Economical welding method for nickel-based alloy composite plate

Abstract

The invention discloses an economical welding method for a nickel-based alloy composite board. The nickel-based alloy composite board comprises a base material layer and a nickel-based alloy composite material layer, and a transition layer is arranged at the bonding interface of the base material layer and the nickel-based alloy composite material layer. The economical welding method comprises the steps that a composite groove is machined in the position, corresponding to a base material layer, of the welding section of the nickel base alloy composite plate, and the composite groove comprises a vertical inclined part, a horizontal part and a transition arc arranged between the vertical inclined part and the horizontal part; a rectangular groove is formed in the position, corresponding to the transition layer, of the welding section of the nickel-based alloy; a groove is not machined in the position, corresponding to the nickel-based alloy composite material layer, of the welding section of the nickel-based alloy composite plate; carrying out self-fusion welding on the nickel-based alloy composite material layer by adopting laser welding; a carbon steel welding wire matched with the base material layer is used, and laser welding is adopted for conducting wire filling welding on the transition layer; and welding the base material layer by adopting hot wire pulse argon tungsten-arc welding.

Description

Technical Field

[0001] The invention relates to a welding method, in particular to a welding method for a composite plate. Background Art

[0002] Because it contains a large amount of precious metal elements, the unit price of nickel-based alloys is dozens of times that of low-alloy carbon steel. Therefore, in engineering construction that requires the use of nickel-based alloys (high corrosion resistance requirements), material cost is a very important consideration. At this time, the use of nickel-based alloy composite plates can meet construction needs to a certain extent.

[0003] However, because the base material of the nickel-based alloy composite plate contains two metals with different components, nickel-based alloy and carbon steel, different welding materials are needed to weld the composite layer and the base layer separately during welding, and add a transition layer between the two, which is the so-called multi-layer and multi-pass welding. Among them, the base layer welding generally uses carbon steel welding wire, which is relatively cheap, while the transition layer and the composite layer are both made of nickel-based alloy welding materials, which are also dozens of times more expensive than carbon steel welding materials. In this way, as the length of the weld increases, the use of nickel-based alloy welding materials will also increase significantly, which is a huge construction cost for some large projects.

[0004] The Chinese patent document with publication number CN113042895A and publication date June 29, 2021, entitled "A welding method for a nickel-steel composite structure" discloses: when the composite layer is welded first, laser self-fusion welding is also used to complete the connection of the composite layer, and then the carbon steel welding wire is used in conjunction with the arc welding method to complete the connection of the nickel-based alloy composite plate under this welding sequence. The entire connection process can also be done without using carbon steel welding wire, but it mainly targets the problem of decreased corrosion resistance of the composite layer caused by element migration at the interface between the composite layer and the substrate layer, and no measures are taken to control the problem of martensiticization of the microstructure of the carbon steel weld. Summary of the invention

[0005] One of the purposes of the present invention is to provide an economical welding method for nickel-based alloy composite plates, which can complete the whole process of reliable connection of nickel-based alloy composite plates using only carbon steel welding materials. In particular, carbon steel welding materials can be used to weld a transition layer weld to complete the composition transition of the nickel-based alloy to the substrate layer, thereby achieving reliable connection of the nickel-based alloy composite plates without using nickel-based alloy welding materials, reducing the welding cost of the nickel-based alloy composite plates, and generating considerable economic benefits.

[0006] In order to achieve the above object, the present invention provides an economical welding method for 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 bonding interface between the substrate layer and the nickel-based alloy composite layer; wherein the economical welding method comprises the steps of:

[0007] Processing a composite groove at a position corresponding to the base material layer on the welding cross section of the nickel-based alloy composite plate, wherein the composite groove includes a vertical inclined portion, a horizontal portion, and a transition arc disposed between the vertical inclined portion and the horizontal portion; opening a rectangular groove at a position corresponding to the transition layer on the welding cross section of the nickel-based alloy; and not processing a groove at a position corresponding to the nickel-based alloy composite material layer on the welding cross section of the nickel-based alloy composite plate;

[0008] Laser welding is used to perform autogenous welding on the nickel-based alloy composite layer;

[0009] Use carbon steel welding wire that matches the base material layer and laser welding to fill the transition layer;

[0010] The base material layer is welded by hot wire pulse tungsten inert gas arc welding.

[0011] The welding method of the present invention avoids the martensitic transformation of the carbon steel weld due to excessive melting of the alloy elements in the transition layer weld, so that the carbon steel welding material can be used to fill the transition layer weld to complete the good transition of the nickel-based alloy to the carbon steel structure, and realize the reliable connection of the nickel-based alloy composite plate. The present invention is applied to the welding process of nickel-based alloy composite plate components in engineering, which can greatly reduce the use of nickel-based alloy welding materials and generate considerable economic benefits.

[0012] Furthermore, in the economical welding method for nickel-based alloy composite plates described in the present invention, the single-side width w1 / 2 of the rectangular groove is ≥ the laser spot radius of laser welding.

[0013] In this embodiment, rectangular grooves are opened on both sides of the transition layer weld position. When two nickel-based alloy composite plates are welded, the sum of the widths w1 of the two rectangular grooves is greater than the laser spot diameter, which can ensure that the laser autogenous welding of the composite layer weld is completed smoothly without melting the carbon steel substrate.

[0014] Furthermore, in the economical welding method for nickel-based alloy composite plates described in the present invention, the thickness b3 of the rectangular groove satisfies 0.2mm≤b3≤0.5b2, where b2 represents the distance from the surface of the nickel-based alloy composite layer to the bonding interface between it and the substrate layer, and its unit parameter is mm.

[0015] In this embodiment, the thickness b3 of the rectangular groove, i.e., the distance between the base material layer weld step and the bonding interface of the base material layer and the nickel-based alloy clad material layer, can be controlled within a certain range and the smaller the better. However, if b3 is too small, the base material layer weld, especially the first layer of several welds, will require a very shallow penetration during welding to avoid penetrating the base material layer to the nickel-based alloy clad material layer. Therefore, the range of b3 can be limited to 0.2mm≤b3≤0.5b2mm.

[0016] Furthermore, in the economical welding method for nickel-based alloy composite plates described in the present invention, the angle α between the vertical inclined portion and the vertical direction is ≥(1.5b1)°, where b1 represents the distance from the surface of the substrate layer to the bonding interface between it and the nickel-based alloy composite layer, and its unit parameter is mm.

[0017] Furthermore, in the economical welding method for nickel-based alloy composite plates described in the present invention, the extension length w2 of the horizontal portion is ≥(5+0.1b1), where b1 represents the distance from the surface of the substrate layer to the bonding interface between the substrate layer and the nickel-based alloy composite layer, and its unit parameter is mm.

[0018] In this embodiment, in order to facilitate the subsequent hot wire pulse tungsten inert gas arc welding operation, the extension length w2 of the horizontal portion is controlled to be ≥ (5+0.1b1).

[0019] Furthermore, in the economical welding method for nickel-based alloy composite plates described in the present invention, the radius of the transition arc r≥0.2w2, where w2 represents the extension length of the horizontal portion, and its unit parameter is mm.

[0020] For the implementation of the smaller rectangular groove thickness b3 (for example, the implementation of b3 as 0.2mm≤b3≤0.5b2 mentioned above), since this implementation will result in a greater restriction on the heat input during carbon steel weld welding, in order to avoid the generation of unfused welding defects in this case, it is preferred to control the radius of the transition arc r≥0.2w2.

[0021] Furthermore, in the economical welding method for nickel-based alloy composite plates described in the present invention, in the step of using laser welding to perform self-fusion welding on the nickel-based alloy composite layer: the laser spot diameter used is ≤1mm, the laser power is controlled to be 4.0-5.0KW, the welding speed is 2.5-3.0m / min, and the positive defocus is 0-5mm.

[0022] Furthermore, in the economical welding method for nickel-based alloy composite plates described in the present invention, in the step of performing wire-filling welding on the transition layer by laser welding, the diameter of the laser spot used is ≤1 mm.

[0023] Furthermore, in the economical welding method for nickel-based alloy composite plates described in the present invention, in the step of using laser welding to filler wire welding the transition layer: the laser power is controlled to be 5.0-6.0KW, the welding speed is 4.0-5.0m / min, the positive defocus is 5-10mm, the wire feeding speed is 0.5-1.0m / min, and the wire feeding angle is 30-45°.

[0024] In this embodiment, with the specially designed groove form, the transition layer weld will melt part of the composite layer weld downwards, which can ultimately ensure that the ratio of the carbon steel component (including carbon steel parent material and carbon steel welding wire) and the nickel-based alloy component melted into the transition layer weld does not exceed 1:1, and the transition layer weld can still maintain the parent phase full austenite structure.

[0025] Furthermore, in the economical welding method for nickel-based alloy composite plates described in the present invention, in the step of welding the substrate layer using hot wire pulse tungsten inert gas arc welding: the welding voltage is controlled to be 13.0-15.0V, the peak current is 160-200A, the base current is 80-120A, the duty cycle is 50-80%, the pulse frequency is 5-10Hz, the hot wire current is 80-100A, the welding speed is 150-180mm / min, and the wire feeding speed is 2.6-3.2m / min.

[0026] In this embodiment, the transition layer weld obtained by a special process can ensure that the dilution rate of the carbon steel weld, especially the carbon steel weld in direct contact with the transition layer, relative to the composite layer weld is less than 2.0%, and the structure will not be transformed into a martensitic structure as a whole.

[0027] The economical welding method of the nickel-based alloy composite plate of the present invention has the following advantages and beneficial effects compared with the prior art:

[0028] The welding method of the present invention realizes the weld connection of the composite material layer through laser self-melting welding. At the same time, through special groove design and welding process, carbon steel welding materials can be used to achieve a good transition from the nickel-based alloy to the substrate layer structure, thereby obtaining a reliable transition layer weld.

[0029] The welding method of the present invention avoids the overall martensitication of the carbon steel weld due to excessive melting of the transition layer weld alloy elements, thereby achieving reliable connection of the nickel-based alloy composite plate without using nickel-based alloy welding materials, reducing the welding cost of the nickel-based alloy composite plate, and generating considerable economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The figure schematically shows the groove diagram used in the economical welding method of the nickel-based alloy composite plate of the present invention.

[0031] Figure 2 The figure shows the morphology of the welded joint of the nickel-based alloy composite plate prepared by the economical welding method of Example 1 of the present invention after being corroded by nitric acid.

[0032] Figure 3The metallographic structure photograph of the transition layer / carbon steel substrate layer weld joint cross section of the welded joint of the nickel-based alloy composite plate prepared by the economical welding method of Example 1 of the present invention after being corroded by nitric alcohol is shown. DETAILED DESCRIPTION

[0033] The economical welding method for the nickel-based alloy composite plate of the present invention will be further explained and illustrated below in conjunction with specific embodiments and drawings of the specification, but such explanation and illustration do not constitute an improper limitation on the technical solution of the present invention.

[0034] The object of the present invention is to provide an economical welding method for nickel-based alloy composite plates. Figure 1 Shows two spliced ​​nickel-based alloy composite plates A and B. Figure 1 The dotted line O in the figure represents a joint. The nickel-based alloy composite plate comprises a substrate layer 1 and a nickel-based alloy composite material layer 2, wherein a transition layer is provided at a bonding interface between the substrate layer 1 and the nickel-based alloy composite material layer 2. Figure 1 The symbol "b1" represents the distance between the surface of the carbon steel substrate layer and the bonding interface between it and the nickel-based alloy composite layer, and the symbol "b2" represents the distance between the surface of the nickel-based alloy composite layer and the bonding interface between it and the carbon steel substrate layer.

[0035] In a specific embodiment, a nickel-based alloy composite plate with a composite plate grade of Incoloy825 / X52 can be used, that is, the base material layer material is X52, and the nickel-based alloy composite material layer material is Incoloy825. The plate thickness of the nickel-based alloy composite plate is 13 mm, wherein b1 of the nickel-based alloy composite plate is 10 mm, and b2 is 3 mm.

[0036] In some embodiments, an economical welding method for nickel-based alloy clad plates comprises the steps of:

[0037] 100: Processing at the welding position of two spliced ​​nickel-based alloy composite plates A and B as follows Figure 1 The groove shown. A composite groove is processed at a position corresponding to the base material layer on the welding cross section of the nickel-based alloy composite plate, and the composite groove includes a vertical inclined portion 6, a horizontal portion 8, and a transition arc 7 arranged in sequence between the vertical inclined portion and the horizontal portion, wherein the extension length of the horizontal portion is Figure 1 Indicated by "w2"; a rectangular groove is opened at the position corresponding to the transition layer on the welding section of the nickel-based alloy, and the single-side width of the rectangular groove is Figure 1 In the figure, w1 / 2 is used to represent the thickness of the rectangular groove. Figure 1 Indicated by b3; no groove is processed at the position corresponding to the nickel-based alloy composite layer on the welding cross section of the nickel-based alloy composite plate, that is, the welding surface of the nickel-based alloy composite layer is a vertical plane.

[0038] 200: Laser welding is used to perform autogenous welding on the nickel-based alloy composite layer to form a composite layer weld 3.

[0039] 300: Use carbon steel welding wire that matches the base material layer and use laser welding to fill the transition layer with wire to form a transition layer weld 4.

[0040] 400: Use carbon steel welding wire that matches the carbon steel substrate layer, and adopt hot wire pulse tungsten inert gas arc welding to perform wire welding on the carbon steel substrate layer to form a substrate layer weld 5.

[0041] Preferably, in some embodiments, the single-side width w1 / 2 of the rectangular groove is ≥ the laser spot radius of laser welding, that is, the total width w1 of the two rectangular grooves formed by the two spliced ​​nickel-based alloy composite plates A and B is ≥ the laser spot diameter of laser welding. This design can ensure that the laser autogenous welding of the nickel-based alloy composite layer weld is successfully completed without melting the carbon steel substrate.

[0042] Preferably, in some embodiments, the range of b3, i.e., the thickness of the rectangular groove, can be limited to 0.2 mm ≤ b3 ≤ 0.5 b2, wherein b2 represents the distance from the surface of the nickel-based alloy composite layer to the bonding interface between the nickel-based alloy composite layer and the substrate layer, and its unit parameter is mm.

[0043] Preferably, in some embodiments, the included angle α between the vertical inclined portion and the vertical direction is ≥(1.5b1)°, where b1 represents the distance from the surface of the substrate layer to the bonding interface between the substrate layer and the nickel-based alloy composite layer, and its unit parameter is mm. In this embodiment, the subsequent hot wire pulse tungsten inert gas arc welding operation can be facilitated by controlling the included angle α.

[0044] Preferably, in some embodiments, the extension length w2 of the horizontal portion is ≥(5+0.1b1), where b1 represents the distance from the surface of the substrate layer to the bonding interface between the substrate layer and the nickel-based alloy composite layer, and the unit parameter is mm.

[0045] Preferably, in some embodiments, the radius of the transition arc r≥0.2w2, where w2 represents the extension length of the horizontal portion, and its unit parameter is mm. In this embodiment, the generation of incomplete fusion welding defects can be avoided.

[0046] Preferably, in some embodiments, in step 200, laser autogenous welding is used to form a composite layer weld 3, the laser spot diameter used is ≤1mm, the laser power can be controlled to be 4.0-5.0KW, the welding speed is 2.5-3.0m / min, and the positive defocus is 0-5mm.

[0047] In step 300, laser wire welding is used to weld the transition layer weld 4. The filler metal can use a carbon steel welding material that matches the performance of the base material layer, such as ER50-6. The laser spot diameter used is ≤1mm, the laser power can be controlled to be 5.0-6.0KW, the welding speed is 4.0-5.0m / min, the positive defocus is 5-10mm, the wire feeding speed is 0.5-1.0m / min, and the wire feeding angle is 30-45°.

[0048] By adopting this preferred embodiment, through the specially designed groove form, the transition layer weld will melt part of the composite layer weld downwards, which can ultimately ensure that the ratio of the carbon steel component (including carbon steel parent material and carbon steel welding wire) and the nickel-based alloy component melted into the transition layer weld does not exceed 1:1, and the transition layer weld can still maintain the parent phase full austenite structure.

[0049] In step 400, the carbon steel weld 5 is welded using a carbon steel welding wire ER50-6 that matches the base material of the substrate layer. The welding method adopts hot wire pulse tungsten inert gas arc welding, and the welding voltage is controlled to be 13.0-15.0V, the peak current is 160-200A, the base current is 80-120A, the duty cycle is 50-80%, the pulse frequency is 5-10Hz, the hot wire current is 80-100A, the welding speed is 150-180mm / min, and the wire feeding speed is 2.6-3.2m / min.

[0050] By adopting this preferred embodiment, the transition layer weld obtained by a special process can ensure that the dilution rate of the carbon steel weld, especially the carbon steel weld in direct contact with the transition layer, relative to the composite layer weld is less than 2.0%, and the structure will not be transformed into a martensitic structure as a whole.

[0051] In order to further reflect the preferred implementation of this case, Table 1 lists the characteristic parameters of the grooves used in the preferred embodiments 1-5 of the present invention.

[0052] Table 1.

[0053]

[0054] Table 2 lists the welding process parameters used in step 200 of forming a composite material layer weld in preferred embodiments 1-5 of the present invention.

[0055] Table 2.

[0056] serial number Laser spot diameter(mm) Laser power(KW) Welding speed (m / min) Defocus (mm) Example 1 0.5 4.5 2.6 0 Example 2 0.8 4.0 2.5 +3 Example 3 0.5 5.0 3.0 0 Example 4 0.8 4.8 2.6 +5 Example 5 1.0 4.6 2.8 0

[0057] 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.

[0058] Table 3.

[0059]

[0060] Table 4 lists the welding process parameters used in step 400 of forming the base material layer weld in preferred embodiments 1-5 of the present invention.

[0061] Table 4.

[0062]

[0063] In addition, in order to prove the implementation effect of the preferred embodiment, Table 5 lists the Cr element content of the base material and weld of each layer of the nickel-based alloy composite plate obtained by welding in Example 1 of the present invention. By calculation, it can be obtained that the dilution rate of the transition layer weld relative to the composite layer weld is 58.96%, and the dilution rate of the carbon steel weld directly in contact with the transition layer relative to the composite layer weld is 1.86% (lower than 2.0%), thereby avoiding the formation of martensitic structure in the carbon steel weld.

[0064] Table 5.

[0065]

[0066] Figure 2 The figure shows the morphology of the welded joint of the composite plate prepared by the economical welding method of Example 1 of the present invention after being corroded by nitric acid.

[0067] from Figure 2 It can be seen from the figure that the weld joint is well bonded, indicating that the method of the present invention can achieve effective connection of nickel-based alloy composite plates.

[0068] Figure 3 The metallographic structure photograph of the transition layer / carbon steel weld joint section of the welded joint of the composite plate prepared by the economical welding method of Example 1 of the present invention after being corroded by nitric alcohol is shown.

[0069] from Figure 3 It can be seen that the transition layer weld cannot be corroded by nitric acid, indicating that it still retains the base material austenite corrosion-resistant structure, while a large number of ferrite grains can be seen in the carbon steel weld adjacent to the transition layer, and no obvious martensite structure appears, which shows that the purpose of the invention is achieved, that is, the carbon steel welding material is used to complete the structure / composition transition of the transition layer weld of the nickel-based alloy composite plate to the carbon steel weld, and the composite plate joint connection is reliable.

[0070] It should be noted that the combination of the various technical features in this case is not limited to the combination described in the claims of this case or the combination described in the specific embodiments. All technical features recorded in this case can be freely combined or combined in any way unless there is a contradiction between them.

[0071] It should also be noted that the above-listed embodiments are only specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and similar changes or modifications made therewith can be directly derived or easily associated with the contents disclosed by those skilled in the art from the present invention, and all should belong to the protection scope of the present invention.

Claims

1. An economical welding method for a nickel-based alloy composite plate, wherein the nickel-based alloy composite plate comprises a substrate layer and a nickel-based alloy composite layer, wherein a transition layer is provided at a bonding interface between the substrate layer and the nickel-based alloy composite layer; characterized in that: The economical welding method comprises the steps of: Processing a composite groove at a position corresponding to the base material layer on the welding cross section of the nickel-based alloy composite plate, wherein the composite groove includes a vertical inclined portion, a horizontal portion, and a transition arc disposed between the vertical inclined portion and the horizontal portion; opening a rectangular groove at a position corresponding to the transition layer on the welding cross section of the nickel-based alloy; and not processing a groove at a position corresponding to the nickel-based alloy composite material layer on the welding cross section of the nickel-based alloy composite plate; Laser welding is used to perform autogenous welding on the nickel-based alloy composite layer; Use carbon steel welding wire that matches the base material layer and laser welding to fill the transition layer; The base material layer is welded by hot wire pulse tungsten inert gas arc welding.

2. The economical welding method for nickel-based alloy composite plates according to claim 1, characterized in that: The single-side width w1 / 2 of the rectangular groove is ≥ the laser spot radius of laser welding.

3. The economical welding method for nickel-based alloy composite plates according to claim 1, characterized in that: The thickness b3 of the rectangular groove satisfies 0.2mm≤b3≤0.5b2, wherein b2 represents the distance from the surface of the nickel-based alloy composite layer to the bonding interface between the nickel-based alloy composite layer and the substrate layer, and its unit parameter is mm.

4. The economical welding method for nickel-based alloy composite plates according to claim 1, characterized in that: The included angle α between the vertical inclined portion and the vertical direction is ≥(1.5b1)°, where b1 represents the distance from the surface of the substrate layer to the bonding interface between the substrate layer and the nickel-based alloy composite layer, and its unit parameter is mm.

5. The economical welding method for nickel-based alloy composite plates according to claim 1, characterized in that: The extension length w2 of the horizontal portion is ≥(5+0.1b1), where b1 represents the distance from the surface of the substrate layer to the bonding interface between the substrate layer and the nickel-based alloy composite layer, and its unit parameter is mm.

6. The economical welding method for nickel-based alloy composite plates according to claim 1, characterized in that: The radius r of the transition arc is ≥0.2w2, where w2 represents the extension length of the horizontal portion, and its unit parameter is mm.

7. The economical welding method for nickel-based alloy composite plates according to claim 1, characterized in that: In the step of using laser welding to perform self-melting welding on the nickel-based alloy composite layer: the laser spot diameter used is ≤1mm, the laser power is controlled to be 4.0-5.0KW, the welding speed is 2.5-3.0m / min, and the positive defocus is 0-5mm.

8. The economical welding method for nickel-based alloy composite plates according to claim 1, characterized in that: In the step of performing wire welding on the transition layer by laser welding, the diameter of the laser spot used is ≤1 mm.

9. The economical welding method for nickel-based alloy composite plates according to claim 1, characterized in that: In the step of using laser welding to filler wire welding the transition layer: control the laser power to 5.0-6.0KW, the welding speed to 4.0-5.0m / min, the positive defocus to 5-10mm, the wire feeding speed to 0.5-1.0m / min, and the wire feeding angle to 30-45°.

10. The economical welding method for nickel-based alloy composite plates according to claim 1, characterized in that: In the step of welding the substrate layer using hot wire pulse tungsten inert gas arc welding: control the welding voltage to 13.0-15.0V, the peak current to 160-200A, the base current to 80-120A, the duty cycle to 50-80%, the pulse frequency to 5-10Hz, the hot wire current to 80-100A, the welding speed to 150-180mm / min, and the wire feeding speed to 2.6-3.2m / min.

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