Large-wall-thickness Al-Mg alloy laser-MIG compounding and friction stir welding coupled welding device for ships

Abstract

The invention relates to the technical field of ship manufacturing welding, in particular to a large-wall-thickness Al-Mg alloy laser-MIG composite and friction stir welding coupled welding device and method for ships, and the device comprises a sequential system 1, a friction stir welding module 2 and a laser-MIG composite welding module 3; the laser-MIG composite welding module 3 comprises a laser sensing return device 3A, a welding gun swing control device 3B and a laser-MIG composite welding gun 3C; the laser-MIG composite welding gun 3C comprises an MIG welding gun and a laser welding gun, the MIG welding gun and the laser welding gun are coaxially arranged, an optical fiber laser is arranged in the laser-MIG composite welding gun 3C, the optical fiber laser has the functions of laser visual sensing, preheating and post-heating, and the device solves the contradiction between the penetration depth and the defect when a traditional welding method is adopted for the thick plate aluminum alloy for the ship. Axial force needed during friction stir welding can be reduced through laser preheating, the pressure of a main shaft of equipment is remarkably reduced, and the service life of a stirring head is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of shipbuilding welding, and in particular to a welding device for coupling laser-MIG composite and friction stir welding of thick-walled Al-Mg alloys for ships. Background Art

[0002] Al-Mg alloy extruded and rolled plates are widely used in shipbuilding. They offer corrosion resistance and weight reduction in complex marine environments, while also ensuring the rigidity and strength required for practical applications. They are suitable for welding cryogenic liquid transport tanks, such as LNG cargo tanks. Existing technical solutions typically utilize laser-MIG hybrid welding or friction stir welding for welding Al-Mg alloy extruded and rolled plates. Laser-MIG hybrid welding requires multiple passes for thick aluminum alloys and strict control of interlayer temperature. High heat input can easily lead to component deformation. Friction stir welding has limited single-pass penetration (typically ≤12-14mm) and is less adaptable to complex joints, such as corner joints. Friction stir welding equipment requires high rigidity and high cost for welding thick aluminum alloys. The two processes, when used alone or in combination, struggle to balance production efficiency and quality.

[0003] In summary, there is an urgent need for a thick-walled Al-Mg alloy welding device and method for ships to solve the problems of insufficient penetration, porosity defects and residual stress existing in the traditional single welding method. Summary of the Invention

[0004] The present invention aims to solve the technical problem of how to provide a device and method for welding thick-walled Al-Mg alloy for ships.

[0005] In order to achieve the above-mentioned object, the first aspect of the present invention provides a welding device for coupling laser-MIG composite and friction stir welding of thick-walled Al-Mg alloy for ships, wherein the device comprises:

[0006] Timing system 1, friction stir welding module 2 and laser-MIG hybrid welding module 3;

[0007] The friction stir welding module 2 and the laser-MIG hybrid welding module 3 are connected to the timing system 1 through a hydraulic integrated transmission device;

[0008] The timing system 1 includes a control system and a coupling mechanism;

[0009] The control system is a multi-parameter collaborative module, and the parameters include laser power, friction stir welding speed and downward pressure;

[0010] The coupling mechanism is an integration of the laser head, the friction stir welding main shaft and the sub-shaft;

[0011] The friction stir welding module 2 includes a pressure feedback servo system and an adaptive pressure regulating device 2A;

[0012] The laser-MIG hybrid welding module 3 includes a laser sensor feedback device 3A, a welding gun swing control device 3B and a laser-MIG hybrid welding gun 3C;

[0013] The welding gun swing control device 3B is connected to the laser-MIG composite welding gun 3C via a universal swing ball head 3BC;

[0014] The laser-MIG composite welding gun 3C includes a MIG welding gun and a laser welding gun, which are coaxially arranged. A fiber laser is provided in the laser-MIG composite welding gun 3C, and the fiber laser has laser vision sensing, preheating and post-heating functions.

[0015] A second aspect of the present invention provides a welding method using the above-mentioned welding device, wherein the method comprises:

[0016] Mechanical grinding, butt forging, welding;

[0017] The welding comprises:

[0018] The adaptive pressure regulating device 2A of the friction stir welding module 2 is used to adaptively regulate the spindle downward pressure according to the different flatness of the welding surface;

[0019] The adaptive adjustment method of the spindle pressure of the friction stir welding comprises: using the laser line emitted by the fiber laser of the laser-MIG hybrid welding gun 3C to the weld to identify the weld, and transmitting the signal back to the timing system 1 through the laser visual sensing function of the fiber laser. The timing system 1 tracks the weld through the image processing algorithm, and can accurately calculate the X, Y, Z coordinates of the current position of the weld and the weld flatness during the welding process, and feedback and adjustment based on the adaptive pressure of the friction stir welding are performed through the thermal radiation signal fed back by the laser line, and the temperature deviation ΔZ=Z is calculated by material -Z(t), real-time tracking and correction, where Z material is the original Z-axis coordinate of the weld, and Z(t) is the real-time Z-axis coordinate of the weld during the welding process. When a deviation occurs, the timing system 1 identifies the deviation signal ΔZ through the laser sensor feedback device 3, and transmits the spindle pressure adjustment signal to the friction stir welding module 2 according to the deviation signal ΔZ;

[0020] The laser line emitted by the fiber laser of the laser-MIG hybrid welding gun 3C to the weld is used to identify the weld, and the signal is transmitted back to the timing system 1 through the laser vision sensing function of the fiber laser. The timing system 1 tracks the weld through the image processing algorithm and can calculate the X, Y, Z coordinates of the current position of the weld and the amount of misalignment during the welding process. The thermal radiation signal fed back by the laser line is used to adjust and feedback control the molten pool temperature. The temperature deviation ΔD=T is calculated by set -T(t), real-time tracking and correction, while the deviation ΔD is used as the input variable for adjusting the welding speed V and laser power P, where V is in mm / min and laser power P is in W;

[0021] The functional relationship is expressed as

[0022] V correction =f(ΔD)=V0*(1+K V *|ΔD|), P correction =g(ΔD)=P0*(1+K p *|ΔD|),

[0023] Among them, V0 and P0 are the reference welding speed and laser power preset by the timing system 1, K V and K p is the gain coefficient determined based on a large number of process tests;

[0024] When a deviation occurs, the timing system 1 transmits the f(ΔD) and g(ΔD) signals to the laser-MIG hybrid welding module 3 through the laser sensor feedback device 3, thereby realizing dynamic adjustment of the welding process parameters of the laser-MIG hybrid welding module 3;

[0025] Laser-MIG hybrid welding is used to weld the root weld and the main body filling, and friction stir welding is used to perform secondary treatment on the weld surface or heat-affected zone to eliminate pores and reduce residual stress. The laser-MIG hybrid welding and friction stir welding tools move in the same direction, and friction stir welding immediately stirs the tail of the molten pool.

[0026] The beneficial effects of the present invention are:

[0027] 1. The present invention provides a coupled laser-MIG composite and friction stir welding welding method for thick-walled Al-Mg alloy for ships, which achieves root deep penetration welding through laser-MIG composite welding and then performs cover welding through friction stir welding to reduce overall heat input.

[0028] 2. The present invention provides a coupled laser-MIG composite and friction stir welding welding method for thick-walled Al-Mg alloy for ships, which combines the "fusion welding" of laser-MIG with the "solid phase welding" of friction stir welding to solve the contradiction between the penetration depth and defects of thick-plate aluminum alloy for ships.

[0029] 3. The present invention provides a laser-MIG composite and friction stir welding coupling welding method for thick-walled Al-Mg alloy for ships, which can reduce the axial force required for FSW through laser preheating, extend the life of the stirring head and significantly reduce the main shaft pressure of the equipment.

[0030] 4. The present invention provides a coupled laser-MIG composite and friction stir welding welding equipment for thick-walled Al-Mg alloys for ships, which can be installed on a gantry or cantilever robot. It integrates a laser-MIG composite welding gun head and a friction stir welding tool head, adopts a modular design, and realizes rapid switching or synchronous operation through timing coupling, thereby improving the production efficiency and welding quality when the two welding methods are combined separately.

[0031] 5. The present invention provides a coupled laser-MIG composite and friction stir welding welding equipment for thick-walled Al-Mg alloys for ships, which can realize weld tracking, temperature monitoring, and adaptive parameter adjustment (such as laser power, friction stir welding speed / down force).

[0032] 6. The present invention provides a coupled laser-MIG composite and friction stir welding welding equipment for thick-walled Al-Mg alloys for ships. The equipment can dynamically allocate the energy ratio of laser-MIG composite and friction stir welding according to the plate thickness, optimize the welding process parameters, and take into account both welding efficiency and microstructure performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of the welding equipment of the present invention;

[0034] Figure 2 Schematic diagram of the adaptive pressure friction stir welding module 2;

[0035] Figure 3 Schematic diagram of laser-MIG hybrid welding module 3;

[0036] Figure 4 This is a connection diagram of the laser-MIG hybrid welding module 3. DETAILED DESCRIPTION

[0037] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0038] In the present invention, the thickness of the thick-walled Al-Mg alloy for ships is 8-25 mm.

[0039] In the existing technology, when traditional friction stir welding is used in combination with laser MIG hybrid welding, the next weld can only be welded after the previous weld is completed, and the two welding methods cannot be used on the same welding position, resulting in the inability to eliminate metallurgical defects inside the weld after a single weld is completed, such as pores and cracks after laser-MIG hybrid welding and weak root connection of friction stir welding, and the production efficiency is too low.

[0040] In the present invention, the inventors found that if the laser-MIG composite welding gun head and the stir friction welding tool head can be coupled, the welding defects generated by the previous weld during the welding process, such as pores, cracks, and weak root connections, can be eliminated, greatly improving production efficiency and product qualification rate and reducing the number of weld rework times.

[0041] To achieve this goal, the inventors attempted to optimize the welding device and welding method. The inventors found that the above-mentioned purpose can be achieved by specific control parameters and settings.

[0042] A first aspect of the present invention provides a welding device for coupling laser-MIG composite and friction stir welding of thick-walled Al-Mg alloy for ships, wherein the device comprises:

[0043] Timing system 1, friction stir welding module 2 and laser-MIG hybrid welding module 3;

[0044] The friction stir welding module 2 and the laser-MIG hybrid welding module 3 are connected to the timing system 1 via a hydraulic integrated transmission device;

[0045] The timing system 1 includes a control system and a coupling mechanism;

[0046] The control system is a multi-parameter collaborative module, and the parameters include laser power, friction stir welding speed and downward pressure;

[0047] The coupling mechanism is an integration of the laser head, the friction stir welding main shaft and the sub-shaft;

[0048] The friction stir welding module 2 includes a pressure feedback servo system and an adaptive pressure regulating device 2A;

[0049] The laser-MIG hybrid welding module 3 includes a laser sensor feedback device 3A, a welding gun swing control device 3B and a laser-MIG hybrid welding gun 3C;

[0050] The welding gun swing control device 3B is connected to the laser-MIG composite welding gun 3C via a universal swing ball head 3BC;

[0051] The laser-MIG composite welding gun 3C includes a MIG welding gun and a laser welding gun, which are coaxially arranged. A fiber laser is provided in the laser-MIG composite welding gun 3C, and the fiber laser has laser vision sensing, preheating and post-heating functions.

[0052] According to the instruction manual Figure 3 As can be seen from the schematic diagram of the laser-MIG hybrid welding module 3, the laser welding gun and the MIG welding gun are integrated. Figure 3 The dot-dash line is the axis of the laser welding gun and the MIG welding gun.

[0053] In the present invention, the coupling of laser-MIG composite and friction stir welding can simplify the welding process of thick-walled aluminum plates for ships, reduce the number of multi-layer welds, significantly improve the welding speed, and realize the temporal coupling of "melting welding" and "solid phase welding". The laser-MIG welding gun and the friction stir welding stirring head are integrated into the same motion mechanism, and sequential or synchronous welding is achieved through a collaborative control system, which solves the contradiction between the penetration depth and defects of thick-plate aluminum alloys for ships when using traditional welding methods; laser preheating can also reduce the axial force required for friction stir welding, significantly reduce the main shaft pressure of the equipment and extend the life of the stirring head; the modular design can quickly switch between laser-MIG composite welding and friction stir welding, and realize segmented coupling and synchronous composite process.

[0054] According to the present invention, the distance between the center of the laser head and the center of the friction stir welding spindle is 50-200 mm.

[0055] In the present invention, the horizontal distance between the module and the adaptive pressure stir friction welding module 2 is adjusted by using a PLC+industrial computer.

[0056] According to the present invention, the angle between the laser-MIG hybrid welding gun 3C and the vertical direction is 0-90°.

[0057] In the present invention, the laser-MIG composite welding module 3 welding gun swing control device 3B is connected to the coaxial laser-MIG composite welding gun 3C of the laser-MIG composite welding module 3 through a universal swing ball head 3BC, which can realize the coaxial integrated laser-MIG composite welding gun device 3C with a 0-90° angle with the vertical direction, adapt to complex welds, and improve the efficiency of equipment use.

[0058] According to the present invention, the laser-MIG hybrid welding module 3 rotates 360° within the plane of the timing system 1 .

[0059] In the present invention, the timing system 1 controls the laser-MIG hybrid welding module 3 through PLC+industrial computer, so that the module can rotate 360° in the plane of the timing system 1 to adapt to welds in all directions.

[0060] A second aspect of the present invention provides a welding method using the above-mentioned welding device, wherein the method comprises:

[0061] Mechanical grinding, butt forging, welding;

[0062] The welding comprises:

[0063] The adaptive pressure regulating device 2A of the friction stir welding module 2 is used to adaptively regulate the spindle downward pressure according to the different flatness of the welding surface;

[0064] The adaptive adjustment method of the spindle pressure of the friction stir welding comprises: using the laser line emitted by the fiber laser of the laser-MIG hybrid welding gun 3C to the weld to identify the weld, and transmitting the signal back to the timing system 1 through the laser visual sensing function of the fiber laser. The timing system 1 tracks the weld through the image processing algorithm, and can accurately calculate the X, Y, Z coordinates of the current position of the weld and the weld flatness during the welding process, and feedback and adjustment based on the adaptive pressure of the friction stir welding are performed through the thermal radiation signal fed back by the laser line, and the temperature deviation ΔZ=Z is calculated by material -Z(t), real-time tracking and correction, where Z material is the original Z-axis coordinate of the weld, and Z(t) is the real-time Z-axis coordinate of the weld during the welding process. When a deviation occurs, the timing system 1 identifies the deviation signal ΔZ through the laser sensor feedback device 3, and transmits the spindle pressure adjustment signal to the friction stir welding module 2 according to the deviation signal ΔZ;

[0065] The laser line emitted by the fiber laser of the laser-MIG hybrid welding gun 3C to the weld is used to identify the weld, and the signal is transmitted back to the timing system 1 through the laser vision sensing function of the fiber laser. The timing system 1 tracks the weld through the image processing algorithm and can calculate the X, Y, Z coordinates of the current position of the weld and the amount of misalignment during the welding process. The thermal radiation signal fed back by the laser line is used to adjust and feedback control the molten pool temperature. The temperature deviation ΔD=T is calculated by set -T(t), real-time tracking and correction, while the deviation ΔD is used as the input variable for adjusting the welding speed V and laser power P, where V is in mm / min and laser power P is in W;

[0066] The functional relationship is expressed as

[0067] V correction =f(ΔD)=V0*(1+K V *|ΔD|), P correction =g(ΔD)=P0*(1+K p *|ΔD|),

[0068] Among them, V0 and P0 are the reference welding speed and laser power preset by the timing system 1, K V and K p is the gain coefficient determined based on a large number of process tests;

[0069] When a deviation occurs, the timing system 1 transmits the f(ΔD) and g(ΔD) signals to the laser-MIG hybrid welding module 3 through the laser sensor feedback device 3, thereby realizing dynamic adjustment of the welding process parameters of the laser-MIG hybrid welding module 3;

[0070] Laser-MIG hybrid welding is used to weld the root weld and the main body filling, and friction stir welding is used to perform secondary treatment on the weld surface or heat-affected zone to eliminate pores and reduce residual stress. The laser-MIG hybrid welding and friction stir welding tools move in the same direction, and friction stir welding immediately stirs the tail of the molten pool.

[0071] In the present invention, the gain coefficient may be positive or negative, depending on the degree of influence of the deviation direction on the heat input.

[0072] In the present invention, the high energy density of the laser and the bridging ability of the MIG are utilized to perform laser-MIG composite welding of the root weld and the main body filler, and the timing of heat input and mechanical action is precisely controlled. The equipment adopts an adaptive pressure control method, and stir friction welding can also be performed on irregular surfaces.

[0073] According to the present invention, the rotation speed of the friction stir welding is 1300-4000 rpm, and the welding speed is 1000-2100 mm / min.

[0074] According to the present invention, the laser power of the laser-MIG hybrid welding is 3500-12000W, and the welding current is 130-600A.

[0075] Test Method

[0076] The test method for ultrasonic testing is GB / T 11345-2013 "Ultrasonic testing technology, testing levels and assessment for non-destructive testing of welds".

[0077] The test method for mechanical properties (specifically, tensile strength and yield strength) is ISO 6892 "Metallic materials - Tensile tests - Part 1: Test methods at room temperature".

[0078] The flatness test method is to use a welding inspection ruler, which can be a precision straight ruler.

[0079] Example 1

[0080] A ship-used LNG tank assembly with an 18mm thick 5083-H111 aluminum alloy bottom plate is butt-welded. The specific implementation steps are as follows:

[0081] (a) Bottom plate: 5083-H111 aluminum alloy rolled plate, 3500 mm wide × 1500 mm long × 18 mm thick;

[0082] (b) Before welding, mechanically grind the area of ​​the base plate to be welded to remove the oxide film and oil stains on the surface of the base plate;

[0083] (c) Place the polished base plate on the workbench with the butt joint clearance of 0 mm. Use a special hydraulic fixture to clamp it and apply a forging force perpendicular to the weld and parallel to the workbench.

[0084] (d) Welding: Laser-MIG hybrid welding and friction stir welding were coupled. Laser-MIG hybrid welding was first performed for full penetration, and friction stir welding was performed for pore removal. The horizontal spacing between the two welding methods was 60 mm. The laser power was 6000 W, the welding current was 140 A, the friction stir welding spindle speed was 1600 rpm, and the welding speed was 850 mm / min.

[0085] The laser line emitted by the fiber laser of the laser-MIG hybrid welding gun 3C to the weld is used to identify the weld, and the signal is transmitted back to the timing system 1 through the laser vision sensing function of the fiber laser. The timing system 1 tracks the weld through the image processing algorithm and can accurately calculate the X, Y, Z coordinates of the current position of the weld and the weld flatness during the welding process. The heat radiation signal fed back by the laser line is used to feedback and adjust the adaptive pressure of the friction stir welding. The temperature deviation ΔZ=Z is calculated. material -Z(t), real-time tracking and correction, where Z material is the original Z-axis coordinate of the weld, and Z(t) is the real-time Z-axis coordinate of the weld during the welding process. When a deviation occurs, the timing system 1 identifies the deviation signal ΔZ through the laser sensor feedback device 3, and transmits the spindle pressure adjustment signal to the friction stir welding module 2 according to the deviation signal ΔZ;

[0086] The laser line emitted by the fiber laser of the laser-MIG hybrid welding gun 3C to the weld is used to identify the weld, and the signal is transmitted back to the timing system 1 through the laser vision sensing function of the fiber laser. The timing system 1 tracks the weld through the image processing algorithm and can calculate the X, Y, Z coordinates of the current position of the weld and the amount of misalignment during the welding process. The thermal radiation signal fed back by the laser line is used to adjust and feedback control the molten pool temperature. The temperature deviation ΔD=T is calculated by set -T(t), real-time tracking and correction, while the deviation ΔD is used as the input variable for adjusting the welding speed V and laser power P, where V is in mm / min and laser power P is in W;

[0087] The functional relationship is expressed as

[0088] V correction =f(ΔD)=V0*(1+K V *|ΔD|), P correction =g(ΔD)=P0*(1+K p *|ΔD|),

[0089] Among them, V0 and P0 are the reference welding speed and laser power preset by the timing system 1, K V and K p is the gain coefficient determined based on a large number of process tests;

[0090] When a deviation occurs, the timing system 1 transmits the f(ΔD) and g(ΔD) signals to the laser-MIG hybrid welding module 3 through the laser sensor feedback device 3, thereby realizing dynamic adjustment of the welding process parameters of the laser-MIG hybrid welding module 3;

[0091] (e) Post-weld inspection: 100% ultrasonic inspection of the weld seam is performed, with no internal pores and a flatness of less than 1 mm, meeting the requirements for subsequent processing.

[0092] Example 2

[0093] A ship side and bottom outer plate assembly, 22mm thick 5083-O aluminum alloy plates are butt-welded. The specific implementation steps are as follows:

[0094] (a) Bottom plate: 5083-O aluminum alloy rolled plate, 3000 mm wide × 2000 mm long × 22 mm thick;

[0095] (b) Before welding, mechanically grind the area of ​​the base plate to be welded to remove the oxide film and oil stains on the surface of the base plate;

[0096] (c) Place the polished base plate on the workbench with the butt joint clearance of 0 mm. Use a special hydraulic fixture to clamp it and apply a forging force perpendicular to the weld and parallel to the workbench.

[0097] (d) Welding: Laser-MIG hybrid and friction stir welding were coupled. Laser-MIG hybrid welding was first performed for full penetration, and friction stir welding was performed for laser-MIG hybrid base welding to remove pores and cover welding. The horizontal spacing between the two welding methods was 80 mm. The laser power was 6800 W, the welding current was 150 A, the friction stir welding spindle speed was 1200 rpm, and the welding speed was 800 mm / min.

[0098] The laser line emitted by the fiber laser of the laser-MIG hybrid welding gun 3C to the weld is used to identify the weld, and the signal is transmitted back to the timing system 1 through the laser vision sensing function of the fiber laser. The timing system 1 tracks the weld through the image processing algorithm and can accurately calculate the X, Y, Z coordinates of the current position of the weld and the weld flatness during the welding process. The heat radiation signal fed back by the laser line is used to feedback and adjust the adaptive pressure of the friction stir welding. The temperature deviation ΔZ=Z is calculated. material -Z(t), real-time tracking and correction, where Z material is the original Z-axis coordinate of the weld, and Z(t) is the real-time Z-axis coordinate of the weld during the welding process. When a deviation occurs, the timing system 1 identifies the deviation signal ΔZ through the laser sensor feedback device 3, and transmits the spindle pressure adjustment signal to the friction stir welding module 2 according to the deviation signal ΔZ;

[0099] The laser line emitted by the fiber laser of the laser-MIG hybrid welding gun 3C to the weld is used to identify the weld, and the signal is transmitted back to the timing system 1 through the laser vision sensing function of the fiber laser. The timing system 1 tracks the weld through the image processing algorithm and can calculate the X, Y, Z coordinates of the current position of the weld and the amount of misalignment during the welding process. The thermal radiation signal fed back by the laser line is used to adjust and feedback control the molten pool temperature. The temperature deviation ΔD=T is calculated by set -T(t), real-time tracking and correction, while the deviation ΔD is used as the input variable for adjusting the welding speed V and laser power P, where V is in mm / min and laser power P is in W;

[0100] The functional relationship is expressed as

[0101] V correction =f(ΔD)=V0*(1+K V *|ΔD|), P correction =g(ΔD)=P0*(1+K p *|ΔD|),

[0102] Among them, V0 and P0 are the reference welding speed and laser power preset by the timing system 1, K V and K p is the gain coefficient determined based on a large number of process tests;

[0103] When a deviation occurs, the timing system 1 transmits the f(ΔD) and g(ΔD) signals to the laser-MIG hybrid welding module 3 through the laser sensor feedback device 3, thereby realizing dynamic adjustment of the welding process parameters of the laser-MIG hybrid welding module 3;

[0104] (e) Post-weld inspection: 100% ultrasonic inspection of welds was conducted to confirm the absence of internal pores. Mechanical properties were randomly inspected to confirm that the welded joints had essentially no strength loss and a flatness of less than 1.6 mm, meeting the requirements for subsequent hull processing.

[0105] Example 3

[0106] A 16mm thick 5083-O aluminum alloy extruded sheet for ship portholes is butt-welded. The specific implementation steps are as follows:

[0107] (a) A 16 mm thick 5083-O aluminum alloy extruded sheet for ship portholes;

[0108] (b) Before welding, mechanically grind the area of ​​the base plate to be welded to remove the oxide film and oil stains on the surface of the base plate;

[0109] (c) Place the polished 16 mm thick 5083-O aluminum alloy extruded sheet on a workbench with a 0 mm butt gap. Clamp it with a dedicated hydraulic fixture and apply a forging force perpendicular to the weld and parallel to the workbench.

[0110] (d) Welding: Laser-MIG hybrid and friction stir welding were coupled. Laser-MIG hybrid welding was first performed to achieve full penetration of the weld, and friction stir welding was performed to remove pores from the laser-MIG hybrid base weld and then to weld the cover. The horizontal spacing between the two welding methods was 60 mm. The laser power was 4200 W, the welding current was 130 A, the spindle speed of the friction stir welding was 1500 rpm, and the welding speed was 1000 mm / min.

[0111] The laser line emitted by the fiber laser of the laser-MIG hybrid welding gun 3C to the weld is used to identify the weld, and the signal is transmitted back to the timing system 1 through the laser vision sensing function of the fiber laser. The timing system 1 tracks the weld through the image processing algorithm and can accurately calculate the X, Y, Z coordinates of the current position of the weld and the weld flatness during the welding process. The heat radiation signal fed back by the laser line is used to feedback and adjust the adaptive pressure of the friction stir welding. The temperature deviation ΔZ=Z is calculated. material -Z(t), real-time tracking and correction, where Z material is the original Z-axis coordinate of the weld, and Z(t) is the real-time Z-axis coordinate of the weld during the welding process. When a deviation occurs, the timing system 1 identifies the deviation signal ΔZ through the laser sensor feedback device 3, and transmits the spindle pressure adjustment signal to the friction stir welding module 2 according to the deviation signal ΔZ;

[0112] The laser line emitted by the fiber laser of the laser-MIG hybrid welding gun 3C to the weld is used to identify the weld, and the signal is transmitted back to the timing system 1 through the laser vision sensing function of the fiber laser. The timing system 1 tracks the weld through the image processing algorithm and can calculate the X, Y, Z coordinates of the current position of the weld and the amount of misalignment during the welding process. The thermal radiation signal fed back by the laser line is used to adjust and feedback control the molten pool temperature. The temperature deviation ΔD=T is calculated by set -T(t), real-time tracking and correction, while the deviation ΔD is used as the input variable for adjusting the welding speed V and laser power P, where V is in mm / min and laser power P is in W;

[0113] The functional relationship is expressed as

[0114] V correction =f(ΔD)=V0*(1+K V *|ΔD|), P correction =g(ΔD)=P0*(1+K p *|ΔD|),

[0115] Among them, V0 and P0 are the reference welding speed and laser power preset by the timing system 1, K V and K p is the gain coefficient determined based on a large number of process tests;

[0116] When a deviation occurs, the timing system 1 transmits the f(ΔD) and g(ΔD) signals to the laser-MIG hybrid welding module 3 through the laser sensor feedback device 3, thereby realizing dynamic adjustment of the welding process parameters of the laser-MIG hybrid welding module 3;

[0117] (e) Post-weld inspection: 100% ultrasonic inspection of welds shall be conducted to ensure that there are no internal pores, weak connections or incomplete fusion defects at the weld roots, and spot checks of mechanical properties shall be conducted to ensure that there is basically no strength loss in the welded joints, the flatness is less than 1mm, and the requirements for subsequent processing of the hull portholes are met.

[0118] Comparative Example 1

[0119] A ship bulwark is made by butt welding 15mm thick 5182-H32 aluminum alloy rolled plates. The specific steps are as follows:

[0120] (a) A 15 mm thick 5182-H32 aluminum alloy rolled plate for ship bulwarks;

[0121] (b) Before welding, mechanically grind the area of ​​the base plate to be welded to remove the oxide film and oil stains on the surface of the base plate;

[0122] (c) Place the polished 15 mm thick 5182-H32 aluminum alloy rolled plate on a workbench with a 0 mm butt joint clearance. Clamp it with a dedicated hydraulic fixture and apply a forging force perpendicular to the weld and parallel to the workbench.

[0123] (d) Welding: Friction stir welding was used, the stirring head was 15 mm, the spindle speed of friction stir welding was 1200 rpm, and the welding speed was 600 mm / min.

[0124] (e) Post-weld inspection: 100% ultrasonic inspection of the weld seam is performed, and there is a weak connection on the back of the weld seam, and the flatness is greater than 2mm.

[0125] The welding device and method provided by the present invention can simplify the welding process of thick-walled aluminum plates for ships, reduce the number of multi-layer welds, significantly improve the welding speed, and realize the time coupling of "melting welding" and "solid phase welding". The laser-MIG welding gun and the stir friction welding stirring head are integrated into the same motion mechanism, and sequential or synchronous welding is achieved through a collaborative control system, which solves the contradiction between the penetration depth and defects of thick-plate aluminum alloys for ships when using traditional welding methods; laser preheating can also reduce the axial force required for stir friction welding, significantly reduce the equipment spindle pressure and extend the life of the stirring head; the modular design can quickly switch between laser-MIG composite welding and stir friction welding, and realize segmented coupling and synchronous composite processes.

[0126] The above description is only a preferred specific implementation method of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, can make equivalent replacements or changes based on the technical solutions and inventive concepts of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A welding device for coupling laser-MIG composite and friction stir welding of thick-walled Al-Mg alloy for ships, characterized in that: The device comprises: Timing system 1, friction stir welding module 2 and laser-MIG hybrid welding module 3; The friction stir welding module 2 and the laser-MIG hybrid welding module 3 are connected to the timing system 1 through a hydraulic integrated transmission device; The timing system 1 includes a control system and a coupling mechanism; The control system is a multi-parameter collaborative module, and the parameters include laser power, friction stir welding speed and downward pressure; The coupling mechanism is an integration of the laser head, the friction stir welding main shaft and the sub-shaft; The friction stir welding module 2 includes a pressure feedback servo system and an adaptive pressure regulating device 2A; The laser-MIG hybrid welding module 3 includes a laser sensor feedback device 3A, a welding gun swing control device 3B and a laser-MIG hybrid welding gun 3C; The welding gun swing control device 3B is connected to the laser-MIG composite welding gun 3C via a universal swing ball head 3BC; The laser-MIG composite welding gun 3C includes a MIG welding gun and a laser welding gun, which are coaxially arranged. A fiber laser is provided in the laser-MIG composite welding gun 3C, and the fiber laser has laser vision sensing, preheating and post-heating functions.

2. The welding device according to claim 1, characterized in that The distance between the center of the laser head and the center of the friction stir welding spindle is 50-200 mm.

3. The welding device according to claim 1, characterized in that The angle between the laser-MIG composite welding gun 3C and the vertical direction is 0-90°.

4. The welding device according to claim 1, characterized in that The laser-MIG hybrid welding module 3 rotates 360° within the plane of the timing system 1 .

5. A welding method using the welding device according to any one of claims 1 to 4, characterized in that: The method comprises: Mechanical grinding, butt forging, welding; The welding comprises: The adaptive pressure regulating device 2A of the friction stir welding module 2 is used to adaptively adjust the spindle downward pressure according to the different flatness of the welding surface; The adaptive adjustment method of the spindle pressure of the friction stir welding comprises: using the laser line emitted by the fiber laser of the laser-MIG hybrid welding gun 3C to the weld to identify the weld, and transmitting the signal back to the timing system 1 through the laser visual sensing function of the fiber laser. The timing system 1 tracks the weld through the image processing algorithm, and can accurately calculate the X, Y, Z coordinates of the current position of the weld and the weld flatness during the welding process, and feedback and adjustment based on the adaptive pressure of the friction stir welding are performed through the thermal radiation signal fed back by the laser line, and the temperature deviation ΔZ=Z is calculated by material -Z(t), real-time tracking and correction, where Z material is the original Z-axis coordinate of the weld, and Z(t) is the real-time Z-axis coordinate of the weld during the welding process. When a deviation occurs, the timing system 1 identifies the deviation signal ΔZ through the laser sensor feedback device 3, and transmits the spindle pressure adjustment signal to the friction stir welding module 2 according to the deviation signal ΔZ; The laser line emitted by the fiber laser of the laser-MIG hybrid welding gun 3C to the weld is used to identify the weld, and the signal is transmitted back to the timing system 1 through the laser vision sensing function of the fiber laser. The timing system 1 tracks the weld through the image processing algorithm and can calculate the X, Y, Z coordinates of the current position of the weld and the amount of misalignment during the welding process. The thermal radiation signal fed back by the laser line is used to adjust and feedback control the molten pool temperature. The temperature deviation ΔD=T is calculated by set -T(t), real-time tracking and correction, while the deviation ΔD is used as the input variable for adjusting the welding speed V and laser power P, where V is in mm / min and laser power P is in W; The functional relationship is expressed as V correction =f(ΔD)=V0*(1+K V *|ΔD|),P correction =g(ΔD)=P0*(1+K p *|ΔD|), Among them, V0 and P0 are the reference welding speed and laser power preset by the timing system 1, K V and K p is the gain coefficient determined based on a large number of process tests; When a deviation occurs, the timing system 1 transmits the f(ΔD) and g(ΔD) signals to the laser-MIG hybrid welding module 3 through the laser sensor feedback device 3, thereby realizing dynamic adjustment of the welding process parameters of the laser-MIG hybrid welding module 3; Laser-MIG hybrid welding is used to weld the root weld and the main body filling, and friction stir welding is used to perform secondary treatment on the weld surface or heat-affected zone to eliminate pores and reduce residual stress. The laser-MIG hybrid welding and friction stir welding tools move in the same direction, and friction stir welding immediately stirs the tail of the molten pool.

6. The welding method according to claim 5, characterized in that The rotation speed of the friction stir welding is 1300-4000 rpm, and the welding speed is 1000-2100 mm / min.

7. The welding method according to claim 5, characterized in that The laser power of the laser-MIG composite welding is 3500-12000W, and the welding current is 130-600A.

8. The welding method according to claim 5, characterized in that The image processing algorithm of the timing system 1 includes feature point recognition and / or weld centerline extraction.

Images