Welding process of nickel-based alloy N06059 and heat-resistant alloy 14Cr1MoR clad plate

Abstract

The application discloses a nickel-based alloy N06059 and heat-resistant alloy 14Cr1MoR composite plate welding process and belongs to the technical field of welding, which specifically comprises groove processing, base layer welding, hydrogen removal processing, transition layer welding, complex layer welding and post-weld heat treatment in sequence. According to the different welding process requirements of the heat-resistant alloy steel and the nickel-chromium-molybdenum alloy, the groove is designed reasonably (double U-shaped groove), the complex layer adopts the groove removing process, the welding of the complex layer is completely separated from the welding of the base layer, and the hidden danger of the fusion complex layer during the welding of the base layer is eliminated; argon arc welding is selected for the welding of the transition layer and the complex layer, the welding heat input is controlled, the dilution effect of the base layer material on the transition layer is reduced, the time of the complex layer weld at high temperature is reduced, the ability of the complex layer weld to resist intergranular corrosion is avoided to be reduced, the post-weld heat treatment temperature is selected as 670 DEG C, the sensitization temperature of the N06059 is avoided, the intergranular corrosion sensitization of the complex layer caused by the heat treatment is prevented, and the welding of the 14Cr1MoR heat-resistant low alloy steel and the N06059 nickel-chromium-molybdenum alloy composite plate is successfully realized.

Description

Technical Field

[0001] This invention belongs to the field of welding technology, specifically relating to a welding process for a composite plate of nickel-based alloy N06059 and heat-resistant alloy 14Cr1MoR. Background Technology

[0002] 14Cr1MoR is a CrMo heat-resistant low-alloy steel, prone to porosity and delayed cracking defects during welding. The welding conditions are quite stringent: before welding, the bevel must be cleaned to remove rust, oil, water, and other sources of hydrogen; preheating to above 150℃ is necessary to reduce stress during welding and slow the cooling rate; continuous heating and uninterrupted welding are required to ensure the interpass temperature does not fall below the preheating temperature; each weld must be completed in one pass; post-heating (hydrogen removal heat treatment) must be performed immediately after each weld, heating the weld to 350℃, holding it at that temperature for 1 hour, and then slowly cooling it to room temperature; non-destructive testing (NDT) can only be performed 24 hours after welding, after the time when delayed cracking is most likely to occur.

[0003] N06059 is a nickel-based alloy, belonging to the nickel-chromium-molybdenum alloy series. Due to its high alloying element content, it is susceptible to hot cracking or porosity during welding due to external impurities. It is crucial to control the time the weld zone spends at high temperatures to prevent a decrease in resistance to intergranular corrosion. The following points should be noted during welding: Beveling should be done mechanically. This equipment uses a composite plate; the cladding layer is grooved and beveled using a planer. Before assembly, use an alloy rotary file to clean the cladding layer and the 10mm area on both sides. Clean the bevel with alcohol or acetone before welding. Similarly, clean the welding wire with alcohol or acetone to reduce impurities adhering to the bevel or welding wire surface from entering the weld, preventing cracks or porosity. Control the interpass temperature during welding, reducing the time the weld spends at high temperatures. The interpass temperature should not exceed 150℃ as required by NB / T47015. Weld in multiple layers and multiple passes with slight oscillations; the width of each weld pass should not exceed 8mm. Strictly clean the interpasses to prevent impurity accumulation; a stainless steel wire brush must be used for cleaning.

[0004] Due to production requirements, equipment is needed to manufacture composite plates with a 14Cr1MoR base layer and a N06059 composite layer. However, the welding process requirements for 14Cr1MoR and N06059 are quite different. It is necessary to solve the problem that the base layer welding cannot be fused to the cladding base material, the transition layer welding must fuse both the base layer and the cladding layer, and the base layer should be diluted as much as possible to avoid cracking defects in the transition layer. At the same time, it is necessary to ensure that the chemical composition of the cladding weld and the intergranular corrosion resistance of the cladding weld are basically the same as those of the base material. Summary of the Invention

[0005] To address the significant differences in welding process requirements between 14Cr1MoR and N06059 materials, the inability of layer welding to fuse to the cladding base material, the need for fusion of both the base layer and the cladding layer in transition layer welding, and the occurrence of crack defects in the transition layer, this invention provides a welding process for a composite plate of nickel-based alloy N06059 and heat-resistant alloy 14Cr1MoR. This process solves the problem of significant differences in welding processes between nickel-chromium-molybdenum alloys and low-alloy alloys, which leads to crack defects in the transition layer of the composite plate. It also avoids the hot cracking and porosity issues that easily occur in N06059 cladding layer welding and ensures the intergranular corrosion resistance of the cladding weld.

[0006] This invention is achieved through the following technical solution:

[0007] A welding process for a composite plate of nickel-based alloy N06059 and heat-resistant alloy 14Cr1MoR includes, in sequence, beveling, base layer welding, hydrogen removal treatment, transition layer welding, cladding layer welding, and stress relief heat treatment, specifically as follows:

[0008] (1) Beveling: The welding parts of the composite plate of nickel-based alloy N06059 and heat-resistant alloy 14Cr1MoR are processed to form a double U-shaped beveling at the base and a multi-layer groove beveling, and the beveling is cleaned and inspected.

[0009] (2) Base welding: The base weld is preheated to 150℃~200℃. Argon arc welding is used to form the base layer, and submerged arc welding is used to fill the inner edge to form the base layer. Submerged arc welding is used to fill and cover the outer edge to form the base layer and the base layer cover layer. The base weld is then completed. Radiographic testing is performed on the base weld, and the inner surface is penetrated.

[0010] (3) Hydrogen removal treatment: Hydrogen removal treatment should be carried out immediately after the base layer welding is completed, and the temperature should be kept warm and cooled slowly;

[0011] (4) Transition layer welding: The transition layer is welded on the inner edge using argon arc welding process, and the transition layer is subjected to penetrant testing;

[0012] (5) Double layer welding: Argon arc welding process is used to weld the double layer on the inner edge;

[0013] (6) Stress relief heat treatment.

[0014] Furthermore, the root radius of the double U-shaped bevel of the base layer is R=10mm, the bevel angle is 8°, the blunt edge is 2+1mm, and the assembly gap is 3+1mm.

[0015] Further, in step (2), the argon arc welding current is 150-220A and the voltage is 12-14V, and the submerged arc welding current is 470-580A and the voltage is 28-34V.

[0016] Furthermore, in step (4), the argon arc welding current is 150-220A and the voltage is 12-14V; in step (5), the argon arc welding current is 150-180A and the voltage is 12-14V.

[0017] Further, in step (2), the welding wire used for argon arc welding is ER55-B2 with a diameter of 2.5mm, and the welding wire used for submerged arc welding is ER55-B2 with a diameter of 4.0mm; in step (4), the welding wire used for argon arc welding is φ2.5mm ERNiCrMo-3, which includes the following components by weight percentage: C 0.10%, Mn 0.50%, Fe 5.0%, P 0.02%, S 0.015%, Si 0.50%, Cu 0.5 0%, Cr20-23%, Mo8-10%, Nb3.15-4.15%, with the balance being Ni; the welding wire used for argon arc welding in step (5) is φ2.5mm ERNiCrMo-13, which includes the following components by weight percentage: C0.01%, Mn0.10%, Fe1.5%, P0.015%, S0.005%, Si0.10%, Cr22-24%, Mo15-16.5%, with the balance being Ni.

[0018] Furthermore, the conditions for hydrogen removal treatment in step (3) are to heat to 350°C with a flame, hold for 1 hour, and then cool slowly.

[0019] Further, in step (4), the transition layer is preheated to 200°C before welding.

[0020] Furthermore, in step (5), the interlayer temperature of the tandem welding is ≤100℃, and a stainless steel wire wheel is used to clean the weld after each layer is welded.

[0021] Furthermore, in step (6), the heat treatment temperature for stress relief is 670℃ and the holding time is 200min.

[0022] Furthermore, the radiographic testing and penetrant testing of the base layer are carried out 24 hours after the base layer welding is completed, and the penetrant testing of the transition layer is carried out 24 hours after the transition layer welding is completed.

[0023] Beneficial effects

[0024] Based on the different welding process requirements of heat-resistant alloy steel and nickel-chromium-molybdenum alloy, this invention rationally designs the bevel shape and welding materials for the transition layer, and adopts different welding parameters to successfully weld 14Cr1MoR heat-resistant low-alloy steel to N06059 nickel-chromium-molybdenum alloy composite plate, which has the following advantages:

[0025] (1) The bevel design is reasonable, and the grooving process is adopted for the cladding layer, which completely separates the welding of the cladding layer from the welding of the base layer, eliminating the hidden danger of fusion of the cladding layer when welding the base layer;

[0026] (2) Argon arc welding is selected for the transition layer and the cladding layer. The amount of welding heat input is controlled to reduce the dilution effect of the base material on the transition layer, reduce the time the cladding layer weld stays at high temperature, and avoid the decline in the intergranular corrosion resistance of the cladding layer weld.

[0027] (3) The heat treatment temperature for stress relief is selected as 670℃ to avoid the sensitization temperature of N06059 and to prevent intergranular corrosion sensitization of the cladding layer caused by heat treatment. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the bevel structure in this invention;

[0029] Figure 2 This is a schematic diagram of the structure of each layer of the welded joint in this invention, wherein: 1. Base layer, 2. Base layer filling layer, 3. Base layer cover layer, 4. Transition layer, 5. Overlapping layer. Detailed Implementation

[0030] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0031] Example 1

[0032] A welding process for an 80+4mm 14Cr1MoR heat-resistant low-alloy steel composite plate with N06059 nickel-chromium-molybdenum alloy includes, in sequence, beveling, base layer welding, hydrogen removal treatment, transition layer welding, cladding layer welding, and stress relief heat treatment, specifically as follows:

[0033] (1) Beveling: The welding parts of the composite plate of nickel-based alloy N06059 and heat-resistant alloy 14Cr1MoR are processed to form a double U-shaped bevel at the base and a grooving pattern at the tandem. The bevel after processing is as follows: Figure 1 As shown, the base layer has a bevel root radius R=10mm, a bevel angle of 8°, a blunt edge of 2+1mm, and an assembly gap of 3+1mm; the cladding layer has a 5mm radius removed and processed into a 22° bevel, with a bevel root radius R=5mm. The bevel is then cleaned and inspected (the bevel and the area within 20mm on both sides are cleaned to remove rust, grease, and dust before assembly).

[0034] (2) Base layer welding: The base layer weld is preheated to 200℃. Argon arc welding is used to form the base layer root layer 1 (argon arc welding wire type ER55-B2). Submerged arc welding is used to fill the inner edge to form the base layer filler layer 2. Submerged arc welding is used to fill and cover the outer edge to form the base layer filler layer 2 and the base layer cover layer 3 (welding wire type ER55-B2). The base layer weld is then completed. 24 hours after the welding is completed, the base layer weld is subjected to radiographic testing and the inner surface is subjected to penetrant testing. According to NB / T47013.5-2015, Grade I is qualified.

[0035] The argon arc welding current is 190A and the voltage is 14V, while the submerged arc welding current is 550A and the voltage is 32V.

[0036] (3) Hydrogen removal treatment: Hydrogen removal treatment shall be carried out immediately after the base welding is completed (using flame heating to 350℃ and holding for 1 hour), followed by slow cooling.

[0037] (4) Transition layer welding: The transition layer 4 (welding wire ERNiCrMo-3, which includes the following components by weight percentage: C 0.10%, Mn 0.50%, Fe 5.0%, P 0.02%, S 0.015%, Si 0.50%, Cu 0.50%, Cr 22%, Mo 9.5%, Nb 3.85%, with the balance being Ni) is welded on the inner edge using argon arc welding with a welding current of 180A and a voltage of 14V. After 24 hours of welding, the transition layer is subjected to penetration testing, and it is qualified according to NB / T47013.5-2015 as Grade I.

[0038] (5) Double layer welding: Argon arc welding process is used to weld the double layer 5 (ERNiCrMo-13, which includes the following components by weight percentage: C0.01%, Mn0.10%, Fe1.5%, P0.015%, S0.005%, Si0.10%, Cr23%, Mo16%, balance Ni) on the inner edge. The argon arc welding current is 180A and the voltage is 14V. The interlayer temperature of the double layer welding is controlled below 100℃. After each layer is welded, a stainless steel wire wheel is used to clean the weld.

[0039] (6) Stress relief heat treatment, with a holding temperature of 670℃ and a holding time of 200min. The schematic diagram of each layer of the welded joint after welding in Example 1 is shown below. Figure 2 As shown.

[0040] The welding process parameters for the composite plate of nickel-based alloy N06059 and heat-resistant alloy 14Cr1MoR are shown in Table 1 below:

[0041] Table 1 Welding process parameters

[0042]

[0043] While the specific embodiments of the present invention have been described above, they are not intended to limit the scope of protection of the invention. Those skilled in the art should understand that various modifications that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A welding process for a composite plate of nickel-based alloy N06059 and heat-resistant alloy 14Cr1MoR, characterized in that, The process includes, in sequence, beveling, base welding, hydrogen removal treatment, transition layer welding, cladding layer welding, and stress relief heat treatment, specifically: (1) Beveling treatment: The welding parts of the composite plates of nickel-based alloy N06059 and heat-resistant alloy 14Cr1MoR are processed to form a double U-shaped beveling at the base and a grooved beveling at the cladding. The beveling is cleaned and inspected. The root radius of the double U-shaped beveling at the base is 10mm, the beveling angle is 8°, the blunt edge is 2+1mm, and the assembly gap is 3+1mm. The cladding is removed by 5mm and processed into a 22° beveling. The root radius of the cladding is 5mm. (2) Base welding: The base weld is preheated to 150℃~200℃. Argon arc welding is used to form the base layer, and submerged arc welding is used to fill the inner edge to form the base layer. Submerged arc welding is used to fill and cover the outer edge to form the base layer and the base layer cover layer. The base weld is then completed. Radiographic testing is performed on the base weld, and the inner surface is penetrated. (3) Hydrogen removal treatment: After the base layer is welded, it is immediately heated to 350°C with a flame, kept at that temperature for 1 hour, and then slowly cooled. (4) Transition layer welding: The transition layer is welded on the inner edge using argon arc welding process, and the transition layer is subjected to penetrant testing; (5) Double layer welding: Argon arc welding process is used to weld the double layer on the inner edge; (6) Stress relief heat treatment.

2. The welding process for the composite plate of nickel-based alloy N06059 and heat-resistant alloy 14Cr1MoR according to claim 1, characterized in that, Step (2) The welding current for argon arc welding is 150-220A and the voltage is 12-14V. The welding current for submerged arc welding is 470-580A and the voltage is 28-34V.

3. The welding process for the composite plate of nickel-based alloy N06059 and heat-resistant alloy 14Cr1MoR according to claim 1, characterized in that, In step (4), the argon arc welding current is 150-220A and the voltage is 12-14V; in step (5), the argon arc welding current is 150-180A and the voltage is 12-14V.

4. The welding process for the composite plate of nickel-based alloy N06059 and heat-resistant alloy 14Cr1MoR according to claim 1, characterized in that, In step (2), the welding wire for argon arc welding is ER55-B2 with a specification of 2.5mm, and the welding wire for submerged arc welding is ER55-B2 with a specification of 4.0mm. In step (4), the welding wire for argon arc welding is φ2.5mm ERNiCrMo-3, which includes the following components by weight percentage: C 0.10%, Mn 0.50%, Fe 5.0%, P 0.02%, S 0.015%, Si 0.50%, Cu 0.50%, Cr 20-23%, Mo 8-10%, Nb 3.15-4.15%, with the balance being Ni. In step (5), the welding wire for argon arc welding is φ2.5mm ERNiCrMo-13, which includes the following components by weight percentage: C 0.01%, Mn 0.10%, Fe 1.5%, P 0.015%, S 0.005%, Si 0.10%, Cr 22-24%, Mo 15-16.5%, with the balance being Ni.

5. The welding process for the composite plate of nickel-based alloy N06059 and heat-resistant alloy 14Cr1MoR according to claim 1, characterized in that, Step (4) Preheat the transition layer to 200°C before welding.

6. The welding process for the composite plate of nickel-based alloy N06059 and heat-resistant alloy 14Cr1MoR according to claim 1, characterized in that, Step (5) The interlayer temperature of the tandem welding layer is ≤100℃. After each layer is welded, a stainless steel wire wheel is used to clean the weld.

7. The welding process for the composite plate of nickel-based alloy N06059 and heat-resistant alloy 14Cr1MoR according to claim 1, characterized in that, Step (6) The heat treatment temperature for stress relief is 670℃ and the holding time is 200min.

8. The welding process for the composite plate of nickel-based alloy N06059 and heat-resistant alloy 14Cr1MoR according to claim 1, characterized in that, Radiographic testing and penetrant testing of the base layer are conducted 24 hours after the base layer welding is completed, and penetrant testing of the transition layer is conducted 24 hours after the transition layer welding is completed.

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