CN114147385B - Welding wire for CMT fusion welding butt joint of copper-steel composite plate and preparation and welding method - Google Patents

Abstract

The welding wire for CMT fusion welding of copper-steel composite boards disclosed by the invention includes a flux core and a welding skin, wherein the flux core is composed of the following components in terms of mass percentage: 40-50% of Cr powder, 10-20% of Co powder, Si 5-10% of B powder, 5-10% of B powder, 5-10% of Ce powder, the rest is Ni powder, and the sum of the mass percentages of the above components is 100%. This welding wire is specially used to solve the problem of joint cracking during butt welding of copper-steel explosive clad plates. Also provided are a preparation method of a welding wire for CMT fusion welding of copper-steel clad plates and a welding method using the welding wire for copper-steel clad plates.

Description

Welding wire for CMT welding butt joint of copper-steel composite plate and its preparation and welding method

technical field

The invention belongs to the field of metal materials, and in particular relates to a welding wire for CMT fusion welding of copper-steel composite plates, and also relates to a preparation method of a welding wire for CMT fusion welding of copper-steel composite plates and the use of the welding wire for copper - Welding methods for steel clad panels.

Background technique

In recent years, due to the development of explosive welding technology, the preparation of large-area dissimilar metal laminated composite plates has become possible, such as titanium-steel, copper-steel, titanium-aluminum, titanium-copper and other composite plates. Because these explosive composite panels have the excellent properties of their respective metals, they are favored by engineering practice. In the process of applying explosive composite panels to engineering practice, butt connection of composite panels is unavoidable. For example, in the preparation process of structures such as pipelines and pressure vessels, both longitudinal seam welding and circumferential seam welding are required. Therefore, the key to ensuring the safe operation of metal layered composite structures is to achieve high-quality connections of their butt joints. In the process of butt connection of dissimilar metal clad plates, it is necessary to use a transition layer weld near the interface to realize its connection with the base metal welds on both sides. The selection of alloying elements in the transition layer weld needs to meet at least two conditions: (1) it cannot form brittle intermetallic compounds with the base metals on both sides; (2) it must ensure high-quality metallurgical bonding with the base metals on both sides.

CMT (Cold metal transfer), also known as cold metal transfer technology, has inherent advantages in the field of dissimilar metal welding due to the low and controllable heat input of the CMT welding process, and is currently the preferred process for dissimilar metal welding connections in engineering.

The invention aims at the copper-steel explosive composite plate used in the electrolysis industry, based on the metallurgical reaction characteristics between Cu-Fe, designs and develops its transition layer welding material, and adopts CMT cold metal transition technology to carry out high-quality automatic butt joint connection of the composite plate .

Contents of the invention

The first object of the present invention is to provide a welding wire for CMT fusion welding of copper-steel clad plates, which is specially used to solve the problem of joint cracking in the process of butt welding of copper-steel clad plates.

The second object of the present invention is to provide a method for preparing a welding wire for CMT fusion welding of copper-steel clad plates.

The third object of the present invention is to provide a welding method for copper-steel clad plates.

The first technical solution adopted in the present invention is that the welding wire for CMT welding butt joint of copper-steel clad plate includes a flux core and a welding skin, wherein the flux core is composed of the following components by mass percentage: 40% to 50% of Cr powder, 10-20% of Co powder, 5-10% of Si powder, 5-10% of B powder, 5-10% of Ce powder, and the rest of Ni powder. The sum of the mass percentages of the above components is 100%.

The present invention is also characterized in that,

The welding skin is a pure nickel strip with a thickness of 0.3mm and a width of 7mm.

The particle size of the medicinal powder is 200-300 mesh, and the purity of the powder is ≥99.90%.

The filling amount of the medicinal powder in the welding wire is controlled at 30-35wt%.

The second technical scheme adopted in the present invention is, the preparation method of copper-steel clad plate CMT fusion welding butt joint welding wire, concrete steps are as follows:

Step 1: Weigh the powder according to mass percentage: 40-50% of Cr powder, 10-20% of Co powder, 5-10% of Si powder, 5-10% of B powder, 5-10% of Ce powder, and the rest is Ni powder , the sum of the mass percentages of the above components is 100%;

Step 2: Put the medicinal powder weighed in step 1 into a vacuum heating furnace for heating at a heating temperature of 200-250°C and a holding time of 1-2 hours to remove the crystal water in the medicinal powder; place the dried medicinal powder in Fully mix in the powder mixer, the mixing time is 2-4h;

Step 3: Use pure nickel strip as the welding skin, use alcohol to remove the grease on the surface of the pure nickel strip, wrap the powder prepared in step 2 in the pure nickel strip through the flux-cored wire drawing equipment, and the aperture of the first drawing die is 2.6 mm;

Step 4: After the first process is drawn, the diameter of the mold aperture is reduced in turn, and finally a flux cored wire with a diameter of 1.2mm is obtained;

Step 5: After the flux-cored wire is drawn, it is wound on the wire reel by a wire winding machine, and finally sealed in a flux-cored wire vacuum packaging bag for use.

The present invention is also characterized in that,

In step 3, the pure nickel strip has a thickness of 0.3mm and a width of 7mm.

In step 1, the particle size of the medicinal powder is 200-300 mesh, and the purity of the powder is ≥99.90%.

In step 3, the filling amount of the medicinal powder in the welding wire is controlled at 30-35 wt%.

The second technical scheme adopted in the present invention is the welding method of copper-steel clad plate, and the specific implementation method is as follows:

First, an asymmetrical X-shaped groove is made at the welding place of the copper-steel composite plate, and the transition layer on the copper side is welded. The above-mentioned copper-steel composite plate CMT fusion welding butt joint welding wire is used. When the composite plate is welded, the butt joint test plate remains 1.5-2.0mm gap, the welding process is CMT-pulse mode, the welding current is 200-250A, the welding speed is 30-35cm/min, and the preheating temperature is 100-150℃; then turn the test plate over and weld the steel side , use ER50-6 welding wire, welding wire diameter 1.2mm, welding process CMT mode, welding current 150-200A for bottoming, 200-250A for filling and covering welding, welding speed 40-45cm/min; finally turn the test plate over , For the cover welding of the copper side, use ERCuSi-Al welding wire, the diameter of the welding wire is 1.2mm, the welding process is CMT-pulse mode, the welding current is 300-350A, and the preheating temperature is 200-300°C.

The present invention is also characterized in that,

The specific parameters of the asymmetrical X-shaped groove opened at the welding point of the copper-steel composite plate are: the angle of the groove on the steel side is 60±5°, the angle of the groove on the copper side is 90±5°, and the size of the blunt side is 2- 3mm.

The beneficial effects of the present invention are:

(1) The inventive method adopts nickel-based welding wire to carry out the welding of the copper-steel transition layer, and the weldability between the nickel-based welding wire and the bottom steel layer is better, and the weldability with the copper layers on both sides is also better.

(2) The method of the present invention adopts CMT technology to carry out the direct welding butt joint of copper-steel clad plates. Since CMT is based on the principle of cold metal transition, when welding copper-steel dissimilar materials, the welding heat input can be precisely controlled. When welding the nickel-based transition layer, a small fusion ratio between the nickel-based weld and the bottom steel layer can be ensured; when welding the copper layer, the brazing of the copper weld can be achieved by virtue of the low melting point of copper itself The welding effect further reduces the fusion ratio.

(3) The method of the present invention first carries out the welding of nickel-based transition layer, which can ensure better weld seam formation when welding the copper cover surface on it. After the nickel-based weld is welded, the filling and cover welding of the steel side can ensure that there is enough heat for the final copper layer welding, thereby reducing the preheating time of the copper side welding and improving production efficiency.

(4) The nickel-based transition layer welding wire used in the method of the present invention realizes good metallurgical bonding with the bottom steel and the copper on both sides through the main element Ni. On this basis, based on the Cr and Co elements in the powder, the strength and toughness of the nickel-based weld can be improved; relying on the Si and B elements in the powder, the melting point of the nickel-based weld can be reduced on the basis of deoxidation; Ce is a rare earth element that purifies the grain boundaries of nickel-based welds and improves the high-temperature mechanical properties of nickel-based welds.

(5) The welding wire developed by the present invention has few types of medicinal powder, which is convenient for large-scale production. The diameter of the welding wire is 1.2mm, which can be used for both MAG/MIG welding and TIG welding, with wide adaptability.

Description of drawings

Fig. 1 is the copper-steel clad plate groove form used in the inventive method;

Fig. 2 is butt welding sequence of copper-steel clad plate in the inventive method;

Fig. 3 is the topographical view of the copper-steel clad plate butt joint nickel-based weld welded that is prepared by Example 2 of the present invention;

Fig. 4 is the microstructural topography figure of the nickel transition layer welding seam when the nickel-base flux-cored welding wire prepared by Example 2 of the present invention is carrying out butt welding of copper-steel clad plate;

Fig. 5 is the microstructural topography diagram of the nickel-based weld seam and the copper layer interface when the nickel-based flux-cored welding wire prepared in Example 2 of the present invention is butt-welded with a copper-steel composite plate;

Fig. 6 is the fracture morphology of the butt joint welded in Example 2 of the present invention after stretching.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

The invention provides a welding wire for CMT fusion welding of copper-steel composite plates, which includes a flux core and a weld skin, wherein the flux core is composed of the following components in terms of mass percentage: 40-50% of Cr powder, 10-20% of Co powder, Si powder is 5-10%, B powder is 5-10%, Ce powder is 5-10%, and the rest is Ni powder. The sum of the mass percentages of the above components is 100%.

The welding skin is a pure nickel strip with a thickness of 0.3mm and a width of 7mm.

The particle size of the medicinal powder is 200-300 mesh, and the purity of the powder is ≥99.90%.

The filling amount of the medicinal powder in the welding wire is controlled at 30-35wt%.

The present invention also provides a preparation method of welding wire for CMT fusion welding of copper-steel composite plate, the specific steps are as follows:

Step 1: Weigh the powder according to mass percentage: 40-50% of Cr powder, 10-20% of Co powder, 5-10% of Si powder, 5-10% of B powder, 5-10% of Ce powder, and the rest is Ni powder , the sum of the mass percentages of the above components is 100%;

In step 1, the particle size of the medicinal powder is 200-300 mesh, and the purity of the powder is ≥99.90%.

Step 2: Put the medicinal powder weighed in step 1 into a vacuum heating furnace for heating at a heating temperature of 200-250°C and a holding time of 1-2 hours to remove the crystal water in the medicinal powder; place the dried medicinal powder in Fully mix in the powder mixer, the mixing time is 2-4h;

Step 3: Use pure nickel strip as the welding skin, use alcohol to remove the grease on the surface of the pure nickel strip, wrap the powder prepared in step 2 in the pure nickel strip through the flux-cored wire drawing equipment, and the aperture of the first drawing die is 2.6 mm;

In step 3, the pure nickel strip has a thickness of 0.3mm and a width of 7mm.

In step 3, the filling amount of the medicinal powder in the welding wire is controlled at 30-35 wt%.

Step 4: After the first process is drawn, the diameter of the mold aperture is reduced in turn, and finally a flux cored wire with a diameter of 1.2mm is obtained;

Step 5: After the flux-cored wire is drawn, it is wound on the wire reel by a wire winding machine, and finally sealed in a flux-cored wire vacuum packaging bag for use.

The role and function of the main alloy components in the nickel-based welding wire are as follows:

Ni element in nickel-based welding wire is the main alloying element. The metallurgical bonding between Ni and the main alloying element Fe of the bottom steel matrix is good, and the metallurgical bonding between Ni and the main element Cu of the copper layers on both sides is also good. Therefore, the selection of transition layer welds with Ni as the main element can ensure its high-quality connection between the steel layer and the copper layer.

Cr element is the main element in the powder of nickel-based welding wire, which can effectively ensure the strength and toughness of the nickel-based transition layer weld. The metallurgical combination between Cr and Ni is good, and there is no brittle phase between Cr and Fe and Cu.

The addition of Co element to the nickel-based welding wire powder can further improve the strength and toughness of the weld, and supplement the adverse effects of Cr burning on the weld during the welding process.

Si and B elements are added to the flux core of the nickel-based welding wire, and the Si element can deoxidize the weld, thereby reducing the tendency of weld porosity. Si and B elements can significantly reduce the melting point of nickel-based welds, improve the wettability of the weld and the base metal, thereby ensuring excellent weld formation.

Adding Ce rare earth element to nickel-based welding wire powder can purify the grain boundary of nickel-based welding seam. Nickel-based welds usually form coarse austenite grains and have a high tendency to hot cracking. After the Ce element is added, it can refine the grains while purifying the grain boundaries, thereby effectively improving the ability of the nickel-based weld to resist hot cracking.

The present invention also provides a welding method for copper-steel composite panels, as shown in Figure 2, the specific implementation is as follows:

First, an asymmetrical X-shaped groove is opened at the welding place of the copper-steel composite plate (as shown in Figure 1), and the transition layer on the copper side is welded. When welding, leave a gap of 1.5-2.0mm between the test plates, the welding process is CMT-pulse mode, the welding current is 200-250A, the welding speed is 30-35cm/min, and the preheating temperature is 100-150°C; then the test plate Flip over to weld the steel side, use ER50-6 welding wire, the diameter of the welding wire is 1.2mm, the welding process is in CMT mode, the welding current for bottoming is 150-200A, the welding current for filling and covering is 200-250A, and the welding speed is 40-45cm/min ;Finally, turn the test board over and perform cover welding on the copper side, using ERCuSi-Al welding wire with a diameter of 1.2mm, the welding process is CMT-pulse mode, the welding current is 300-350A, and the preheating temperature is 200-300°C .

The specific parameters of the asymmetrical X-shaped groove opened at the welding point of the copper-steel composite plate are: the angle of the groove on the steel side is 60±5°, the angle of the groove on the copper side is 90±5°, and the size of the blunt side is 2- 3mm.

Example 1

Step 1: Take the powder by mass: 40% of Cr powder, 10% of Co powder, 5% of Si powder, 5% of B powder, 5% of Ce powder, and the rest are Ni powder. The sum of the mass percentages of the above components is 100 %;

Step 2: Put the powder weighed in step 1 into a vacuum heating furnace for heating at a temperature of 200°C and a holding time of 1 hour to remove the crystal water in the powder; place the dried powder in a powder mixer Carry out sufficient mixing, the mixing time is 2h;

Step 3: Use pure nickel strip as the welding skin, use alcohol to remove the grease on the surface of the pure nickel strip, wrap the powder prepared in step 2 in the pure nickel strip through the flux-cored wire drawing equipment, and the aperture of the first drawing die is 2.6 mm;

Step 4: After the first process is drawn, the diameter of the mold aperture is reduced in turn, and finally a flux cored wire with a diameter of 1.2mm is obtained;

Step 5: After the flux-cored wire is drawn, it is wound on the wire reel by a wire winding machine, and finally sealed in a flux-cored wire vacuum packaging bag for use.

In step 1, the particle size of each medicinal powder weighed is 200 mesh;

In step 1, the purity of the powder is ≥99.90%;

In step 3, the pure nickel strip has a thickness of 0.3mm and a width of 7mm;

In step 3, the filling amount of the flux cored wire is controlled at 30wt%.

The nickel-based flux-cored wire provided in Example 1 is used to weld the copper-steel composite plate. The composite plate has an asymmetrical X-shaped groove, in which the steel side groove angle is 55°, the copper side groove angle is 85°, blunt The edge size is 2mm. When the composite board is welded, leave a gap of 1.5mm between the butt test boards. First, weld the transition layer on the copper side, using the above-mentioned nickel-based welding wire, the welding process is CMT-pulse mode, the welding current is 200-250A, the welding speed is 30-35cm/min, and the preheating temperature is 100-150℃; The test plate is turned over, and the steel side is welded, using ER50-6 welding wire, the diameter of the welding wire is 1.2mm, the welding process is CMT mode, the welding current of the bottom is 150-200A, the welding current of the filling and the cover is 200-250A, and the welding speed is 40-45cm /min; Finally, turn the test board over and weld the copper side cover, using ERCuSi-Al welding wire, the diameter of the welding wire is 1.2mm, the welding process is CMT-pulse mode, the welding current is 300-350A, and the preheating temperature is 200- 300°C.

After testing, the tensile strength of the welded joint of the copper-steel clad plate is 360MPa, and the elongation is 15%.

Example 2

Step 1: Weigh the medicinal powder according to mass percentage: 50% of Cr powder, 20% of Co powder, 10% of Si powder, 10% of B powder, 10% of Ce powder, and the sum of the mass percentages of the above components is 100%;

Step 2: Put the powder weighed in step 1 into a vacuum heating furnace for heating at a temperature of 250°C and a holding time of 2 hours to remove the crystal water in the powder; place the dried powder in a powder mixer Carry out sufficient mixing, the mixing time is 4h;

Step 3: Use pure nickel strip as the welding skin, use alcohol to remove the grease on the surface of the pure nickel strip, wrap the powder prepared in step 2 in the pure nickel strip through the flux-cored wire drawing equipment, and the aperture of the first drawing die is 2.6 mm;

Step 4: After the first process is drawn, the diameter of the mold aperture is reduced in turn, and finally a flux cored wire with a diameter of 1.2mm is obtained;

Step 5: After the flux-cored wire is drawn, it is wound on the wire reel by a wire winding machine, and finally sealed in a flux-cored wire vacuum packaging bag for use.

In step 1, the particle size of each medicated powder weighed is 300 mesh;

In step 1, the purity of the powder is ≥99.90%;

In step 3, the pure nickel strip has a thickness of 0.3mm and a width of 7mm;

In step 3, the filling amount of the flux cored wire is controlled at 35wt%.

The nickel-based flux-cored wire provided in Example 2 is used to weld the copper-steel composite plate. The composite plate has an asymmetrical X-shaped groove, in which the steel side groove angle is 65°, the copper side groove angle is 95°, blunt The edge size is 3mm. When the composite board is welded, leave a gap of 2.0mm between the butt test boards. First, weld the transition layer on the copper side, using the above-mentioned nickel-based welding wire, the welding process is CMT-pulse mode, the welding current is 200-250A, the welding speed is 30-35cm/min, and the preheating temperature is 100-150℃; The test plate is turned over, and the steel side is welded, using ER50-6 welding wire, the diameter of the welding wire is 1.2mm, the welding process is CMT mode, the welding current of the bottom is 150-200A, the welding current of the filling and the cover is 200-250A, and the welding speed is 40-45cm /min; Finally, turn the test board over and weld the copper side cover, using ERCuSi-Al welding wire, the diameter of the welding wire is 1.2mm, the welding process is CMT-pulse mode, the welding current is 300-350A, and the preheating temperature is 200- 300°C.

After testing, the tensile strength of the welded joint of the copper-steel clad plate is 395MPa, and the elongation is 17%.

Figure 3 shows the morphology of the welded nickel-based weld of the copper-steel clad plate butt joint prepared in Example 2; it can be seen from the figure that the nickel-based weld is well formed and no macroscopic cracks are seen. Figure 4 shows the microstructure of the nickel-based weld. It can be seen from the figure that the weld is dominated by cellular dendrites. Figure 5 is the microstructure topography diagram of the interface between the nickel-based weld and the copper layer. It can be seen from the figure that the interface is well bonded and no cracks occur. Tensile tests were carried out on the butt joints of the above-mentioned copper-steel composite plates. The tensile fracture morphology is shown in Figure 6. It can be seen from the figure that the fracture is dominated by dimples, which proves that the joints have good toughness.

Example 3

Step 1: Take the powder by mass respectively: 45% of Cr powder, 15% of Co powder, 8% of Si powder, 8% of B powder, 8% of Ce powder, and the rest are Ni powder. The sum of the mass percentages of the above components is 100 %;

Step 2: Put the medicinal powder weighed in step 1 into a vacuum heating furnace for heating at a temperature of 220°C and a holding time of 1.5 hours to remove the crystal water in the medicinal powder; place the dried medicinal powder in a powder mixer Fully mixed in, the mixing time is 3h;

Step 3: Use pure nickel strip as the welding skin, use alcohol to remove the grease on the surface of the pure nickel strip, wrap the powder prepared in step 2 in the pure nickel strip through the flux-cored wire drawing equipment, and the aperture of the first drawing die is 2.6 mm;

Step 4: After the first process is drawn, the diameter of the mold aperture is reduced in turn, and finally a flux cored wire with a diameter of 1.2mm is obtained;

Step 5: After the flux-cored wire is drawn, it is wound on the wire reel by a wire winding machine, and finally sealed in a flux-cored wire vacuum packaging bag for use.

In step 1, the particle size of each medicinal powder weighed is 250 mesh;

In step 1, the purity of the powder is ≥99.90%;

In step 3, the pure nickel strip has a thickness of 0.3mm and a width of 7mm;

In step 3, the filling amount of the flux cored wire is controlled at 32wt%.

The nickel-based flux-cored wire provided in Example 3 is used to weld the copper-steel composite plate. The composite plate has an asymmetrical X-shaped groove, in which the steel side groove angle is 65°, the copper side groove angle is 85°, blunt The edge size is 2.5mm. When the composite board is welded, leave a gap of 1.8mm between the butt test boards. First, weld the transition layer on the copper side, using the above-mentioned nickel-based welding wire, the welding process is CMT-pulse mode, the welding current is 200-250A, the welding speed is 30-35cm/min, and the preheating temperature is 100-150℃; The test plate is turned over, and the steel side is welded, using ER50-6 welding wire, the diameter of the welding wire is 1.2mm, the welding process is CMT mode, the welding current of the bottom is 150-200A, the welding current of the filling and the cover is 200-250A, and the welding speed is 40-45cm /min; Finally, turn the test board over and weld the copper side cover, using ERCuSi-Al welding wire, the diameter of the welding wire is 1.2mm, the welding process is CMT-pulse mode, the welding current is 300-350A, and the preheating temperature is 200- 300°C.

After testing, the tensile strength of the welded joint of the copper-steel composite plate is 388MPa, and the elongation is 21%.

Example 4

Step 1: Weigh the medicinal powder according to mass percentage: 42% of Cr powder, 17% of Co powder, 6% of Si powder, 9% of B powder, 5% of Ce powder, and the rest are Ni powder. The sum of the mass percentages of the above components is 100 %;

Step 2: Put the powder weighed in step 1 into a vacuum heating furnace for heating at a temperature of 240°C and a holding time of 1.6 hours to remove the crystal water in the powder; place the dried powder in a powder mixer Fully mixed, the mixing time is 3.5h;

Step 3: Use pure nickel strip as the welding skin, use alcohol to remove the grease on the surface of the pure nickel strip, wrap the powder prepared in step 2 in the pure nickel strip through the flux-cored wire drawing equipment, and the aperture of the first drawing die is 2.6 mm;

Step 4: After the first process is drawn, the diameter of the mold aperture is reduced in turn, and finally a flux cored wire with a diameter of 1.2mm is obtained;

Step 5: After the flux-cored wire is drawn, it is wound on the wire reel by a wire winding machine, and finally sealed in a flux-cored wire vacuum packaging bag for use.

In step 1, the particle size of each medicated powder weighed is 300 mesh;

In step 1, the purity of the powder is ≥99.90%;

In step 3, the pure nickel strip has a thickness of 0.3mm and a width of 7mm;

In step 3, the filling amount of the flux cored wire is controlled at 30wt%.

The nickel-based flux-cored wire provided in Example 4 is used to weld the copper-steel composite plate. The composite plate has an asymmetrical X-shaped groove, in which the steel side groove angle is 55°, the copper side groove angle is 95°, blunt The edge size is 2.4mm. When the composite board is welded, leave a gap of 1.6mm between the butt test boards. First, weld the transition layer on the copper side, using the above-mentioned nickel-based welding wire, the welding process is CMT-pulse mode, the welding current is 200-250A, the welding speed is 30-35cm/min, and the preheating temperature is 100-150℃; The test plate is turned over, and the steel side is welded, using ER50-6 welding wire, the diameter of the welding wire is 1.2mm, the welding process is CMT mode, the welding current of the bottom is 150-200A, the welding current of the filling and the cover is 200-250A, and the welding speed is 40-45cm /min; Finally, turn the test board over and weld the copper side cover, using ERCuSi-Al welding wire, the diameter of the welding wire is 1.2mm, the welding process is CMT-pulse mode, the welding current is 300-350A, and the preheating temperature is 200- 300°C.

After testing, the tensile strength of the welded joint of the copper-steel clad plate is 372MPa, and the elongation is 25%.

Example 5

Step 1: Weigh the powder respectively by mass percentage: 48% of Cr powder, 19% of Co powder, 5% of Si powder, 6% of B powder, 9% of Ce powder, and the rest are Ni powder. The sum of the mass percentages of the above components is 100 %;

Step 2: Put the powder weighed in step 1 into a vacuum heating furnace for heating at a temperature of 250°C and a holding time of 1.3 hours to remove the crystal water in the powder; place the dried powder in a powder mixer Fully mixed in, the mixing time is 2.9h;

Step 3: Use pure nickel strip as the welding skin, use alcohol to remove the grease on the surface of the pure nickel strip, wrap the powder prepared in step 2 in the pure nickel strip through the flux-cored wire drawing equipment, and the aperture of the first drawing die is 2.6 mm;

Step 4: After the first process is drawn, the diameter of the mold aperture is reduced in turn, and finally a flux cored wire with a diameter of 1.2mm is obtained;

Step 5: After the flux-cored wire is drawn, it is wound on the wire reel by a wire winding machine, and finally sealed in a flux-cored wire vacuum packaging bag for use.

In step 1, the particle size of each medicinal powder weighed is 200 mesh;

In step 1, the purity of the powder is ≥99.90%;

In step 3, the pure nickel strip has a thickness of 0.3mm and a width of 7mm;

In step 3, the filling amount of the flux cored wire is controlled at 35wt%.

The nickel-based flux-cored wire provided in Example 5 is used to weld copper-steel composite plates. The composite plate has an asymmetrical X-shaped groove, in which the steel side groove angle is 55°, the copper side groove angle is 85°, blunt The edge size is 2.1mm. When the composite board is welded, leave a gap of 1.9mm between the butt test boards. First, weld the transition layer on the copper side, using the above-mentioned nickel-based welding wire, the welding process is CMT-pulse mode, the welding current is 200-250A, the welding speed is 30-35cm/min, and the preheating temperature is 100-150℃; The test plate is turned over, and the steel side is welded, using ER50-6 welding wire, the diameter of the welding wire is 1.2mm, the welding process is CMT mode, the welding current of the bottom is 150-200A, the welding current of the filling and the cover is 200-250A, and the welding speed is 40-45cm /min; Finally, turn the test board over and weld the copper side cover, using ERCuSi-Al welding wire, the diameter of the welding wire is 1.2mm, the welding process is CMT-pulse mode, the welding current is 300-350A, and the preheating temperature is 200- 300°C.

After testing, the tensile strength of the welded joint of the copper-steel clad plate is 402MPa, and the elongation is 15%.

Claims (7)

1. The welding wire for CMT fusion welding butt joint of the copper-steel composite plate is characterized by comprising a flux core and a welding skin, wherein the flux core comprises the following components in percentage by mass: 40 to 50 percent of Cr powder, 10 to 20 percent of Co powder, 5 to 10 percent of Si powder, 5 to 10 percent of B powder, 5 to 10 percent of Ce powder and the balance of Ni powder, wherein the sum of the mass percentages of the components is 100 percent; the welding skin is a pure nickel strip, the thickness is 0.3mm, and the width is 7mm; the filling amount of the traditional Chinese medicine powder in the welding wire is controlled to be 30-35wt%.

2. The welding wire for CMT fusion welding and butting of copper-steel composite plates according to claim 1, wherein the granularity of powder is 200-300 meshes, and the purity of the powder is more than or equal to 99.90%.

3. The preparation method of the welding wire for the CMT fusion welding butt joint of the copper-steel composite plate is characterized by comprising the following specific steps of:

step 1: weighing the following medicinal powder in percentage by mass: 40 to 50 percent of Cr powder, 10 to 20 percent of Co powder, 5 to 10 percent of Si powder, 5 to 10 percent of B powder, 5 to 10 percent of Ce powder and the balance of Ni powder, wherein the sum of the mass percentages of the components is 100 percent;

and 2, step: heating the medicinal powder weighed in the step 1 in a vacuum heating furnace at the heating temperature of 200-250 ℃ for 1-2h, and removing crystal water in the medicinal powder; putting the dried medicinal powder into a powder mixer for fully mixing for 2-4h;

and step 3: a pure nickel strip is adopted as a welding skin, oil on the surface of the pure nickel strip is removed by alcohol, the powder prepared in the step 2 is wrapped in the pure nickel strip by flux-cored wire drawing equipment, and the aperture of a first drawing die is 2.6mm; in the step 3, the filling amount of the traditional Chinese medicine powder in the welding wire is controlled to be 30 to 35wt%;

and 4, step 4: after the drawing of the first process is finished, the aperture of the die is reduced in sequence, and finally the flux-cored wire with the diameter of 1.2mm is obtained;

and 5: and after the flux-cored wire is drawn, the flux-cored wire is wound on a wire reel through a wire winding machine and finally sealed in a flux-cored wire vacuum packaging bag for later use.

4. A method of preparing a welding wire for CMT fusion welding docking of copper-steel composite plates according to claim 3, characterized in that in step 3, the pure nickel strip has a thickness of 0.3mm and a width of 7mm.

5. The preparation method of the welding wire for CMT fusion welding butt joint of the copper-steel composite plate as claimed in claim 3, wherein in the step 1, the granularity of the powder is 200-300 meshes, and the purity of the powder is more than or equal to 99.90%.

6. The welding method of the copper-steel composite plate is characterized by comprising the following specific steps of:

firstly, forming an asymmetric X-shaped groove at the welding position of the copper-steel composite plate, welding a copper side transition layer, adopting the welding wire for the CMT fusion welding butt joint of the copper-steel composite plate according to any one of claims 1-2, and when the composite plate is welded, leaving a gap of 1.5-2.0mm for a butt joint test plate, wherein the welding process is a CMT-pulse mode, the welding current is 200-250A, the welding speed is 30-35cm/min, and the preheating temperature is 100-150 ℃; then, turning the test plate, welding the steel side, adopting an ER50-6 welding wire with the diameter of 1.2mm, adopting a CMT mode of a welding process, setting a bottom welding current of 150-200A, and setting a filling and cover welding current of 200-250A, wherein the welding speed is 40-45cm/min; finally, turning over the test plate, performing facing welding on the copper side, adopting an ERCuSi-Al welding wire with the diameter of 1.2mm, adopting a CMT-pulse mode as a welding process, controlling the welding current to be 300-350A and the preheating temperature to be 200-300 ℃.

7. The method for welding the copper-steel composite plate according to claim 6, wherein the specific parameters of the asymmetric X-shaped groove formed at the welding position of the copper-steel composite plate are as follows: the angle of the bevel on the steel side is 60 +/-5 degrees, the angle of the bevel on the copper side is 90 +/-5 degrees, and the size of the truncated edge is 2-3mm.

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