An automated welding method for optimizing the weld microstructure of nickel-based alloy composite plates

Abstract

This invention discloses an automated welding method for optimizing the weld microstructure of a nickel-based alloy composite plate. The nickel-based alloy composite plate includes a substrate layer and a nickel-based alloy composite layer, with a transition layer at the interface between the substrate layer and the nickel-based alloy composite layer. The automated welding method includes the following steps: machining a trapezoidal bevel on the welding cross-section of the nickel-based alloy composite plate corresponding to the position of the substrate layer; machining a U-shaped bevel on the welding cross-section of the nickel-based alloy composite plate corresponding to the position of the transition layer; not machining a bevel on the welding cross-section of the nickel-based alloy composite plate corresponding to the position of the nickel-based alloy composite layer; performing self-fusion welding of the nickel-based alloy composite layer using laser welding; using a carbon steel welding wire matched to the substrate layer, performing filler wire welding of the transition layer using laser welding; and welding the substrate layer using hot-wire oscillating tungsten inert gas welding.

Description

Technical Field

[0001] This invention relates to a welding method, and more particularly to a welding method for composite plates. Background Technology

[0002] Bimetallic composite panels, containing two different component metals, can meet both structural and functional requirements. For example, nickel-based alloy composite panels, composed of high-strength low-alloy structural steel and nickel-based alloys, can provide good corrosion resistance while ensuring sufficient toughness, and have already been applied to a certain scale in engineering projects.

[0003] However, the design characteristics of multi-component metals endow materials with multi-layered properties, but also pose challenges to the welding process. The chemical compositions of the two metals can easily affect each other during welding, thereby deteriorating the mechanical or corrosion resistance of the joint. Therefore, in engineering, the connection of nickel-based alloy composite plates generally adopts multi-layer, multi-pass welding, that is, the weld is divided into a cladding layer and a transition layer nickel-based alloy weld, and a base carbon steel weld, which are welded separately. There are two welding sequences for such a welding process: the base layer-transition layer-cladding layer welding sequence and the cladding layer-transition layer-base layer welding sequence.

[0004] The first welding sequence is commonly used in engineering. In this sequence, a transition layer weld is added to achieve a compositional transition from carbon steel to nickel-based alloy welds, which can effectively avoid a decrease in the corrosion resistance of the cladding weld. However, for some special scenarios, such as the closed welding of small composite components, the second welding sequence must be used due to limited operating space. In this case, although the cladding is welded first, a transition layer is still needed to achieve a compositional transition from nickel-based alloy to carbon steel to avoid a decrease in the mechanical properties of the carbon steel weld. However, since nickel-based alloys contain very high levels of alloying elements such as Cr and Ni, carbon steel welds are prone to developing hard and brittle martensitic structures due to excessive welding dilution. This phenomenon is discussed in the paper "Additive manufacturing of functionally graded transition joints between ferritic and austenitic alloys".

[0005] Currently, the common solution to this problem in engineering is to use nickel-based alloy welding materials for the entire weld seam. However, this approach significantly increases the amount of nickel-based alloy welding materials used, and the unit price of nickel-based alloy welding materials is often dozens of times higher than that of carbon steel welding materials, thus greatly increasing the cost of welding materials. On the other hand, because nickel-based alloys have lower yield strength, all-nickel-based alloy weld seams reduce the overall structural strength of the joint, which poses a safety hazard for some composite plate components with high strength requirements. In other words, there is a contradiction between the use of mixed welding materials and the control of joint microstructure and performance in the welding sequence of cladding layer-transition layer-base layer for nickel-based alloy composite plates.

[0006] Chinese patent document CN112122783A, published on December 25, 2020, entitled "A Laser Butt Welding Method for Carbon Steel-Nickel Alloy Composite Plates", discloses that the laser welding self-fusion or filler wire welding method realizes the connection of composite plates in the welding sequence of cladding layer-transition layer-base layer. However, the invention mainly aims to solve the problem of the inability to weld composite plate components under closed welding conditions, without paying attention to the problem of joint microstructure deterioration. Summary of the Invention

[0007] One of the objectives of this invention is to provide an automated welding method for optimizing the weld microstructure of nickel-based alloy composite plates. This method, under the premise of using mixed welding materials, is based on the welding sequence of composite layer-transition layer-substrate layer, and specially designs the groove and weld bead arrangement. It comprehensively uses multiple welding methods and rationalizes the process window, thereby avoiding the overall martensitization of the carbon steel weld microstructure of the substrate layer and achieving a reliable connection of the composite plate under this welding sequence.

[0008] To achieve the above objectives, the present invention provides an automated welding method for optimizing the weld microstructure of a nickel-based alloy composite plate. The nickel-based alloy composite plate includes a substrate layer and a nickel-based alloy composite layer, wherein a transition layer is provided at the interface between the substrate layer and the nickel-based alloy composite layer. The automated welding method includes the following steps:

[0009] A trapezoidal bevel is machined on the welding section of the nickel-based alloy composite plate at the position corresponding to the base material layer; a U-shaped bevel is machined on the welding section of the nickel-based alloy at the position corresponding to the transition layer; no bevel is machined on the welding section of the nickel-based alloy composite plate at the position corresponding to the nickel-based alloy composite layer.

[0010] Laser welding was used to perform self-fusion welding on nickel-based alloy composite layers;

[0011] Using carbon steel welding wire that matches the base layer, laser welding is used to filler wire welding the transition layer;

[0012] The substrate layer is welded using hot-wire oscillating tungsten inert gas welding.

[0013] In this invention, the inventors, through a special bevel design, combined with multiple welding methods and optimized processes, achieved a reliable connection of nickel-based alloy composite plates in the welding sequence of composite layer-transition layer-base layer. Specifically, the automated welding method for optimizing the weld microstructure of nickel-based alloy composite plates described in this invention effectively avoids overall martensitization of the carbon steel weld microstructure in the base layer during the composite layer-transition layer-base layer welding sequence, thereby improving the connection reliability of the joint. Compared with existing technologies, the automated welding method for optimizing the weld microstructure of nickel-based alloy composite plates described in this invention can significantly reduce the amount of nickel-based alloy welding materials used, improving the structural strength of the joint while reducing welding costs. Furthermore, the composite plate welding method proposed in this invention employs automated welding technology and parameterized welding processes, which have a lower dependence on the welding qualifications and skill levels of the welding operators, demonstrating good scalability.

[0014] Furthermore, in the automated welding method for optimizing the weld structure of nickel-based alloy composite plates described in this invention, the angle α between the inclined portion of the trapezoidal bevel and the vertical direction is ≥ (1.5b1)°, where b1 represents the distance from the surface of the substrate layer to its interface with the nickel-based alloy composite layer, and its unit parameter is mm.

[0015] Furthermore, in the automated welding method for optimizing the weld structure of nickel-based alloy composite plates described in this invention, the bottom width w2 of the trapezoidal groove on one side is ≥ (5 + 0.1b1), where b1 represents the distance from the surface of the substrate layer to the interface between it and the nickel-based alloy composite layer, and its unit parameter is mm.

[0016] Furthermore, in the automated welding method for optimizing the weld structure of nickel-based alloy composite plates described in this invention, the distance b4 between the bottom of the trapezoidal groove and the interface between the substrate layer and the nickel-based alloy composite layer is 1-2 mm.

[0017] In this implementation, the base weld can be machined into a trapezoidal bevel. Considering the operability of hot wire oscillating tungsten inert gas welding of the base weld, the angle α between the inclined part of the trapezoidal bevel and the vertical direction can be controlled at α≥(1.5b1)°, the bottom width w2 of one side of the trapezoidal bevel can be controlled at w2≥(5+0.1b1), and the distance b4 between the bottom of the trapezoidal bevel and the interface between the base layer and the nickel-based alloy composite layer can be controlled between 1-2mm.

[0018] Furthermore, in the automated welding method for optimizing the weld structure of nickel-based alloy composite plates described in this invention, the single-side width w1 / 2 of the U-shaped groove is 1-1.5 mm.

[0019] Furthermore, in the automated welding method for optimizing the weld structure of nickel-based alloy composite plates described in this invention, the radius r of the arc portion of the U-shaped groove is ≥ 0.25w1, where w1 represents twice the width of a single side of the U-shaped groove, and its unit parameter is mm.

[0020] In this implementation, to ensure successful laser autofusion welding of the composite layer without melting the carbon steel, and to prevent incomplete fusion defects due to the high viscosity and poor fluidity of the nickel-based alloy molten pool, the transition layer weld position can be machined into a U-shaped bevel. Simultaneously, to ensure successful welding of the composite layer without melting the carbon steel base material, the width w1 of the U-shaped bevel should be greater than the laser spot diameter. To allow for smooth gas escape from the molten pool, the straight edge angle of the U-shaped bevel can be maintained at 90 degrees, and w1, while greater than the laser spot diameter, should not be too small, being controlled within the range of 2-3 mm. That is, the single-side width w1 / 2 of the U-shaped bevel should be controlled between 1-1.5 mm, and the radius r of the arc portion of the U-shaped bevel should be controlled to r≥0.25w1.

[0021] Furthermore, in the automated welding method for optimizing the weld structure of nickel-based alloy composite plates described in this invention, in the step of performing self-fusion welding of the nickel-based alloy composite layer using laser welding: the laser spot diameter is ≤1mm, the laser power is controlled at 3.0-4.0KW, the welding speed is 2.0-2.5m / min, and the positive defocusing amount is 0-5mm.

[0022] Furthermore, in the automated welding method for optimizing the weld structure of nickel-based alloy composite plates described in this invention, in the step of using laser welding to perform filler wire welding on the transition layer, the diameter of the laser spot used is ≤1mm.

[0023] Furthermore, in the automated welding method for optimizing the weld structure of nickel-based alloy composite plates described in this invention, in the step of using laser welding to perform filler wire welding on the transition layer: the laser power is controlled to be 4.0-5.0KW, the welding speed is 2.0-3.0m / min, the positive defocusing amount is 5-10mm, the wire feeding speed is 1.5-2.0m / min, and the wire feeding angle is 30-45°.

[0024] In this implementation, by using a specially designed bevel pattern, the width of the top of the transition layer weld, approximately the width w1 of the U-shaped bevel, can be controlled to be less than 3mm, thereby promoting the control of a low dilution rate level for carbon steel welds, especially carbon steel weld beads that are in direct contact with the transition layer weld.

[0025] Furthermore, in the automated welding method for optimizing the weld structure of nickel-based alloy composite plates described in this invention, in the step of welding the substrate layer using hot-wire oscillating tungsten inert gas welding: the welding voltage is controlled at 12.0-14.0V, the welding current at 140-180A, the welding speed at 120-150mm / min, the wire feed speed at 1.8-2.6m / min, the hot-wire current at 60-100A, and the oscillation width at 1-4mm.

[0026] In this implementation, due to the high alloying degree of the nickel-based alloy, controlling the dilution rate of the carbon steel weld, especially the carbon steel weld bead in direct contact with the transition layer weld, is extremely difficult. Therefore, based on the special groove design and the application of laser filler wire welding process for the transition layer, hot-wire oscillating tungsten inert gas welding is also required when welding the base layer weld. Simultaneously, the application of this welding process can effectively reduce the penetration depth while ensuring good weld formation. Combined with the narrower width of the resulting transition layer weld, the dilution rate of the carbon steel weld, especially the carbon steel weld bead in direct contact with the transition layer weld, relative to the cladding layer weld, can ultimately be controlled below 2.0%, preventing overall martensitization of the carbon steel weld microstructure.

[0027] The automated welding method for optimizing the weld microstructure of nickel-based alloy composite plates described in this invention has the following advantages and beneficial effects compared to existing technologies:

[0028] The automated welding method for optimizing the weld microstructure of nickel-based alloy composite plates described in this invention can effectively avoid the overall martensitization of the carbon steel weld microstructure of nickel-based alloy composite plates under the cladding-transition-base layer welding sequence, thereby improving the connection reliability of composite plate components.

[0029] The automated welding method for optimizing the weld structure of nickel-based alloy composite plates described in this invention significantly reduces welding costs and effectively improves the structural strength of the joint compared to the current industrial practice of using all-nickel-based alloy materials to fill this problem.

[0030] The automated welding method for optimizing the weld microstructure of nickel-based alloy composite plates described in this invention employs automated welding methods for each layer of welds, and the process specifications are highly parameterized. Therefore, the operation is simple and reliable, which reduces the reliance on highly skilled welding personnel and makes it highly scalable. Attached Figure Description

[0031] Figure 1 The diagram schematically illustrates the bevel used in the automated welding method for optimizing the weld structure of nickel-based alloy composite plates according to the present invention.

[0032] Figure 2The cross-sectional morphology of a nickel-based alloy composite plate joint prepared by the automated welding method for optimizing the weld microstructure of nickel-based alloy composite plates according to Example 1 of the present invention is shown.

[0033] Figure 3 The image shows a metallographic photograph of the weld joint of a nickel-based alloy composite plate after etching with nitric acid alcohol, at the weld joint interface of the transition layer / carbon steel substrate layer, using the automated welding method for optimizing the weld microstructure of nickel-based alloy composite plates according to Embodiment 1 of the present invention. Detailed Implementation

[0034] The automated welding method for optimizing the weld structure of nickel-based alloy composite plates according to the present invention will be further explained and described below with reference to specific embodiments and accompanying drawings. However, this explanation and description do not constitute an undue limitation on the technical solution of the present invention.

[0035] The purpose of this invention is to provide an automated welding method for optimizing the weld microstructure of nickel-based alloy composite plates. Figure 1 The image shows two spliced ​​nickel-based alloy composite plates, A and B. Figure 1 The dashed line O in the figure represents the splicing seam. This nickel-based alloy composite plate includes a carbon steel substrate layer 1, a nickel-based alloy composite layer 2, and a transition layer at the interface between the carbon steel substrate layer 1 and the nickel-based alloy composite layer 2. Figure 1 The designation “b1” indicates the distance between the surface of the carbon steel substrate layer and the interface between it and the nickel-based alloy composite layer, and the designation “b2” indicates the distance between the surface of the nickel-based alloy composite layer and the interface between it and the carbon steel substrate layer.

[0036] In one specific embodiment, a nickel-based alloy composite plate with the grade Incoloy 825 / X52 can be used, wherein the carbon steel substrate layer material is X52 and the nickel-based alloy composite layer material is Incoloy 825. The thickness of the nickel-based alloy composite plate is 13mm, wherein b2 of the nickel-based alloy composite plate is 3mm and b1 is 10mm.

[0037] In some embodiments, an automated welding method for optimizing the weld microstructure of nickel-based alloy composite plates includes the following steps:

[0038] 100: Processing at the welding position of the two spliced ​​nickel-based alloy composite plates A and B as follows Figure 1 The bevel shown. Specifically, a trapezoidal bevel is machined on the welding section of the nickel-based alloy composite plate at the position corresponding to the substrate layer. This trapezoidal bevel includes a vertically inclined portion 6 and a horizontal portion 7 arranged sequentially. The extension width of the horizontal portion 7 (i.e., the width of the bottom of one side of the trapezoidal bevel) is... Figure 1 The distance at the interface between the horizontal part 7 and the substrate layer 1 and the nickel-based alloy composite layer 2, indicated by "w2", is... Figure 1The designation is "b4"; a U-shaped bevel 8 is made on the welding section of the nickel-based alloy composite plate corresponding to the transition layer. The width of one side of this U-shaped bevel is w1 / 2, and the radius of the bottom arc of the transition layer U-shaped bevel is r. No bevel is machined on the welding section of the nickel-based alloy composite plate corresponding to the nickel-based alloy composite layer; that is, the welding surface of the nickel-based alloy composite layer is a vertical plane, and the thickness of the bevel is... Figure 1 In Chinese, we use "b3" to represent b3, where b3 = b2 - r.

[0039] 200: Laser welding is used to perform self-fusion welding on the nickel-based alloy composite layer to form the composite layer weld 3.

[0040] 300: Using carbon steel welding wire that matches the base layer, laser welding is used to filler wire welding the transition layer to form the transition layer weld 4.

[0041] 400: Using carbon steel welding wire that matches the carbon steel base layer, hot wire oscillation tungsten inert gas welding is used to filler wire welding of the carbon steel base layer to form the base layer weld 5.

[0042] Preferably, in some embodiments, the angle α between the vertically inclined portion 6 of the trapezoidal bevel and the vertical direction can be controlled to α ≥ (1.5b1)°, where b1 represents the distance from the surface of the substrate layer to its interface with the nickel-based alloy composite layer, with the unit parameter being mm. In this embodiment, controlling the angle α facilitates the welding operability of subsequent hot-wire oscillating tungsten inert gas welding.

[0043] Preferably, in some embodiments, the bottom width of one side of the trapezoidal bevel (i.e., the extended width of the horizontal portion 7) w2 can be controlled to w2≥(5+0.1b1), where b1 represents the distance from the surface of the substrate layer to its interface with the nickel-based alloy composite layer, with the unit parameter being mm. In this embodiment, controlling w2 facilitates the welding operability of subsequent hot-wire oscillating tungsten inert gas welding.

[0044] Preferably, in some embodiments, the distance b4 between the bottom of the trapezoidal bevel and the interface between the substrate layer and the nickel-based alloy composite layer can be controlled between 1-2 mm. In this embodiment, controlling b4 facilitates the welding operability of subsequent hot-wire oscillating tungsten inert gas welding.

[0045] Preferably, in some embodiments, the width of one side of the U-shaped bevel can be controlled to be w1 / 2 ≥ the laser spot radius of the laser welding, that is, the total width w1 of the two U-shaped bevels formed by the two spliced ​​nickel-based alloy composite plates A and B is ≥ the laser spot diameter of the laser welding. This design can ensure that the laser self-fusion welding of the nickel-based alloy composite layer weld is successfully completed without melting the carbon steel substrate.

[0046] Preferably, in some embodiments, in order to allow the molten pool gas to be discharged smoothly, the straight edge angle of the U-shaped bevel can be maintained at 90 degrees, and w1 should be greater than the diameter of the laser spot but not too small, controlled within the range of 2-3 mm. That is, the single-side width w1 / 2 of the U-shaped bevel is controlled between 1-1.5 mm, and the radius r of the arc part of the U-shaped bevel is controlled at r≥0.25w1.

[0047] Preferably, in some embodiments, in step 200, laser autofusion welding is used to form the composite layer weld 3. The laser spot diameter can be controlled to be ≤1mm, the laser power to be 3.0-4.0KW, the welding speed to be 2.0-2.5m / min, and the positive defocusing amount to be 0-5mm.

[0048] In step 300, laser filler wire welding is used to weld the transition layer weld 4. The filler metal can be ERNiCrMo-3. The laser spot diameter is ≤1mm, the laser power is controlled at 4.0-5.0KW, the welding speed is 2.0-3.0m / min, the positive defocusing amount is 5-10mm, the wire feeding speed is 1.5-2.0m / min, and the wire feeding angle is 30-45°.

[0049] In this implementation, by using a specially designed bevel pattern, the width of the top of the transition layer weld, approximately the width w1 of the U-shaped bevel, can be controlled to be less than 3mm, thereby promoting the control of a low dilution rate level for carbon steel welds, especially carbon steel weld beads that are in direct contact with the transition layer weld.

[0050] In step 400, carbon steel weld wire ER50-6, which is matched with the base material, is used to weld the carbon steel weld 5. The welding method is hot wire oscillation tungsten inert gas welding, and the welding voltage is controlled at 12.0-14.0V, the welding current is 140-180A, the welding speed is 120-150mm / min, the wire feed speed is 1.8-2.6m / min, the hot wire current is 60-100A, and the oscillation width is 1-4mm.

[0051] In this implementation, due to the high alloying degree of the nickel-based alloy, controlling the dilution rate of the carbon steel weld, especially the carbon steel weld bead in direct contact with the transition layer weld, is extremely difficult. Therefore, based on the special groove design and the application of laser filler wire welding process for the transition layer, hot-wire oscillating tungsten inert gas welding is also required when welding the base layer weld. Simultaneously, the application of this welding process can effectively reduce the penetration depth while ensuring good weld formation. Combined with the narrower width of the resulting transition layer weld, the dilution rate of the carbon steel weld, especially the carbon steel weld bead in direct contact with the transition layer weld, relative to the cladding layer weld, can ultimately be controlled below 2.0%, preventing overall martensitization of the carbon steel weld microstructure.

[0052] To further illustrate the preferred embodiments of this invention, Table 1 lists the characteristic parameters of the bevel used in the preferred embodiments 1-5 of this invention.

[0053] Table 1.

[0054] <![CDATA[b3(mm)]]> α(°) <![CDATA[w1(mm)]]> r(mm) <![CDATA[w2(mm)]]> <![CDATA[b4(mm)]]> Example 1 2 15 2 1 6 1 Example 2 2.5 15 2 0.5 8 2 Example 3 1.5 18 2 1.5 7 1 Example 4 2 20 3 1 7 2 Example 5 1.5 25 3 1.5 6 1.5

[0055] Table 2 lists the welding process parameters used in step 200 of forming the composite layer weld in preferred embodiments 1-5 of the present invention.

[0056] Table 2.

[0057]

[0058] Table 3 lists the welding process parameters used in step 300 of forming the transition layer weld in preferred embodiments 1-5 of the present invention.

[0059] Table 3.

[0060]

[0061] Table 4 lists the welding process parameters used in step 400 of forming the substrate layer weld in preferred embodiments 1-5 of the present invention.

[0062] Table 4.

[0063]

[0064] In addition, to demonstrate the implementation effect of the preferred embodiment, Table 5 lists the Cr content of each layer of base material and weld in the joint of the nickel-based alloy composite plate obtained by welding according to Embodiment 1 of the present invention. By calculation, it can be found that the dilution rate of the carbon steel weld bead in direct contact with the transition layer relative to the cladding weld bead is 1.86% (less than 2.00%), thus avoiding the formation of martensitic structure in the carbon steel weld bead of the base layer.

[0065] Table 5.

[0066]

[0067] Figure 2 The cross-sectional morphology of a nickel-based alloy composite plate joint prepared by the automated welding method for optimizing the weld microstructure of nickel-based alloy composite plates according to Example 1 of the present invention is shown.

[0068] from Figure 2 It can be seen that the joint of the nickel-based alloy composite plate prepared by the present invention has good fusion, which confirms that the method of the present invention can achieve good connection of nickel-based alloy composite plates.

[0069] Figure 3The image shows a metallographic photograph of the weld joint of a nickel-based alloy composite plate after etching with nitric acid alcohol, at the weld joint interface of the transition layer / carbon steel substrate layer, using the automated welding method for optimizing the weld microstructure of nickel-based alloy composite plates according to Embodiment 1 of the present invention.

[0070] from Figure 3 It can be seen that after nitric acid-alcohol corrosion, the metallographic structure at the interface between the transition layer weld and the carbon steel weld shows that the transition layer weld was not corroded, indicating that it still maintains the austenitic structure of the base material. The carbon steel weld shows a large number of ferrite grains and no obvious martensite structure. This shows that the application of the method of the present invention can successfully achieve a good transition of the weld structure of the nickel-based alloy composite plate joint under the welding sequence of cladding layer-transition layer-base layer.

[0071] It should be noted that the combination of the technical features in this case is not limited to the combination methods described in the claims of this case or the combination methods described in the specific embodiments. All technical features described in this case can be freely combined or combined in any way, unless they contradict each other.

[0072] It should also be noted that the embodiments listed above are merely specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and similar changes or modifications made thereto are those that can be directly derived or easily conceived by those skilled in the art from the content disclosed in the present invention, and should all fall within the protection scope of the present invention.

Claims

1. An automated welding method for optimizing the weld microstructure of a nickel-based alloy composite plate, wherein the nickel-based alloy composite plate comprises a substrate layer and a nickel-based alloy composite layer, and a transition layer is provided at the interface between the substrate layer and the nickel-based alloy composite layer; characterized in that, The automated welding method includes the following steps: A trapezoidal bevel is machined on the welding section of the nickel-based alloy composite plate at the position corresponding to the substrate layer; wherein the bottom width of the trapezoidal bevel on one side, w2, is ≥ (5 + 0.1b1), where b1 represents the distance from the surface of the substrate layer to its interface with the nickel-based alloy composite layer, and its unit parameter is mm; the distance b4 between the bottom of the trapezoidal bevel and the interface between the substrate layer and the nickel-based alloy composite layer is 1-2 mm; a U-shaped bevel is machined on the welding section of the nickel-based alloy composite plate at the position corresponding to the transition layer; the width of the U-shaped bevel on one side, w1 / 2, is 1-1.5 mm; the radius r of the arc portion of the U-shaped bevel is ≥ 0.25w1, where w1 represents twice the width of the U-shaped bevel on one side, and its unit parameter is mm; no bevel is machined on the welding section of the nickel-based alloy composite plate at the position corresponding to the nickel-based alloy composite layer. Laser welding was used to perform self-fusion welding on nickel-based alloy composite layers; Using carbon steel welding wire that matches the base layer, laser welding is used to filler wire welding the transition layer; The substrate layer is welded using hot-wire oscillating tungsten inert gas welding.

2. The automated welding method as described in claim 1, characterized in that, The angle α between the inclined part of the trapezoidal bevel and the vertical direction is ≥ (1.5b1)°, where b1 represents the distance from the surface of the substrate layer to the interface between it and the nickel-based alloy composite layer, and its unit parameter is mm.

3. The automated welding method as described in claim 1, characterized in that, In the step of self-fusion welding of nickel-based alloy composite layers using laser welding: the laser spot diameter is ≤1mm, the laser power is controlled at 3.0-4.0KW, the welding speed is 2.0-2.5m / min, and the positive defocusing amount is 0-5mm.

4. The automated welding method as described in claim 1, characterized in that, In the step of using laser welding to perform filler wire welding on the transition layer, the diameter of the laser spot used is ≤1mm.

5. The automated welding method as described in claim 1, characterized in that, In the step of using laser welding to perform filler wire welding on the transition layer: the laser power is controlled at 4.0-5.0KW, the welding speed is 2.0-3.0m / min, the positive defocusing amount is 5-10mm, the wire feeding speed is 1.5-2.0m / min, and the wire feeding angle is 30-45°.

6. The automated welding method as described in claim 1, characterized in that, In the step of welding the substrate layer using hot wire oscillation tungsten inert gas welding: the welding voltage is controlled at 12.0-14.0V, the welding current at 140-180A, the welding speed at 120-150mm / min, the wire feed speed at 1.8-2.6m / min, the hot wire current at 60-100A, and the oscillation width at 1-4mm.

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