Iron-based high-temperature alloy, iron-based high-temperature alloy welding wire, and additive manufacturing method

Abstract

The present invention relates to an iron-based high-temperature alloy, an iron-based high-temperature alloy welding wire, and an additive manufacturing method, which include, by mass percentage, Cr 9-10%, Co 3-4%, W 3-4%, Cu 1-2%, Mn 0.1-0.5%, Nb 0.05-0.14%, Si 0.05-0.13%, V 0.06-0.13%, B 0.005-0.03%, Ni 0.01-0.05%, N 0.005-0.012%, C 0.05-0.15%, Ti 0.0005-0.0015%, and the balance is Fe and inevitable impurity elements. The iron-based high-temperature alloy provided by the present invention adjusts each element and utilizes the coupling effect between the adjusted elements, so that the manufactured large structural parts have no defects such as cracks and pores, and have excellent high-temperature mechanical properties such as high heat resistance and high strength.

Description

Technical Field

[0001] The present invention relates to the field of additive manufacturing, and in particular to an iron-based high-temperature alloy, an iron-based high-temperature alloy welding wire, and an additive manufacturing method. Background Art

[0002] At present, G115 series heat-resistant steel has excellent organizational stability in the high temperature range. In addition, it also has good room temperature tensile properties, impact properties, high temperature mechanical properties and durability. It is currently a widely used heat-resistant steel.

[0003] For example, CN114635071A discloses a smelting method of martensitic heat-resistant steel G115, which belongs to the field of heat-resistant steel smelting technology, including the process flow of EAF electric furnace smelting + LF refining + VD vacuum treatment + die casting steel ingot + steel ingot forging into consumable electrode + electroslag remelting. By accurately controlling the chemical composition of the steel, strictly controlling the gas content, improving the purity of the steel, and greatly improving the segregation of W, the produced G115 meets the standards of CSTM 00017-2017, Q / OAPD 2753-2017 and Q / OAPD 2253-2017

[0004] CN114635023A discloses a method for producing a martensitic heat-resistant steel billet, belonging to the technical field of heat-resistant steel hot processing, and includes the following steps: 1) electroslag ingot homogenization heat treatment, in which a special step-type heating curve is designed to reduce thermal stress; 2) electroslag ingot forging heating; 3) using an upsetting device to perform upsetting + drawing forging more than three times; 4) annealing heat treatment; 5) tempering heat treatment.

[0005] However, the existing G115 series heat-resistant steel has poor forming performance when used for additive manufacturing. The molded parts are prone to defects such as cracks and pores. At the same time, the heat resistance and impact toughness of the molded parts will also deteriorate after heat treatment, which is not conducive to the performance of additive manufacturing products. Summary of the invention

[0006] In view of the problems existing in the prior art, the purpose of the present invention is to provide an iron-based high-temperature alloy, an iron-based high-temperature alloy welding wire, and an additive manufacturing method to solve the problems that the existing G115 series heat-resistant steel has poor forming performance when used for additive manufacturing, and the molded parts are prone to defects such as cracks and pores. At the same time, the heat resistance and impact toughness of the molded parts will also deteriorate after heat treatment, which is not conducive to the performance of additive manufacturing products.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides an iron-based high-temperature alloy, wherein the iron-based high-temperature alloy comprises, by mass percentage:

[0009] Cr 9-10%, Co 3-4%, W 3-4%, Cu 1-2%, Mn 0.1-0.5%, Nb 0.05-0.14%, Si0.05-0.13%, V 0.06-0.13%, B 0.005-0.03%, Ni 0.01-0.05%, N 0.005-0.012%, C0.05-0.15%, Ti 0.0005-0.0015%, the balance is Fe and unavoidable impurity elements.

[0010] The iron-based high-temperature alloy provided by the present invention has excellent high-temperature performance and mechanical properties by adjusting each element and utilizing the coupling effect between the adjusted elements. It has good process performance for additively manufactured molded parts. The manufactured large structural parts are free from defects such as cracks and pores, and can meet the use requirements of integrated arc additive manufacturing of nuclear power high-temperature duct heat exchangers. The printed parts have good forming performance and have excellent high-temperature mechanical properties such as high heat resistance and high strength.

[0011] As a preferred technical solution of the present invention, the iron-based high-temperature alloy comprises, by mass percentage:

[0012] Cr 9.6-9.7%, Co 3-3.2%, W 3.4-3.6%, Cu 1.3-1.5%, Mn 0.2-0.4%, Nb0.09-0.11%, Si 0.09-0.11%, V 0.09-0.11%, B 0.009-0.02%, Ni 0.02-0.04%, N0.008-0.01%, C 0.09-0.11%, Ti 0.0009-0.0011%, and the balance is Fe and unavoidable impurity elements.

[0013] In a second aspect, the present invention provides an iron-based high-temperature alloy welding wire, which is prepared using the iron-based high-temperature alloy described in the first aspect.

[0014] As a preferred technical solution of the present invention, the preparation includes: mixing materials according to the mass percentage ratio, then smelting, and then preparing thick wire through a down-draw continuous casting and winding system combined with a cooling circulation system, and then making welding wire through an electric pulse toughening drawing process.

[0015] In a third aspect, the present invention provides an additive manufacturing method for heat-resistant steel, the additive manufacturing method comprising manufacturing the wire of the iron-based high-temperature alloy described in the second aspect by using a cold metal transition arc additive manufacturing method.

[0016] As a preferred technical solution of the present invention, the diameter of the wire used in the manufacturing is 1.5-1.7 mm.

[0017] As a preferred technical solution of the present invention, the wire feeding speed in the manufacturing is 3-5m / min.

[0018] As a preferred technical solution of the present invention, the cladding speed in the manufacturing is 0.3-0.6 m / min.

[0019] As a preferred technical solution of the present invention, the welding current in the manufacturing is 188-250A.

[0020] As a preferred technical solution of the present invention, the welding voltage in the manufacturing process is 22-23V.

[0021] Compared with the prior art solutions, the present invention has the following beneficial effects:

[0022] (1) It can realize the integrated forming of complex internal channel structures of iron-based high-temperature alloys with additive performance exceeding 1000MPa.

[0023] (2) The additively manufactured product can achieve a tensile strength of ≥560 MPa at 600°C. In particular, after further heat treatment, the tensile strength of the obtained product at 600°C can be ≥757 MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a photo of the additively manufactured product obtained in Application Example 1 of the present invention.

[0025] The present invention is further described in detail below. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims. DETAILED DESCRIPTION

[0026] To better illustrate the present invention and facilitate understanding of the technical solution of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0027] This embodiment provides an iron-based high-temperature alloy, and the iron-based high-temperature alloy includes, by mass percentage:

[0028] Cr 9-10%, Co 3-4%, W 3-4%, Cu 1-2%, Mn 0.1-0.5%, Nb 0.05-0.14%, Si0.05-0.13%, V 0.06-0.13%, B 0.005-0.03%, Ni 0.01-0.05%, N 0.005-0.012%, C0.05-0.15%, Ti 0.0005-0.0015%, the balance is Fe and unavoidable impurity elements.

[0029] Further preferably, the iron-based high-temperature alloy comprises, by mass percentage:

[0030] Cr 9.6-9.7%, Co 3-3.2%, W 3.4-3.6%, Cu 1.3-1.5%, Mn 0.2-0.4%, Nb0.09-0.11%, Si 0.09-0.11%, V 0.09-0.11%, B 0.009-0.02%, Ni 0.02-0.04%, N0.008-0.01%, C 0.09-0.11%, Ti 0.0009-0.0011%, and the balance is Fe and unavoidable impurity elements.

[0031] In the present invention, the mass percentage of Cr in the iron-based high-temperature alloy is 9-10%, for example, it can be 9%, 9.1%, 9.2%, 9.3%, 9.4%, 9.5%, 9.6%, 9.7%, 9.8%, 9.9% or 10%, etc., but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0032] In the present invention, the mass percentage of Co in the iron-based high-temperature alloy is 3-4%, for example, it can be 3%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.8%, 3.9% or 4%, etc., but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0033] In the present invention, the mass percentage of W in the iron-based high-temperature alloy is 3-4%, for example, it can be 3%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.8%, 3.9% or 4%, etc., but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0034] In the present invention, the mass percentage of Cu in the iron-based high-temperature alloy is 1-2%, for example, it can be 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9% or 2%, etc., but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0035] In the present invention, the mass percentage of Mn in the iron-based high-temperature alloy is 0.1-0.5%, for example, it can be 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45% or 0.5%, etc., but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0036] In the present invention, the Nb content of the iron-based high-temperature alloy is 0.05-0.14% by mass, for example, it can be 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13% or 0.14%, etc., but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0037] In the present invention, the mass percentage of Si in the iron-based high-temperature alloy is 0.05-0.13%, for example, it can be 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12% or 0.13%, etc., but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0038] In the present invention, the mass percentage of V in the iron-based high-temperature alloy is 0.06-0.13%, for example, it can be 0.06%, 0.065%, 0.07%, 0.075%, 0.08%, 0.085%, 0.09%, 0.095%, 0.1%, 0.105%, 0.11%, 0.115%, 0.12%, 0.125% or 0.13%, etc., but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0039] In the present invention, the mass percentage of the iron-based high-temperature alloy B is 0.005-0.03%, for example, it can be 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.01%, 0.012%, 0.014%, 0.016%, 0.018%, 0.02%, 0.022%, 0.024%, 0.026%, 0.028% or 0.03%, etc., but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0040] In the present invention, the mass percentage of Ni in the iron-based high-temperature alloy is 0.01-0.05%, for example, it can be 0.01%, 0.015%, 0.02%, 0.025%, 0.03%, 0.035%, 0.04%, 0.045% or 0.05%, etc., but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0041] In the present invention, the mass percentage of N in the iron-based high-temperature alloy is 0.005-0.012%, for example, it can be 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.01%, 0.0105%, 0.011%, 0.0115% or 0.012%, etc., but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0042] In the present invention, the mass percentage of C in the iron-based high-temperature alloy is 0.05-0.15%, for example, it can be 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14% or 0.15%, etc., but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0043] In the present invention, the mass percentage of the iron-based high-temperature alloy Ti is 0.0005-0.0015%, for example, it can be 0.0005%, 0.0006%, 0.0007%, 0.0008%, 0.0009%, 0.0010%, 0.0011%, 0.0012%, 0.0013%, 0.0014% or 0.0015%, etc., but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0044] In the present invention, when C, N and B are controlled to be at specific contents, the strength of the weld metal decreases due to the reduction of the C content; the toughness decreases when the C content is increased, and the tendency of pores and cracks to appear in the weld increases. N solid solution in the matrix can improve the strength, and excessive N will form nitrides, which are easy to become crack sources and are not conducive to high temperature strength. B is easily combined with N to form BN during the solidification of the molten pool metal, reducing the content of solid solution N; B can also refine the grains; solid solution B can inhibit the precipitation of proeutectoid ferrite between austenite crystals, improve crack resistance, and reduce hydrogen embrittlement. However, when the B element content is high, if the N content is too high, coarse BN particles may be formed, which will seriously weaken the toughness of the steel itself, and will also consume the B element, which is not conducive to the high temperature strength of the steel. Comprehensively consider the relationship between C, N and B, that is, to improve the welding processability, and at the same time control the amount and distribution of carbides to prevent the formation of nitrides.

[0045] In the present invention, the content of Cr element is controlled to ensure that it can be dissolved in the matrix within this range, play a role of solid solution strengthening, and form a Cr2O3 oxide film to improve the high temperature oxidation and corrosion resistance, form carbides, and play a precipitation strengthening role. Although increasing the Cr content is beneficial to high temperature corrosion resistance, too high a Cr content will reduce the endurance strength.

[0046] In the present invention, W is a typical solid solution strengthening element. Since the atomic radius of W is larger than that of Mo, the lattice distortion caused by W solid solution is larger than that of Mo element, so the solid solution strengthening effect of W is more obvious than that of Mo. However, when the W content is too high, it is easy to cause the generation of delta ferrite, which is very unfavorable to the comprehensive properties of steel. Therefore, the present invention controls W to be 3-4%.

[0047] In the present invention, by controlling the Nb and V contents within a specific range and utilizing the synergistic effect between the two, stable carbides can be formed, thereby improving the creep limit and the endurance strength of the steel.

[0048] In the present invention, controlling the Co element to be within a specific content range can inhibit the formation of delta ferrite in the steel, thereby ensuring the performance of the steel.

[0049] In the present invention, Cu solid solution in the matrix can hinder dislocation movement and thus reduce the creep rate, but excessive Cu content is prone to cracking and increases crack sensitivity, so in the present invention, the Cu content is controlled to be 1-2%.

[0050] In the present invention, Ti is controlled to be 0.0005-0.0015% because excessive Ti is prone to form nitrides, and the Ti content must be strictly controlled to prevent it from combining with C and N to form carbonitrides.

[0051] Furthermore, the present invention exemplarily provides a method for preparing the aforementioned iron-based high-temperature alloy, comprising: preparing the materials according to the mass percentage ratio, then smelting, and then preparing a thick wire with a diameter of 5-7mm through a down-draw continuous casting and winding system combined with a cooling circulation system, and then undergoing an electric pulse toughening drawing process, controlling the drawing process temperature to 1000-1100°C, first drawing to 3-5mmmm, then drawing to 2-2.5mm, and finally drawing to 1.5-1.7mm to make a special wire for arc additive.

[0052] Among them, if the required high-temperature alloy is not a welding wire type high-temperature alloy but an alloy body in other forms, it can be cast after smelting, such as powder making or direct casting to form a primary product of a designed shape.

[0053] Furthermore, the present invention provides an additive manufacturing method for heat-resistant steel, the additive manufacturing method comprising: manufacturing the aforementioned iron-based high-temperature alloy wire by cold metal transition arc additive manufacturing;

[0054] During the manufacturing process, a protective atmosphere can be designed, such as argon or other commonly used protective gases in the art.

[0055] The diameter of the wire used in the manufacturing is 1.5-1.7 mm, for example, 1.5 mm, 1.55 mm, 1.6 mm, 1.65 mm or 1.7 mm, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0056] Among them, the wire feeding speed in the manufacturing is 3-5m / min, for example, it can be 3m / min, 3.2m / min, 3.4m / min, 3.6m / min, 3.8m / min, 4m / min, 4.2m / min, 4.4m / min, 4.6m / min, 4.8m / min or 5m / min, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0057] Wherein, the cladding speed in the manufacturing is 0.3-0.6 m / min, for example, it can be 0.3 m / min, 0.32 m / min, 0.34 m / min, 0.36 m / min, 0.38 m / min, 0.4 m / min, 0.42 m / min, 0.44 m / min, 0.46 m / min, 0.48 m / min, 0.5 m / min, 0.52 m / min, 0.54 m / min, 0.56 m / min, 0.58 m / min or 0.6 m / min, etc., but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0058] Among them, the welding current in the manufacturing is 188-250A, for example, it can be 188A, 190A, 195A, 200A, 205A, 210A, 215A, 220A, 225A, 230A, 235A, 240A, 245A or 250A, but is not limited to the listed values. Other unlisted values ​​within the range also meet the requirements.

[0059] Among them, the welding voltage in the manufacturing is 22-23V, for example, it can be 22V, 22.1V, 22.2V, 22.3V, 22.4V, 22.5V, 22.6V, 22.7V, 22.8V, 22.9V or 23V, but is not limited to the listed values, and other unlisted values ​​within the range also meet the requirements.

[0060] Furthermore, the product obtained by additive manufacturing can be heat treated, specifically including keeping at 1050-1100°C for 1-1.5h, and then cooling to 750-800°C for 3-3.5h. The keeping at 1050-1100°C for 1-1.5h can improve the element segregation and non-uniform precipitation inside the organization during the non-equilibrium solidification process; the keeping at 750-800°C for 3-3.5h can make the secondary strengthening phase particles fully precipitate, and obtain better strength-plasticity synergy performance.

[0061] Further, in order to illustrate the high efficiency performance of the iron-based high-temperature alloy provided by the present invention and the advantages of being applicable to additive manufacturing of high-temperature resistant alloys, actual examples are used for illustration, as follows:

[0062] Example 1

[0063] This embodiment provides an iron-based high-temperature alloy, and the iron-based high-temperature alloy includes, by mass percentage:

[0064] Cr 9.7%, Co 3.1%, W 3.5%, Cu 1.4%, Mn 0.3%, Nb 0.1%, Si 0.1%, V0.1%, B 0.01%, Ni 0.03%, N 0.009%, C 0.1%, Ti 0.001%, and the balance is Fe and inevitable impurity elements.

[0065] Example 2

[0066] This embodiment provides an iron-based high-temperature alloy, and the iron-based high-temperature alloy includes, by mass percentage:

[0067] Cr 9.6%, Co 3.2%, W 3.6%, Cu 1.5%, Mn 0.2%, Nb 0.11%, Si 0.11%, V0.09%, B 0.02%, Ni 0.02%, N 0.007%, C 0.12%, Ti 0.0008%, and the balance is Fe and inevitable impurity elements.

[0068] Example 3

[0069] This embodiment provides an iron-based high-temperature alloy, and the iron-based high-temperature alloy includes, by mass percentage:

[0070] Cr 9%, Co 3%, W 4%, Cu 2%, Mn 0.1%, Nb 0.05%, Si 0.05%, V 0.06%, B 0.03%, Ni 0.01%, N 0.005%, C 0.05%, Ti 0.0005%, and the balance is Fe and inevitable impurity elements.

[0071] Example 4

[0072] This embodiment provides an iron-based high-temperature alloy, and the iron-based high-temperature alloy includes, by mass percentage:

[0073] Cr 10%, Co 4%, W 3%, Cu 1%, Mn 0.5%, Nb 0.14%, Si 0.13%, V 0.13%, B 0.005%, Ni 0.05%, N 0.012%, C 0.15%, Ti 0.0015%, and the balance is Fe and inevitable impurity elements.

[0074] Application Example 1

[0075] This application example provides an iron-based high-temperature alloy welding wire, which is prepared using the iron-based high-temperature alloy provided in Example 1. The preparation process is as follows:

[0076] The ingredients are mixed according to the mass percentage ratio, followed by smelting. Then, the thick wire with a diameter of 6mm is prepared through a down-draw continuous casting and winding system combined with a cooling circulation system. Then, the wire is subjected to an electric pulse toughening drawing process, and the drawing process temperature is controlled at 1070°C. The wire is first drawn to 4.5mm, then to 2.4mm, and finally to 1.6mm to make a special wire for arc additive manufacturing.

[0077] The obtained welding wire is also used for additive manufacturing of heat-resistant steel to illustrate the properties of iron-based high-temperature alloys. The process is as follows:

[0078] Manufactured using cold metal transfer arc additive manufacturing;

[0079] The diameter of the wire used in the manufacturing is 1.6 mm; the wire feeding speed in the manufacturing is 4 m / min; the cladding speed in the manufacturing is 0.5 m / min; the welding current in the manufacturing is 220 A; and the welding voltage in the manufacturing is 22.5 V.

[0080] Application Example 2

[0081] This application example provides an iron-based high-temperature alloy welding wire, which is prepared using the iron-based high-temperature alloy provided in Example 1. The preparation process is as follows:

[0082] The ingredients are mixed according to the mass percentage ratio, followed by smelting. Then, the thick wire with a diameter of 6.5mm is prepared through a down-draw continuous casting and winding system combined with a cooling circulation system. Then, the wire is subjected to an electric pulse toughening drawing process, and the drawing process temperature is controlled at 1040°C. The wire is first drawn to 4mm, then to 2.2mm, and finally to 1.5mm to make a special wire for arc additive manufacturing.

[0083] The obtained welding wire is also used for additive manufacturing of heat-resistant steel to illustrate the properties of iron-based high-temperature alloys. The process is as follows:

[0084] Manufactured using cold metal transfer arc additive manufacturing;

[0085] The diameter of the wire used in the manufacturing is 1.5 mm; the wire feeding speed in the manufacturing is 4.5 m / min; the cladding speed in the manufacturing is 0.4 m / min; the welding current in the manufacturing is 200 A; and the welding voltage in the manufacturing is 22.8 V.

[0086] Application Example 3

[0087] This application example provides an iron-based high-temperature alloy welding wire, which is prepared using the iron-based high-temperature alloy provided in Example 1. The preparation process is as follows:

[0088] The ingredients are mixed according to the mass percentage ratio, followed by smelting. Then, the thick wire with a diameter of 7mm is prepared through a down-draw continuous casting and winding system combined with a cooling circulation system. Then, the wire is subjected to an electric pulse toughening drawing process, and the drawing process temperature is controlled at 1100°C. The wire is first drawn to 5mmmm, then to 2.5mm, and finally to 1.7mm to make a special wire for arc additive manufacturing.

[0089] The obtained welding wire is also used for additive manufacturing of heat-resistant steel to illustrate the properties of iron-based high-temperature alloys. The process is as follows:

[0090] Manufactured using cold metal transfer arc additive manufacturing;

[0091] The diameter of the wire used in the manufacturing is 1.7mm; the wire feeding speed in the manufacturing is 5m / min; the cladding speed in the manufacturing is 0.6m / min; the welding current in the manufacturing is 250A; and the welding voltage in the manufacturing is 22V.

[0092] Application Example 4

[0093] This application example provides an iron-based high-temperature alloy welding wire, which is prepared using the iron-based high-temperature alloy provided in Example 1. The preparation process is as follows:

[0094] The ingredients are mixed according to the mass percentage ratio, followed by smelting. Then, the thick wire with a diameter of 5mm is prepared through the down-draw continuous casting and winding system combined with the cooling circulation system. Then, the wire is subjected to the electric pulse toughening drawing process, and the drawing process temperature is controlled at 1000℃. The wire is first drawn to 3mm, then to 2mm, and finally to 1.5mm to make special wire for arc additive manufacturing.

[0095] The obtained welding wire is also used for additive manufacturing of heat-resistant steel to illustrate the properties of iron-based high-temperature alloys. The process is as follows:

[0096] Manufactured using cold metal transfer arc additive manufacturing;

[0097] The diameter of the wire used in the manufacturing is 1.5mm; the wire feeding speed in the manufacturing is 3m / min; the cladding speed in the manufacturing is 0.3m / min; the welding current in the manufacturing is 188A; and the welding voltage in the manufacturing is 23V.

[0098] Application Example 5

[0099] The only difference from Application Example 1 is that the additively manufactured product is heat treated by keeping it at 1080°C for 1.2 hours and then cooling it to 780°C for 3 hours.

[0100] The products obtained from the application examples and comparative application examples were subjected to defect analysis and mechanical property testing. Specifically, the test was conducted in accordance with GB / T 228.1-2010 "Metallic Materials Tensile Test Part 1: Room Temperature Test Method". The test temperatures during the test were 500°C, 600°C, 700°C, 750°C and 800°C. The product obtained from application example 1 is shown in the figure below. Figure 1 shown.

[0101] Table 1

[0102]

[0103]

[0104] It can be seen from the results of the above embodiments that the iron-based high-temperature alloy provided by the present invention has excellent high-temperature performance and mechanical properties by adjusting the elements and utilizing the coupling effect between the adjusted elements. It has good process performance for additively manufactured molded parts. The manufactured large structural parts are free of defects such as cracks and pores, and can meet the use requirements of integrated arc additive manufacturing of nuclear power high-temperature duct heat exchangers. The printed parts have good forming performance and have excellent high-temperature mechanical properties such as high heat resistance and high strength.

[0105] It is stated that the present invention illustrates the detailed structural features of the present invention through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the components selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0106] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0107] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0108] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. An iron-based high-temperature alloy, characterized in that: The iron-based high-temperature alloy comprises, by mass percentage: Cr 9-10%, Co 3-4%, W 3-4%, Cu 1-2%, Mn 0.1-0.5%, Nb 0.05-0.14%, Si 0.05-0.13%, V0.06-0.13%, B 0.005-0.03%, Ni 0.01-0.05%, N 0.005-0.012%, C 0.05-0.15%, Ti 0.0005-0.0015%, the balance is Fe and unavoidable impurity elements.

2. The iron-based high-temperature alloy according to claim 1, characterized in that: The iron-based high-temperature alloy comprises, by mass percentage: Cr 9.6-9.7%, Co 3-3.2%, W 3.4-3.6%, Cu 1.3-1.5%, Mn 0.2-0.4%, Nb 0.09-0.11%, Si0.09-0.11%, V 0.09-0.11%, B 0.009-0.02%, Ni 0.02-0.04%, N 0.008-0.01%, C 0.09-0.11%, Ti 0.0009-0.0011%, the balance is Fe and unavoidable impurity elements.

3. An iron-based high-temperature alloy welding wire, characterized in that: The iron-based high-temperature alloy welding wire is prepared using the iron-based high-temperature alloy as claimed in claim 1 or 2.

4. The iron-based high-temperature alloy welding wire according to claim 3, characterized in that: The preparation comprises: mixing materials according to the mass percentage ratio, then smelting, and then preparing thick wire through a down-drawing continuous casting and winding system combined with a cooling circulation system, and then making welding wire through an electric pulse toughening drawing process.

5. An additive manufacturing method for heat-resistant steel, characterized in that: The additive manufacturing method comprises manufacturing the wire of the iron-based high-temperature alloy according to claim 3 or 4 by using a cold metal transition arc additive manufacturing method.

6. The additive manufacturing method according to claim 5, characterized in that: The diameter of the wire used in the manufacture was 1.5-1.7 mm.

7. The additive manufacturing method according to claim 5, characterized in that: The wire feeding speed in the manufacturing process is 3-5 m / min.

8. The additive manufacturing method according to claim 5, characterized in that: The cladding speed in the manufacturing process is 0.3-0.6 m / min.

9. The additive manufacturing method according to claim 5, characterized in that: The welding current in the manufacturing process is 188-250A.

10. The additive manufacturing method according to claim 5, characterized in that: The welding voltage in the manufacturing process is 22-23V.

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