An iron-chromium-aluminum alloy suitable for use in lead-based reactors and a method of heat treating the same

Abstract

The application provides an iron-chromium-aluminum alloy and a heat treatment method thereof, which are suitable for lead-based reactors. The iron-chromium-aluminum alloy is composed of the following components in percentage by weight: chromium: 10.0-14.0%; aluminum: 3.0-5.0%; silicon: 0.2-1.0%; manganese: 0.2-0.7%; titanium: 0.30-0.75%; carbon: 0.08-0.12%; nitrogen: 0.01-0.03%; sulfur and phosphorus: less than 100 ppm; and the balance of Fe and inevitable trace elements. The iron-chromium-aluminum alloy can form a dense oxide film on the surface of the material, thereby preventing the corrosion of liquid lead and lead alloy, and is particularly suitable for structural materials of lead-based reactors.

Description

Technical Field

[0001] The present invention relates to the technical field of structural materials for lead-based piles, and in particular to an iron-chromium-aluminum alloy suitable for lead-based piles and a heat treatment method thereof. Background Art

[0002] The neutrons in the lead-based fast neutron reactor (lead-based reactor for short) are not moderated, and the nuclear fission reaction is initiated by fast neutrons. At the same time, fast neutrons can 238 U is converted into fissile 239 The utilization of Pu can greatly increase the utilization rate of uranium resources by 140 times compared with pressurized water reactors, thereby allowing limited uranium resources to provide more nuclear power energy for human society.

[0003] Lead-based reactors use liquid lead (Pb) or lead-bismuth alloy (PbBi) as coolant. Compared with other coolants, lead-bismuth alloy or lead has the following advantages: (1) Lead and bismuth have large atomic weights and small neutron moderation cross sections, which can increase the volume ratio of coolant to fuel and reduce the core power density; (2) Due to the high boiling point of lead-bismuth alloy and lead, cavitation is not easily generated. If the coolant outlet temperature is increased to 800℃, it can be used in a wider range of applications such as hydrogen production; (3) Lead or lead-bismuth alloy is chemically inert and will not produce the same danger as sodium-water reaction when in contact with water; (4) Lead-bismuth alloy and lead have excellent heat transfer properties and can quickly transfer the heat of nuclear reactions in the reactor. Reactors using liquid lead or lead-bismuth alloy as coolant are the most promising reactor types in modern nuclear energy systems and are also expected to be the first fourth-generation advanced nuclear energy systems to achieve industrial demonstration and commercial application.

[0004] In lead-based reactors, reactor structural materials (such as 316L, T91, and EP823) come into direct contact with high-temperature liquid lead or lead-bismuth alloys. This high-temperature, flowing liquid lead or lead-bismuth alloy can cause dissolution corrosion of the reactor structural materials and lead to liquid metal embrittlement, seriously endangering the safety and service life of the reactor. Within a certain range of temperature and oxygen content, the oxygen in the liquid lead or lead-bismuth alloy reacts only with elements such as chromium on the material surface to form a protective oxide film, which can mitigate and inhibit further corrosion to a certain extent and prevent embrittlement of the structural material through isolation. However, at higher temperatures in liquid lead or lead-bismuth alloys, especially above 550°C, the strength of the structural materials decreases significantly, the materials become severely oxidized, and dissolution corrosion cannot be suppressed. Therefore, developing suitable structural materials is key to solving the corrosion problem of key lead-based reactor components and increasing the operating temperature of lead-based reactors. Summary of the Invention

[0005] In view of the above problems, the present invention proposes an iron-chromium-aluminum alloy suitable for lead-based stacks and a heat treatment method thereof, which overcomes the above problems or at least partially solves the above problems.

[0006] An object of the present invention is to provide an iron-chromium-aluminum alloy suitable for lead-based stacks, which has the properties of resistance to corrosion by liquid lead and lead alloys and has good high-temperature strength and welding properties.

[0007] Another object of the present invention is to provide a heat treatment method for Fe-Cr-Al alloy, so that the alloy has good room temperature mechanical properties and high temperature strength.

[0008] According to one aspect of the present invention, there is provided an iron-chromium-aluminum alloy suitable for a lead-based stack, wherein the iron-chromium-aluminum alloy contains 0.30% to 0.75% titanium and 0.01% to 0.03% nitrogen by weight.

[0009] Optionally, the iron-chromium-aluminum alloy consists of the following components in terms of weight percentage:

[0010] Chromium: 10.0% to 14.0%; Aluminum: 3.0% to 5.0%; Silicon: 0.2% to 1.0%; Manganese: 0.2% to 0.7%; Titanium: 0.30% to 0.75%; Carbon: 0.08% to 0.12%; Nitrogen: 0.01% to 0.03%; Sulfur and phosphorus are both less than 100 ppm; the remainder is Fe and unavoidable trace elements.

[0011] Optionally, the iron-chromium-aluminum alloy consists of the following components in terms of weight percentage:

[0012] Chromium: 10.0%; Aluminum: 4.0%; Silicon: 0.7%; Manganese: 0.7%; Titanium: 0.30%; Carbon: 0.08%; Nitrogen: 0.01%; Sulfur: <100 ppm; Phosphorus: <100 ppm; the remainder is Fe and unavoidable trace elements.

[0013] Optionally, the iron-chromium-aluminum alloy consists of the following components in terms of weight percentage:

[0014] Chromium: 10.0%; Aluminum: 4.0%; Silicon: 0.7%; Manganese: 0.2%; Titanium: 0.50%; Carbon: 0.10%; Nitrogen: 0.02%; Sulfur: <100 ppm; Phosphorus: <100 ppm; the remainder is Fe and unavoidable trace elements.

[0015] Optionally, the iron-chromium-aluminum alloy consists of the following components in terms of weight percentage:

[0016] Chromium: 12.0%; Aluminum: 5.0%; Silicon: 0.7%; Manganese: 0.2%; Titanium: 0.50%; Carbon: 0.10%; Nitrogen: 0.02%; Sulfur: <100 ppm; Phosphorus: <100 ppm; the remainder is Fe and unavoidable trace elements.

[0017] Optionally, the iron-chromium-aluminum alloy consists of the following components in terms of weight percentage:

[0018] Chromium: 12.0%; Aluminum: 5.0%; Silicon: 0.7%; Manganese: 0.2%; Titanium: 0.75%; Carbon: 0.10%; Nitrogen: 0.03%; Sulfur: <100 ppm; Phosphorus: <100 ppm; the remainder is Fe and unavoidable trace elements.

[0019] According to another aspect of the present invention, there is also provided a heat treatment method for the aforementioned iron-chromium-aluminum alloy suitable for lead-based stacks, comprising performing a solid solution treatment on the iron-chromium-aluminum alloy, wherein the solid solution treatment comprises:

[0020] Keep at 1020℃~1120℃ for 20~45min, and then quickly cool to room temperature by water quenching.

[0021] Optionally, after the solution treatment, the heat treatment method further comprises performing a stabilization treatment on the iron-chromium-aluminum alloy, wherein the stabilization treatment specifically comprises:

[0022] Keep at 860℃~950℃ for 20~45min and then air cool to room temperature.

[0023] The iron-chromium-aluminum alloy suitable for lead-based stacks provided by the present invention contains, in addition to some traditional components, 0.30% to 0.75% titanium and 0.01% to 0.03% nitrogen by weight percentage. Compared with traditional iron-chromium-aluminum alloys, a certain amount of titanium and nitrogen are added to the composition of the iron-chromium-aluminum alloy of the present invention. Due to the precursor and synergistic effect of titanium, it is conducive to the formation of a dense α-aluminum oxide film on the surface of the material to prevent the corrosion of liquid lead and lead alloys, so that the iron-chromium-aluminum alloy of the present invention has the performance of resisting the corrosion of liquid lead and lead alloys. At the same time, due to the presence of titanium and nitrogen, a large amount of MX-type nano-Ti (C, N) reinforcing phase can be precipitated inside the iron-chromium-aluminum alloy, thereby significantly improving the mechanical properties of the iron-chromium-aluminum alloy and its joints. This allows the iron-chromium-aluminum alloy of the present invention to also have good high-temperature strength and welding performance, and is particularly suitable for structural materials of lead-based stacks.

[0024] Furthermore, in the heat treatment method for the Fe-Cr-Aluminum alloy provided by the present invention, the alloy undergoes a solution treatment and a stabilization treatment. This heat treatment process allows a large amount of high-temperature stable MX-type nano-Ti(C,N) reinforcement phase to be dispersed and precipitated within the alloy, and can inhibit abnormal grain growth at the alloy weld joint, thereby significantly improving the mechanical properties of the Fe-Cr-Aluminum alloy and its joints. The Fe-Cr-Aluminum alloy not only has good room temperature mechanical properties and high temperature strength, but also has good weldability.

[0025] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are specifically listed below.

[0026] Based on the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art will become more aware of the above and other objects, advantages and features of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0028] Figure 1 This is a transmission electron microscope (TEM) micrograph of the iron-chromium-aluminum alloy according to Example 1 of the present invention;

[0029] Figure 2 The metallographic structure of the corrosion interface of the iron-chromium-aluminum alloy in liquid lead-bismuth alloy at 600°C / 400h according to Example 1 of the present invention is shown;

[0030] Figure 3 The metallographic structure of the corrosion interface of the iron-chromium-aluminum alloy in liquid lead-bismuth alloy at 700°C for 400h according to Example 2 of the present invention is shown;

[0031] Figure 4 The metallographic structure of the corrosion interface of the iron-chromium-aluminum alloy in Example 3 of the present invention in liquid lead-bismuth alloy at 800°C for 400h is shown;

[0032] Figure 5Scanning electron microscopy (SEM) observations of the microstructure and element distribution of the corrosion interface of the iron-chromium-aluminum alloy in liquid lead-bismuth alloy under conditions of a) 700°C / 400h and b) 800°C / 400h according to Example 1 of the present invention are shown. DETAILED DESCRIPTION

[0033] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0034] In order to solve the technical problem that key components of lead-based reactors are prone to corrosion and it is difficult to increase the operating temperature of lead-based reactors, the present invention provides an iron-chromium-aluminum alloy suitable for lead-based reactors and a heat treatment method thereof.

[0035] Through research, the inventors of this application have discovered that for existing iron-chromium-aluminum alloy structural materials, within a certain temperature and oxygen content range in a lead-based reactor, the oxygen in the liquid lead or lead-bismuth alloy used as a coolant reacts only with elements such as chromium on the material surface to form an oxide film. This oxide film has limited protective effects, particularly at temperatures above 550°C, where the structural material's strength decreases significantly, the material becomes severely oxidized, and dissolution corrosion cannot be prevented.

[0036] Based on the above findings, the inventors of the present application improved the composition of the iron-chromium-aluminum alloy material and creatively introduced titanium and nitrogen to enhance its corrosion resistance and high-temperature performance.

[0037] In particular, an embodiment of the present invention provides an iron-chromium-aluminum alloy suitable for lead-based reactors, wherein the alloy comprises, by weight, 0.30% to 0.75% titanium and 0.01% to 0.03% nitrogen. Specifically, the titanium content by weight can be any value within the range of 0.30% to 0.75%, for example, 0.30%, 0.32%, 0.35%, 0.38%, 0.40%, 0.42%, 0.45%, 0.48%, 0.50%, 0.52%, 0.55%, 0.58%, 0.60%, 0.62%, 0.65%, 0.68%, 0.70%, 0.72%, or 0.75%. The weight percentage content of nitrogen can be any value within the range of 0.01% to 0.03%, for example, 0.01%, 0.013%, 0.015%, 0.018%, 0.02%, 0.023%, 0.025%, 0.028%, or 0.03%.

[0038] The iron-chromium-aluminum alloy suitable for lead-based reactors provided by the embodiments of the present application contains, in addition to some conventional components, 0.30% to 0.75% of titanium and 0.01% to 0.03% of nitrogen in terms of percentage by weight. Compared with conventional iron-chromium-aluminum alloys, the iron-chromium-aluminum alloy of the embodiments of the present application has a certain amount of titanium and nitrogen added to its composition. Due to the precursor and synergistic effect of titanium, a dense α-aluminum oxide film can be formed on the surface of the material to prevent corrosion of liquid lead and lead alloy, so that the iron-chromium-aluminum alloy of the present application has the performance of resisting corrosion of liquid lead and lead alloy. At the same time, due to the presence of titanium and nitrogen, a large amount of MX type nano Ti(C, N) reinforcing phase can be precipitated in the iron-chromium-aluminum alloy, thereby significantly improving the mechanical properties of the iron-chromium-aluminum alloy and its joints. This makes the iron-chromium-aluminum alloy of the present application also have good high-temperature strength and welding performance, and is particularly suitable for structural materials of lead-based reactors.

[0039] In some further embodiments, the iron-chromium-aluminum alloy suitable for lead-based reactors can be composed of the following components in terms of percentage by weight:

[0040] Chromium: 10.0% to 14.0%; aluminum: 3.0% to 5.0%; silicon: 0.2% to 1.0%; manganese: 0.2% to 0.7%; titanium: 0.30% to 0.75%; carbon: 0.08% to 0.12%; nitrogen: 0.01% to 0.03%; both sulfur and phosphorus are less than 100 ppm; the balance is Fe and unavoidable trace elements.

[0041] Specifically, the percentage by weight of chromium can be any value within 10.0% to 14.0%, for example, it can be 10.0%, 10.2%, 10.5%, 10.7%, 11.0%, 11.2%, 11.5%, 11.7%, 12.0%, 12.2%, 12.5%, 12.7%, 13.0%, 13.2%, 13.5%, 13.7%, or 14.0%, etc.

[0042] The percentage by weight of aluminum can be any value within 3.0% to 5.0%, for example, it can be 3.0%, 3.2%, 3.5%, 3.7%, 4.0%, 4.2%, 4.5%, 4.7%, 4.9%, or 5.0%, etc.

[0043] The percentage by weight of silicon can be any value within 0.2% to 1.0%, for example, it can be 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, or 1.0%, etc.

[0044] The weight percentage content of manganese can be any value within the range of 0.2% to 0.7%, for example, it can be 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65% or 0.7%.

[0045] The weight percentage content of carbon can be any value within the range of 0.08% to 0.12%, for example, it can be 0.08%, 0.085%, 0.09%, 0.095%, 0.10%, 0.105%, 0.11%, 0.115% or 0.12%.

[0046] The embodiments of the present invention optimize the components other than titanium and nitrogen in the iron-chromium-aluminum alloy and their contents accordingly, thereby simplifying the composition of the iron-chromium-aluminum alloy to a certain extent. At the same time, the components work synergistically, so that the iron-chromium-aluminum alloy as a whole stably exhibits good resistance to liquid lead and lead alloy corrosion, high-temperature strength and welding performance.

[0047] In a specific embodiment, the iron-chromium-aluminum alloy suitable for lead-based stacks is composed of the following components by weight percentage:

[0048] Chromium: 10.0%; Aluminum: 4.0%; Silicon: 0.7%; Manganese: 0.7%; Titanium: 0.30%; Carbon: 0.08%; Nitrogen: 0.01%; Sulfur: <100 ppm; Phosphorus: <100 ppm; the remainder is Fe and unavoidable trace elements.

[0049] In another specific embodiment, the iron-chromium-aluminum alloy suitable for lead-based stacks is composed of the following components in terms of weight percentage:

[0050] Chromium: 10.0%; Aluminum: 4.0%; Silicon: 0.7%; Manganese: 0.2%; Titanium: 0.50%; Carbon: 0.10%; Nitrogen: 0.02%; Sulfur: <100 ppm; Phosphorus: <100 ppm; the remainder is Fe and unavoidable trace elements.

[0051] In another specific embodiment, the iron-chromium-aluminum alloy suitable for lead-based stacks is composed of the following components in percentage by weight:

[0052] Chromium: 12.0%; Aluminum: 5.0%; Silicon: 0.7%; Manganese: 0.2%; Titanium: 0.50%; Carbon: 0.10%; Nitrogen: 0.02%; Sulfur: <100 ppm; Phosphorus: <100 ppm; the remainder is Fe and unavoidable trace elements.

[0053] In another specific embodiment, the iron-chromium-aluminum alloy suitable for lead-based stacks is composed of the following components in percentage by weight:

[0054] Chromium: 12.0%; Aluminum: 5.0%; Silicon: 0.7%; Manganese: 0.2%; Titanium: 0.75%; Carbon: 0.10%; Nitrogen: 0.03%; Sulfur: <100 ppm; Phosphorus: <100 ppm; the balance being Fe and unavoidable trace elements.

[0055] Further, the embodiment of the present application also provides a heat treatment method of the iron-chromium-aluminum alloy suitable for lead-based reactors.

[0056] In some embodiments, the heat treatment method comprises solid solution treatment of the iron-chromium-aluminum alloy. The solid solution treatment specifically comprises: holding at 1020-1120℃ for 20-45 min, and then rapidly cooling to room temperature by water quenching.

[0057] The holding temperature of the solid solution treatment is preferably 1040-1100℃, and more preferably 1060-1080℃. The holding time is preferably 25-40 min, and more preferably 30-35 min.

[0058] In some embodiments, after the solid solution treatment, the heat treatment method can further comprise stabilization treatment of the iron-chromium-aluminum alloy. The stabilization treatment specifically comprises: holding at 860-950℃ for 20-45 min, and then air cooling to room temperature.

[0059] The holding temperature of the stabilization treatment is preferably 880-930℃, and more preferably 900-920℃.

[0060] In the heat treatment method of the iron-chromium-aluminum alloy provided by the embodiment of the present application, the alloy is subjected to solid solution treatment and stabilization treatment. The heat treatment process causes a large number of high-temperature stable MX type nanometer Ti(C, N) reinforcing phases to be dispersedly precipitated in the alloy, and can inhibit abnormal grain growth at the welded joint of the alloy, thereby significantly improving the mechanical properties of the iron-chromium-aluminum alloy and its joint, so that the iron-chromium-aluminum alloy not only has good room temperature mechanical properties and high temperature strength, but also has good welding performance.

[0061] Of course, those skilled in the art can understand that, before the solid solution treatment of the alloy, the raw materials of iron, chromium, aluminum, silicon, manganese, titanium, nitrogen, etc. can be mixed according to the composition of the iron-chromium-aluminum alloy, and an alloy ingot can be prepared by using a common melting method (such as vacuum induction melting method, etc.). The ingot is sampled for chemical composition analysis, and after the composition analysis is qualified, the ingot is subjected to forging and hot rolling treatment, etc. The melting, forging and hot rolling processes mentioned herein should be the technology known to those skilled in the art, and in order not to obscure the focus of the present application, they are not specifically introduced herein.

[0062] The following describes the embodiments of the present invention through specific embodiments. Those skilled in the art will readily understand the other advantages and effects of the present invention from the contents disclosed in this specification. The present invention may also be implemented or applied through different specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0063] Example 1

[0064] The iron-chromium-aluminum alloy material suitable for the lead-based reactor in this embodiment is composed of the following components by weight percentage:

[0065] Chromium: 10.0%; Aluminum: 4.0%; Silicon: 0.7%; Manganese: 0.7%; Titanium: 0.30%; Carbon: 0.08%; Nitrogen: 0.01%; Sulfur: <100 ppm; Phosphorus: <100 ppm; the remainder is Fe and unavoidable trace elements.

[0066] Example 2

[0067] The iron-chromium-aluminum alloy material suitable for the lead-based reactor in this embodiment is composed of the following components by weight percentage:

[0068] Chromium: 10.0%; Aluminum: 4.0%; Silicon: 0.7%; Manganese: 0.2%; Titanium: 0.50%; Carbon: 0.10%; Nitrogen: 0.02%; Sulfur: <100 ppm; Phosphorus: <100 ppm; the remainder is Fe and unavoidable trace elements.

[0069] Example 3

[0070] The iron-chromium-aluminum alloy material suitable for the lead-based reactor in this embodiment is composed of the following components by weight percentage:

[0071] Chromium: 12.0%; Aluminum: 5.0%; Silicon: 0.7%; Manganese: 0.2%; Titanium: 0.50%; Carbon: 0.10%; Nitrogen: 0.02%; Sulfur: <100 ppm; Phosphorus: <100 ppm; the remainder is Fe and unavoidable trace elements.

[0072] Example 4

[0073] The iron-chromium-aluminum alloy material suitable for the lead-based reactor in this embodiment is composed of the following components by weight percentage:

[0074] Chromium: 12.0%; Aluminum: 5.0%; Silicon: 0.7%; Manganese: 0.2%; Titanium: 0.75%; Carbon: 0.10%; Nitrogen: 0.03%; Sulfur: <100 ppm; Phosphorus: <100 ppm; the remainder is Fe and unavoidable trace elements.

[0075] Comparative Example 1

[0076] Comparative Example 1 uses commercial 316L stainless steel, which has the following composition (by weight percentage): chromium: 16% to 18%; nickel: 10% to 14%; manganese: <2.0%; silicon: <1.0%, sulfur: <0.03%; carbon: <0.03%; and the remainder is iron.

[0077] Comparative Example 2

[0078] Comparative Example 2 uses the existing iron-chromium-aluminum alloy for accident-tolerant cladding, which has the following composition (by weight percentage): chromium: 20% to 23%; Al: 5.8%; manganese: 0.4%; silicon: 0.7%; carbon: 0.08%; and the rest is iron.

[0079] According to the composition of the iron-chromium-aluminum alloy materials described in Examples 1 to 4, iron, chromium, aluminum, silicon, manganese, and titanium were mixed according to weight percentages and prepared into four alloy ingots using vacuum induction melting. Samples of the four ingots were then taken for chemical composition analysis. After forging and hot rolling, the four ingots were subjected to solution treatment and stabilization treatment according to the heat treatment method of the present invention to produce iron-chromium-aluminum alloy profiles with corresponding compositions for performance testing.

[0080] The three iron-chromium-aluminum alloys of Examples 1-3 of the present invention, the commercial 316L stainless steel for nuclear power plants of Comparative Example 1, and the iron-chromium-aluminum alloy for accident-tolerant cladding of Comparative Example 2 were subjected to corrosion tests in high-temperature liquid lead-bismuth alloy. The corrosion conditions were: corrosion temperatures of 600°C, 700°C, and 800°C, and corrosion times of 400 h. Figures 2 to 4 Table 1 shows the metallographic structures of the corrosion interfaces of the iron-chromium-aluminum alloys of Examples 1-3 after corrosion at 600°C, 700°C, and 800°C for 400 hours, respectively. Table 1 also shows the corrosion behaviors of the iron-chromium-aluminum alloys of Examples 1-3 after corrosion at 600°C, 700°C, and 800°C for 400 hours. Table 1 also shows the corrosion test results of commercial 316L stainless steel for nuclear power plants of Comparative Example 1 after corrosion at 600°C, 700°C, and 800°C for 400 hours, respectively, and the corrosion test results of the iron-chromium-aluminum alloy for accident-tolerant cladding of Comparative Example 2 after corrosion at 700°C and 800°C for 400 hours, respectively.

[0081] Table 1 High temperature liquid lead-bismuth alloy corrosion test results

[0082]

[0083]

[0084] The experimental data in Table 1 demonstrates that the iron-chromium-aluminum alloys of Examples 1 to 3 all exhibit excellent corrosion resistance in high-temperature liquid lead-bismuth alloys. A comparison of the corrosion behavior of commercial 316L stainless steel and the iron-chromium-aluminum alloys used for fault-tolerant cladding in high-temperature lead-bismuth alloys demonstrates that the iron-chromium-aluminum alloys of the present invention exhibit far superior compatibility with these alloys.

[0085] The test results of the tensile mechanical properties of the iron-chromium-aluminum alloys of Examples 1-4 are listed in Table 2 below.

[0086] Table 2 Tensile mechanical properties test results

[0087] Yield strength (MPa) Tensile strength (MPa) Elongation (%) Sectional shrinkage (%) Example 1 443 586 28.5 62 Example 2 506 586 17.5 19 Example 3 485 591 30 59 Example 4 495 588 27 48

[0088] It can be seen from Table 2 that the iron-chromium-aluminum alloy of the present invention has good mechanical properties.

[0089] In the description provided herein, numerous specific details are described. However, it is understood that embodiments of the present invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0090] At this point, those skilled in the art will recognize that, although a number of exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications consistent with the principles of the present invention may be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and deemed to cover all such other variations or modifications.

Claims

1. An iron-chromium-aluminum alloy for lead-based stacks, characterized in that: The iron-chromium-aluminum alloy consists of the following components by weight percentage: Chromium: 10.0% to 14.0%; Aluminum: 3.0% to 5.0%; Silicon: 0.2% to 1.0%; Manganese: 0.2% to 0.7%; Titanium: 0.30% to 0.75%; Carbon: 0.08% to 0.12%; Nitrogen: 0.01% to 0.03%; Sulfur and Phosphorus are both less than 100 ppm; The balance is Fe and unavoidable trace elements, thus providing resistance to liquid lead and lead alloy corrosion. The iron-chromium-aluminum alloy undergoes the following solution treatment: keeping at 1020°C to 1120°C for 20 to 45 minutes, and then rapidly cooling to room temperature by water quenching; and stabilization treatment: keeping at 860°C to 950°C for 20 to 45 minutes and then air cooling to room temperature, so that an MX-type nano-Ti(C,N) reinforcement phase is precipitated inside the iron-chromium-aluminum alloy.

2. The iron-chromium-aluminum alloy for lead-based stacks according to claim 1, characterized in that: The iron-chromium-aluminum alloy consists of the following components by weight percentage: Chromium: 10.0%; Aluminum: 4.0%; Silicon: 0.7%; Manganese: 0.7%; Titanium: 0.30%; Carbon: 0.08%; Nitrogen: 0.01%; Sulfur: <100 ppm; Phosphorus: <100 ppm; the remainder is Fe and unavoidable trace elements.

3. The iron-chromium-aluminum alloy for lead-based stacks according to claim 1, characterized in that: The iron-chromium-aluminum alloy consists of the following components by weight percentage: Chromium: 10.0%; Aluminum: 4.0%; Silicon: 0.7%; Manganese: 0.2%; Titanium: 0.50%; Carbon: 0.10%; Nitrogen: 0.02%; Sulfur: <100 ppm; Phosphorus: <100 ppm; the remainder is Fe and unavoidable trace elements.

4. The iron-chromium-aluminum alloy for lead-based stacks according to claim 1, characterized in that: The iron-chromium-aluminum alloy consists of the following components by weight percentage: Chromium: 12.0%; Aluminum: 5.0%; Silicon: 0.7%; Manganese: 0.2%; Titanium: 0.50%; Carbon: 0.10%; Nitrogen: 0.02%; Sulfur: <100 ppm; Phosphorus: <100 ppm; the remainder is Fe and unavoidable trace elements.

5. The iron-chromium-aluminum alloy for lead-based stacks according to claim 1, characterized in that: The iron-chromium-aluminum alloy consists of the following components by weight percentage: Chromium: 12.0%; Aluminum: 5.0%; Silicon: 0.7%; Manganese: 0.2%; Titanium: 0.75%; Carbon: 0.10%; Nitrogen: 0.03%; Sulfur: <100 ppm; Phosphorus: <100 ppm; the remainder is Fe and unavoidable trace elements.

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