A nickel-chromium-molybdenum alloy welding electrode, its preparation method and application method

Abstract

This invention belongs to the field of welding materials technology, specifically relating to a nickel-chromium-molybdenum alloy welding electrode and its preparation and application methods. The welding electrode comprises a core and a coating. The cladding metal of the electrode comprises the following components by weight percentage: C 0.03–0.05%, Mn 0.4–0.7%, Cr 15.5–15.8%, Ni 5.7–5.9%, Mo 0.8–0.95%, Si ≤0.30%, S ≤0.020%, P ≤0.030%, with the balance being Fe and unavoidable impurities. By adjusting the nickel-chromium-molybdenum content, the welding performance and various mechanical properties of the electrode can be appropriately balanced, making it suitable for various post-weld heat treatment methods and improving the electrode's adaptability and versatility.

Description

Technical Field

[0001] This invention belongs to the field of welding materials technology, specifically relating to a nickel-chromium-molybdenum alloy welding electrode and its preparation and application methods. Background Technology

[0002] Special equipment such as nuclear power and aviation equipment are generally assembled by welding multiple in-core components. Some components, such as valves, also need to be repaired by welding due to defects generated during the casting process. In addition to ensuring that the mechanical properties meet the original design requirements, the composition and color of the base material also need to be homogeneous. Therefore, the welding materials are required to be diverse, highly specialized, and have high requirements.

[0003] Special equipment components require heat treatment to relieve stress after casting. After welding repair, due to their complex composition and structure, they still require heat treatment similar to the base material. Different heat treatment methods are used depending on the casting being repaired and the defects. Heat treatment specifications include, but are not limited to, tempering, quenching, quenching + tempering, and solution treatment. Different heat treatment methods place different requirements on welding electrodes. If the welding electrode and the heat treatment method are incompatible, the mechanical properties of the weld powder formed under the heat treatment conditions will not meet the actual requirements. This leads to easy wear and cracking of the weld, resulting in poor mechanical properties of the weldment.

[0004] In the prior art, Chinese Patent No. CN112475660A discloses a wear-resistant surfacing welding electrode and its preparation method. By innovating and limiting the main components of the electrode coating and the core, the electrode can exhibit good crack resistance, as well as certain hardness and wear resistance under the heat treatment process of 913℃*8h air cooling + 885℃*8h liquid quenching + 676℃*5h furnace cooling.

[0005] However, most current welding electrodes can only meet the heat treatment requirements under certain specific conditions, which greatly limits their application in manufacturing. Therefore, it is necessary to develop a welding electrode that can meet the requirements of multiple heat treatment methods. Summary of the Invention

[0006] In view of the fact that most existing welding electrodes mentioned in the background technology can only meet the heat treatment requirements under certain specific conditions, the present invention improves the welding performance of the welding electrode by controlling the nickel, chromium and molybdenum content in the welding electrode, ensuring that it can meet various post-weld heat treatment requirements.

[0007] The specific technical solution of the present invention is as follows:

[0008] A nickel-chromium-molybdenum alloy welding electrode, comprising a core and a coating, wherein the coating comprises the following components by weight: carbonate 15.0–25.0 parts; titanium dioxide 25.0–35.0 parts; fluoride 4–8 parts; silicon oxide 2.0–5.0 parts; electrolytic manganese 2.0–5.0 parts; metallic chromium 8.0–14.0 parts; metallic nickel 7.0–12.0 parts; chromium nitride 0.5–1.5 parts; metallic molybdenum 2.5–5.0 parts; and CMC 0.5–1.2 parts.

[0009] Furthermore, the welding core comprises the following weight components: C: ≤0.030 parts; Mn: 1.50~2.20 parts; Si: ≤0.35 parts; S: ≤0.015 parts; P: ≤0.022 parts; Cr: 16.0~17.5 parts; Ni: ≤1.0; Mo: ≤0.50 parts; Cu: ≤0.50 parts; N: ≤0.050 parts; the balance being Fe.

[0010] Furthermore, the mass ratio of the core and the coating is 65% for the core and 35% for the coating.

[0011] Furthermore, the cladding metal of the welding electrode comprises the following components in weight percentages: C 0.03-0.05%, Mn 0.4-0.7%, Cr 15.5-15.8%, Ni 5.7-5.9%, Mo 0.8-0.95%, Si≤0.30%, S≤0.020%, P≤0.030%, with the balance being Fe and unavoidable impurities.

[0012] The present invention also provides a method for preparing nickel-chromium-molybdenum alloy welding electrodes, comprising the following steps: (1) mixing each component of the coating raw material according to the ratio, and then adding an adhesive to mix and obtain a mixture; (2) adding the mixture prepared in step (1) and the welding core to a pressure coating machine, uniformly preparing and shaping it on the surface of the welding core, and then baking it at low temperature and high temperature to obtain the welding electrode.

[0013] Furthermore, the adhesive is potassium sodium water glass with a potassium-sodium ratio of 3:1; the weight ratio of the adhesive to the raw material of the drug coating is 0.18 to 0.21:1; the low-temperature baking temperature is 80 to 120°C, and the high-temperature baking temperature is 360°C.

[0014] This invention also provides a method for using nickel-chromium-molybdenum alloy welding electrodes, comprising the following steps:

[0015] S1. Welding: First, heat the welding rod and the workpiece to be welded. After heating, set the welding parameters and weld.

[0016] S2. Heat treatment: The welded workpiece is heat treated to obtain a complete welded part.

[0017] Furthermore, in step S1, the electrode baking temperature is 350℃, the baking time is 1h, and the workpiece heating temperature is 150℃; the welding parameters include: welding current 150~160A, welding voltage 22V, interpass temperature less than or equal to 110℃, and welding heat input 11KJ / cm.

[0018] Furthermore, the heat treatment in step S2 can be any one of the following three methods: a. holding at 580°C for 4 hours and then air-cooling to room temperature; b. holding at 590°C for 8 hours and then cooling in the furnace to 300°C and then air-cooling to room temperature; c. holding at 1030°C for 1 hour and then air-cooling to 590°C, then holding at 1030°C for 8 hours, then cooling in the furnace to 300°C and then air-cooling to room temperature.

[0019] The beneficial effects of this invention are:

[0020] (1) By adjusting the content of nickel, chromium and molybdenum, the welding performance and various mechanical properties of the welding electrode of the present invention can be properly matched so that it can meet various heat treatment methods after welding, thereby improving the adaptability and versatility of the welding electrode.

[0021] (2) The welding electrode of the present invention exhibits excellent welding performance during the welding process, with a stable arc, easy slag removal, minimal spatter, aesthetically pleasing weld formation, and good all-position operability. The alloying elements of the deposited metal are reasonably controlled, resulting in good mechanical properties. Attached Figure Description

[0022] Figure 1 This is a physical image of a nickel-chromium-molybdenum alloy welding electrode according to Embodiment 1 of the present invention. Detailed Implementation

[0023] The specific embodiments of the present invention will be clearly and completely described below with reference to specific examples. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer shall apply. Unless otherwise specified, the instruments, reagents, or raw materials used are commercially available conventional products.

[0024] First, this invention provides a nickel-chromium-molybdenum alloy welding electrode, wherein the electrode comprises a core and a coating, with the core accounting for 65% and the coating accounting for 35% by mass. The outer diameter of the electrode coating is Φ4.0 x 6.95–7.05 mm.

[0025] The coating used in this invention comprises the following parts by weight: carbonate 15.0-25.0 parts; titanium dioxide 25.0-35.0 parts; fluoride 4-8 parts; silicon dioxide 2.0-5.0 parts; electrolytic manganese 2.0-5.0 parts; metallic chromium 8.0-14.0 parts; metallic nickel 7.0-12.0 parts; chromium nitride 0.5-1.5 parts; metallic molybdenum 3 parts; CMC 0.5-1.2 parts.

[0026] The welding core used in this invention is ER430L, which comprises the following weight parts: C: ≤0.030 parts; Mn: 1.50~2.20 parts; Si: ≤0.35 parts; S: ≤0.015 parts; P: ≤0.023 parts; Cr: 16.0~17.5 parts; Ni: ≤1.0; Mo: ≤0.50 parts; Cu: ≤0.50 parts; N: ≤0.050 parts; balance Fe.

[0027] The cladding metal of the welding electrode in this invention comprises the following components in weight percentages: C 0.03-0.05%, Mn 0.4-0.7%, Cr 15.5-15.8%, Ni 5.7-5.9%, Mo 0.8-0.95%, Si≤0.30%, S≤0.020%, P≤0.030%, with the balance being Fe and unavoidable impurities.

[0028] This invention also provides a method for preparing nickel-chromium-molybdenum alloy welding electrodes, comprising the following steps:

[0029] (1) After mixing the components of the raw material of the drug coating evenly according to the ratio, add the adhesive and mix to obtain a mixture;

[0030] Specifically, the raw materials for preparing the drug coating are mixed in a mixer according to the component ratio and stirred for 5 minutes to ensure uniform mixing. Then, a binder is added to the mixer and stirred for another 5 minutes to ensure the binder is evenly dispersed in the raw materials, resulting in a mixture. The binder used in this invention is potassium-sodium water glass, with a potassium-to-sodium ratio of 3:1, and the weight ratio of the binder to the drug coating raw materials is 0.18–0.21:1.

[0031] (2) The mixture prepared in step (1) and the welding core are added to the pressure coating machine, and after being uniformly formed on the surface of the welding core, the welding rod is obtained by low temperature and high temperature baking.

[0032] Specifically, the mixture prepared in step (1) and the welding core are sequentially added to the pressure coating machine, and the pressure parameters are set to produce welding rods. In this invention, the welding core is first cut, and the size can be adjusted according to actual production requirements. The pressure of the pressure coating machine is set to 140 MPa. After pressure coating is completed, the product is first baked at 80-120°C, and then baked at 360°C.

[0033] This invention also provides a method for using nickel-chromium-molybdenum alloy welding electrodes, comprising the following steps:

[0034] S1. Welding: First, heat the welding rod and the workpiece to be welded. After heating, set the welding parameters and weld.

[0035] Specifically, the prepared welding rods and the workpieces to be welded are baked and heated. The workpieces targeted for welding in this invention include complex structures such as aerospace casting valves, which require secondary heat treatment after welding. The welding rod baking temperature is 350℃, the baking time is 1 hour, and the workpiece baking temperature is 150℃. The welding machine is a ZX5-500 thyristor rectifier arc welding machine, with a welding current of 150-160A, a welding voltage of 22V, an interpass temperature of less than or equal to 110℃, and a welding heat input of 11KJ / cm².

[0036] S2. Heat treatment: The welded workpiece is heat treated to obtain a complete welded part.

[0037] Specifically, the welded workpiece is heat-treated according to the corresponding manufacturing requirements. The welding electrode prepared in this invention can satisfy any of the following heat treatment methods:

[0038] a. Hold at 580℃ for 4 hours, then air-cool to room temperature; b. Hold at 590℃ for 8 hours, then cool with the furnace to 300℃, and then air-cool to room temperature; c. Hold at 1030℃ for 1 hour, then air-cool to 590℃, then hold for another 8 hours, then cool with the furnace to 300℃, and then air-cool to room temperature.

[0039] Example 1

[0040] In this embodiment, the medicated skin comprises the following weight parts:

[0041] Carbonate: 22 parts; Titanium dioxide: 31 parts; Fluoride: 6.5 parts; Silicon oxide: 4 parts; Electrolytic manganese: 4 parts; Metallic chromium: 13 parts; Metallic nickel: 11 parts; Chromium nitride: 1 part; Metallic molybdenum: 2.5 parts; CMC: 1 part.

[0042] The core material is ER430L, comprising the following parts by weight: C: ≤0.030 parts; Mn: 1.50~2.20 parts; Si: ≤0.35 parts; S: ≤0.015 parts; P: ≤0.023 parts; Cr: 16.0~17.5 parts; Ni: ≤1.0 part; Mo: ≤0.50 parts; Cu: ≤0.50 parts; N: ≤0.050 parts; balance Fe. The core material to coating mass ratio is 65% core material and 35% coating.

[0043] The cladding metal comprises the following components in weight percentages: C 0.42%, Mn 0.51%, Cr 15.55%, Ni 5.7%, Mo 0.89%, Si 0.50%, S 0.008%, P 0.024%, with the balance being Fe and unavoidable impurities.

[0044] This embodiment also provides a method for preparing a nickel-chromium-molybdenum alloy welding electrode, comprising the following steps: mixing the raw materials for preparing the coating according to the component ratio and adding them to a mixer, stirring for 5 minutes to ensure uniform mixing of the raw materials. Then, adding a binder to the mixer and stirring for 5 minutes to ensure the binder is uniformly dispersed in the raw materials to obtain a mixture. The binder used in this invention is potassium-sodium water glass, with a potassium-sodium ratio of 3:1, and the weight ratio of the binder added to the coating raw materials is 0.19:1.

[0045] The mixture prepared in step (1) and the welding core are added sequentially to the pressure coating machine, and the pressure parameters are set to produce welding rods. In this invention, the welding core is first cut, and the size can be adjusted according to actual production requirements. The pressure of the pressure coating machine is set to 14 MPa. After pressure coating is completed, the product is first baked at 100°C, and then baked at 360°C.

[0046] This embodiment also provides a method for using nickel-chromium-molybdenum alloy welding electrodes, including the following steps:

[0047] The prepared welding rods and the workpiece to be welded were baked and heated. In this embodiment, the workpiece being welded is an aviation valve manufactured by Anhui Yingliu Co., Ltd. The welding rod baking temperature was 350℃, the baking time was 1 hour, and the workpiece baking temperature was 150℃. The welding machine was a ZX5-500 thyristor rectifier arc welding machine, with a welding current of 155A, a welding voltage of 22V, an interpass temperature of less than or equal to 110℃, and a welding heat input of 11KJ / cm².

[0048] The welded workpiece is then heat-treated according to the corresponding manufacturing requirements. In this embodiment, the heat treatment method is as follows: the workpiece is held at 580°C for 4 hours and then cooled to room temperature.

[0049] Example 2

[0050] The difference between this embodiment and Embodiment 1 lies in the weight percentages of the cladding metal components and the weight percentages of the coating components used in preparing the welding electrode. Specifically: carbonate: 18 parts; titanium dioxide: 31 parts; fluoride: 5 parts; silicon oxide: 4 parts; electrolytic manganese: 3 parts; metallic chromium: 12 parts; metallic nickel: 11.5 parts; metallic chromium nitride: 1 part; metallic molybdenum: 3 parts; CMC: 1 part. The mass ratio of the core to the coating is 65% for the core and 35% for the coating. The cladding metal comprises the following components by weight percentage: CO 37%, Mn 0.471%, Cr 15.21%, Ni 5.75%, Mo 0.899%, Si 0.421%, S 0.009%, P 0.024%, with the balance being Fe and unavoidable impurities.

[0051] The welding electrode prepared in this embodiment can meet the following heat treatment method: after holding at 590°C for 8 hours, it is cooled to 300°C in the furnace and then air-cooled to room temperature.

[0052] Example 3

[0053] The difference between this embodiment and Embodiment 1 lies in the weight percentages of the cladding metal components and the weight percentages of the coating components used in preparing the welding electrode. Specifically: carbonate: 22 parts; titanium dioxide: 28 parts; fluoride: 4 parts; silicon oxide: 3 parts; electrolytic manganese: 4 parts; metallic chromium: 12 parts; metallic nickel: 11.5 parts; metallic chromium nitride: 1 part; metallic molybdenum: 4.5 parts; CMC: 1 part. The mass ratio of the core to the coating is 65% for the core and 35% for the coating.

[0054] The cladding metal comprises the following components in weight percentages: C 0.44%, Mn 0.622%, Cr 15.38%, Ni 5.75%, Mo 0.915%, Si 0.432%, S 0.008%, P 0.023%, with the balance being Fe and unavoidable impurities.

[0055] The welding electrode prepared in this embodiment can meet the following heat treatment method: after holding at 1030°C for 1 hour, air cooling to 590°C and then holding at 1030°C for 8 hours, then furnace cooling to 300°C and then air cooling to room temperature.

[0056] Comparative Example 1

[0057] The difference between this comparative example and Example 1 lies in the weight percentages of the cladding metal components and the weight percentages of the coating components used in preparing the welding electrode. Specifically: carbonate: 21 parts; titanium dioxide: 31 parts; fluoride: 4 parts; silicon oxide: 3 parts; electrolytic manganese: 4 parts; metallic chromium: 7 parts; metallic nickel: 13 parts; metallic chromium nitride: 1 part; metallic molybdenum: 7 parts; CMC: 1 part. The mass ratio of the core to the coating is 2:10. The cladding metal comprises the following components by weight percentage: C 0.45%, Mn 0.677%, Cr 13.88%, Ni 6.52%, Mo 1.415%, Si 0.234%, S 0.011%, P 0.024%, with the balance being Fe and unavoidable impurities.

[0058] Comparative Example 2

[0059] The difference between this comparative example and Example 1 lies in the weight percentages of the cladding metal components and the weight percentages of the coating components used in preparing the welding electrode. Specifically: carbonate: 20 parts; titanium dioxide: 30 parts; fluoride: 6 parts; silicon oxide: 4 parts; electrolytic manganese: 4 parts; metallic chromium: 17 parts; metallic nickel: 11.5 parts; chromium nitride: 1 part; metallic molybdenum: 7 parts; CMC: 1 part. The mass ratio of the welding core to the coating is 2:10.

[0060] The cladding metal comprises the following components in weight percentages: C 0.40%, Mn 0.622%, Cr 16.57%, Ni 5.72%, Mo 1.28%, Si 0.502%, S 0.001%, P 0.020%, with the balance being Fe and unavoidable impurities.

[0061] Performance testing

[0062] The properties of the cladding metal of the welding electrodes were tested according to GB / T 228.1-2010 Metallic Materials - Tensile Testing - Part 1: Test Method at Room Temperature. The mechanical properties of the cladding metal of the nickel-chromium-molybdenum alloy welding electrodes prepared in each example are shown in Table 1.

[0063] Table 1: Test results of mechanical properties of welding electrodes prepared in Examples 1-3

[0064]

[0065] In summary, by adjusting the content of nickel, chromium, and molybdenum, the welding electrode of the present invention can appropriately adjust its welding performance and various mechanical properties, making it suitable for various post-weld heat treatment methods and improving the adaptability and versatility of the welding electrode.

[0066] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered exemplary and not restrictive in all respects. Furthermore, it should be understood that although this specification describes embodiments, it does not encompass only one technical solution. This descriptive method is merely for clarity, and those skilled in the art should consider the specification as a whole. The technical solutions in the embodiments can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A nickel-chromium-molybdenum alloy welding electrode, the electrode comprising a core and a coating, characterized in that, The medicated coating comprises the following weight components: Carbonate: 15.0–25.0 parts; Titanium dioxide: 25.0–35.0 parts; Fluoride: 4–8 parts; Silicon oxide: 2.0–5.0 parts; Electrolytic manganese: 2.0–5.0 parts; Metallic chromium: 8.0–14.0 parts; Metallic nickel: 7.0–12.0 parts; Chromium nitride: 0.5–1.5 parts; Molybdenum metal: 2.5–5.0 parts; CMC: 0.5–1.2 parts; The welding core comprises the following parts by weight: C: ≤0.030 parts; Mn: 1.50~2.20 parts; Si: ≤0.35 parts; S: ≤0.015 parts; P: ≤0.022 parts; Cr: 16.0~17.5 parts; Ni: ≤1.0; Mo: ≤0.50 parts; Cu: ≤0.50 parts; N: ≤0.050 parts; balance Fe; The mass ratio of the core and the coating is 65% for the core and 35% for the coating.

2. The nickel-chromium-molybdenum alloy welding electrode according to claim 1, characterized in that, The cladding metal of the welding electrode comprises the following components in weight percentages: C 0.03-0.05%, Mn 0.4-0.7%, Cr 15.5-15.8%, Ni 5.7-5.9%, Mo 0.8-0.95%, Si≤0.30%, S≤0.020%, P≤0.030%, with the balance being Fe and unavoidable impurities.

3. The method for preparing nickel-chromium-molybdenum alloy welding electrodes according to any one of claims 1-2, characterized in that, Includes the following steps: (1) After mixing the components of the raw material of the drug coating evenly according to the ratio, add the binder and mix to obtain a mixture; (2) The mixture prepared in step (1) and the welding core are added to the pressure coating machine, and after being uniformly formed on the surface of the welding core, the welding rod is obtained by low temperature and high temperature baking.

4. The method for preparing a nickel-chromium-molybdenum alloy welding electrode according to claim 3, characterized in that, The binder is potassium sodium water glass with a potassium-sodium ratio of 3:1; the weight ratio of the binder to the raw material of the drug coating is 0.18 to 0.21:1; the low-temperature baking temperature is 80 to 120°C, and the high-temperature baking temperature is 360°C.

5. The method of using the nickel-chromium-molybdenum alloy welding electrode according to any one of claims 1-2, characterized in that, Includes the following steps: S1. Welding: First, heat the welding rod and the workpiece to be welded. After heating, set the welding parameters and weld. S2. Heat treatment: The welded workpiece is heat treated to obtain a complete welded part.

6. The method of using a nickel-chromium-molybdenum alloy welding electrode according to claim 5, characterized in that, In step S1, the electrode baking temperature is 350℃, the baking time is 1h, and the workpiece heating temperature is 150℃. The welding parameters include: welding current 150~160A, welding voltage 22V, interpass temperature less than or equal to 110℃, and welding heat input 11KJ / cm.

7. The method of using a nickel-chromium-molybdenum alloy welding electrode according to claim 5, characterized in that, The heat treatment in step S2 can be any one of the following three methods: a. holding at 580°C for 4 hours and then air-cooling to room temperature; b. holding at 590°C for 8 hours and then cooling in the furnace to 300°C and then air-cooling to room temperature; c. holding at 1030°C for 1 hour and then air-cooling to 590°C, then holding at 1030°C for 8 hours, then cooling in the furnace to 300°C and then air-cooling to room temperature.

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