Ni-Cr-Fe alloy welding wire and preparation method and application thereof

Abstract

The invention provides a Ni-Cr-Fe alloy welding wire as well as a preparation method and application thereof, and the Ni-Cr-Fe alloy welding wire is characterized by comprising the following components in percentage by weight: 0.020-0.030% of C, 0.020-0.030% of Cr, 0.020-0.030% of Fe, 0.020-0.030% of Ni, 0.020-0.030% of Less than or equal to 0.50% of Si; mn < = 1.0%; p < = 0.0050%; s < = 0.0050%; cr: 28.0 to 31.5%; 0.10% to 0.50% of Mo; 0.50% or less of Ti; 0.10% to 0.30% of Al; the sum of the weight percentage of Nb and the weight percentage of Ta is 0.75-0.95%; 8.0% to 10.0% of Fe; cu is less than or equal to 0.02%; co is less than or equal to 0.02%; bi < = 0.002%; b < = 0.005%; zr < = 0.002%; n is less than or equal to 0.02%; w and V are less than 0.02%; o < = 0.0015%; h < = 0.0005%; less than 0.001% of Pb; less than 0.001% of As; less than 0.003% of Sb; less than 0.005% of Sn; the balance is Ni; and other impurity elements are less than or equal to 0.10%. The stability of the product is improved by controlling the relation and proportion of key elements such as Al, Ti, Nb, Mo, C, N and Mn.

Description

Technical Field

[0001] The invention relates to the technical field of welding materials, and in particular to a Ni-Cr-Fe alloy welding wire and a preparation method and application thereof. Background Art

[0002] With the development of nuclear industry, nickel-based alloys are more and more widely used in nuclear power equipment, and nickel-based alloy welding materials have also been widely used. Because 690 nickel-based alloy has excellent stress corrosion resistance and can maintain high plasticity and toughness at high temperatures, it is widely used in nuclear power projects. Among them, 690 nickel-based alloy welding materials are mainly used in nuclear power equipment reactor pressure vessels, steam generators, pressurizers and other nuclear island main equipment safety end welds and corrosion-resistant layer cladding.

[0003] At present, the 690 nickel-based alloy welding materials used in the main equipment of the nuclear island mainly rely on imports. Domestic institutes and welding wire manufacturers also have related research and development work, but because of the possible application risks of the high-temperature strength, impact toughness, and thermal cracks of the cladding metal of the 690 nickel-based alloy welding materials, domestic application has not yet been achieved.

[0004] For example, the Chinese invention patent with authorization announcement number CN 111889916 B and announcement date of December 10, 2021, discloses a nickel-based alloy welding wire for welding dissimilar steel of nuclear island main equipment and a preparation and use method; the Chinese invention patent with authorization announcement number CN113319468 B and announcement date of April 14, 2023, discloses a composition design method of a nickel-based alloy welding wire for nuclear power to prevent welding cracks and a nickel-based alloy welding wire for nuclear power; The authorization announcement number is CN 102581513 B, and the authorization announcement date is January 14, 2015. This patent discloses a nickel-based welding wire for the main equipment of the nuclear island of a nuclear power plant; the application publication number is CN 113737057 A, and the application publication date is December 3, 2021. This patent discloses a method for preparing nuclear-grade nickel-based high-temperature alloy welding wire materials.

[0005] None of the above patents clearly mention the control relationship and ratio between Al, Ti, Nb, Mo, C, N and Mn elements, as well as the preparation method for high purity and cleanliness control of welding wire. Summary of the invention

[0006] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a Ni-Cr-Fe alloy welding wire and a preparation method and application thereof, so as to solve the problem that the existing Ni-Cr-Fe alloy welding materials for nuclear power equipment mainly rely on imports and are costly.

[0007] To achieve the above-mentioned purpose and other related purposes, the present invention is obtained by including the following technical solutions.

[0008] The present invention provides a Ni-Cr-Fe alloy welding wire, which is composed of the following components in weight percentage: C: 0.020~0.030%; Si≤0.50%; Mn≤1.0%; P≤0.0050%; S≤0.0050%; Cr: 28.0~31.5%; Mo: 0.10~0.50%; Ti≤0.50%; Al: 0.10~0.30%; The sum of the weight percentages of Nb and Ta: 0.75~0.95%; Fe: 8.0~10.0%; Cu≤0.020%; Co≤0.020%; Bi≤0.002%; B≤0.005%; Zr≤0.002%; N≤0.020%; W and V<0.02%; O≤0.0015%; H≤0.0005%; Pb<0.001%; ​​As<0.001%; ​​Sb<0.003%; Sn<0.005%; The balance is Ni; Other impurity elements ≤0.10%.

[0009] The general formula of Ni-Cr-Fe alloy welding wire in the prior art is mainly to meet the standard requirements or to reduce the weight percentage range of elements on the basis of the standards. Although the key elements meet the standard requirements, the stability is not high during the actual development and application process, and some indicators do not meet the application requirements. In the above-mentioned technical scheme of the present application, the stability of the product is improved by adjusting the relationship and ratio of key elements such as Al, Ti, Nb, Mo, C, N and Mn.

[0010] Preferably, the sum of the weight percentages of Al and Ti is ≤0.40%; Mo: 0.15-0.35%. The above ratio ensures the high temperature strength of the cladding metal after welding while improving the toughness and crack sensitivity of the cladding metal after welding. If the sum of the weight percentages of Al and Ti is too high, it will cause more slag on the surface of the welding wire after welding and increase the crack sensitivity after welding.

[0011] Preferably, the content ratio of Nb to Mn is 0.8-1.0. The above ratio can ensure the high temperature strength of the cladding metal after welding, the fluidity of the welding process and the crack sensitivity resistance of the welding wire. If the content ratio of Nb to Mn is too low or too high, Nb element segregation is likely to occur, resulting in low melting point eutectic and increased crack sensitivity.

[0012] Preferably, the ratio of C to N is 1.25 to 2.0. The above ratio can ensure the high temperature strength and crack sensitivity of the cladding metal after welding. Too low or too high a ratio of C to N can easily increase the crack sensitivity.

[0013] Preferably, the sum of the ratio of N to Ti and the ratio of C to Nb is 0.08 to 0.12. The above ratio has the effect of ensuring the high temperature strength and crack sensitivity of the cladding metal after welding. If the sum of the ratio of N to Ti and the ratio of C to Nb is too high, the crack sensitivity will be increased; if it is too low, the high temperature strength of the cladding metal after welding will be reduced.

[0014] The present invention also provides a method for preparing the above-mentioned Ni-Cr-Fe alloy welding wire, comprising the following steps: (1) preparing an ingot according to the above composition formula, and subjecting it to homogenization treatment and forging treatment in sequence to obtain a square billet; (2) hot rolling the square billet into a round coil; (3) The coil is subjected to solution treatment and pickling in sequence, and then subjected to multiple drawing passes and intermediate product heat treatment, and finally drawn into a finished welding wire, thereby obtaining a Ni-Cr-Fe alloy welding wire.

[0015] Preferably, in step (1), the ingot is prepared by a triple process of vacuum induction, electroslag remelting and vacuum consumables.

[0016] Preferably, in step (1), electroslag remelting is performed at least twice; the temperature of the homogenization treatment is ≥1160°C and the holding time is ≥24h. Performing electroslag remelting at least twice has the effect of improving the purity and uniformity of the alloy ingot. The role of homogenization treatment is to improve the uniformity of the composition and reduce element segregation.

[0017] Preferably, in step (1), during forging, at least two upsetting processes and two drawing processes are performed.

[0018] More preferably, step (1) further comprises heat treating the ingot before and after upsetting and stretching, with the heat treatment temperature being ≥1140°C and the holding time being ≥1h.

[0019] Preferably, in step (3), the temperature of the solution treatment is ≥1040°C, and the holding time of the solution treatment is ≥5 min.

[0020] Preferably, step (3) further includes performing a surface treatment process on the intermediate product during the multi-pass drawing process and after the heat treatment to remove surface impurities and defects.

[0021] More preferably, the amount of surface impurities and defects removed is at least 0.20 mm.

[0022] More preferably, after drawing the welding wire to a finished product, a cleaning step is also included, first using a degreasing liquid for ultrasonic cleaning, and then using pure water for cleaning, and the total ultrasonic cleaning time is at least 2 minutes.

[0023] The present invention also provides an application of the Ni-Cr-Fe alloy welding wire in surfacing welding of nuclear island main equipment.

[0024] As described above, the present invention has the following beneficial effects: (1) By controlling the relationship and ratio of key elements such as Al, Ti, Nb, Mo, C, N and Mn, the stability of the product is improved; (2) The purity of the product components and the uniformity of its structure are improved by performing at least two electroslag remelting, homogenization and upsetting and drawing processes; (3) The surface cleanliness of the product is improved by performing surface treatment on the intermediate product of the coil and cleaning the finished product. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Shown is a photograph of the ingot subjected to homogenization treatment in Example 1. DETAILED DESCRIPTION

[0026] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0027] It should be noted that the process equipment or devices not specifically specified in the following embodiments are all conventional equipment or devices in the art.

[0028] In addition, it should be understood that one or more method steps mentioned in the present invention do not exclude the existence of other method steps before or after the combination step or the insertion of other method steps between these explicitly mentioned steps, unless otherwise specified; it should also be understood that the combination connection relationship between one or more devices / apparatuses mentioned in the present invention does not exclude the existence of other devices / apparatuses before or after the combination device / apparatus or the insertion of other devices / apparatuses between these explicitly mentioned two devices / apparatuses, unless otherwise specified. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or the scope of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the present invention without substantially changing the technical content.

[0029] Example 1 The present invention provides a method for preparing a Ni-Cr-Fe alloy welding wire, comprising the following steps: (1) The chemical composition design of Ni-Cr-Fe alloy welding wire is completed according to the following weight percentage components: C: 0.020%; Si: 0.15%; Mn: 0.80%; P: 0.0030%; S: 0.0003%; Cr: 29.50%; Mo: 0.15%; Ti: 0.25%; Al: 0.10%; Nb+Ta: 0.80%; Fe: 8.85%; Cu: 0.015%; Co: 0.005%; Bi: 0.001%; ​​B: 0.001%; ​​Zr: 0.002%; N: 0.015%; W+V: 0.01%; O: 0.0015%; H: 0.0005%; Pb: 0.0005%; As: 0.0005%; Sb: 0.001%; ​​Sn: 0.001%; ​​the balance is Ni; other impurity elements ≤ 0.10%.

[0030] Select raw materials that meet the weight percentage of the above chemical composition elements and perform smelting. The smelting process sequence is first to perform vacuum induction smelting in a 6T vacuum induction smelting furnace, then perform two electroslag remelting smelting on the ingot after induction smelting, and finally perform vacuum consumable smelting to obtain an ingot; The ingot was surface ground and then homogenized at a temperature of 1220°C for 48 hours. The sample after homogenization is shown in the following figure. Figure 1 As shown, from Figure 1 It can be seen that there is no continuous precipitation phase at the grain boundary of the homogenized sample; the homogenized ingot is forged to prepare square billets, the heat treatment temperature before forging is 1140℃, the holding time is 3h, the forging process includes two upsetting and two drawing processes, the upsetting and drawing are one-third of the original ingot length, the upsetting and drawing are carried out alternately, and the heat treatment is carried out between the first upsetting and drawing and the second upsetting and drawing, the heat treatment temperature is 1140℃, and the holding time is 3h; (2) rolling the square billet into a round coil on a continuous hot rolling mill at a rolling temperature of 1160°C. The specification of the round coil after rolling is φ5.5 mm; (3) The coil is subjected to solution treatment at a temperature of 1080°C for 5 minutes, and then pickled to remove surface oxide scale and defects. The coil is subjected to rough drawing, intermediate product heat treatment, fine drawing and intermediate product heat treatment, and finished product drawing to the finished product specification. In this case, the finished product specification is φ1.0 mm. During the rough drawing and intermediate product heat treatment process, a surface treatment process is added to remove surface impurities and defects, with a removal amount of 0.2mm.

[0031] Finally, the finished welding wire was drawn to φ1.0mm, and the surface of the finished welding wire was cleaned online, and ultrasonic cleaning was carried out in degreasing liquid and pure water successively. The total ultrasonic cleaning time was 5 minutes, and finally Ni-Cr-Fe alloy welding wire was obtained.

[0032] The Ni-Cr-Fe alloy welding wire prepared in this embodiment is subjected to butt groove cladding according to the welding process parameters of automatic tungsten inert gas arc welding, welding current of 180-280A, welding voltage of 10-15V, and interlayer temperature of 145°C-225°C, and the cladding metal is tested after cladding.

[0033] Test results: The tensile strength of the cladding metal at 360℃ is ≥495Mpa; Charpy impact energy is ≥210J; there is no obvious cracking on the tensile surface after the bending test; there is no tendency of intergranular corrosion; there are no cracks, incomplete penetration, incomplete fusion, slag inclusions, undercuts, pores and micro cracks in macro and microscopic inspections.

[0034] Example 2 The present invention provides a method for preparing a Ni-Cr-Fe alloy welding wire, comprising the following steps: (1) The chemical composition design of Ni-Cr-Fe alloy welding wire is completed according to the following weight percentage components: C: 0.030%; Si: 0.15%; Mn: 0.95%; P: 0.0030%; S: 0.0003%; Cr: 29.50%; Mo: 0.35%; Ti: 0.30%; Al: 0.10%; Nb+Ta: 0.95%; Fe: 8.85%; Cu: 0.015%; Co: 0.005%; Bi: 0.001%; ​​B: 0.001%; ​​Zr: 0.002%; N: 0.020%; W+V: 0.01%; O: 0.0015%; H: 0.0005%; Pb: 0.0005%; As: 0.0005%; Sb: 0.001%; ​​Sn: 0.001%; ​​the balance is Ni; other impurity elements ≤ 0.10%; Select raw materials that meet the weight percentage of the above chemical composition elements and perform smelting. The smelting process sequence is first to perform vacuum induction smelting in a 6T vacuum induction smelting furnace, then perform two electroslag remelting smelting on the ingot after induction smelting, and finally perform vacuum consumable smelting to obtain an ingot; The ingot was surface ground and then homogenized. The homogenization temperature was 1160°C and the holding time was 60h. There was no continuous precipitation phase at the grain boundary of the homogenized sample. The homogenized ingot was forged to prepare square billets. The heat treatment temperature before forging was 1180°C and the holding time was 2h. The forging process included two upsetting and two drawing processes. The upsetting and drawing were one-third of the original ingot length. The upsetting and drawing were performed alternately. Heat treatment was performed between the first upsetting and drawing and the second upsetting and drawing. The heat treatment temperature was 1180°C and the holding time was 2h. (2) rolling the square billet into a round coil on a continuous hot rolling mill at a rolling temperature of 1180°C. The specification of the round coil after rolling is φ5.5 mm; (3) The coil is subjected to solution treatment at a temperature of 1060°C for 6.5 minutes, and then pickled to remove surface scale and defects. The coil is subjected to rough drawing, intermediate product heat treatment, fine drawing and intermediate product heat treatment, and finished product drawing to the finished product specification. In this case, the finished product specification is φ1.0 mm. During the rough drawing and intermediate product heat treatment process, a surface treatment process is added to remove surface impurities and defects, with a removal amount of 0.2mm.

[0035] Finally, the finished welding wire was drawn to φ1.0mm, and the surface of the finished welding wire was cleaned online, and ultrasonic cleaning was carried out in degreasing liquid and pure water successively. The total ultrasonic cleaning time was 5 minutes, and finally Ni-Cr-Fe alloy welding wire was obtained.

[0036] The Ni-Cr-Fe alloy welding wire prepared in this embodiment is subjected to butt groove cladding according to the welding process parameters of automatic tungsten inert gas arc welding, welding current of 180-280A, welding voltage of 10-15V, and interlayer temperature of 145°C-225°C, and the cladding metal is tested after cladding.

[0037] Test results: The tensile strength of the cladding metal at 360℃ is ≥515Mpa; Charpy impact energy is ≥180J; there is no obvious cracking on the tensile surface after the bending test; there is no tendency of intergranular corrosion; there are no cracks, incomplete penetration, incomplete fusion, slag inclusions, undercuts, pores and micro cracks in macro and microscopic inspections.

[0038] Example 3 The present invention provides a method for preparing a Ni-Cr-Fe alloy welding wire, comprising the following steps: (1) The chemical composition design of Ni-Cr-Fe alloy welding wire is completed according to the following weight percentage components: C: 0.030%; Si: 0.15%; Mn: 0.90%; P: 0.0030%; S: 0.0003%; Cr: 29.50%; Mo: 0.20%; Ti: 0.25%; Al: 0.15%; Nb+Ta: 0.75%; Fe: 8.85%; Cu: 0.015%; Co: 0.005%; Bi: 0.001%; ​​B: 0.001%; ​​Zr: 0.002%; N: 0.020%; W+V: 0.01%; O: 0.0015%; H: 0.0005%; Pb: 0.0005%; As: 0.0005%; Sb: 0.001%; ​​Sn: 0.001%; ​​the balance is Ni; other impurity elements ≤ 0.10%; Select raw materials that meet the weight percentage of the above chemical composition elements and perform smelting. The smelting process sequence is first to perform vacuum induction smelting in a 6T vacuum induction smelting furnace, then perform two electroslag remelting smelting on the ingot after induction smelting, and finally perform vacuum consumable smelting to obtain an ingot; The ingot was surface ground and then homogenized. The homogenization temperature was 1250°C and the holding time was 24h. There was no continuous precipitation phase at the grain boundary of the homogenized sample. The homogenized ingot was forged to prepare square billets. The heat treatment temperature before forging was 1200°C and the holding time was 1h. The forging process included two upsetting and two drawing processes. The upsetting and drawing were one-third of the original ingot length. The upsetting and drawing were performed alternately. Heat treatment was performed between the first upsetting and drawing and the second upsetting and drawing. The heat treatment temperature was 1200°C and the holding time was 1h. (2) rolling the square billet into a round coil on a continuous hot rolling mill at a rolling temperature of 1140°C. The specification of the round coil after rolling is φ5.5 mm; (3) The coil is subjected to solution treatment at a temperature of 1040°C for 7.5 minutes, and then pickled to remove surface scale and defects. The coil is subjected to rough drawing, intermediate product heat treatment, fine drawing and intermediate product heat treatment, and finished product drawing to the finished product specification. In this case, the finished product specification is φ1.0 mm. During the rough drawing and intermediate product heat treatment process, a surface treatment process is added to remove surface impurities and defects, with a removal amount of 0.2mm.

[0039] Finally, the finished welding wire was drawn to φ1.0mm, and the surface of the finished welding wire was cleaned online, and ultrasonic cleaning was carried out in degreasing liquid and pure water successively. The total ultrasonic cleaning time was 5 minutes, and finally Ni-Cr-Fe alloy welding wire was obtained.

[0040] The Ni-Cr-Fe alloy welding wire prepared in this embodiment is subjected to butt groove cladding according to the welding process parameters of automatic tungsten inert gas arc welding, welding current of 180-280A, welding voltage of 10-15V, and interlayer temperature of 145°C-225°C, and the cladding metal is detected after cladding.

[0041] Test results: The tensile strength of the cladding metal at 360℃ is ≥505Mpa; Charpy impact energy is ≥200J; there is no obvious cracking on the tensile surface after the bending test; there is no tendency of intergranular corrosion; there are no cracks, incomplete penetration, incomplete fusion, slag inclusions, undercuts, pores and micro cracks in macro and micro inspections.

[0042] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A Ni-Cr-Fe alloy welding wire, characterized in that: It is composed of the following components in weight percentage: C: 0.020~0.030%; Si≤0.50%; Mn≤1.0%; P≤0.0050%; S≤0.0050%; Cr: 28.0~31.5%; Mo: 0.10~0.50%; Ti≤0.50%; Al: 0.10~0.30%; The sum of the weight percentages of Nb and Ta: 0.75~0.95%; Fe: 8.0~10.0%; Cu≤0.020%; Co≤0.020%; Bi≤0.002%; B≤0.005%; Zr≤0.002%; N≤0.020%; W and V<0.02%; O≤0.0015%; H≤0.0005%; Pb<0.001%; ​​As<0.001%; ​​Sb<0.003%; Sn<0.005%; The balance is Ni; Other impurity elements ≤0.10%.

2. The Ni-Cr-Fe alloy welding wire according to claim 1, characterized in that: The sum of the weight percentages of Al and Ti is ≤0.40%; Mo: 0.15~0.35%.

3. The Ni-Cr-Fe alloy welding wire according to claim 1, characterized in that: The content ratio of Nb to Mn is 0.8~1.0; the content ratio of C to N is 1.25~2.0; the sum of the content ratio of N to Ti and the content ratio of C to Nb is 0.08~0.

12.

4. A method for preparing a Ni-Cr-Fe alloy welding wire according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) preparing an ingot according to the above composition formula, and subjecting it to homogenization treatment and forging treatment in sequence to obtain a square billet; (2) hot rolling the square billet into a round coil; (3) The coil is subjected to solution treatment and pickling in sequence, and then subjected to multiple drawing passes and intermediate product heat treatment, and finally drawn into a finished welding wire, thereby obtaining a Ni-Cr-Fe alloy welding wire.

5. The preparation method according to claim 4, characterized in that: In step (1), the ingot is prepared by a triple process of vacuum induction, electroslag remelting and vacuum consumables.

6. The preparation method according to claim 5, characterized in that: In step (1), electroslag remelting is performed at least twice; the temperature of the homogenization treatment is ≥1160°C, and the holding time is ≥24h.

7. The preparation method according to claim 1, characterized in that: In step (1), during forging, at least two upsetting treatments and two drawing treatments are performed; and the ingot is heat treated before and after the upsetting and drawing, with the heat treatment temperature being ≥1140°C and the holding time being ≥1h.

8. The preparation method according to claim 4, characterized in that: In step (3), the temperature of the solution treatment is ≥1040°C, and the holding time of the solution treatment is ≥5min.

9. The preparation method according to claim 4, characterized in that: Step (3) also includes a surface treatment process for the intermediate product during the multi-pass drawing process and after the heat treatment to remove surface impurities and defects; the amount of surface impurities and defects removed is at least 0.20 mm; after drawing to the finished welding wire, a cleaning process is also included, first using ultrasonic cleaning with a degreasing liquid and then using pure water for cleaning, and the total ultrasonic cleaning time is at least 2 minutes.

10. Use of the Ni-Cr-Fe alloy welding wire as claimed in any one of claims 1 to 3 in cladding welding of nuclear island main equipment.

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