A combined connection method for base welding of dissimilar materials

Abstract

The present invention relates to the field of welding technology, and specifically discloses a combined connection method for base welding of dissimilar materials. The combined connection method, first, designs and prepares a group of welding materials, the welding materials match the respective connected parent materials, and the welding materials match each other; second, selects a suitable heat source and adopts a corresponding cladding method for cladding to prepare a composite weld cladding layer; third, designs and processes the groove; fourth, selects a suitable heat source and adopts a corresponding connection method for connection to prepare a composite weld connection layer. The combined connection method provided by the present invention has a variety of optional heat source types, efficient design and development of welding materials and connection processes, good welding flexibility, high efficiency, low cost, excellent base welding composite weld partitioning, can avoid the formation of brittle structure, heat input is precisely controllable, stress and deformation are small, weld formation is beautiful, and the comprehensive performance of the welding joint is good, which can realize base welding connection of dissimilar materials with large differences in physical properties and poor chemical compatibility.

Description

Technical Field

[0001] The invention belongs to the technical field of welding, and in particular relates to a combined connection method for base welding of dissimilar materials. Background Art

[0002] There is a wide demand for advanced dissimilar material connection structures in the fields of shipbuilding, aerospace, nuclear industry, petrochemical industry, mechanical equipment, automobiles, marine engineering, medical equipment, sports equipment, etc. However, due to the significant differences in the physical and chemical properties of dissimilar materials such as high-temperature alloys, high-entropy alloys, medium-entropy alloys, intermetallic compounds, composite materials, refractory metals, non-ferrous metals, stainless steel, etc., the conventional welding methods currently used, such as fusion welding, brazing, pressure welding, and fusion brazing, cannot perfectly solve the problem of these dissimilar material connections, especially for the connection of dissimilar materials in medium and thick plates. Among them, the base welding connection technology is the key link in the multi-layer and multi-pass welding of dissimilar materials in medium and thick plates, and has a vital impact on the performance of the joints. Therefore, these problems have led to limited application of dissimilar material connection structures in medium and thick plates in important industrial fields.

[0003] For the connection of dissimilar materials in medium and thick plates, due to the limitation of the power of the heat source equipment, multi-layer and multi-pass welding must be adopted. To this end, first of all, it is necessary to realize the efficient and high-quality preparation of the composite weld of the base welding of dissimilar materials, so as to solve the problems of difficulty in developing welding materials for base welding of dissimilar materials, poor welding flexibility, complex connection process, high stress, easy generation of brittle structure, poor weld performance, and difficulty in preparing composite welds. Secondly, the prepared base welding weld must be able to adapt to the next multi-layer and multi-pass welding process, such as spatially arranged three-wire consumable electrode gas shielded welding process (three-wire composite consumable electrode gas shielded welding process), double-wire composite gas shielded welding and single-wire gas shielded welding combined connection process, wire additive connection process, and double-wire composite gas shielded welding and tandem double-wire gas shielded welding combined connection process, etc., to ensure efficient and high-quality realization of multi-layer and multi-pass filling welding of dissimilar materials in medium and thick plates, so that the filling welding process is stable, the filling welding composite weld is well formed, the structure is excellent, and the comprehensive performance of the welding joint is high.

[0004] Therefore, in order to realize the base welding of dissimilar materials, the pre-prepared base welding seam must be controlled by partitioning, so that different regions and interfaces form a structure with excellent comprehensive performance to avoid the formation of brittle structure. At the same time, the physical properties of the prepared base welding composite welding joint form a gentle gradient transition perpendicular to the weld direction to avoid sudden changes in physical properties, thereby reducing welding stress and deformation. However, due to the particularity of the base welding connection position, the large difference in physical properties and poor chemical compatibility between dissimilar materials, and the large difference in physical properties and poor interface chemical compatibility between the components of the dissimilar materials themselves, the use of a welding material and a corresponding welding process, or a welding material and a corresponding set of welding processes, or a set of two welding materials and a corresponding welding process, or a set of two welding materials and a corresponding set of two welding processes cannot achieve efficient and high-quality preparation of the base welding composite weld of dissimilar materials.

[0005] In summary, how to efficiently achieve the connection of dissimilar materials with the backing weld in order to reduce costs, how to effectively avoid the performance degradation or even cracking caused by the formation of brittle structure in the weld, how to reduce the large welding stress and deformation caused by the difference in physical properties of dissimilar materials, and how to achieve the partition preparation of the composite weld of the backing weld of dissimilar materials in medium and thick plates to adapt to the next filling welding process are the core issues that need to be solved in the backing weld connection of dissimilar materials. In order to solve these welding problems, the use of a single welding material and a single welding process, a single welding material and a combined welding process, a combination of two welding materials and a single welding process, and a combination of two welding materials and the corresponding combination of two welding processes cannot achieve the backing weld connection of dissimilar materials with high efficiency and quality. The welding materials and welding processes must be accurately decomposed, and three complex combinations of welding materials and matching combined welding processes must be used to form a new backing weld connection technology to perfectly solve the backing weld connection problem of dissimilar materials. Summary of the invention

[0006] In view of the problems of poor welding flexibility, low efficiency, high cost, difficulty in welding material design and development, difficulty in welding process design and implementation, easy generation of brittle structure, large welding stress and deformation, difficulty in regulating the structure and performance of the base welding composite weld, poor comprehensive performance of the welded joint, difficulty in preparing the base welding composite weld, and inability to adapt to the next step of multi-layer and multi-pass filling welding process, the present invention proposes a combined connection method for base welding of dissimilar materials.

[0007] In order to achieve the above-mentioned object of the invention, the present invention is implemented by adopting the following technical solutions:

[0008] (1) According to the composition, components, physical and chemical properties of the base material 1 and the base material 2 in the dissimilar materials to be connected, a group of welding materials, including welding material 1, welding material 2 and welding material 3, are designed, wherein welding material 1 matches base material 1, welding material 2 matches base material 2, welding material 3 matches both welding material 1 and welding material 2, and welding material 1, welding material 2 and welding material 3 are prepared;

[0009] (2) Selecting a suitable heat source and adopting a corresponding cladding method to perform cladding to prepare a composite weld cladding layer, first, cleaning the cladding surface of the base material 1, directing the heat source to the cladding surface of the base material 1, setting the heat source process parameters, starting the gas supply system and the heat source equipment, using the welding material 1 to perform heat source cladding, and preparing the cladding layer 1 on the surface of the base material 1; second, cleaning the cladding surface of the base material 2, directing the heat source to the cladding surface of the base material 2, setting the heat source process parameters, starting the gas supply system and the heat source equipment, using the welding material 2 to perform heat source cladding, and preparing the cladding layer 2 on the surface of the base material 2, or cleaning the surface of the cladding layer 1, directing the heat source to the surface of the cladding layer 1, setting the heat source process parameters, starting the gas supply system and the heat source equipment, using the welding material 3 to perform heat source cladding, and preparing the cladding layer 3 on the surface of the cladding layer 1;

[0010] (3) Design appropriate groove form and size, process and clean the groove according to the methods and process requirements of base welding and filling welding;

[0011] (4) Select a suitable heat source and adopt a corresponding connection method to connect, prepare a composite weld connection layer, set the heat source process parameters, start the gas supply system and the heat source equipment, point the heat source to the groove position, and use welding material 3 to connect the connected surfaces of the cladding layer 1 and the cladding layer 2, or use welding material 2 to connect the connected surfaces of the cladding layer 3 and the base material 2.

[0012] The basic principle of a combined connection method for root welding of dissimilar materials is as follows:

[0013] First, design and prepare a group of three welding materials, decompose the welding materials, and make the composition, components, content, structure, and performance of the prepared base welding partition composite weld meet the requirements. The physical properties of different base materials are very different, the chemical compatibility is poor, and the physical properties of the components of the different base materials themselves are very different and the interface chemical compatibility is poor. It is easy to produce brittle structure by using one welding material and one or two corresponding connection processes. It is also difficult to avoid the generation of brittle structure by using two welding materials and one or two corresponding connection processes, resulting in poor performance and large stress and deformation. To this end, firstly, according to the characteristics of the parent material, a group of three welding materials are designed, requiring that welding material 1 has good chemical compatibility with parent material 1, welding material 2 has good chemical compatibility with parent material 2, and welding material 3 has good chemical compatibility with both welding material 1 and welding material 2, so as to avoid the formation of brittle structure; secondly, the physical properties of welding material 1 and parent material 1 are slightly different, the physical properties of welding material 2 and parent material 2 are slightly different, and the physical properties of welding material 3 and welding material 1 and welding material 2 are slightly different, so that the physical properties of the partitioned composite weld formed after welding form a relatively gentle gradient transition, reducing welding stress and deformation, thereby solving the problem of large welding stress and deformation caused by large differences in the physical properties of dissimilar parent materials. Therefore, by designing a set of three welding materials in an organic combination, the type, composition, components and content of the welding materials are decomposed and designed, so that welding material 1 matches base material 1, welding material 2 matches base material 2, and welding material 3 matches both welding material 1 and welding material 2 (matching refers to good chemical compatibility between materials, small difference in physical properties, etc.), and matching connection processes are used for cladding and connection one by one, which facilitates the regulation of the composition, component, content, structure and physical properties of each zone and interface layer of the composite weld, so that the comprehensive performance of each zone of the composite weld is excellent.

[0014] Second, select a suitable heat source and use the corresponding cladding method for cladding, prepare the composite weld cladding layer, and prepare for the next connection. In order to achieve the connection of the base weld composite weld, the heat source is directed to the surface of a parent material or cladding layer for cladding or additive manufacturing. Due to the complexity of the composition, components, content, structure of different regions of the composite weld and the particularity of the base weld position, the use of a welding material and a corresponding connection process, or a welding material and a corresponding combined connection process, or a group of two welding materials and a corresponding connection process (such as double-wire consumable arc welding and double-wire non-consumable arc welding), or a group of two welding materials and a corresponding combination of two connection processes cannot achieve efficient and high-quality preparation of the base weld composite weld. The welding materials and connection processes must be finely decomposed. First, the base weld composite weld cladding layer is prepared using two matching welding materials and cladding methods and processes to prepare the base weld composite weld connection layer in the next step using matching welding materials and connection methods and processes.

[0015] Third, design and prepare appropriate groove forms and sizes to meet the method and process requirements of base welding and filling welding of dissimilar materials, improve welding efficiency and reduce costs. At the same time, the appropriate groove form and size should also make the physical properties of the prepared base welding composite connection joint form a gentle gradient transition perpendicular to the weld direction to avoid sudden changes in physical properties, thereby reducing welding stress and deformation. After using a heat source to prepare two cladding layers, the groove is designed and prepared according to the requirements of the base welding connection method and process and the filling welding connection method and process. The groove includes a base welding groove and a filling welding groove to prepare for the next step of preparing the base welding connection layer and meet the filling welding connection method and process requirements. That is, by using appropriate base welding grooves and filling welding grooves, the various regions of the composite weld prepared by the base welding process can match the various regions of the composite weld prepared by the filling welding process, and the chemical compatibility of each region is good, and the difference in physical properties of each region is small, which improves welding efficiency, reduces welding costs, and reduces welding stress and deformation. The connection sequence of the base welding combined connection method is: first use a heat source for cladding to prepare a cladding layer, then open a groove, and finally use a heat source for base welding connection; if the process sequence is to first open a groove, then use a heat source for cladding, then adjust the groove, and finally connect, the groove will be damaged due to the action of the heat source, and the groove form and size cannot meet the requirements, nor can they meet the needs of the next base welding connection process and the filling welding connection process, so the groove after cladding must be trimmed. Therefore, the design and processing of the groove are very important in the implementation order of the entire connection method. At the same time, the design and preparation of a suitable groove form and size must also make the physical properties of the formed welded joint form a gentle gradient transition perpendicular to the weld direction. This makes the combined connection method have the advantages of high connection efficiency, small stress and deformation, small groove processing amount, welding material saving and low welding cost.

[0016] Fourth, select a suitable heat source and use the corresponding connection method to connect, prepare the composite weld connection layer, so as to realize the preparation of the composite weld of the base weld and meet the composition, components, content and structure requirements of the composite weld of the base weld. After completing the preparation of the cladding layer, design the groove form and size, process and clean the groove, and then use matching welding materials, point the heat source to the groove position, and use a suitable heat source and connection method to connect the cladding layer and the cladding layer or the cladding layer and the parent material, so as to finally realize the preparation of the composite weld of the base weld. Due to the use of combined welding materials and matching combined welding processes, the prepared composite weld of the base weld has excellent partitioning, which can effectively isolate elements with poor chemical compatibility and avoid the formation of brittle structure, so as to meet the composition, components, content and structure requirements of the composite weld of the base weld partition, so that the composite weld of the base weld is beautiful in shape and the comprehensive performance of the base weld joint is good.

[0017] In summary, by accurately decomposing the welding materials and connection processes, designing and adopting a combination of three welding materials and the corresponding combined connection processes, it is possible to prepare base welding composite welds with high efficiency and high quality, effectively isolate elements with poor chemical compatibility, avoid the formation of brittle structures, and prepare composite welds with a moderate physical property gradient transition, thereby reducing the large welding stress and deformation caused by the difference in physical properties. The prepared base welding composite welds have excellent structure and good comprehensive performance of the welding joints.

[0018] Compared with the prior art, the combined connection method for base welding of dissimilar materials provided by the present invention has the following beneficial effects: multiple types of heat sources can be selected, multiple cladding and connection methods can be selected, the design and development of combined welding materials and combined connection processes are efficient, the welding flexibility is good, the welding efficiency is high, the cost is low, the base welding composite weld is excellent in partitioning, the formation of brittle structure can be avoided, the heat input is precisely controllable, the welding stress and deformation are small, the base welding composite weld is beautiful in formation, the welding joint structure and performance are easy to regulate, the internal quality of the base welding composite weld is excellent, and the comprehensive performance of the base welding welding joint is good, which can meet the next step of multi-layer and multi-pass filling welding method and process requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a connection flow chart of a combined connection method for base welding of dissimilar materials.

[0020] Figure 2 It is the groove design drawing of Example 1, wherein 1 is TC4 titanium alloy base material, 2 is 304 stainless steel base material, 3 is vanadium-based alloy cladding layer, 4 is copper-nickel alloy cladding layer, 5 is base material thickness, 6 is 304 stainless steel base material upper groove arc radius, 7 is TC4 titanium alloy base material upper groove arc radius, 8 is 304 stainless steel base material lower groove arc radius, 9 is TC4 titanium alloy base material lower groove arc radius, 10 is 304 stainless steel base material bottoming Height of blunt edge of weld, 11 is the upper bevel angle of 304 stainless steel base material, 12 is the upper bevel angle of TC4 titanium alloy base material, 13 is the lower bevel angle of 304 stainless steel base material, 14 is the lower bevel angle of TC4 titanium alloy base material, 15 is the upper bevel angle of 304 stainless steel base material base weld, 16 is the lower bevel angle of 304 stainless steel base material base weld, 17 is the upper bevel depth, 18 is the height of blunt edge of TC4 titanium alloy base material base weld, and 19 is the root gap.

[0021] Figure 31 is the groove design drawing of Example 2, wherein 1 is TA15 titanium alloy base material, 2 is Inconel718 nickel-based alloy, 3 is vanadium-based alloy cladding layer, 4 is copper-nickel alloy cladding layer, 5 is base material thickness, 6 is TA15 titanium alloy base material bottom welding groove arc radius, 7 is Inconel718 nickel-based alloy base material bottom welding groove arc radius, 8 is Inconel718 nickel-based alloy base material upper groove arc radius, 9 is TA15 titanium alloy base material upper groove arc radius, 10 is 11 is the arc radius of the lower groove of the Inconel718 nickel-based alloy base material, 12 is the upper groove angle of the Inconel718 nickel-based alloy base material, 13 is the upper groove angle of the TA15 titanium alloy base material, 14 is the lower groove angle of the Inconel718 nickel-based alloy base material, 15 is the lower groove angle of the TA15 titanium alloy base material, 16 is the blunt edge height of the base weld, 17 is the groove depth of the base weld, 18 is the upper groove depth, and 19 is the root gap.

[0022] Figure 4 It is the groove design drawing of Example 3, wherein 1 is TA2 pure titanium base material, 2 is Ta1 pure tantalum base material, 3 is vanadium-based alloy cladding layer, 4 is vanadium-niobium alloy cladding layer, 5 is base material thickness, 6 is Ta1 pure tantalum base material groove arc radius, 7 is TA2 pure titanium base material groove arc radius, 8 is groove depth, 9 is base weld blunt edge height, 10 is Ta1 pure tantalum base material groove angle, 11 is TA2 pure titanium base material groove angle, and 12 is root gap.

[0023] Figure 5 It is the groove design drawing of Example 4, wherein 1 is 304 stainless steel base material, 2 is TA15 titanium alloy base material, 3 is nickel-based alloy cladding layer, 4 is vanadium-based alloy cladding layer, 5 is base material thickness, 6 is TA15 titanium alloy base material groove arc radius, 7 is 304 stainless steel base material groove arc radius, 8 is groove depth, 9 is base weld blunt edge height, 10 is TA15 titanium alloy base material groove arc radius, 11 is 304 stainless steel base material groove arc radius, and 12 is root gap.

[0024] Figure 6 It is the groove design drawing of Example 5, wherein 1 is TaW2.5 tantalum alloy base material, 2 is Inconel625 nickel-based alloy base material, 3 is niobium-based alloy cladding layer, 4 is vanadium-based alloy cladding layer, 5 is base material thickness, 6 is Inconel625 nickel-based alloy base material groove angle, 7 is TaW2.5 tantalum alloy base material groove arc radius, 8 is groove depth, 9 is base weld groove blunt edge height, 10 is TaW2.5 tantalum alloy base material groove angle, and 11 is root gap.

[0025] Figure 7It is the groove design drawing of Example 6, wherein 1 is TiAl intermetallic compound base material, 2 is 40Cr steel base material, 3 is titanium-based alloy cladding layer, 4 is copper-based alloy cladding layer, 5 is base material thickness, 6 is 40Cr steel base material groove arc radius, 7 is TiAl intermetallic compound base material groove arc radius, 8 is 40Cr steel base material root weld groove angle, 9 is TiAl intermetallic compound base material root weld groove angle, 10 is root weld groove depth, 11 is root weld blunt edge height, and 12 is root gap.

[0026] Figure 8 is the groove design drawing of Example 7, wherein 1 is TiB P / TC4 composite material base material, 2 is 316L stainless steel base material, 3 is titanium-based alloy cladding layer, 4 is vanadium-based alloy cladding layer, 5 is base material thickness, 6 is 316L stainless steel base material groove angle, 7 is TiB P / TC4 composite material base material groove angle, 8 is groove depth, 9 is base weld blunt edge height, 10 is base weld groove angle, 11 is root gap.

[0027] Fig. 9 It is the groove design drawing of Example 8, wherein 1 is TC4 titanium alloy base material, 2 is TaNb3 tantalum alloy base material, 3 is titanium-based alloy cladding layer, 4 is niobium-based alloy cladding layer, 5 is base material thickness, 6 is TaNb3 tantalum alloy base material groove angle, 7 is TC4 titanium alloy base material groove angle, 8 is groove depth, 9 is base weld blunt edge height, 10 is TaNb3 tantalum alloy base material groove angle, 11 is TC4 titanium alloy base material groove angle, and 12 is root gap. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0029] The embodiment of the present invention provides a combined connection method for base welding of dissimilar materials. The method comprises the following steps:

[0030] (1) According to the composition, components, physical and chemical properties of the base material 1 and the base material 2 in the dissimilar materials to be connected, a group of welding materials, including welding material 1, welding material 2 and welding material 3, are designed, wherein welding material 1 matches base material 1, welding material 2 matches base material 2, welding material 3 matches both welding material 1 and welding material 2, and welding material 1, welding material 2 and welding material 3 are prepared;

[0031] (2) Selecting a suitable heat source and adopting a corresponding cladding method to perform cladding to prepare a composite weld cladding layer, first, cleaning the cladding surface of the base material 1, directing the heat source to the cladding surface of the base material 1, setting the heat source process parameters, starting the gas supply system and the heat source equipment, using the welding material 1 to perform heat source cladding, and preparing the cladding layer 1 on the surface of the base material 1; second, cleaning the cladding surface of the base material 2, directing the heat source to the cladding surface of the base material 2, setting the heat source process parameters, starting the gas supply system and the heat source equipment, using the welding material 2 to perform heat source cladding, and preparing the cladding layer 2 on the surface of the base material 2, or cleaning the surface of the cladding layer 1, directing the heat source to the surface of the cladding layer 1, setting the heat source process parameters, starting the gas supply system and the heat source equipment, using the welding material 3 to perform heat source cladding, and preparing the cladding layer 3 on the surface of the cladding layer 1;

[0032] (3) Design appropriate groove form and size, process and clean the groove according to the methods and process requirements of base welding and filling welding;

[0033] (4) Select a suitable heat source and adopt a corresponding connection method to connect, prepare a composite weld connection layer, set the heat source process parameters, start the gas supply system and the heat source equipment, point the heat source to the groove position, and use welding material 3 to connect the connected surfaces of the cladding layer 1 and the cladding layer 2, or use welding material 2 to connect the connected surfaces of the cladding layer 3 and the base material 2.

[0034] Specifically, in step (1), a group of welding materials is designed and prepared according to the physical and chemical properties of the base material 1 and the base material 2 in the dissimilar materials to be connected. The group of welding materials includes three welding materials. The welding material 1 and the welding material 2 are required to match the base material 1 and the base material 2 respectively clad, and the welding material 3 is required to match the welding material 1 and the welding material 2. That is, the welding material 1 is required to have good chemical compatibility with the base material 1 and the physical property difference is small, the welding material 2 is required to have good chemical compatibility with the base material 2 and the physical property difference is small, and the welding material 3 is required to have good chemical compatibility with the welding material 1 and the physical property difference is small, so as to avoid the formation of brittle structure, so that the composition, components, content, structure and performance of the prepared base welding partition composite weld meet the requirements, and at the same time, the physical property difference of the partition composite weld formed after welding is small, forming a relatively gentle gradient transition, so that the welding stress and deformation are small.

[0035] In step (2), a suitable heat source is selected and a corresponding cladding method is used for cladding so as to manufacture two cladding layer parts of the base welding composite weld, and a cladding layer 1 is prepared on the surface of the base material 1, and a cladding layer 2 is prepared on the surface of the base material 2, or a cladding layer 1 is prepared on the surface of the base material 1, and a cladding layer 3 is prepared on the surface of the cladding layer 1, so as to meet the composition, component, content, and structure requirements of the cladding layer of the base welding composite weld and prepare for the next step of connection.

[0036] In step (3), according to the method and process requirements of base welding and filling welding, the groove form and size are designed, and the groove is processed and cleaned to facilitate the next step of base welding connection, meet the requirements of base welding composite weld zoning, and can adapt to the process requirements of filling welding, that is, each zone of the composite weld prepared by the base welding process can match each zone of the composite weld prepared by the filling welding process, each zone has good chemical compatibility, and the difference in physical properties is small. At the same time, the welding efficiency is improved, the welding cost is reduced, and the welding material is saved. The appropriate groove form and size also make the physical properties of the prepared base welding composite connection joint form a gentle gradient transition in the direction perpendicular to the weld, avoiding sudden changes in physical properties, thereby reducing welding stress and deformation.

[0037] In step (4), a suitable heat source is selected and a corresponding connection method is used for connection to realize the preparation of the base welding composite weld connection layer to meet the composition, component, content and structural requirements of the base welding composite weld connection layer.

[0038] Preferably, the types of welding materials include wires and powders, so that the composition, components and content of the welding materials are easier to design and adjust, and a wider range of cladding and connection methods are adopted.

[0039] Preferably, the wire diameter is 0.6-2.4 mm, the wire feeding speed is 0.5-20 m / min, the powder mesh is 50-650 mesh, and the powder feeding speed is 8-240 g / min. By selecting a suitable wire diameter and powder mesh, and by adjusting the wire feeding speed and the powder feeding speed, a variety of cladding and connection methods can be adapted, which facilitates the regulation of the composition, components and structure of the composite weld, so that the composite weld has excellent partitioning, beautiful forming, and reduced deformation and stress.

[0040] Preferably, the filling welding process includes a spatially arranged three-wire consumable electrode gas shielded welding process, a double-wire composite gas shielded welding and a single-wire gas shielded welding combined connection process, a wire additive connection process, and a double-wire composite gas shielded welding and a tandem double-wire gas shielded welding combined connection process, so that each zone of the composite weld prepared by the filling welding process can match each zone of the composite weld prepared by the corresponding base welding process, that is, each zone has good chemical compatibility and small difference in physical properties.

[0041] Preferably, the shielding gas of the gas supply system is at least one of Ar, He, CO2, O2, and N2, and the gas flow rate is 10 to 50 L / min. Different shielding gases are selected according to the types of base materials and welding materials, connection costs and efficiency, so that the cladding and connection are carried out under gas protection to ensure the internal quality and weld formation of the base welding composite weld. At the same time, the shielding gas serves as a medium for generating electric arc and plasma arc, maintaining the stable combustion of electric arc and plasma arc, so that when the consumable arc, non-consumable arc and plasma arc are used as heat sources, the cladding and connection process are stable.

[0042] Preferably, the types of heat sources include consumable arc heat source, non-consumable arc heat source, plasma arc heat source, laser heat source and laser + arc composite heat source, which are used to melt welding materials and base materials for cladding and connection.

[0043] Preferably, the cladding and connection methods corresponding to the consumable arc heat source include single-wire consumable arc welding and double-wire consumable arc welding, which facilitates the base welding cladding and connection of dissimilar materials of different thicknesses, thereby improving the preparation efficiency and forming quality.

[0044] Preferably, the twin wires of the twin-wire consumable electrode arc welding may have the same or different compositions, which facilitates the adjustment and preparation of composite welds with complex compositions, components and structures.

[0045] Preferably, the cladding and connection methods corresponding to the non-consumable arc heat source include single-wire non-consumable arc welding and double-wire non-consumable arc welding, which facilitates the base welding cladding and connection of dissimilar materials of different thicknesses, thereby improving the preparation efficiency and forming quality.

[0046] Preferably, the twin wires of the twin-wire non-melting electrode arc welding may have the same or different compositions, which facilitates the adjustment and preparation of composite welds with complex compositions, components and structures.

[0047] Preferably, the cladding and connection methods corresponding to the plasma arc heat source include plasma spray welding and plasma wire-filling welding, which facilitates the base welding cladding and connection of dissimilar materials of different thicknesses, thereby improving the preparation efficiency and forming quality.

[0048] Preferably, the cladding and connection methods corresponding to the laser heat source include laser wire filling welding and powder feeding laser cladding, which facilitates the base welding cladding and connection of dissimilar materials of different thicknesses, thereby improving the preparation efficiency and forming quality.

[0049] Preferably, the cladding and connection method corresponding to the laser + arc composite heat source is laser melting electrode arc hybrid welding, which is convenient for base welding cladding and connection of dissimilar materials of different thicknesses, thereby improving preparation efficiency and forming quality.

[0050] Preferably, the process parameters of the consumable arc heat source, the non-consumable arc heat source and the plasma arc heat source are: an average welding current of 20 to 400 A, an average arc voltage of 8 to 40 V, and a welding speed of 0.3 to 2.4 m / min. By adjusting the heat source process parameters, regulating the heat input, and controlling the melting amount of the welding material and the dilution rate of the parent material, the cladding and connection processes are stable, the base welding composite weld is beautifully formed, the composite weld is well partitioned, and elements with poor chemical compatibility can be effectively isolated, the welding stress and deformation are small, and the internal quality of the weld is excellent.

[0051] Preferably, the process parameters of the laser heat source are: laser power of 0.5-9kW, welding speed of 0.5-4m / min, and the process parameters of the laser + arc composite heat source are: laser power of 1-9kW, average welding current of 20-400A, average arc voltage of 8-40V, and welding speed of 0.5-2m / min. By adjusting the process parameters of the heat source, regulating the heat input, controlling the melting amount of the welding material and the dilution rate of the parent material, the cladding and connection processes are stable, the base welding composite weld is beautifully formed, the composite weld is well partitioned, and elements with poor chemical compatibility can be effectively isolated, the welding stress and deformation are small, and the internal quality of the weld is excellent.

[0052] The combined connection method for base welding of dissimilar materials provided by the present invention can solve the base welding connection problems of dissimilar materials caused by large differences in physical properties of parent materials, poor chemical compatibility and special base welding weld positions. It has a variety of optional heat source types, a variety of optional cladding and connection methods, efficient design and development of combined welding materials and combined welding processes, good welding flexibility, high welding efficiency, low cost, excellent base welding composite weld zoning, which can avoid the formation of brittle structure, precise and controllable heat input, small welding stress and deformation, beautiful base welding composite weld formation, easy regulation of welding joint structure and performance, excellent internal quality of base welding composite weld and good comprehensive performance of base welding welding joint, which can meet the next step of multi-layer and multi-pass filling welding method and process requirements.

[0053] In order to better illustrate the combined connection method for base welding of dissimilar materials provided by the present invention, further examples are given below.

[0054] Example 1

[0055] A combined connection method for bottom welding of dissimilar materials of TC4 titanium alloy and 304 stainless steel, wherein the connecting parent materials are TC4 titanium alloy and 304 stainless steel, the two materials have poor chemical compatibility, the Ti element in the TC4 titanium alloy and the Fe element in the 304 stainless steel are easy to generate brittle structures, and the physical properties such as linear expansion coefficient, thermal conductivity and specific heat capacity of the TC4 titanium alloy and the 304 stainless steel are also quite different, in order to implement the bottom welding connection of dissimilar materials of TC4 titanium alloy and 304 stainless steel, the method specifically comprises the following steps:

[0056] (1) According to the composition, components, physical and chemical properties of the parent materials TC4 titanium alloy and 304 stainless steel in the dissimilar materials to be connected, a group of welding materials, including welding material 1, welding material 2 and welding material 3, are designed, as shown in Table 1, wherein welding material 1 is composed of wire 11 and wire 12, welding material 1 matches the TC4 titanium alloy parent material, welding material 2 matches the 304 stainless steel parent material, welding material 3 matches both welding material 1 and welding material 2, and welding material 1, welding material 2 and welding material 3 are prepared;

[0057] Table 1 Type, composition and content of welding materials

[0058]

[0059] (2) Selecting a consumable arc heat source and a non-consumable arc heat source and adopting corresponding double-wire consumable arc welding and single-wire non-consumable arc welding cladding methods for cladding to prepare a composite weld cladding layer. First, the cladding surface of the TC4 titanium alloy base material is cleaned, and the consumable arc heat source is directed to the cladding surface of the TC4 titanium alloy base material. The consumable arc heat source process parameters are set. The wire 11 of welding material 1 has a diameter of 1.2 mm, a wire feeding speed of 11 m / min, an average welding current of 310 A, and an average arc voltage of 28 V. The wire 12 of welding material 1 has a diameter of 1.2 mm, a wire feeding speed of 9 m / min, an average welding current of 280 A, an average arc voltage of 25 V, a welding speed of 1.9 m / min, and the shielding gas is a mixed gas of Ar and He, with a gas flow rate of 40 L / m in, start the gas supply system and the consumable arc heat source equipment, use welding material 1 to implement consumable arc heat source cladding, and prepare a cladding layer 1 on the surface of the TC4 titanium alloy base material; second, clean the clad surface of the 304 stainless steel base material, point the non-consumable arc heat source to the clad surface of the 304 stainless steel base material, set the process parameters of the non-consumable arc heat source, the wire diameter of the welding material 2 is 1.6mm, the wire feeding speed is 7m / min, the average welding current is 180A, the average arc voltage is 19V, the welding speed is 0.4m / min, the shielding gas is a mixed gas of Ar and O2, and the gas flow rate is 25L / min, start the gas supply system and the non-consumable arc heat source equipment, use welding material 2 to implement non-consumable arc heat source cladding, and prepare a cladding layer 2 on the surface of the 304 stainless steel base material;

[0060] (3) Design the groove form and size according to the methods and process requirements of base welding and filling welding, such as Figure 2 As shown, the base material thickness is 20mm, the arc radius of the upper groove of the TC4 titanium alloy base material is 4mm, the arc radius of the upper groove of the 304 stainless steel base material is 4mm, the arc radius of the lower groove of the TC4 titanium alloy base material is 4mm, the arc radius of the lower groove of the 304 stainless steel base material is 4mm, the blunt edge height of the 304 stainless steel base material base weld is 1mm, the upper groove angle of the TC4 titanium alloy base material is 10°, the upper groove angle of the 304 stainless steel base material is 8°, the lower groove angle of the TC4 titanium alloy base material is 10°, the lower groove angle of the 304 stainless steel base material base weld is 8°, the upper groove angle of the 304 stainless steel base weld is 38°, the lower groove angle of the 304 stainless steel base weld is 38°, the upper groove depth is 8.5mm, the blunt edge height of the TC4 titanium alloy base weld is 3mm, the root gap is 2mm, and the groove is processed and cleaned;

[0061] (4) Select a consumable arc heat source and adopt a single-wire consumable arc welding connection method to prepare a composite weld connection layer, set the consumable arc heat source process parameters, the wire diameter of welding material 3 is 2.0 mm, the wire feeding speed is 12 m / min, the average welding current is 360 A, the average arc voltage is 32 V, the welding speed is 1 m / min, the shielding gas is Ar gas, and the gas flow rate is 48 L / min. Start the gas supply system and the consumable arc heat source equipment, point the consumable arc heat source to the groove position, and use welding material 3 to connect the connected surfaces of the cladding layer 1 and the cladding layer 2.

[0062] Example 2

[0063] A combined connection method for base welding of TA15 titanium alloy and Inconel718 nickel-based alloy materials, wherein the connecting parent materials are TA15 titanium alloy and Inconel718 nickel-based alloy, the two materials have poor chemical compatibility, Ti element in TA15 titanium alloy and Ni, Fe and other elements in Inconel718 nickel-based alloy are prone to generate brittle structure, and the physical properties such as linear expansion coefficient, thermal conductivity and specific heat capacity of TA15 titanium alloy and Inconel718 nickel-based alloy are also quite different, in order to implement base welding connection of dissimilar materials of TA15 titanium alloy and Inconel718 nickel-based alloy, the method specifically comprises the following steps:

[0064] (1) According to the composition, components, physical and chemical properties of the parent materials TA15 titanium alloy and Inconel718 nickel-based alloy in the dissimilar materials to be connected, a group of welding materials, including welding material 1, welding material 2 and welding material 3, are designed, as shown in Table 2, wherein welding material 1 matches the TA15 titanium alloy parent material, welding material 2 matches the Inconel718 nickel-based alloy parent material, welding material 3 matches both welding material 1 and welding material 2, and welding material 1, welding material 2 and welding material 3 are prepared;

[0065] Table 2 Type, composition and content of welding materials

[0066]

[0067] (2) Selecting a laser + arc composite heat source and a laser heat source and using the corresponding laser melting electrode arc composite welding and powder feeding laser cladding method for cladding to prepare a composite weld cladding layer. First, the cladding surface of the TA15 titanium alloy base material is cleaned, and the laser + arc composite heat source is directed to the cladding surface of the TA15 titanium alloy base material. The laser + arc composite heat source process parameters are set. The wire diameter of welding material 1 is 1.6 mm, the wire feeding speed is 19 m / min, the average welding current is 380 A, the average arc voltage is 36 V, the laser power is 8.5 kW, the welding speed is 1.9 m / min, the shielding gas is Ar gas, and the gas flow rate is 35 L / min. The gas supply system and the laser + arc composite heat source equipment are started. Laser + arc composite heat source cladding was performed using welding material 1 to prepare a cladding layer 1 on the surface of the TC4 titanium alloy base material; secondly, the cladding surface of the Inconel718 nickel-based alloy base material was cleaned, the laser heat source was directed to the cladding surface of the Inconel718 nickel-based alloy base material, and the laser heat source process parameters were set. The powder mesh number of welding material 2 was 650 mesh, the powder feeding speed was 60g / min, the laser power was 4kW, the welding speed was 2.5m / min, the shielding gas was a mixed gas of Ar and He, and the gas flow rate was 30L / min. The gas supply system and the laser heat source equipment were started, and the laser heat source cladding was performed using welding material 2 to prepare a cladding layer 2 on the surface of the Inconel718 nickel-based alloy base material;

[0068] (3) Design the groove form and size according to the methods and process requirements of base welding and filling welding, such as Figure 3 As shown, the base material thickness is 15mm, the arc radius of the bottom welding groove of the TA15 titanium alloy base material is 2.1mm, the arc radius of the bottom welding groove of the Inconel718 nickel-based alloy base material is 2.1mm, the arc radius of the upper groove of the Inconel718 nickel-based alloy base material is 3.7mm, the arc radius of the upper groove of the TA15 titanium alloy base material is 3.7mm, the arc radius of the lower groove of the Inconel718 nickel-based alloy base material is 3.4mm, and the arc radius of the lower groove of the TA15 titanium alloy base material is 3.7mm. The arc radius of the lower groove of the gold base material is 3.4mm, the upper groove angle of the Inconel718 nickel-based alloy base material is 10°, the upper groove angle of the TA15 titanium alloy base material is 10°, the lower groove angle of the Inconel718 nickel-based alloy base material is 8°, the lower groove angle of the TC4 titanium alloy base material is 8°, the blunt edge height of the base weld is 1mm, the groove depth of the base weld is 2mm, the upper groove depth is 5.5mm, the root gap is 1.4mm, and the groove is processed and cleaned;

[0069] (4) A non-melting electrode arc heat source is selected and a single-wire non-melting electrode arc welding connection method is used for connection to prepare a composite weld connection layer. The process parameters of the non-melting electrode arc heat source are set. The wire diameter of the welding material 3 is 1.6 mm, the wire feeding speed is 12 m / min, the average welding current is 310 A, the average arc voltage is 21 V, the welding speed is 0.8 m / min, the shielding gas is a mixed gas of Ar and He, and the gas flow rate is 38 L / min. The gas supply system and the non-melting electrode arc heat source equipment are started, the non-melting electrode arc heat source is directed to the groove position, and the connected surfaces of the cladding layer 1 and the cladding layer 2 are connected using the welding material 3.

[0070] Example 3

[0071] A combined connection method for base welding of TA2 pure titanium and Ta1 pure tantalum dissimilar materials, wherein the connecting parent materials are TA2 pure titanium and Ta1 pure tantalum, the two materials have good chemical compatibility, the Ti element in TA2 pure titanium and the Ta element in Ta1 pure tantalum form a solid solution with good comprehensive performance, but the melting point, boiling point, thermal conductivity, specific heat capacity and other physical properties of TA2 pure titanium and Ta1 pure tantalum are quite different, in order to implement base welding connection of TA2 pure titanium and Ta1 pure tantalum dissimilar materials, the method specifically comprises the following steps:

[0072] (1) According to the composition, components, physical and chemical properties of the parent materials TA2 pure titanium and Ta1 pure tantalum in the dissimilar materials to be connected, a group of welding materials, including welding material 1, welding material 2 and welding material 3, are designed, as shown in Table 3, wherein welding material 1 matches the TA2 pure titanium parent material, welding material 2 matches the Ta1 pure tantalum parent material, welding material 3 matches both welding material 1 and welding material 2, and welding material 1, welding material 2 and welding material 3 are prepared;

[0073] Table 3 Type, composition and content of welding materials

[0074]

[0075] (2) Select a plasma arc heat source and a consumable arc heat source and use corresponding plasma spray welding and single-wire consumable arc welding cladding methods to prepare a composite weld cladding layer. First, clean the cladding surface of the TA2 pure titanium base material. Direct the plasma arc heat source to the cladding surface of the TA2 pure titanium base material. Set the plasma arc heat source process parameters. The powder mesh size of welding material 1 is 60 mesh, the powder feeding speed is 220g / min, the average welding current is 380A, the average arc voltage is 38V, the welding speed is 1.5m / min, the shielding gas is a mixed gas of Ar and He, and the gas flow rate is 30L / min. Start the gas supply system and the plasma arc heat source equipment. Use welding material 1 to Plasma arc heat source cladding is applied to prepare cladding layer 1 on the surface of TA2 pure titanium base material; secondly, the cladding surface of Ta1 pure tantalum base material is cleaned, the consumable arc heat source is directed to the cladding surface of Ta1 pure tantalum base material, and the consumable arc heat source process parameters are set. The wire diameter of welding material 1 is 1.6 mm, the wire feeding speed is 10 m / min, the average welding current is 320 A, the average arc voltage is 28 V, the welding speed is 1.1 m / min, the shielding gas is a mixed gas of Ar and He, and the gas flow rate is 32 L / min. The gas supply system and the laser heat source equipment are started, and the consumable arc heat source cladding is applied using welding material 2 to prepare cladding layer 2 on the surface of Ta1 pure tantalum base material;

[0076] (3) Design the groove form and size according to the methods and process requirements of base welding and filling welding, such as Figure 4 As shown, the base material thickness is 10mm, the groove arc radius of Ta1 pure tantalum base material is 13mm, the groove arc radius of TA2 pure titanium base material is 12mm, the groove depth is 8mm, the blunt edge height of the base weld is 1mm, the groove angle of Ta1 pure tantalum base material base weld is 45°, the groove angle of TA2 pure titanium base material base weld is 45°, the root gap is 1.5mm, and the groove is processed and cleaned;

[0077] (4) Select a laser heat source and use a laser wire welding method to prepare a composite weld connection layer. Set the laser heat source process parameters. The wire diameter of welding material 3 is 1.2 mm, the wire feeding speed is 8 m / min, the laser power is 8 kW, the welding speed is 3.6 m / min, the shielding gas is He gas, and the gas flow rate is 40 L / min. Start the gas supply system and the laser heat source equipment, point the laser heat source to the groove position, and use welding material 3 to connect the connected surfaces of the cladding layer 1 and the cladding layer 2.

[0078] Example 4

[0079] A combined connection method for base welding of dissimilar materials of 304 stainless steel and TA15 titanium alloy, wherein the connecting parent materials are 304 stainless steel and TA15 titanium alloy, the two materials have poor chemical compatibility, the Fe and Ni elements in 304 stainless steel and the Ti element in TA15 titanium alloy are easy to generate brittle structures, and the linear expansion coefficient, thermal conductivity, specific heat capacity and other physical properties of 304 stainless steel and TA15 titanium alloy are also quite different, in order to implement base welding connection of dissimilar materials of 304 stainless steel and TA15 titanium alloy, the method specifically comprises the following steps:

[0080] (1) According to the composition, components, physical and chemical properties of the parent materials 304 stainless steel and TA15 titanium alloy in the dissimilar materials to be connected, a group of welding materials, including welding material 1, welding material 2 and welding material 3, are designed, as shown in Table 4, wherein welding material 1 matches the 304 stainless steel parent material, welding material 2 matches the TA15 titanium alloy parent material, welding material 3 matches both welding material 1 and welding material 2, and welding material 1, welding material 2 and welding material 3 are prepared;

[0081] Table 4 Welding material types, composition and content

[0082]

[0083] (2) Selecting a plasma arc heat source and a laser heat source and using the corresponding plasma spray welding method and powder feeding laser cladding method for cladding, respectively, to prepare a composite weld cladding layer. First, the cladding surface of the 304 stainless steel base material is cleaned, and the plasma arc heat source is directed to the cladding surface of the 304 stainless steel base material. The plasma arc heat source process parameters are set. The powder mesh number of welding material 1 is 325 mesh, the powder feeding speed is 150 g / min, the average welding current is 320 A, the average arc voltage is 25 V, the welding speed is 1.2 m / min, the shielding gas is Ar gas, and the gas flow rate is 30 L / min. The gas supply system and the plasma arc heat source equipment are started. Use welding material 1 to implement heat source 1 cladding, and prepare cladding layer 1 on the surface of 304 stainless steel base material; second, clean the cladding surface of TA15 titanium alloy base material, point the laser heat source to the cladding surface of TA15 titanium alloy base material, set the laser heat source process parameters, the powder mesh of welding material 2 is 540 mesh, the powder feeding speed is 100g / min, the laser power is 7kW, the welding speed is 3.5m / min, the protective gas is a mixed gas of Ar and He, the gas flow rate is 35L / min, start the gas supply system and laser heat source equipment, use welding material 2 to implement laser heat source cladding, and prepare cladding layer 2 on the surface of TA15 titanium alloy base material;

[0084] (3) Design the groove form and size according to the methods and process requirements of base welding and filling welding, such as Figure 5As shown, the base material thickness is 8mm, the bevel arc radius of the TA15 titanium alloy base material is 5mm, the bevel arc radius of the 304 stainless steel base material is 5mm, the bevel depth is 5mm, the blunt edge height of the base weld is 1mm, the bevel arc radius of the TA15 titanium alloy base material base weld is 2mm, the bevel arc radius of the 304 stainless steel base material base weld is 2mm, the root gap is 0.5mm, and the bevel is processed and cleaned;

[0085] (4) Select laser + arc composite heat source and adopt laser melting electrode arc composite welding connection method to prepare composite weld connection layer, set laser + arc composite heat source process parameters, the wire diameter of welding material 3 is 0.8 mm, the wire feeding speed is 7 m / min, the average welding current is 140 A, the average arc voltage is 16 V, the laser power is 2 kW, the welding speed is 1.2 m / min, the shielding gas is a mixture of Ar and N2, the gas flow rate is 40 L / min, start the gas supply system and the laser + arc composite heat source equipment, point the laser + arc composite heat source to the groove position, and use welding material 3 to connect the connected surfaces of the cladding layer 1 and the cladding layer 2.

[0086] Example 5

[0087] A combined connection method for TaW2.5 tantalum alloy and Inconel625 nickel-based alloy dissimilar materials bottom welding, the connecting parent materials are TaW2.5 tantalum alloy and Inconel625 nickel-based alloy, the two materials have poor chemical compatibility, Ta and W elements in TaW2.5 tantalum alloy and Ni, Fe and other elements in Inconel625 nickel-based alloy are easy to generate brittle structure, and the melting point, linear expansion coefficient, thermal conductivity and specific heat capacity and other physical properties of TaW2.5 tantalum alloy and Inconel625 nickel-based alloy are also quite different. In order to implement the bottom welding connection of TaW2.5 tantalum alloy and Inconel625 nickel-based alloy dissimilar materials, the method specifically includes the following steps:

[0088] (1) According to the composition, components, physical and chemical properties of the parent materials TaW2.5 tantalum alloy and Inconel625 nickel-based alloy in the dissimilar materials to be connected, a group of welding materials, including welding material 1, welding material 2 and welding material 3, are designed, as shown in Table 5, wherein welding material 1 matches the TaW2.5 tantalum alloy parent material, welding material 2 matches the Inconel625 nickel-based alloy parent material, welding material 3 matches both welding material 1 and welding material 2, and welding material 1, welding material 2 and welding material 3 are prepared;

[0089] Table 5 Type, composition and content of welding materials

[0090]

[0091] (2) Selecting a consumable arc heat source and adopting a single-wire consumable arc welding cladding method to clad and prepare a composite weld cladding layer. First, the clad surface of the TaW2.5 tantalum alloy base material is cleaned, and the consumable arc heat source is directed to the clad surface of the TaW2.5 tantalum alloy base material. The consumable arc heat source process parameters are set. The wire diameter of welding material 1 is 1.6 mm, the wire feeding speed is 8 m / min, the average welding current is 260 A, the average arc voltage is 25 V, the welding speed is 0.8 m / min, the shielding gas is a mixed gas of Ar and He, and the gas flow rate is 30 L / min. The gas supply system and the consumable arc heat source equipment are started. The welding material 1 is used. Implementing consumable arc heat source cladding to prepare a cladding layer 1 on the surface of the TaW2.5 tantalum alloy base material; second, cleaning the surface of the cladding layer 1, directing the consumable arc heat source to the surface of the cladding layer 1, setting the process parameters of the consumable arc heat source, the wire diameter of the welding material 3 is 1.2 mm, the wire feeding speed is 6 m / min, the average welding current is 190 A, the average arc voltage is 22 V, the welding speed is 0.6 m / min, the shielding gas is a mixed gas of Ar and He, the gas flow rate is 25 L / min, the gas supply system and the consumable arc heat source equipment are started, and the consumable arc heat source cladding is implemented using the welding material 3 to prepare a cladding layer 3 on the surface of the cladding layer 1;

[0092] (3) Design the groove form and size according to the methods and process requirements of base welding and filling welding, such as Figure 6 As shown, the base material thickness is 6mm, the groove angle of the Inconel625 nickel-based alloy base material is 30°, the groove arc radius of the TaW2.5 tantalum alloy base material is 5mm, the groove depth is 4mm, the bottom weld groove blunt edge height is 1mm, the TaW2.5 tantalum alloy base material groove angle is 45°, the root gap is 1mm, and the groove is processed and cleaned;

[0093] (4) A plasma arc heat source is selected and a plasma wire-filling welding method is used for connection to prepare a composite weld connection layer. The plasma arc heat source process parameters are set. The wire diameter of welding material 2 is 2.4 mm, the wire feeding speed is 9 m / min, the average welding current is 320 A, the average arc voltage is 33 V, the welding speed is 1.0 m / min, the shielding gas is Ar gas, and the gas flow rate is 25 L / min. The gas supply system and the plasma arc heat source equipment are started, and the plasma arc heat source is directed to the groove position. The welding material 2 is used to connect the cladding layer 3 and the connected surface of the Inconel625 nickel-based alloy base material.

[0094] Example 6

[0095] A combined connection method for bottom welding of dissimilar materials of TiAl intermetallic compound and 40Cr steel, wherein the connecting parent materials are TiAl intermetallic compound and 40Cr steel, the two materials have poor chemical compatibility, Ti and Al elements in the TiAl intermetallic compound and Fe and Cr elements in the 40Cr steel are prone to generate brittle structures, and the melting point, linear expansion coefficient, thermal conductivity, specific heat capacity and other physical properties of the TiAl intermetallic compound and 40Cr steel are also quite different, in order to implement the bottom welding connection of the TiAl intermetallic compound and 40Cr steel dissimilar materials, the method specifically comprises the following steps:

[0096] (1) According to the composition, components, physical and chemical properties of the parent materials TiAl intermetallic compound and 40Cr steel in the dissimilar materials to be connected, a group of welding materials, including welding material 1, welding material 2 and welding material 3, are designed, as shown in Table 6, wherein welding material 1 matches the TiAl intermetallic compound parent material, welding material 2 matches the 40Cr steel parent material, welding material 3 matches both welding material 1 and welding material 2, and welding material 1, welding material 2 and welding material 3 are prepared;

[0097] Table 6 Welding material type, composition and content

[0098]

[0099] (2) A non-melting electrode arc heat source is selected and a single-wire non-melting electrode arc welding cladding method is used for cladding to prepare a composite weld cladding layer. First, the cladding surface of the TiAl intermetallic compound base material is cleaned, and the non-melting electrode arc heat source is directed to the cladding surface of the TiAl intermetallic compound base material. The process parameters of the non-melting electrode arc heat source are set. The wire diameter of welding material 1 is 1.2 mm, the wire feeding speed is 6 m / min, the average welding current is 160 A, the average arc voltage is 12 V, the welding speed is 0.6 m / min, the shielding gas is Ar gas, and the gas flow rate is 12 L / min. The gas supply system and the non-melting electrode arc heat source equipment are started, and the non-melting electrode arc heat source cladding is performed using welding material 1. , prepare a cladding layer 1 on the surface of the TiAl intermetallic compound base material; second, clean the cladding surface of the 40Cr steel base material, direct the non-melting pole arc heat source to the cladding surface of the 40Cr steel base material, set the process parameters of the non-melting pole arc heat source, the wire diameter of the welding material 2 is 1.0mm, the wire feeding speed is 3m / min, the average welding current is 110A, the average arc voltage is 10V, the welding speed is 0.35m / min, the shielding gas is a mixed gas of Ar, CO2 and O2, the gas flow rate is 15L / min, start the gas supply system and the non-melting pole arc heat source equipment, use the welding material 2 to implement the non-melting pole arc heat source cladding, and prepare the cladding layer 2 on the surface of the 40Cr steel base material;

[0100] (3) Design the groove form and size according to the methods and process requirements of base welding and filling welding, such as Figure 7 As shown, the base material thickness is 5 mm, the arc radius of the groove of the TiAl intermetallic compound base material is 3.5 mm, the arc radius of the groove of the 40Cr steel base material is 3.5 mm, the groove angle of the TiAl intermetallic compound base material is 45°, the groove angle of the 40Cr steel base material is 45°, the groove depth of the base weld is 1 mm, the blunt edge height of the base weld is 1 mm, the root gap is 1.5 mm, and the groove is processed and cleaned;

[0101] (4) Select a consumable arc heat source and adopt a single-wire consumable arc welding connection method to prepare a composite weld connection layer, set the consumable arc heat source process parameters, the wire diameter of welding material 3 is 1.2 mm, the wire feeding speed is 9 m / min, the average welding current is 290 A, the average arc voltage is 28 V, the welding speed is 0.8 m / min, the shielding gas is Ar gas, and the gas flow rate is 40 L / min. Start the gas supply system and the consumable arc heat source equipment, point the consumable arc heat source to the groove position, and use welding material 3 to connect the connected surfaces of the cladding layer 1 and the cladding layer 2.

[0102] Example 7

[0103] A method for TiB P / TC4 composite material and 316L stainless steel dissimilar materials base welding combined connection method, the connecting base material is TiB P / TC4 composite material and 316L stainless steel, the two materials have poor chemical compatibility and poor interface chemical compatibility, TiB P The main element Ti in the TC4 composite material and the elements Ni, Cr, Fe in 316L stainless steel are prone to form brittle structures, and TiB P The physical properties of the TiB / TC4 composite material and 316L stainless steel, such as melting point, linear expansion coefficient, thermal conductivity and specific heat capacity, are also quite different. P The base welding connection of TC4 composite material and 316L stainless steel material includes the following steps:

[0104] (1) The base material TiB in the dissimilar materials to be connected as required P Based on the composition, components, physical and chemical properties of TC4 composite materials and 316L stainless steel, a group of welding materials, including welding materials 1, welding materials 2 and welding materials 3, are designed, as shown in Table 7. P / TC4 composite material parent material matches, welding material 2 matches 316L stainless steel parent material, welding material 3 matches welding material 1 and welding material 2, and welding material 1, welding material 2 and welding material 3 are prepared;

[0105] Table 7 Welding material type, composition and content

[0106]

[0107] (2) Selecting a laser heat source and using a powder feeding laser cladding method to prepare a composite weld cladding layer, first, TiB P The cladding surface of the TC4 composite material is cleaned, and the laser heat source is directed to TiB P The cladding surface of the / TC4 composite material parent material was set with the laser heat source process parameters: the powder mesh of welding material 1 was 540 mesh, the powder feeding speed was 90g / min, the laser power was 8kW, the welding speed was 3.7m / min, the shielding gas was a mixed gas of Ar and He, the gas flow rate was 20L / min, the gas supply system and the laser heat source equipment were started, and the laser heat source cladding was carried out using welding material 1. P / TC4 composite material base material surface preparation cladding layer 1; second, the surface of the cladding layer 1 is cleaned, the laser heat source is directed to the surface of the cladding layer 1, and the process parameters of the laser heat source are set. The powder mesh of the welding material 1 is 400 mesh, the powder feeding speed is 20g / min, the laser power is 2kW, the welding speed is 0.8m / min, the protective gas is a mixed gas of Ar and He, and the gas flow rate is 25L / min. The gas supply system and the laser heat source equipment are started, and the laser heat source cladding is performed using the welding material 3 to prepare the cladding layer 3 on the surface of the cladding layer 1;

[0108] (3) Design the groove form and size according to the methods and process requirements of base welding and filling welding, such as Figure 8 As shown, the base material thickness is 4 mm, the groove angle of the 316L stainless steel base material is 35°, and the TiB P / TC4 composite material base material groove angle is 50°, groove depth is 2mm, bottom weld blunt edge height is 1mm, bottom weld groove angle is 35°, root gap is 1.5mm, and groove is processed and cleaned;

[0109] (4) Select laser + arc composite heat source and adopt laser melting electrode arc composite welding connection method to prepare composite weld connection layer, set laser + arc composite heat source process parameters, the wire diameter of welding material 3 is 1.2 mm, the wire feeding speed is 12 m / min, the average welding current is 270 A, the average arc voltage is 26 V, the laser power is 6.5 kW, the welding speed is 1.6 m / min, the shielding gas is a mixture of Ar and He, and the gas flow rate is 30 L / min. Start the gas supply system and laser + arc composite heat source equipment, point the laser + arc composite heat source to the groove position, and use welding material 2 to connect the cladding layer 3 and the connected surface of the 316L stainless steel base material.

[0110] Example 8

[0111] A combined connection method for bottom welding of dissimilar materials of TC4 titanium alloy and TaNb3 tantalum alloy, wherein the connecting parent materials are TC4 titanium alloy and TaNb3 tantalum alloy, the two materials have good chemical compatibility, the main element Ti in the TC4 titanium alloy and the Ta and Nb elements in the TaNb3 tantalum alloy form a solid solution with good comprehensive performance, but the physical properties such as melting point, linear expansion coefficient, thermal conductivity and specific heat capacity of the TC4 titanium alloy and the TaNb3 tantalum alloy are quite different, in order to implement the bottom welding connection of dissimilar materials of TC4 titanium alloy and TaNb3 tantalum alloy, the method specifically comprises the following steps:

[0112] (1) According to the composition, components, physical and chemical properties of the parent materials TC4 titanium alloy and TaNb3 tantalum alloy in the dissimilar materials to be connected, a group of welding materials, including welding material 1, welding material 2 and welding material 3, are designed, as shown in Table 8, wherein welding material 1 matches the TC4 titanium alloy parent material, welding material 2 matches the TaNb3 tantalum alloy parent material, welding material 3 consists of wire 31 and wire 32, welding material 3 matches both welding material 1 and welding material 2, and welding material 1, welding material 2 and welding material 3 are prepared;

[0113] Table 8 Type, composition and content of welding materials

[0114]

[0115] (2) Selecting a consumable arc heat source and adopting a single-wire consumable arc welding cladding method to perform cladding to prepare a composite weld cladding layer. First, the cladding surface of the TC4 titanium alloy base material is cleaned. The consumable arc heat source is directed to the cladding surface of the TC4 titanium alloy base material. The consumable arc heat source process parameters are set. The wire diameter of welding material 1 is 0.8 mm, the wire feeding speed is 4 m / min, the average welding current is 90 A, the average arc voltage is 14 V, the welding speed is 0.7 m / min, the shielding gas is a mixed gas of Ar and He, and the gas flow rate is 20 L / min. The gas supply system and the consumable arc heat source equipment are started. The consumable arc heat source cladding is performed using welding material 1. A cladding layer 1 is prepared on the surface of the TC4 titanium alloy base material; secondly, the cladding surface of the TaNb3 tantalum alloy base material is cleaned, the melting pole arc heat source is directed to the cladding surface of the TaNb3 tantalum alloy base material, and the process parameters of the melting pole arc heat source are set. The wire diameter of the welding material 2 is 1.0 mm, the wire feeding speed is 6 m / min, the average welding current is 120 A, the average arc voltage is 17 V, the welding speed is 0.7 m / min, the shielding gas is a mixed gas of Ar and He, and the gas flow rate is 35 L / min. The gas supply system and the melting pole arc heat source equipment are started, and the melting pole arc heat source cladding is carried out using the welding material 2 to prepare a cladding layer 2 on the surface of the TaNb3 tantalum alloy base material;

[0116] (3) Design the groove form and size according to the methods and process requirements of base welding and filling welding, such as Fig. 9 As shown, the base material thickness is 3mm, the groove angle of TC4 titanium alloy base material is 45°, the groove angle of TaNb3 tantalum alloy base material is 45°, the groove depth is 1.5mm, the blunt edge height of the base weld is 0.5mm, the groove angle of TC4 titanium alloy base material is 45°, the groove angle of TaNb3 tantalum alloy base material is 45°, the root gap is 1.5mm, and the groove is processed and cleaned;

[0117] (4) A non-melting electrode arc heat source is selected and a double-wire non-melting electrode arc welding connection method is used for connection to prepare a composite weld connection layer. The process parameters of the non-melting electrode arc heat source are set. The diameter of the wire 31 of the welding material 3 is 1.2 mm, the wire feeding speed is 5.5 m / min, the average welding current is 240 A, and the average arc voltage is 17 V. The diameter of the wire 32 of the welding material 3 is 1.2 mm, the wire feeding speed is 5.5 m / min, the average welding current is 240 A, the average arc voltage is 16.5 V, the welding speed is 0.5 m / min, the shielding gas is Ar gas, and the gas flow rate is 30 L / min. The gas supply system and the non-melting electrode arc heat source equipment are started, the non-melting electrode arc heat source is directed to the groove position, and the connected surfaces of the cladding layer 1 and the cladding layer 2 are connected using the welding material 3.

[0118] The above embodiments solve the problems of poor welding flexibility, low efficiency, high cost, difficulty in designing and developing welding materials, difficulty in designing welding processes, easy generation of brittle structures, difficulty in preparing composite welds for composite welds for composite welds for composite welds for composite welds for composite welds for composite welds for composite welds, and poor comprehensive performance when connecting dissimilar materials by backing welding of medium and thick plates. By accurately and finely decomposing welding materials and welding processes, efficient and high-quality combined welding materials and matching combined connection processes are designed, the requirements of the methods and processes of backing welding and filling welding for the groove are comprehensively considered, suitable groove forms and sizes are designed, effective gas protection is carried out on the welding area, a variety of heat source types are selected, and a variety of cladding methods and connection methods are adopted. The design and development of combined welding materials and matching combined welding processes are efficient, the welding flexibility is good, and the welding High efficiency, low cost, excellent zoning of the base welding composite weld, no generation of brittle structure, precise and controllable heat input of various methods, small welding stress and deformation, beautiful shape of the prepared base welding composite weld, convenient and efficient regulation of the structure and performance of the base welding joint, excellent internal quality of the base welding composite weld, beautiful shape, no defects such as pores, cracks, slag inclusions, good comprehensive performance of the base welding joint, meeting the technical requirements, the prepared base welding weld can adapt to the next step of spatial arrangement of three-wire consumable electrode gas shielded welding process, double-wire composite gas shielded welding and single-wire gas shielded welding combined connection process, wire additive connection process and double-wire composite gas shielded welding and tandem double-wire gas shielded welding combined connection process and other filling welding processes, so that the various zones of the composite weld prepared by the filling welding process can match the various zones of the composite weld prepared by the corresponding base welding process.

[0119] The combined connection method of the invention can be used not only for the connection of dissimilar materials by backing welding, but also for the connection of dissimilar materials on thin plates.

[0120] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A combined connection method for base welding of dissimilar materials, characterized in that: The following steps are involved: (1) According to the composition, components, physical and chemical properties of the base material 1 and the base material 2 in the dissimilar materials to be connected, a group of welding materials, including welding material 1, welding material 2 and welding material 3, are designed, wherein welding material 1 matches base material 1, welding material 2 matches base material 2, welding material 3 matches both welding material 1 and welding material 2, and welding material 1, welding material 2 and welding material 3 are prepared; (2) Selecting a suitable heat source and adopting a corresponding cladding method to perform cladding to prepare a composite weld cladding layer, first, cleaning the cladding surface of the base material 1, directing the heat source to the cladding surface of the base material 1, setting the heat source process parameters, starting the gas supply system and the heat source equipment, using the welding material 1 to perform heat source cladding, and preparing the cladding layer 1 on the surface of the base material 1; second, cleaning the cladding surface of the base material 2, directing the heat source to the cladding surface of the base material 2, setting the heat source process parameters, starting the gas supply system and the heat source equipment, using the welding material 2 to perform heat source cladding, and preparing the cladding layer 2 on the surface of the base material 2, or cleaning the surface of the cladding layer 1, directing the heat source to the surface of the cladding layer 1, setting the heat source process parameters, starting the gas supply system and the heat source equipment, using the welding material 3 to perform heat source cladding, and preparing the cladding layer 3 on the surface of the cladding layer 1; (3) Design appropriate groove form and size, process and clean the groove according to the methods and process requirements of base welding and filling welding; (4) Select a suitable heat source and adopt a corresponding connection method to connect, prepare a composite weld connection layer, set the heat source process parameters, start the gas supply system and the heat source equipment, point the heat source to the groove position, and use welding material 3 to connect the connected surfaces of the cladding layer 1 and the cladding layer 2, or use welding material 2 to connect the connected surfaces of the cladding layer 3 and the base material 2.

2. A combined connection method for base welding of dissimilar materials as claimed in claim 1, characterized in that: The types of welding materials include wire and powder.

3. A combined connection method for base welding of dissimilar materials as claimed in claim 2, characterized in that: The diameter of the wire is 0.6-2.4 mm, the wire feeding speed is 0.5-20 m / min, the mesh size of the powder is 50-650 mesh, and the powder feeding speed is 8-240 g / min.

4. A combined connection method for base welding of dissimilar materials as claimed in claim 1, characterized in that: The filling welding process includes a spatially arranged three-wire consumable electrode gas shielded welding process, a double-wire composite gas shielded welding and single-wire gas shielded welding combined connection process, a wire additive connection process, and a double-wire composite gas shielded welding and tandem double-wire gas shielded welding combined connection process.

5. A combined connection method for base welding of dissimilar materials as claimed in claim 1, characterized in that: The protective gas of the gas supply system is at least one of Ar, He, CO2, O2, and N2, and the gas flow rate is 10 to 50 L / min.

6. A combined connection method for base welding of dissimilar materials as claimed in claim 1, characterized in that: The types of heat sources include consumable arc heat source, non-consumable arc heat source, plasma arc heat source, laser heat source and laser+arc composite heat source.

7. A combined connection method for base welding of dissimilar materials as claimed in claim 6, characterized in that: The cladding and connection methods corresponding to the consumable arc heat source include single-wire consumable arc welding and double-wire consumable arc welding, the cladding and connection methods corresponding to the non-consumable arc heat source include single-wire non-consumable arc welding and double-wire non-consumable arc welding, and the cladding and connection methods corresponding to the plasma arc heat source include plasma spray welding and plasma wire filling welding.

8. A combined connection method for base welding of dissimilar materials as claimed in claim 6, characterized in that: The cladding and connection methods corresponding to the laser heat source include laser wire welding and powder feeding laser cladding, and the cladding and connection method corresponding to the laser+arc composite heat source is laser melting electrode arc composite welding.

9. A combined connection method for base welding of dissimilar materials as claimed in claim 6, characterized in that: The process parameters of the consumable arc heat source, the non-consumable arc heat source and the plasma arc heat source are: an average welding current of 20 to 400A, an average arc voltage of 8 to 40V, and a welding speed of 0.3 to 2.4m / min.

10. A combined connection method for base welding of dissimilar materials as claimed in claim 6, characterized in that: The process parameters of the laser heat source are: laser power of 0.5-9kW, welding speed of 0.5-4m / min, and the process parameters of the laser+arc composite heat source are: laser power of 1-9kW, average welding current of 20-400A, average arc voltage of 8-40V, and welding speed of 0.5-2m / min.

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