Weld joint structure and welding method of copper / stainless steel explosion composite plate

Abstract

The invention provides a welding seam structure and a welding method of a copper / stainless steel explosion cladding plate. The welding seam structure comprises a stainless steel base layer, an aluminum bronze transition layer and an aluminum bronze cover surface layer which are formed through laser welding. The stainless steel base layer is located in the groove of the stainless steel layer, the aluminum bronze cover surface layer covers the surface of the stainless steel base layer, and the aluminum bronze transition layer is located between the aluminum bronze cover surface layer and the groove of the copper layer. According to the method, a welding seam deposited metal filling strategy of stainless steel bottoming / aluminum bronze transition and capping is adopted, the dilution rate of a welding seam is reduced by regulating and controlling laser welding process parameters, the amount of copper elements dissolved into stainless steel is reduced, crack-free fusion welding of the copper / stainless steel explosion composite plate is achieved, and the welding quality is improved. The method solves the problem that when a copper / stainless steel explosive composite plate is welded through an existing technological method, hot cracks are prone to being generated in a weld joint, and a new solution is provided for high-reliability fusion welding of the copper / stainless steel explosive composite plate.

Description

Technical Field

[0001] This invention relates to the field of composite plate welding technology, and more specifically, to a weld structure and welding method for a copper / stainless steel explosion-proof composite plate. Background Technology

[0002] Copper / stainless steel explosion-proof composite plates overcome the performance limitations of single metals. They leverage the excellent corrosion resistance of TU2 pure copper to withstand strong corrosive media such as acids, alkalis, and seawater, while relying on the high strength and load-bearing capacity of 316L stainless steel. Therefore, copper / stainless steel explosion-proof composite plates have become an ideal choice for key applications such as chemical containers, power plant condensers, marine engineering, and metallurgical equipment, achieving a balance between function and structure, cost and performance.

[0003] However, the following problems exist when performing fusion welding on copper / stainless steel explosion-proof composite plates in the project: I. Hot cracking in the heat-affected zone of stainless steel. When welding copper / stainless steel explosion-proof composite plates using conventional welding processes (such as TIG, MIG, etc.), regardless of whether pure copper welding wire or stainless steel welding wire is used, the excessively wide arc coverage area causes copper elements to penetrate into the grain boundaries of the stainless steel heat-affected zone, resulting in the loss of grain boundary bonding and the formation of network microcracks in the stainless steel heat-affected zone. II. The physical properties of the materials differ too much. (1) The coefficient of linear expansion of TU2 copper at 800℃ is approximately 23 x 10⁻⁶. -6 / ℃, for comparison, the coefficient of linear expansion of 316L stainless steel at 800℃ is approximately 17 x 10. -6 / ℃, the high temperature linear expansion coefficient of copper is about 1.35 times that of stainless steel; (2) the thermal conductivity of copper (about 400 W / m·K) is 25 times that of stainless steel (about 16 W / m·K); (3) the melting point of copper (1083°C) is lower than that of stainless steel (about 1400-1450°C).

[0004] Due to the significant differences in the physical properties of copper and stainless steel, coupled with the penetration of copper into the grain boundaries of the heat-affected zone of stainless steel, copper / stainless steel explosion-proof composite plates are extremely prone to hot cracking and incomplete fusion defects during welding.

[0005] Du Yongqin et al. used carbon steel welding wire for the root pass and ER Ni-1 pure nickel welding wire for the transition, matching the process specifications of shielded metal arc welding, and achieved defect-free welding of copper / carbon steel explosive composite plates. Although ER Ni-1 pure nickel welding wire can obtain crack-free welds, its high viscosity can cause incomplete fusion of the weld sidewalls and excessive grinding and finishing.

[0006] Patent CN107283087A discloses a welding process for welding copper-containing explosive composite plates using flux-cored welding wire. It employs Ag-Cu-Mo-Nb flux-cored welding wire matched with MIG welding process to weld TA1 / Cu / X65 three-layer explosive composite plates. However, flux-cored welding wire has inherent defects such as the need for slag removal after welding and slag inclusion in the weld.

[0007] Chu Qiaoling and others used Cu-Si welding wire to weld titanium / copper / steel three-layer explosive composite plates. Their main idea was to use the composition of copper-based welding wire to suppress the formation of brittle compounds at the interface between dissimilar materials. Based on metallurgical principles and analysis of the welding wire composition, copper-silicon welding wire cannot completely solve the problem of copper infiltration at the grain boundaries of stainless steel.

[0008] In view of this, the present invention is hereby proposed. Summary of the Invention

[0009] The purpose of this invention is to address the shortcomings of existing technologies by providing a weld structure and welding method for copper / stainless steel explosion-bonded composite plates. Based on the metallurgical principle of "like dissolves like," a weld metal filling strategy is adopted, using stainless steel as the base metal, aluminum bronze as the transition metal, and aluminum bronze as the cover metal. By adjusting the laser welding process parameters to reduce the weld dilution rate and the amount of copper dissolved into the stainless steel, crack-free welding of copper / stainless steel explosion-bonded composite plates can be achieved. The weld is free of slag inclusions, has no gaps between the weld metal and the sidewall of the base material, and the weld is smooth and free of undercut. This provides a new solution for highly reliable fusion welding of copper / stainless steel explosion-bonded composite plates.

[0010] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: A weld structure for a copper / stainless steel explosion-proof composite plate includes a stainless steel underlayer 5, an aluminum bronze transition layer 6, and an aluminum bronze cover layer 7 formed by laser welding; the stainless steel underlayer 5 is located within the bevel of the stainless steel layer 1, the aluminum bronze cover layer 7 covers the surface of the stainless steel underlayer 5, and the aluminum bronze transition layer 6 is located between the aluminum bronze cover layer 7 and the bevel of the copper layer 2.

[0011] Furthermore, the stainless steel layer 1 of the copper / stainless steel explosion-proof composite plate has a V-shaped bevel, and the copper layer 2 has an I-shaped bevel.

[0012] Furthermore, the V-shaped bevel angle is 60~70°.

[0013] Furthermore, the blunt edge L of the V-shaped bevel is 0~1mm, and the bevel gap h is 1~2mm.

[0014] Furthermore, the width of the I-bevel is 40~60mm.

[0015] Furthermore, the aluminum bronze in the aluminum bronze transition layer and the aluminum bronze capping layer comprises the following components: 8~10wt% Al, 3~5wt% Fe, 1.5~3wt% Mn, and the balance Cu.

[0016] Furthermore, the total thickness of the copper / stainless steel explosion-proof composite plate is 8~16mm, the thickness t1 of the copper layer is 2~4mm, and the thickness t2 of the stainless steel layer is 6~12mm.

[0017] Furthermore, the thickness of the stainless steel underlayer is 6~12mm, the thickness of the aluminum bronze transition layer is 2~6mm, and the thickness of the aluminum bronze cover layer is 2~6mm.

[0018] A welding method for copper / stainless steel explosion-proof composite plates, which employs laser welding technology to sequentially weld a stainless steel base layer, an aluminum bronze transition layer, and an aluminum bronze cover layer.

[0019] Furthermore, the welding speed of the laser welding process is 1.2m / min to 1.5m / min, and the laser power is 1000 to 1500W.

[0020] Furthermore, the laser welding process employs a wire feeding method where the laser is in front and the welding wire is behind, with a distance of 0 mm between the laser and the welding wire.

[0021] Furthermore, the angle θ between the wire feeding guide and the horizontal axis is 45°~60°.

[0022] Furthermore, for the stainless steel root pass, 1.2mm diameter stainless steel is used as filler wire, and the total height of the deposited metal is controlled to be 6~12mm.

[0023] Furthermore, the aluminum bronze transition layer is welded using aluminum bronze with a diameter of 1.2mm to 1.6mm as filler wire. The aluminum bronze includes the following components: 8 to 10 wt% Al, 3 to 5 wt% Fe, 1.5 to 3 wt% Mn, and balance Cu. The total height of the deposited metal is controlled to be 2 to 6mm, and the width of the deposited metal is 3 to 5mm.

[0024] Furthermore, the aluminum bronze capping layer is welded using aluminum bronze with a diameter of 1.2mm to 1.6mm as filler wire. The aluminum bronze includes the following components: 8 to 10 wt% Al, 3 to 5 wt% Fe, 1.5 to 3 wt% Mn, and the balance Cu. The total height of the deposited metal is 2 to 6mm.

[0025] Furthermore, before the formal welding, the base material surface is cleaned and the bevel is assembled.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The weld structure and welding method of the copper / stainless steel explosion-proof composite plate of the present invention, based on the metallurgical principle of like dissolves like, adopts a weld fusion metal filling strategy of stainless steel as the base layer / aluminum bronze transition and cover layer, and reduces the amount of copper element dissolved into stainless steel by adjusting the laser welding process parameters, thereby achieving crack-free welding of copper / stainless steel explosion-proof composite plate.

[0027] 2. This invention comprehensively utilizes the characteristics of the laser heat source itself and the metallurgical matching of the welding wire composition for metallurgical control, thereby achieving crack-free welding of copper / stainless steel explosive composite plates. Specifically, the characteristics of the laser heat source are utilized: high power density, concentrated heating range, fast welding speed, and precise and controllable heat input; by adjusting the laser welding process parameters, the amount of copper dissolved into the stainless steel is reduced. The metallurgical matching of the welding wire composition is utilized: based on the metallurgical principle of "like dissolves like," a weld metal filling strategy of stainless steel root pass / aluminum bronze transition and cover pass is adopted; the solid solution effect of elements such as Al, Fe, Mn, and Cu in the aluminum bronze is used to achieve the welding of the copper / stainless steel explosive composite plate.

[0028] 3. The present invention selects aluminum bronze as the transition layer and cover layer material, which conforms to the metallurgical principle of similar dissolution, and can simultaneously achieve high welding quality, low production cost (the welding wire does not contain precious metals) and good process window. Attached Figure Description

[0029] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the laser welding method for copper / stainless steel exploded composite plates according to the present invention; Figure 2 This is a schematic diagram of the weld structure of the copper / stainless steel explosion-proof composite plate of the present invention; Explanation of reference numerals in the attached diagram: 1-Stainless steel layer; 2-Copper layer; 3-Laser beam; 4-Wire feeding guide; 5-Stainless steel underlayer; 6-Aluminum bronze transition layer; 7-Aluminum bronze toplayer. Detailed Implementation

[0031] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0032] A weld structure for a copper / stainless steel explosion-proof composite plate includes a stainless steel underlayer 5, an aluminum bronze transition layer 6, and an aluminum bronze capping layer 7 formed by laser welding. The stainless steel underlayer 5 is located within the bevel of the stainless steel layer 1, the aluminum bronze capping layer 7 covers the surface of the stainless steel underlayer 5, and the aluminum bronze transition layer 6 is located between the aluminum bronze capping layer 7 and the bevel of the copper layer 2.

[0033] Based on the metallurgical principle of "like dissolves like," this invention employs a weld metal filling strategy of stainless steel as the base layer, aluminum bronze as the transition and cover layer, utilizing the solid solution effect of elements such as Al, Fe, Mn, and Cu in aluminum bronze to achieve the welding of copper / stainless steel explosion-proof composite plates. Preferably, the stainless steel layer 1 has a V-groove, and the copper layer 2 has an I-groove.

[0034] Preferably, the V-shaped bevel angle is 60~70°, including but not limited to 60°, 61°, 62°, 63°, 64°, 65°, 66°, 67°, 68°, 69°, and 70°.

[0035] Preferably, the blunt edge L of the V-shaped bevel is 0~1mm, and the bevel gap h is 1~2mm.

[0036] Preferably, the width of the I-bevel is 40~60mm, including but not limited to 40mm, 45mm, 50mm, 55mm, and 60mm.

[0037] Preferably, the aluminum bronze comprises the following components: 8~10wt% Al, 3~5wt% Fe, 1.5~3wt% Mn, and balance Cu.

[0038] Preferably, the stainless steel base layer material is similar to the stainless steel layer material of the copper / stainless steel explosion-proof composite plate, both being existing stainless steel materials, such as 022Cr17Ni12Mo2 grade stainless steel (equivalent to commercially available ER316L).

[0039] Preferably, the total thickness of the copper / stainless steel explosion-proof composite plate is 8~16mm (including but not limited to 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm), the copper layer thickness t1 is 2~4mm (including but not limited to 2mm, 3mm, 4mm), and the stainless steel layer thickness t2 is 6~12mm (including but not limited to 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm). The physical and chemical properties of the copper layer of the copper / stainless steel explosion-proof composite plate meet the requirements of TU2 grade in GB / T 5231-2012 standard, and the stainless steel layer is made of existing stainless steel material, such as 022Cr17Ni12Mo2 grade stainless steel (equivalent to commercially available ER316L).

[0040] Preferably, the thickness of the stainless steel underlayer is 6~12mm (including but not limited to 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm), the thickness of the aluminum bronze transition layer is 2~6mm (including but not limited to 2mm, 3mm, 4mm, 5mm, 6mm), and the thickness of the aluminum bronze cover layer is 2~6mm (including but not limited to 2mm, 3mm, 4mm, 5mm, 6mm).

[0041] A welding method for copper / stainless steel explosion-proof composite plates, such as... Figure 1 As shown, a stainless steel base layer, an aluminum bronze transition layer, and an aluminum bronze capping layer are sequentially welded using laser welding technology. Figure 2 As shown. This invention utilizes the characteristics of laser welding, such as high welding speed and precise and controllable heat input. By adjusting the laser welding process parameters, the amount of copper dissolved into stainless steel is reduced. Based on the metallurgical principle of "like dissolves like," a weld metal filling strategy of stainless steel as the base layer / aluminum bronze transition and cover layer is adopted. The solid solution effect of elements such as Al, Fe, Mn, and Cu in aluminum bronze is used to achieve the welding of copper / stainless steel explosion composite plates.

[0042] Preferably, the welding speed of the laser welding process is 1.2m / min to 1.5m / min, including but not limited to 1.2m / min, 1.3m / min, 1.4m / min, and 1.5m / min, and the laser power is 1000 to 1500W, including but not limited to 1000W, 1100W, 1200W, 1300W, 1400W, and 1500W.

[0043] Preferably, the laser welding process uses a wire feeding method where the laser is in front and the welding wire is behind, with a distance of 0 mm between the laser and the welding wire.

[0044] Preferably, the angle θ between the wire feeding guide and the horizontal axis is 45°~60°, including but not limited to 45°, 50°, 55°, and 60°.

[0045] Preferably, the stainless steel filler wire with a diameter of 1.2 mm is used for the stainless steel root pass. The filler wire material is an existing stainless steel material, such as 022Cr17Ni12Mo2 grade stainless steel (equivalent to commercially available ER316L); the total height of the deposited metal is controlled to be 6~12 mm.

[0046] Preferably, the aluminum bronze transition layer is welded using aluminum bronze with a diameter of 1.2mm to 1.6mm (including but not limited to 1.2mm, 1.3mm, 1.4mm, 1.5mm, and 1.6mm) as filler wire. The aluminum bronze comprises the following components: 8 to 10 wt% Al, 3 to 5 wt% Fe, 1.5 to 3 wt% Mn, and the balance Cu. The total height of the deposited metal is controlled to be 2 to 6mm (including but not limited to 2mm, 3mm, 4mm, 5mm, and 6mm), and the width of the deposited metal is 3 to 5mm (including but not limited to 3mm, 4mm, and 5mm).

[0047] Preferably, the aluminum bronze capping layer is welded using aluminum bronze with a diameter of 1.2mm to 1.6mm (including but not limited to 1.2mm, 1.3mm, 1.4mm, 1.5mm, and 1.6mm) as filler wire. The aluminum bronze includes the following components: 8 to 10 wt% Al, 3 to 5 wt% Fe, 1.5 to 3 wt% Mn, and the balance Cu. The total height of the deposited metal is 2 to 6mm. The width of the aluminum bronze transition layer is known to be 3 to 5mm. The width of the aluminum bronze capping layer can be obtained by subtracting the width of the aluminum bronze transition layer from the total bevel width.

[0048] Preferably, the base material surface is cleaned and the bevel is assembled before the formal welding.

[0049] Preferably, the method for cleaning the base material surface is as follows: grind the bevel and both sides of the copper / stainless steel explosion-proof composite plate to be welded until the metal luster is exposed, and then rinse and air dry the area to be welded.

[0050] Preferably, the bevel assembly method is as follows: the copper / stainless steel explosion composite plate to be welded is tack-bonded and assembled using laser filler wire welding. The tack-bonding area is located on one side of the stainless steel layer, specifically inside the V-shaped bevel of the stainless steel layer.

[0051] Preferably, the distance between the spot welding point and the end is 10-15mm, including but not limited to 10mm, 11mm, 12mm, 13mm, 14mm, and 15mm, and the length is 10-15mm, including but not limited to 10mm, 11mm, 12mm, 13mm, 14mm, and 15mm.

[0052] Preferably, the spot welding wire is the same as the wire used for the root pass of the stainless steel welding.

[0053] Example 1 A method for welding copper / stainless steel explosion-proof composite plates, the specific steps of which are as follows: S1) Cleaning of the base material surface: Use a stainless steel wire brush to polish the oil and rust on the bevel of the copper / stainless steel explosion composite plate to be welded and within 50mm on both sides of the bevel until the metal luster is exposed. Then rinse the area to be welded with anhydrous ethanol and let it air dry naturally. S2) Bevel Assembly: Laser filler wire welding is used to tack weld the copper / stainless steel explosion-proof composite plates. The tack welding area is located on one side of the stainless steel layer, specifically inside the V-groove of the stainless steel layer. The tack weld point is 10-15mm from the end and 10-15mm in length. The tack welding wire is the same as the wire used for the root pass of the formal weld; the tack welding wire grade is 022Cr17Ni12Mo2 (equivalent to commercially available ER316L). After tack welding, the assembly quality is inspected to ensure the required bevel root gap is 1mm, the blunt edge is 1mm, and the bevel angle is 60°. S3) Stainless steel layer welding: The back wire feeding method is adopted, that is, the laser is in front and the welding wire is behind. ER316L with a diameter of 1.2mm is used as the filler wire. The distance between the laser and the welding wire is adjusted to 0mm. The angle between the wire feeding guide and the horizontal plane is 45°. The laser power is set to 1200W and the welding speed is 1.2m / min to deposit the root weld. The total height of the stainless steel layer weld metal is controlled to be 6mm. S4) Transition layer welding: A post-feeding method is adopted, using aluminum bronze with a composition of 8wt% Al, 5wt% Fe, 1.5wt% Mn, and balance Cu, and a diameter of 1.2mm as filler wire. The laser and wire spacing is adjusted to 0mm, the angle between the wire guide and the horizontal plane is 45°, and the laser power is set to 1500W and the welding speed is 1.5m / min to deposit the transition layer weld. The total height of the transition layer weld metal is controlled at 2mm, and the total width of the transition layer weld metal is controlled at 3mm. S5) Cover layer welding: The post-feeding method is adopted, using aluminum bronze with a composition of 8wt%Al, 5wt%Fe, 1.5wt%Mn, balance Cu, and a diameter of 1.2mm as filler wire. The laser and wire spacing is adjusted to 0mm, the angle between the wire guide and the horizontal plane is 45°, the laser power is set to 1500W, and the welding speed is 1.5m / min to deposit the transition layer weld. The total height of the cover layer weld metal is controlled to be 2mm. The width of the cover layer weld metal can be obtained by subtracting the width of the transition layer from the total width of the bevel.

[0054] Non-destructive testing: After the base layer, transition layer and cover layer molten metal filling is completed, X-ray non-destructive testing is performed on the weld area. No cracks were detected in the weld area, there were no slag inclusions in the weld, there were no gaps between the weld metal and the sidewall of the base material, and the weld was smooth without undercut.

[0055] Example 2 A method for welding copper / stainless steel explosion-proof composite plates, the specific steps of which are as follows: S1) Cleaning of the base material surface: Use a stainless steel wire brush to polish the oil and rust on the bevel of the copper / stainless steel explosion composite plate to be welded and within 50mm on both sides of the bevel until the metal luster is exposed. Then rinse the area to be welded with anhydrous ethanol and let it air dry naturally. S2) Bevel Assembly: Laser filler wire welding is used to tack weld the copper / stainless steel explosion-proof composite plates. The tack welding area is located on one side of the stainless steel layer, specifically inside the V-groove of the stainless steel layer. The tack weld point is 10-15mm from the end and 10-15mm in length. The tack welding wire is the same as the wire used for the root pass of the formal weld; the tack welding wire grade is 022Cr17Ni12Mo2 (equivalent to commercially available ER316L). After tack welding, the assembly quality is inspected to ensure the required bevel root gap is 1mm, the blunt edge is 1mm, and the bevel angle is 60°. S3) Stainless steel layer welding: The back-feeding method is adopted, that is, the laser is in front and the welding wire is behind. ER316L with a diameter of 1.2mm is used as the filler wire. The distance between the laser and the welding wire is adjusted to 0mm. The angle between the wire feed guide and the horizontal plane is 45°. The laser power is set to 1200W and the welding speed is 1.2m / min to deposit the root weld. The total height of the stainless steel layer weld metal is controlled to be within 8mm. S4) Transition layer welding: The post-feeding method is adopted, using aluminum bronze with a composition of 10wt%Al, 3wt%Fe, 3wt%Mn, and balance Cu, and a diameter of 1.2mm as filler wire. The laser and wire spacing is adjusted to 0mm, the angle between the wire guide and the horizontal plane is 45°, the laser power is set to 1000W, and the welding speed is 1.5m / min to deposit the transition layer weld. The total height of the transition layer weld metal is controlled at 4mm, and the total width of the transition layer weld metal is controlled at 5mm. S5) Cover layer welding: The post-feeding method is adopted, using aluminum bronze with a composition of 10wt%Al, 3wt%Fe, 3wt%Mn, and balance Cu, and a diameter of 1.2mm as filler wire. The laser and wire spacing is adjusted to 0mm, the angle between the wire guide and the horizontal plane is 45°, the laser power is set to 1000W, and the welding speed is 1.5m / min to deposit the transition layer weld. The total height of the cover layer weld metal is controlled to be 4mm. The width of the cover layer weld metal can be obtained by subtracting the width of the transition layer from the total width of the bevel.

[0056] Non-destructive testing: After the base layer, transition layer and cover layer molten metal are filled, X-ray non-destructive testing is performed on the weld area. No cracks were detected in the weld area, there were no slag inclusions in the weld, there were no gaps between the weld metal and the sidewall of the base material, and the weld was smooth without undercut.

[0057] Example 3 A method for welding copper / stainless steel explosion-proof composite plates, the specific steps of which are as follows: S1) Cleaning of the base material surface: Use a stainless steel wire brush to polish the oil and rust on the bevel of the copper / stainless steel explosion composite plate to be welded and within 50mm on both sides of the bevel until the metal luster is exposed. Then rinse the area to be welded with anhydrous ethanol and let it air dry naturally. S2) Bevel Assembly: Laser filler wire welding is used to tack weld the copper / stainless steel explosion-proof composite plates. The tack welding area is located on one side of the stainless steel layer, specifically inside the V-groove of the stainless steel layer. The tack weld point is 10-15mm from the end and 10-15mm in length. The tack welding wire is the same as the wire used for the root pass of the formal weld; the tack welding wire grade is 022Cr17Ni12Mo2 (equivalent to commercially available ER316L). After tack welding, the assembly quality is inspected to ensure the required bevel root gap is 1mm, the blunt edge is 1mm, and the bevel angle is 60°. S3) Stainless steel layer welding: The back-feeding method is adopted, that is, the laser is in front and the welding wire is behind. ER316L with a diameter of 1.2mm is used as the filler wire. The distance between the laser and the welding wire is adjusted to 0mm. The angle between the wire feed guide and the horizontal plane is 45°. The laser power is set to 1200W and the welding speed is 1.2m / min to deposit the root weld. The total height of the stainless steel layer weld metal is controlled to be 12mm. S4) Transition layer welding: The post-feeding method is adopted, using aluminum bronze with a composition of 10wt%Al, 3wt%Fe, 3wt%Mn, and balance Cu, and a diameter of 1.6mm as filler wire. The laser and wire spacing is adjusted to 0mm, the angle between the wire guide and the horizontal plane is 45°, the laser power is set to 1000W, and the welding speed is 1.5m / min to deposit the transition layer weld. The total height of the transition layer weld metal is controlled at 6mm, and the total width of the transition layer weld metal is controlled at 5mm. S5) Cover layer welding: The post-feeding method is adopted, using aluminum bronze with a composition of 10wt%Al, 3wt%Fe, 3wt%Mn, and balance Cu, and a diameter of 1.6mm as filler wire. The laser and wire spacing is adjusted to 0mm, the angle between the wire guide and the horizontal plane is 45°, the laser power is set to 1000W, and the welding speed is 1.5m / min to deposit the transition layer weld. The total height of the cover layer weld metal is controlled to be 6mm. The width of the cover layer weld metal can be obtained by subtracting the width of the transition layer from the total width of the bevel.

[0058] Non-destructive testing: After the base layer, transition layer and cover layer molten metal are filled, X-ray non-destructive testing is performed on the weld area. No cracks were detected in the weld area, there were no slag inclusions in the weld, there were no gaps between the weld metal and the sidewall of the base material, and the weld was smooth without undercut.

[0059] Comparative Example 1 A method for fusion welding of copper / stainless steel explosion-bonded composite plates is as follows: S1) Cleaning of the base material surface: Use a stainless steel wire brush to polish the oil and rust on the bevel of the copper / stainless steel explosion composite plate to be welded and within 50mm on both sides of the bevel until the metal luster is exposed. Then rinse the area to be welded with anhydrous ethanol and let it air dry naturally. S2) Bevel Assembly: The copper / stainless steel explosion-proof composite plates to be welded are tack-welded using gas shielded welding. The tack-welding area is located on one side of the stainless steel layer, specifically inside the V-groove of the stainless steel layer. The tack-welding point is 10-15mm from the end and has a diameter of 10-15mm. The tack-welding wire grade is 022Cr17Ni12Mo2 (equivalent to commercially available ER316L). The tack-welding current is 180A and the welding voltage is 20V. After tack-welding, the assembly quality of the product is inspected to ensure that the process requirements of 1mm bevel root gap, 1mm blunt edge, and 60° bevel angle are met. S3) Stainless steel layer welding: Use ER316L with a diameter of 1.2mm as filler wire, adjust the welding current to 230A, welding voltage to 24V, welding speed to 0.3m / min, and the angle between the wire feed guide and the horizontal plane to 45°. Deposit the root layer weld and control the total height of the deposited metal on the stainless steel side to 6mm. S4) Transition layer welding: Use aluminum bronze with a composition of 10wt%Al, 3wt%Fe, 3wt%Mn, and balance Cu, and a diameter of 1.2mm as filler wire. Adjust the welding current to 160A, welding voltage to 18V, welding speed to 0.3m / min, and the angle between the wire guide and the horizontal plane to 45°. Deposit the transition layer weld, control the total height of the transition layer weld metal to be 2mm, and control the total width of the transition layer weld metal to be 3mm. S5) Cover layer welding: Use aluminum bronze with a composition of 10wt%Al, 3wt%Fe, 3wt%Mn, and balance Cu, and a diameter of 1.2mm as filler wire. Adjust the welding current to 160A, welding voltage to 18V, welding speed to 0.3m / min, and the angle between the wire guide and the horizontal plane to 45°. Deposit the cover layer weld, and control the total height of the deposited metal in the cover layer to be 2mm. The width of the deposited metal in the cover layer can be obtained by subtracting the width of the transition layer from the total width of the bevel.

[0060] Non-destructive testing: After the base coat, transition layer, and cover coat molten metal were deposited, X-ray non-destructive testing was performed on the weld area. The test revealed weld cracks in the transition layer area. The presumed cause is that the welding arc coverage area was too wide, causing copper to penetrate into the stainless steel grain boundaries.

[0061] Experimental Example 1 Experiment 1 used the laser filler wire welding process to conduct a comparative test on several other copper-based welding wires. The test results are shown in Table 1. Table 1. Comparative Test Results of Copper-Based Welding Wires Using Laser Filler Wire Welding Process

[0062] Based on comparative experiments and comprehensive analysis of welding quality, precious metal content (production cost) of welding wire, and process window conditions, and in accordance with the principle of similar-dissolved metallurgy, aluminum bronze welding wire was selected as the welding wire material for the transition layer and the cover layer.

[0063] While the embodiments disclosed in this invention are as described above, their content is merely for the purpose of facilitating understanding of the technical solutions of this invention and is not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and changes to the form and details of the implementation without departing from the core technical solutions disclosed in this invention; however, the scope of protection defined by this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A weld structure for a copper / stainless steel explosion-proof composite plate, characterized in that, It includes a stainless steel underlayer (5), an aluminum bronze transition layer (6), and an aluminum bronze capping layer (7) formed by laser welding; the stainless steel underlayer (5) is located within the bevel of the stainless steel layer (1), the aluminum bronze capping layer (7) covers the surface of the stainless steel underlayer (5), and the aluminum bronze transition layer (6) is located between the aluminum bronze capping layer (7) and the bevel of the copper layer (2).

2. The weld structure of the copper / stainless steel explosion-proof composite plate according to claim 1, characterized in that, The stainless steel layer (1) of the copper / stainless steel explosion composite plate has a V-shaped bevel, and the copper layer (2) has an I-shaped bevel.

3. The weld structure of the copper / stainless steel explosion-proof composite plate according to claim 2, characterized in that, Includes at least one of the following technical features: (1) The V-shaped bevel angle is 60~70°; (2) The blunt edge L of the V-shaped bevel is 0~1mm, and the bevel gap h is 1~2mm; (3) The width of the type I bevel is 40~60mm; (4) The aluminum bronze in the aluminum bronze transition layer and the aluminum bronze cover layer comprises the following components: 8~10wt% Al, 3~5wt% Fe, 1.5~3wt% Mn, and balance Cu; (5) The total thickness of the copper / stainless steel explosion composite plate is 8~16mm, the thickness t1 of the copper layer is 2~4mm, and the thickness t2 of the stainless steel layer is 6~12mm.

4. The weld structure of the copper / stainless steel explosion-proof composite plate according to claim 3, characterized in that, The thickness of the stainless steel underlayer is 6~12mm, the thickness of the aluminum bronze transition layer is 2~6mm, and the thickness of the aluminum bronze cover layer is 2~6mm.

5. A welding method for a copper / stainless steel explosion-proof composite plate, characterized in that: The stainless steel base layer, aluminum bronze transition layer, and aluminum bronze top layer are welded sequentially using laser welding technology.

6. The welding method for the copper / stainless steel explosion-proof composite plate according to claim 5, characterized in that, The laser welding process has a welding speed of 1.2m / min to 1.5m / min and a laser power of 1000 to 1500W.

7. The welding method for copper / stainless steel explosion-proof composite plates according to claim 5 or 6, characterized in that, The laser welding process uses a wire feeding method where the laser is in front and the welding wire is behind, with a distance of 0 mm between the laser and the welding wire.

8. The welding method for the copper / stainless steel explosion-proof composite plate according to claim 7, characterized in that, The angle θ between the wire feeding guide and the horizontal axis is 45°~60°.

9. The welding method for the copper / stainless steel explosion-proof composite plate according to claim 5 or 6, characterized in that, Includes at least one of the following technical features: (1) When welding stainless steel for the root pass, use stainless steel with a diameter of 1.2 mm as filler wire and control the total height of the deposited metal to be 6~12 mm. (2) The aluminum bronze transition layer is welded using aluminum bronze with a diameter of 1.2mm~1.6mm as filler wire. The aluminum bronze includes the following components: 8~10wt%Al, 3~5wt%Fe, 1.5~3wt%Mn, balance Cu. The total height of the deposited metal is controlled to be 2~6mm and the width of the deposited metal is 3~5mm. (3) The aluminum bronze cover layer is welded using aluminum bronze with a diameter of 1.2mm~1.6mm as filler wire. The aluminum bronze includes the following components: 8~10wt%Al, 3~5wt%Fe, 1.5~3wt%Mn, balance Cu, and the total height of the deposited metal is 2~6mm.

10. The welding method for the copper / stainless steel explosion-proof composite plate according to claim 5, characterized in that, Before the actual welding, the base material surface is cleaned and the bevel is assembled.

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