A transition metal layer for preventing interfacial element diffusion, a method of making the same, and a nickel-based alloy / steel pack bonding method

Abstract

The present application relates to a transition metal layer for preventing interfacial element diffusion, a preparation method thereof and a nickel-based alloy / steel assembly method. The preparation method of the transition metal layer for preventing interfacial element diffusion is that raw materials of chromium, molybdenum, niobium, aluminum, titanium and nickel are mixed and melted, and then rapidly cooled and formed by a casting wheel to obtain an amorphous transition metal layer. The assembly method is that the bonding surfaces of a nickel-based alloy and a steel are polished respectively to remove the oxide layers, the transition metal layer is laid on the bonding surface of the steel, the bonding surface of the nickel-based alloy is covered on the transition metal layer, and then the whole assembly is completed. By introducing the intermediate transition metal layer, the element diffusion between the interfaces is inhibited, the actual corrosion resistance thickness of the composite plate cannot be reduced due to element diffusion, and the intermetallic compound at the interface is prevented from being generated, thereby improving the bonding force of the composite plate.

Description

Technical Field

[0001] This invention belongs to the field of metallurgy, specifically relating to a transition metal layer for preventing the diffusion of interfacial elements, its preparation method, and a method for assembling nickel-based alloy / steel billets. Background Technology

[0002] In actual production, during the explosive or hot-rolled composite process of nickel-based alloys / steel, element diffusion at the bonding interface reduces the effective thickness of the composite material, meaning the effective corrosion-resistant layer thickness of the composite plate decreases. For example, if the thicknesses of C276 and Q235B billets are 2mm and 8mm respectively, the thicknesses of C276 and Q235B after metallurgical bonding should be 2mm and 8mm respectively. However, due to element diffusion at the interface, the actual effective corrosion-resistant layer thickness of C276 is less than 2mm. This not only shortens the effective service life of the composite plate but also poses significant safety hazards in environments with high requirements. Furthermore, simply increasing the thickness of C276 to solve the problem of reduced effective corrosion-resistant layer thickness would significantly increase costs, rendering it impractical.

[0003] Therefore, based on this, the technical solution of the present invention is proposed. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a transition metal layer for preventing interfacial element diffusion, its preparation method, and a method for assembling a nickel-based alloy / steel billet. This invention incorporates a transition metal layer between the nickel-based alloy and steel, which can suppress element diffusion between the interfaces and ensure the actual corrosion-resistant thickness of the composite plate. This method not only maintains the actual corrosion-resistant thickness of the composite plate but also avoids the increased cost associated with thickening the C276 steel.

[0005] The present invention provides a method for preparing a transition metal layer to prevent the diffusion of interface elements, wherein the preparation method comprises:

[0006] The raw materials chromium, molybdenum, niobium, aluminum, titanium and nickel are mixed and melted, and then rapidly cooled and shaped by a strip spinning machine to obtain an amorphous transition metal layer.

[0007] Preferably, the raw materials have the following weight percentages: 20-24% chromium, 6-10% molybdenum, 2-6% niobium, 0.3-0.7% aluminum, 0.3-0.7% titanium, and the balance nickel.

[0008] Preferably, the raw materials have the following weight percentages: 22% chromium, 8% molybdenum, 4% niobium, 0.5% aluminum, 0.5% titanium, and the balance nickel.

[0009] Preferably, the melting temperature is 1250–1300°C.

[0010] Preferably, the thickness of the transition metal layer is 0.4 to 0.5 mm.

[0011] Based on the same technical concept, the present invention further provides a transition metal layer obtained by the above preparation method.

[0012] Similarly, based on the same technical concept, the present invention provides a method for assembling nickel-based alloys / steel, wherein the method is as follows:

[0013] The surfaces to be bonded, namely nickel-based alloy and steel, are ground or shot-blasted to remove the oxide layer. Then, the transition metal layer is laid flat on the steel surface to be bonded, and the nickel-based alloy surface to be bonded is covered by the transition metal layer. Finally, the entire blank is assembled.

[0014] Preferably, the nickel-based alloy is one of C276, 825 or 625 nickel-based alloys.

[0015] Preferably, the steel is either carbon steel or alloy steel.

[0016] The beneficial effects of this invention are as follows:

[0017] In the nickel-based alloy / steel billet assembly process, this invention introduces an intermediate transition metal layer to suppress element diffusion between interfaces. This not only ensures that the actual corrosion-resistant thickness of the composite plate does not decrease due to element diffusion, but also prevents the formation of intermetallic compounds at the interface, thereby improving the bonding strength of the composite plate. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is an EDS image of the interface at the edge of a nickel-based alloy / steel composite billet.

[0020] Figure 2 This is an EDS image of the interface at the middle position of the nickel-based alloy / steel composite billet. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0022] Example 1

[0023] This embodiment provides a method for preparing a transition metal layer to prevent the diffusion of interface elements. The preparation method is as follows:

[0024] The raw materials chromium, molybdenum, niobium, aluminum, titanium and nickel are mixed and melted at 1250°C, and then a 0.4 mm transition metal layer is obtained by using a strip spinning machine.

[0025] In this embodiment, the percentage content of each raw material is shown in Table 1.

[0026] Table 1 Percentage content of each component

[0027]

[0028]

[0029] This embodiment also provides a method for assembling nickel-based alloy / steel billets, the method being:

[0030] The surfaces to be bonded, namely 825 nickel-based alloy and Q235B, are polished to remove the oxide layer. Then, the transition metal layer is laid flat on the surface to be bonded of Q235B, and the surface to be bonded of C276 is covered by the transition metal layer. Finally, the entire blank is assembled.

[0031] Example 2

[0032] This embodiment provides a method for preparing a transition metal layer to prevent the diffusion of interface elements. The preparation method is as follows:

[0033] The raw materials chromium, molybdenum, niobium, aluminum, titanium and nickel are mixed and melted at 1300℃, and then a 0.5 mm transition metal layer is obtained by using a strip spinning machine.

[0034] In this embodiment, the percentage content of each raw material is shown in Table 2.

[0035] Table 2 Percentage content of each component

[0036]

[0037]

[0038] This embodiment also provides a method for assembling nickel-based alloy / steel billets, the method being:

[0039] The surfaces to be bonded, namely 625 nickel-based alloy and Q235B, are polished to remove the oxide layer. Then, the transition metal layer is laid flat on the surface to be bonded of Q235B, and the surface to be bonded of C276 is covered by the transition metal layer. Finally, the entire blank is assembled.

[0040] Example 3

[0041] This embodiment provides a method for preparing a transition metal layer to prevent the diffusion of interface elements. The preparation method is as follows:

[0042] The raw materials chromium, molybdenum, niobium, aluminum, titanium and nickel are mixed and melted at 1300℃, and then a 0.4 mm transition metal layer is obtained by vacuum spinning machine.

[0043] In this embodiment, the percentage content of each raw material is shown in Table 3.

[0044] Table 3 Percentage content of each component

[0045] Component types Component content chromium 22％ molybdenum 8％ niobium 4％ aluminum 0.5％ titanium 0.5％ nickel margin

[0046] This embodiment also provides a method for assembling nickel-based alloy / steel billets, the method being:

[0047] The surfaces to be bonded, namely C276 nickel-based alloy and Q235B, are polished to remove the oxide layer. Then, the transition metal layer is laid flat on the surface to be bonded, and the surface to be bonded, namely C276, is covered by the transition metal layer. Finally, the entire blank is assembled.

[0048] To further verify the diffusion of elements at the C276 and Q235B interface, the preform obtained in Example 3 was tested, and the test results are as follows: Figure 1 and Figure 2 As shown in the figure, the addition of the transition metal layer hinders the diffusion of alloying elements to a certain extent. Fe on the Q235B side only diffuses to one-quarter of the intermediate transition metal layer and does not diffuse to the C276 side. Similarly, it can be seen that the content and proportion of elements on the C276 side do not change significantly, and there is no obvious Fe diffusion near the interface as seen in Q235B. This proves that the intermediate transition metal layer inhibits the diffusion of elements on the C276 side, ensuring that the actual corrosion-resistant thickness of the composite plate does not decrease due to element diffusion.

[0049] It is important to emphasize that elemental diffusion does not necessarily prevent it; rather, the interdiffusion of elements between the intermediate transition metal layer material and C276 compensates for the deficiencies in nickel-based alloys such as C276, 825, and 625 caused by elemental diffusion. The interdiffusion of Fe and Ni between Q235B and the intermediate transition metal layer material strengthens the metallurgical bond at the composite interface, thereby increasing the overall bonding strength of the composite plate by 30%.

[0050] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for assembling nickel-based alloy / steel billets, characterized in that, The method for assembling the blanks is as follows: The surfaces to be bonded, namely nickel-based alloy and steel, are ground or shot-blasted to remove the oxide layer. Then, the transition metal layer is laid flat on the steel surface to be bonded, and the nickel-based alloy surface to be bonded is covered by the transition metal layer. Finally, the entire blank is assembled. The nickel-based alloy is one of C276, 825 or 625 nickel-based alloy; The steel is Q235B; The transition metal layer is prepared by mixing and melting raw materials chromium, molybdenum, niobium, aluminum, titanium and nickel, and then rapidly cooling and shaping them through a strip spinning machine to obtain an amorphous transition metal layer. The raw materials of the transition metal layer are: 20-24% chromium, 6-10% molybdenum, 2-6% niobium, 0.3-0.7% aluminum, 0.3-0.7% titanium, and the balance nickel.

2. The method for assembling nickel-based alloy / steel according to claim 1, characterized in that, The raw material weight percentage of the transition metal layer is: 22% chromium, 8% molybdenum, 4% niobium, 0.5% aluminum, 0.5% titanium, and the balance nickel.

3. The method for assembling nickel-based alloy / steel according to claim 1, characterized in that, The melting temperature is 1250~1300℃.

4. The method for assembling nickel-based alloy / steel according to claim 1, characterized in that, The thickness of the transition metal layer is 0.4~0.5 mm.

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