A welding process method for T-type HV joint of aluminum alloy medium plate

Abstract

The application discloses a kind of aluminum alloy medium plate T type HV joint welding process method, the method includes the following steps: S1, the workpiece to be welded is removed oxide film and preheated;S2, using four-step mode and the mode of combining double pulse mode welding;Wherein, S2, it specifically includes the following steps: A, open welding machine and protective gas switch, in the welding machine operation interface, select double pulse mode, and set to carry out;B, using welding current to arc and weld, 10-15mm away from weld tail, using double pulse mode current value welding;C, using arc attenuation current to arc welding at arc collection place.The application adopts the method that four-step mode is combined with double pulse mode, solves the shortcomings that welding quality at arc collection place and around weld is poor, can effectively improve the welding quality of aluminum alloy medium plate T type HV joint, effectively avoid the generation of welding defects, and improve production efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of welding process, in particular to a welding process method for T-shaped HV joint of aluminum alloy medium plate. BACKGROUND

[0002] Aluminum alloy has the advantages of light weight, corrosion resistance, high specific strength, etc., and is widely used in rail transportation, aerospace, shipbuilding, automobile and other industries. In order to ensure that the end of the weld does not crack, the welding quality of the weld at the arc collection position and the end of the weld needs to be controlled when welding the T-shaped HV structure of aluminum alloy medium plate (8mm or more). Taking an 8mm+8mm T-shaped HV joint as an example, the welder usually adopts a 4-step method in actual production. Step 1: use an arc starting current that is 10% to 20% higher than the welding current specified in the welding procedure specification (WPS) to perform arc starting welding at the arc starting position; Step 2: after arc starting, use the current specified in the welding procedure specification to perform welding; Step 3: weld to the end of the weld by 10mm to 15mm, and use a decaying current to perform arc collection welding; Step 4: after the arc pit is filled, stop welding.

[0003] At present, this welding method is prone to cause welding defects such as burn-through, welding protrusions, pores, cracks, inclusions, and shrinkage holes at the tail of the weld and around the weld in actual welding production, affecting the quality of the weld. At the same time, due to a large amount of rework, the production cost is high and the production efficiency is low. SUMMARY

[0004] The purpose of the present application is to provide a welding process method for T-shaped HV joint of aluminum alloy medium plate to solve the problems raised in the background.

[0005] A welding process method for T-shaped HV joint of aluminum alloy medium plate, the method comprising the following steps: S1, removing the oxide film and preheating the workpiece to be welded; S2, welding in a four-step mode combined with a double pulse mode; wherein S2 specifically comprises the following steps:

[0006] A, turn on the welding machine and the protection gas switch, select the double pulse mode in the welding machine operation interface, and set the parameters;

[0007] B, use the welding current to perform arc starting and welding, and use the double pulse mode current value to weld at a distance of 10-15mm from the tail of the weld;

[0008] C, use a decaying current to perform arc collection welding at the arc collection position.

[0009] As a further improvement of the present application, when selecting the double pulse mode in step A of the method, the peak current time is set to 0.7-0.9 seconds to ensure the weld penetration, and the valley current time is set to 1.4-1.7 seconds.

[0010] As a further improvement of the application, in the step A of the method, when the double pulse mode is set, the preset double pulse peak current is 145-155A, the wire feeding speed a1 is 9.0-11.0 (m / min), the arc length b1 is -13, and the thrust c1 is 0; the valley current is 115-125A, the wire feeding speed a2 is 6.0-8.0 (m / min), the arc length b2 is -10, and the thrust c2 is 0.

[0011] As a further improvement of the application, in the step B of the method, the double pulse mode current value welding is used to fill the molten pool and prevent undercut by using the up and down swing and the arc slightly staying on both sides of the weld, and then sequentially welding to the side and back of the surrounding weld.

[0012] As a further improvement of the application, in the step S1 of the method, the organic solvent is used to remove oil stains and dust first, and then the mechanical method is used to clean and remove the oxide film.

[0013] As a further improvement of the application, in the step A of the method, the starting arc current is the welding current required by the welding process specification.

[0014] As a further improvement of the application, in the step A of the method, the shielding gas includes argon, and the concentration of the argon is greater than 99.99%, and the gas flow is 20L / min.

[0015] As a further improvement of the application, in the step C of the method, the closing arc welding is used to draw a circle, a large circle is drawn for the outer circle, a small circle is drawn for the inner circle, and the arc pit is filled until the arc pit is filled.

[0016] As a further improvement of the application, in the step C of the method, the closing arc current is 130A.

[0017] As a further improvement of the application, in the step S1 of the method, the preheating temperature is 70-90℃.

[0018] Compared with the prior art, the application has the following beneficial effects:

[0019] In the application, the 4-step mode and the double pulse mode are combined, the double pulse mode current value welding is used to weld to a distance of 10-15mm from the tail of the weld, the generation of cracks and shrinkage holes can be effectively prevented, the welding quality of the aluminum alloy medium plate T-type HV joint is improved, the generation of welding defects is effectively avoided, and the production efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The method flowchart of the application;

[0021] Figure 2Front view of the weld of the T-type HV joint of the aluminum alloy medium plate of the present application;

[0022] Figure 3 Back view of the weld of the T-type HV joint of the aluminum alloy medium plate of the present application;

[0023] Figure 4 Sectional view of the T-type HV joint of the aluminum alloy medium plate of the present application (t1- plate thickness; t2- bottom plate thickness; S- land; W- bevel angle; b- welding gap);

[0024] Figure 5 Welding product diagram of Example 1;

[0025] Figure 6 Welding product diagram of Example 2;

[0026] Figure 7 Welding diagram of the product of the comparative example;

[0027] Figure 8 Back forming diagram of the product of the comparative example. Embodiment

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. Embodiment

[0029] Please refer to Figures 1-4 and Figure 5 The present application provides the following technical solutions: a welding process method for a T-type HV joint of an aluminum alloy medium plate, which comprises the following steps: S1, removing the oxidation film from the workpiece to be welded and preheating; S2, welding in a four-step mode combined with a double-pulse mode, and the specific operation steps are as follows:

[0030] The oil stains and dust on the surface of the workpiece to be welded are removed with an organic solvent, and the oxidation film on the welding part of the workpiece is cleaned and removed by mechanical method, and the workpiece is preheated, and the preheating temperature is 70℃;

[0031] The welding machine and the protection gas switch are turned on, and in order to ensure the welding quality, the protection gas is preferably 99.999% high-purity argon gas with a gas flow of 20L / min;

[0032] Select double pulse mode, and set parameters, peak current time is set to 0.7-0.9 seconds to ensure weld penetration, trough current time is set to 1.4 seconds, preset double pulse peak current is 145A, wire feeding speed a1 is 9.0 (m / min), arc length b1 is -13, thrust c1 is 0; trough current is 115A, wire feeding speed a2 is 6.0 (m / min), arc length b2 is -10, thrust c2 is 0;

[0033] The welding current is used for arc striking and welding, the arc striking current is the welding current required by the welding process specification, at a distance of 10mm from the tail of the weld, the double pulse mode current value is used for welding, the upper and lower swing, the arc slightly stays on both sides of the weld, the molten pool is filled, and the undercut is prevented, and then the welding is sequentially welded to the surrounding weld on the side and back of the weld;

[0034] The welding current is used for arc striking and welding, the arc striking current is the welding current required by the welding process specification, at a distance of 10mm from the tail of the weld, the double pulse mode current value is used for welding, the upper and lower swing, the arc slightly stays on both sides of the weld, the molten pool is filled, and the undercut is prevented, and then the welding is sequentially welded to the surrounding weld on the side and back of the weld; Figure 5 Embodiment

[0035] Please refer to Figures 1-4 and Figure 6 The present application provides the following technical scheme: a welding process method for an aluminum alloy medium plate T-shaped HV joint, the method comprises the following steps: S1, removing the oxidation film and preheating the workpiece to be welded; S2, welding in a four-step mode combined with a double pulse mode, the specific operation steps are as follows:

[0036] The surface of the workpiece to be welded is cleaned of oil stains and dust with an organic solvent, and the oxidation film on the welding part of the workpiece is removed by mechanical cleaning, and the workpiece is preheated, the preheating temperature is 90 DEG C;

[0037] The welding machine and the protection gas switch are turned on, in order to ensure the welding quality, the protection gas is preferably 99.999% high-purity argon, and the gas flow is 20L / min;

[0038] Select double pulse mode, and set parameters, peak current time is set to 0.9 seconds to ensure weld penetration, trough current time is set to 1.7 seconds, preset double pulse peak current is 155A, wire feeding speed a1 is 11.0 (m / min), arc length b1 is -13, thrust c1 is 0; trough current is 125A, wire feeding speed a2 is 8.0 (m / min), arc length b2 is -10, thrust c2 is 0;

[0039] ​The welding current is used for arc striking and welding, the arc striking current is the welding current required by the welding procedure specification, at 15mm from the tail of the weld, the welding is performed using the double pulse mode current value, the molten pool is filled and the undercut is prevented by using the method of up and down swing and the arc slightly staying on both sides of the weld, and then the welding is sequentially performed to the surrounding welds on the side and back of the weld;

[0040] The welding is performed using the arc striking decay current at the arc striking position, the arc striking current is 130A, the large circle is drawn at the outer circle and the small circle is drawn at the inner circle until the crater is filled, and the welding result is as shown in Figure 6 .

[0041] The four-step method is used for the 8mm+8mm T-type HV joint, and the specific operation steps are as follows:

[0042] In the first step, the arc striking welding is performed using the arc striking current which is 10% to 20% higher than the welding current specified in the welding procedure specification (WPS) at the arc striking position;

[0043] In the second step, after the arc striking, the welding is performed using the current specified in the welding procedure specification;

[0044] In the third step, the welding is performed to the tail end 10mm~15mLm, and the arc striking decay current is used for arc striking welding;

[0045] In the fourth step, after the crater is filled and the welding is completed, the welding is stopped, and the welding result is as shown in Figure 7 and 8 .

[0046] In the present application, the method combining the four-step mode and the double pulse mode is adopted, the welding is performed to the tail end 10mm~15mm of the weld using the double pulse mode current value, the peak current time is set to 0.7 seconds to ensure the weld penetration, the valley current time is set to 1.5 seconds, the molten pool is filled and the undercut is prevented by using the method of up and down swing and the arc slightly staying on both sides of the weld, and then the welding is sequentially performed to the surrounding welds on the side and back of the weld, the arc striking decay current of 130A is used at the arc striking position, the large circle is drawn at the outer circle and the small circle is drawn at the inner circle until the crater is filled, which can effectively prevent the generation of cracks and shrinkage holes, solve the poor welding quality at the arc striking position and the surrounding welds, effectively improve the welding quality of the aluminum alloy medium plate T-type HV joint, effectively avoid the generation of welding defects, and improve the production efficiency.

[0047] It is to be understood that the terminology used herein such as first and second, and the like, is only used to distinguish one entity or action from another entity or action, and does not necessarily require or imply any such actual relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0048] While embodiments of the present application have been shown and described with reference to particular embodiments thereof, it will be understood by those skilled in the art that various changes in form and details can be made therein without departing from the spirit and scope of the application. The scope of the application is defined by the appended claims and their equivalents.

Claims

1. A method of welding a T-type HV joint of an aluminum alloy plate, characterized by: The method comprises the following steps: S1, removing the oxide film and preheating the workpiece to be welded; S2, welding in a four-step mode combined with a double-pulse mode; wherein S2 specifically comprises the following steps: A, turn on the welding machine and the protective gas switch, select the double-pulse mode in the welding machine operation interface, and set the parameters; B, use the welding current to start the arc and weld, use the double-pulse mode current value to weld at a distance of 10-15 mm from the tail of the weld; C, use the arc collection decay current to collect the arc for welding.

2. The aluminum alloy plate T-HV joint welding process method according to claim 1, characterized in that: In step A of the method, when the double-pulse mode is selected, the peak current time is set to 0.7-0.9 seconds to ensure the weld penetration, and the valley current time is set to 1.4-1.7 seconds.

3. The aluminum alloy plate T-HV joint welding process method of claim 1, wherein: In step A of the method, when the double-pulse mode is set, the preset double-pulse peak current is 145-155 A, the wire feeding speed a1 is 9.0-11.0 (m / min), the arc length b1 is -13, and the thrust c1 is 0; the valley current is 115-125 A, the wire feeding speed a2 is 6.0-8.0 (m / min), the arc length b2 is -10, and the thrust c2 is 0.

4. The aluminum alloy plate T-HV joint welding process method of claim 1, wherein: In step B of the method, the double-pulse mode current value welding uses the up and down swing, and the arc slightly stays on both sides of the weld to fill the molten pool and prevent undercutting, and then sequentially welds to the side and back of the surrounding weld.

5. The aluminum alloy plate T-HV joint welding process method of claim 1, wherein: In step S1 of the method, when removing the oxide film, first use an organic solvent to remove oil and dust, and then use a mechanical method to clean and remove the oxide film.

6. The aluminum alloy plate T-HV joint welding process method of claim 1, wherein: In step A of the method, the starting arc current is the welding current required by the welding process specification.

7. The aluminum alloy plate T-HV joint welding process method of claim 1, wherein: The protective gas in step A of the method comprises argon, and the concentration of the argon is greater than 99.99%, and the gas flow is 20 L / min.

8. The aluminum alloy plate T-HV joint welding process method of claim 1, wherein: In step C of the method, the arc collection welding uses the circle drawing method, the outer circle draws a large circle, the inner circle draws a small circle, and the arc pit is filled until full.

9. The aluminum alloy plate T-HV joint welding process method of claim 1, wherein: In step C of the method, the arc collection current is 130 A.

10. The aluminum alloy plate T-HV joint welding process of claim 1, wherein: In step S1 of the method, the preheating temperature is 70-90°C.

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