas pipe, the first The side-blowing protective gas pipe and the second side-blowing protective gas pipe are respectively installed on both sides of the weld seam. 10. The welding device for synchronous wire feeding and powder feeding with dual heat sources as claimed in claim 9, wherein the central axis of the side-blowing shielding gas pipe is set to point to the position of the weldment surface where the front heat source acts, and The included angle of the plane where the weldment is located is 30-60°.