Laser-arc hybrid welding method and laser-arc hybrid welding system

Abstract

The present application discloses a laser-arc hybrid welding method and a laser-arc hybrid welding system. The laser-arc hybrid welding method includes the following steps: operating an arc welding machine at a set pulse current; and obtaining the real-time welding current during the welding process, and controlling the power of the laser beam output by the laser according to the real-time welding current so that the power of the laser beam is at a first set value before the molten droplet falls into the molten pool and at a second set value after the molten droplet falls into the molten pool, wherein the first set value is less than the second set value. The laser is in a low-power state during the formation and detachment of the molten droplet, which can reduce the influence on the detachment process of the molten droplet and enable the molten droplet to stably fall into the molten pool. The laser is in a high-power state after the molten droplet falls into the molten pool, which increases the heat input, is beneficial to the penetration of the molten droplet in the molten pool, and increases the penetration depth. Synchronize the laser and the pulsed arc periodically to achieve coordinated control, improve the energy utilization rate of the laser, and improve the welding quality.

Description

Technical Field

[0001] The present application relates to the field of welding technology, and particularly to a laser-arc hybrid welding method and a laser-arc hybrid welding system. Background Art

[0002] The laser-arc hybrid welding method proposed in recent years combines the characteristics of laser welding and arc welding. It can not only increase the welding penetration depth, but also improve the weld formation and reduce the formation of welding defects such as pores and undercuts. However, in current hybrid welding applications, a laser heat source with a constant power is mainly used, and it cannot be well coupled with the pulse waveform of the arc energy.

[0003] It should be noted here that the statements in this background art section only provide background art related to the present application and do not necessarily constitute prior art. Summary of the Invention

[0004] The present application provides a laser-arc hybrid welding method and a laser-arc hybrid welding system to improve the welding quality.

[0005] The first aspect of the present application provides a laser-arc hybrid welding method, including the following steps:

[0006] Operating an arc welding machine at a set pulse current; and

[0007] Obtaining the real-time welding current during the welding process, and controlling the power of the laser beam output by the laser according to the real-time welding current so that the power of the laser beam is at a first set value before the molten droplet falls into the molten pool and at a second set value after the molten droplet falls into the molten pool, where the first set value is less than the second set value.

[0008] In some embodiments, controlling the power of the laser beam output by the laser according to the real-time welding current includes: converting the real-time welding current into a current digital wave signal, and obtaining an output waveform through the current digital wave signal, where the output waveform is the waveform of the power of the laser beam.

[0009] In some embodiments, obtaining the output waveform through the current digital wave signal includes: setting the triggering mode of the output waveform according to the current digital wave signal to obtain the basic waveform of the laser beam, and the triggering mode includes rising edge triggering or falling edge triggering.

[0010] In some embodiments, obtaining the output waveform through the current digital wave signal further includes: obtaining the output waveform according to the basic waveform and set waveform parameters, where the set waveform parameters include at least one of a delay trigger time, a peak duration, a laser power value, and the number of pulses.

[0011] In some embodiments, obtaining the output waveform according to the base waveform and the set waveform parameters includes: adjusting the peak duration so that the output waveform drops to the base value when the current digital wave signal drops to the base value or rises to the peak value.

[0012] A second aspect of the present application provides a laser-arc hybrid welding system, including a welding platform, a laser, an arc welding machine, and a control device. The laser is used to emit pulsed laser. The arc welding machine is used to generate a pulsed arc to cooperate with the pulsed laser for welding. The control device is connected to the laser and the arc welding machine, and the control device is configured to execute the welding method as described above.

[0013] In some embodiments, the laser-arc hybrid welding system includes a current sensor. The current sensor is configured to collect the real-time welding current during the welding process through the wire of the arc welding machine and send the collected real-time welding current to the control device.

[0014] In some embodiments, the control device further includes a signal comparator and a controller. The signal comparator and the controller are connected. The signal comparator is configured to convert the real-time welding current into a current digital wave signal. The controller is configured to adjust the output power of the laser according to the current digital wave signal.

[0015] In some embodiments, the control device further includes a level converter. The level converter is connected to the controller and the laser. The level converter is configured to receive the current digital wave signal from the controller and convert the current digital wave signal into an analog wave signal and then deliver it to the laser.

[0016] In some embodiments, the laser-arc hybrid welding system further includes a monitoring device. The monitoring device is used to monitor the weld seam in real time.

[0017] Based on the technical solution provided by the present application, the laser-arc hybrid welding method includes the following steps: making the arc welding machine work under a set pulsed current; and obtaining the real-time welding current during the welding process, and controlling the power of the laser beam output by the laser according to the real-time welding current so that the power of the laser beam is at a first set value before the molten droplet falls into the molten pool and at a second set value after the molten droplet falls into the molten pool, where the first set value is less than the second set value. Before the molten droplet falls into the molten pool, it includes the formation stage and the detachment stage of the molten droplet. The laser is in a low-power state during the formation and detachment of the molten droplet, which can reduce the influence on the detachment process of the molten droplet and make the molten droplet fall stably into the molten pool. The laser is in a high-power state after the molten droplet falls into the molten pool, increasing the heat input, which is beneficial to the penetration of the molten droplet in the molten pool and increases the penetration depth. Synchronize the laser and the pulsed arc periodically to achieve coordinated control, improve the energy utilization rate of the laser and improve the welding quality.

[0018] Through the following detailed description of the exemplary embodiments of the present application with reference to the accompanying drawings, other features and advantages of the present application will become clear. Brief Description of the Drawings

[0019] The drawings described herein are provided to further understand the present application and form a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0020] Figure 1 It is a schematic diagram of the laser-arc hybrid welding method according to an embodiment of the present application.

[0021] Figure 2 It is a schematic diagram of the laser-arc hybrid welding system.

[0022] Figure 3 It is a schematic diagram of the reverse coupling of the laser power waveform and the arc waveform.

[0023] Figure 4 It is a schematic diagram of the weld obtained by single-arc welding.

[0024] Figure 5 It is a schematic diagram of the weld obtained under the condition of forward coupling of the laser and the arc.

[0025] Figure 6 It is a schematic diagram of the weld obtained under the condition of reverse coupling of the laser and the arc. Detailed Description of the Embodiments

[0026] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way constitutes a limitation to the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0027] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that for ease of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and devices should be regarded as part of the specification. In all the examples shown and discussed here, any specific values should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0028] For ease of description, spatial relative terms such as "above", "on top of", "on the upper surface", "upper" etc. may be used here to describe the spatial positional relationship of one device or feature to other devices or features as shown in the figures. It should be understood that the spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figure is inverted, the device described as "above other devices or structures" or "on top of other devices or structures" will then be positioned "below other devices or structures" or "beneath other devices or structures". Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device can also be positioned in other different ways, and corresponding interpretations should be made for the spatial relative descriptions used here.

[0029] Due to the significant differences in the characteristics of the two heat sources, laser and arc, although the current main welding methods utilize their respective characteristics to achieve a good composite effect, they cannot fully utilize their respective advantages to achieve the best welding effect. It is difficult for a continuous laser mode or a single-pulse laser mode to match the arc energy waveform, and there are certain differences in energy input, which will also affect welding stability. Even when a pulse waveform is added to the laser heat source, the main adopted scheme is still single-pulse - arc or single high-frequency laser pulse to improve the surface forming, and the improvement effect on the overall welding quality is limited.

[0030] For this reason, referring to Figure 1 , the present application provides a laser-arc hybrid welding method, including the following steps:

[0031] S1, operating the arc welding machine 2 under a set pulse current; and

[0032] S2. Obtain the real-time welding current during the welding process, and control the power of the laser beam output by the laser 1 according to the real-time welding current so that the power of the laser beam is at a first set value before the molten droplet falls into the molten pool and at a second set value after the molten droplet falls into the molten pool, where the first set value is less than the second set value.

[0033] Before the molten droplet falls into the molten pool, it includes the formation stage and the detachment stage of the molten droplet. The laser is in a low-power state during the formation and detachment of the molten droplet, which can reduce the influence on the detachment of the molten droplet and enable the molten droplet to stably fall into the molten pool. The laser is in a high-power state after the molten droplet falls into the molten pool, increasing the heat input of the laser, which is beneficial to the penetration of the molten droplet in the molten pool and increases the penetration depth. Synchronize the laser and the pulse arc cycle to achieve coordinated control, improve the energy utilization rate of the laser, and improve the welding quality.

[0034] In some embodiments, controlling the power of the laser beam output by the laser 1 according to the real-time welding current includes: converting the real-time welding current into a current digital wave signal, and obtaining the output waveform through the current digital wave signal, where the output waveform is the waveform of the power of the laser beam. Specifically, the collected real-time welding current is an analog waveform signal, so converting it into a digital waveform signal with low noise and good stability can improve the control accuracy.

[0035] In some embodiments, obtaining the output waveform through the current digital wave signal includes: setting the trigger mode of the output waveform according to the current digital wave signal to obtain the basic waveform of the laser beam, where the trigger mode includes rising edge trigger or falling edge trigger. Specifically, when the trigger mode is set to falling edge trigger, when the current digital wave signal drops to the base value, the basic waveform will be triggered and rise to the peak value. When the trigger mode is set to rising edge trigger, when the current digital wave signal rises to the peak value, the basic waveform will be triggered and rise to the peak value.

[0036] In some embodiments, obtaining the output waveform through the current digital wave signal further includes: obtaining the output waveform according to the basic waveform and the set waveform parameters, where the set waveform parameters include at least one of the delay trigger time, the peak duration, the laser power value, and the number of pulses. Specifically, by adjusting the delay trigger time and the peak duration, the coupling effect between the laser and the arc can be adjusted, the welding quality can be changed, and thus a wider range of welding requirements can be met.

[0037] In some embodiments, obtaining the output waveform according to the base waveform and the set waveform parameters includes: adjusting the peak duration so that when the current digital wave signal decreases to the base value or increases to the peak value, the output waveform decreases to the base value. Specifically, in the embodiment of the falling-edge trigger mode, when the current digital wave signal decreases to the base value, the base waveform is triggered to rise to the peak value. Adjust the peak duration of the base waveform so that when the peak of the base waveform ends and decreases to the base value, the current digital wave signal just increases to the peak value. At this time, the inverse coupling of the arc current and the laser power is achieved, as Figure 3 shown.

[0038] The following will combine Figure 3 to describe in detail the cooperation process of the arc and the laser in the embodiment of the inverse coupling of the arc current and the laser power waveforms. The whole process of the molten droplet from formation to falling into the molten pool is divided into four stages, namely the first melting stage, the second melting stage, the first transition stage, and the second transition stage. In the first melting stage, a new molten droplet begins to melt at the end of the melting wire. At this time, the arc current power is at the base value, and the laser current power is at the peak value. The high-power laser acts on the molten pool to maintain the stability of the molten pool and obtain a larger penetration depth to cooperate with the molten droplet that fell into the molten pool in the previous round. In the second melting stage, the molten metal gradually increases at the end of the wire to form a molten droplet shape. At this time, the arc current power rises to the peak value, and the laser power is at the base value, reducing the influence of the laser action to enable the rapid and stable formation of the molten droplet. In the first transition stage, under the combined action of gravity and electromagnetic force, the molten droplet detaches from the end of the wire and transitions into the molten pool. At this time, the arc current decreases from the peak value to the base value, and the laser power is still at the base value, reducing the influence of the laser on the detachment of the molten droplet to achieve a stable transition. In the second transition stage, the molten droplet enters the molten pool. At this time, the arc current is at the base value, and the laser power is at the peak value. The stirring action of the high-energy laser on the molten pool promotes the rapid fusion of the molten droplet that has entered the molten pool with the molten pool and makes the molten pool flow stably, maintaining the stability of the welding process and obtaining a larger penetration depth.

[0039] Referring to Figure 2 , the present application also provides a laser-arc hybrid welding system, including a welding platform, a laser 1, an arc welding machine 2, and a control device 3. The laser 1 is used to emit pulsed laser. The arc welding machine 2 is used to generate pulsed arc to cooperate with the pulsed laser for welding. The control device 3 is connected to the laser 1 and the arc welding machine 2. The control device 3 is configured to execute the welding method as described above. Through this laser-arc hybrid welding system, the welding current can be automatically collected and the output power of the laser 1 can be adjusted according to the collected data, so that the arc heat source and the laser heat source are coupled to improve the welding quality.

[0040] As Figure 2As shown, in some embodiments, the laser-arc hybrid welding system further includes a current sensor 4. The current sensor 4 is configured to collect the real-time welding current during the welding process and send the collected real-time welding current to the control device 3. The coil of the current sensor 4 sleevs the wire of the arc welding machine 2 to obtain the welding current in real time.

[0041] Still referring to Figure 2 , in some embodiments, the control device 3 includes a signal comparator 31 and a controller 32. The signal comparator 31 and the controller 32 are connected. The signal comparator 31 is configured to convert the real-time welding current into a current digital wave signal. The controller 32 is configured to adjust the output power of the laser 1 according to the current digital wave signal. Specifically, a suitable trigger level is set in the signal comparator 31, so as to convert the analog waveform signal collected by the current sensor 4 into a digital waveform signal with low noise and good stability. The controller 32 can be programmed and controlled using XOMS software or other adapted software, and can adjust the set waveform parameters to obtain the desired output waveform. For example, when adjusting the peak duration of the laser 1 in the controller 32 so that the current digital wave signal drops to the base value, the waveform of the laser power rises to the peak, so that the two are inversely coupled, improving the welding quality.

[0042] In some embodiments, the effective value of the set arc current is 240 A, the arc voltage is 24 V, the wire feeding speed is 10.6 m / min, the welding speed is 0.9 m / min, the welding torch angle is 35°, the dry elongation of the welding wire is set to 15 mm, the shielding gas flow rate is 17 L / min, and the distance between the laser wire is 3 mm. Set the controller 33 so that the peak value of the laser power is 5 kW (i.e., the second set value) and the base value is 1 kW (i.e., the first set value). First, without adding laser during the welding process, the weld formation is obtained as Figure 4 shown. It can be seen that the penetration is relatively shallow, the width of the front of the weld is uneven, and the penetration effect on the back is poor; then, the waveforms of the welding current and the laser power are in-phase coupled, that is, high-power laser is added during the rising, peak, and falling periods of the current, and low-power laser is added during the base value period of the arc current. The weld formation is obtained as Figure 5 shown. It can be seen that the penetration has a certain increase, the formation of the front of the weld is uniform, the penetration effect on the back is poor, and the penetration is unstable; finally, the waveforms of the welding current and the laser power are inversely coupled, that is, low-power laser is added during the rising, peak, and falling periods of the current, and high-power laser is added during the base value period of the arc current. The weld formation is obtained as Figure 6 shown. It can be seen that the penetration has a large increase, the formation of the front of the weld is uniform, the penetration on the back is good, and the overall weld is uniformly fully penetrated.

[0043] In some embodiments, referring to Figure 2, the control device 3 further includes a level converter 33. The level converter 33 is connected to the controller 32 and the laser 1. The level converter 33 is configured to receive a current digital wave signal from the controller 32, and convert the current digital wave signal into an analog wave signal and then deliver it to the laser 1.

[0044] In some embodiments, the laser-arc hybrid welding system further includes a monitoring device. The monitoring device is used to monitor the weld seam in real time. The user can adjust the welding process according to the monitoring results. Specifically, the monitoring device includes a high-speed camera and a processor, and the high-speed camera can acquire the surface topography of the weld seam in real time.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them; although the present application has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that it is still possible to modify the specific implementation manners of the present application or perform equivalent replacements for some technical features; without departing from the spirit of the technical solutions of the present application, they should all be covered within the scope of the technical solutions claimed in the present application.

Claims

1. A laser-arc hybrid welding method, characterized in that, The method includes the following steps: Operating the arc welding machine (2) at a set pulsed current; and Obtaining the real-time welding current during the welding process, and controlling the power of the laser beam output by the laser (1) according to the real-time welding current so that the power of the laser beam is at a first set value before the molten droplet falls into the molten pool and at a second set value after the molten droplet falls into the molten pool, where the first set value is less than the second set value. Before the molten droplet falls into the molten pool, it includes the formation stage and the detachment stage of the molten droplet. The value of the arc current in the formation stage is greater than the value of the arc current in the detachment stage, and the power of the laser beam in the formation stage and the detachment stage is at a base value.

2. The laser-arc hybrid welding method according to claim 1, characterized in that Controlling the power of the laser beam output by the laser (1) according to the real-time welding current includes: converting the real-time welding current into a current digital wave signal, and obtaining an output waveform through the current digital wave signal, where the output waveform is the waveform of the power of the laser beam.

3. The laser-arc hybrid welding method according to claim 2, characterized in that, Obtaining the output waveform through the current digital wave signal includes: setting the triggering mode of the output waveform according to the current digital wave signal to obtain the basic waveform of the laser beam, where the triggering mode includes rising edge triggering or falling edge triggering.

4. The laser-arc hybrid welding method according to claim 3, wherein Obtaining the output waveform through the current digital wave signal further includes: obtaining the output waveform according to the basic waveform and set waveform parameters, where the set waveform parameters include at least one of a delay trigger time, a peak duration, a laser power value, and the number of pulses.

5. The laser-arc hybrid welding method according to claim 4, characterized in that, Obtaining the output waveform according to the basic waveform and set waveform parameters includes: adjusting the peak duration so that the output waveform drops to the base value when the current digital wave signal drops to the base value or rises to the peak value.

6. A laser-arc hybrid welding system, characterized in that, It includes: A welding platform; A laser (1) for emitting pulsed laser; An arc welding machine (2) for generating a pulsed arc to cooperate with the pulsed laser for welding; And A control device (3) connected to the laser (1) and the arc welding machine (2), and the control device (3) is configured to execute the welding method according to any one of claims 1 to 5.

7. The laser-arc hybrid welding system according to claim 6, wherein, The laser-arc hybrid welding system further includes a current sensor (4) configured to collect the real-time welding current during the welding process and send the collected real-time welding current to the control device (3).

8. The laser-arc hybrid welding system according to claim 6, wherein, The control device (3) includes a signal comparator (31) and a controller (32). The signal comparator (31) is connected to the controller (32). The signal comparator (31) is configured to convert the real-time welding current into a current digital wave signal, and the controller (32) is configured to adjust the output power of the laser (1) according to the current digital wave signal.

9. The laser-arc hybrid welding system according to claim 8, wherein The control device (3) further includes a level converter (33). The level converter (33) is connected to the controller (32) and the laser (1). The level converter (33) is configured to receive the current digital wave signal from the controller (32), and convert the current digital wave signal into an analog wave signal and then transmit it to the laser (1).

10. The laser-arc hybrid welding system according to claim 6, wherein, The laser-arc hybrid welding system further includes a monitoring device, and the monitoring device is used to monitor the weld seam in real time.

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