Iron-nickel-based high-temperature alloy, ultra-thin strip foil and preparation method

Abstract

The present invention relates to an iron-nickel-based high-temperature alloy, an ultra-thin strip foil and a preparation method, and belongs to the technical field of high-temperature alloys. The composition of the iron-nickel-based high-temperature alloy is C: 0.06%-0.10%; Cr: 21.0%-22.0%; Mo: 8.5%-9.5%; W: 0.30%-0.60%; Co: 0.55%-1.50%; Fe: 17.5%-20.5%; Al≤0.40%; Ti≤0.10%; Si≤0.9%; S≤0.008%; P≤0.020%; the remainder is Ni. With the mutual cooperation of the above-mentioned elements, the hardness and strength of the iron-nickel-based high-temperature alloy are reduced, and its deformation coordination and plasticity are improved, and the elongation after fracture at room temperature is ≥50.4%. The ultra-thin strip foil is prepared using the iron-nickel-based high-temperature alloy of the present invention, and the ultra-thin strip foil has better performance and the yield rate can reach more than 95%.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature alloys, and in particular to an iron-nickel-based high-temperature alloy, an ultra-thin strip foil material and a preparation method thereof. Background Art

[0002] In recent years, the use of strip foil to manufacture honeycomb structures has met the needs of lightweight aviation and aerospace engines. Strip foil plays a crucial role in reducing structural weight and improving engine performance. Therefore, the quality of the strip foil directly affects the quality of honeycomb structures. Generally, iron-nickel-based superalloys have excellent mechanical properties and oxidation resistance, as well as low cost and good hot and cold processing properties. Therefore, iron-nickel-based superalloys are often used to manufacture strip foil, which is widely used in aviation, aerospace, petrochemical, and energy fields.

[0003] However, there are still some problems with strip foils made of iron-nickel-based high-temperature alloys, mainly including internal organizational problems such as excessive carbide quantity, obvious carbide bands, uneven organization, and the presence of mixed crystals, as well as high cold deformation resistance, poor plasticity, and easy cracking at large deformation amounts. These problems have led to unstable quality and performance of strip foils, seriously restricting the good application of strip foils.

[0004] Therefore, there is an urgent need for an iron-nickel-based high-temperature alloy with uniform structure and excellent plasticity and other properties for the preparation of higher quality strip foils. Summary of the Invention

[0005] In view of the above analysis, the present invention provides an iron-nickel based high temperature alloy, an ultra-thin strip foil and a preparation method thereof, so as to solve the problem of unstable quality and performance of existing strip foils.

[0006] The purpose of the present invention is mainly achieved through the following technical solutions:

[0007] The invention provides an iron-nickel-based high-temperature alloy. The iron-nickel-based high-temperature alloy comprises, by mass percentage, the following components: C: 0.06%-0.10%; Cr: 21.0%-22.0%; Mo: 8.5%-9.5%; W: 0.30%-0.60%; Co: 0.55%-1.50%; Fe: 17.5%-20.5%; Al≤0.40%; Ti≤0.10%; Si≤0.9%; S≤0.008%; P≤0.020%; and the balance is Ni.

[0008] Furthermore, the composition of the iron-nickel-based high-temperature alloy includes, by mass percentage: C: 0.06%-0.08%; Cr: 21.0%-22.0%; Mo: 8.5%-9.0%; W: 0.30%-0.45%; Co: 0.55%-1.0%; Fe: 17.5%-20.5%; Al≤0.40%; Ti≤0.10%; Si≤0.9%; S≤0.008%; P≤0.020%; and the balance is Ni.

[0009] Furthermore, the composition of the iron-nickel-based high-temperature alloy further includes B: 0.005%-0.01% by mass.

[0010] Furthermore, the iron-nickel-based high-temperature alloy structure includes an austenite matrix, M6C type carbides, M 23 C6 type carbide and TCP phase.

[0011] Furthermore, the M6C carbide and the M 23 The content of C6 type carbide is ≤3.0%.

[0012] Furthermore, the M6C carbide and the M 23 The content of C6 type carbide is ≤2.5%.

[0013] Furthermore, the M6C carbide and the M 23 The content of C6 type carbide is ≤2.0%.

[0014] Furthermore, the room temperature tensile elongation after break of the iron-nickel based high temperature alloy is ≥50.4%.

[0015] The present invention also provides a method for preparing an iron-nickel-based high-temperature alloy, which adopts a vacuum induction melting and electroslag remelting two-step smelting process to prepare the iron-nickel-based high-temperature alloy, comprising the following steps:

[0016] S1: Vacuum induction melting: Raw materials are weighed according to the element ratio of the iron-nickel-based high-temperature alloy, added into a vacuum induction furnace, and fully melted, refined, and impurity-removed under vacuum conditions. The steel is then cast into electrode rods under argon protection.

[0017] S2: electroslag remelting: the electrode rod is subjected to electroslag remelting in an electroslag smelting furnace to produce an iron-nickel based high temperature alloy.

[0018] Furthermore, in the vacuum induction melting, the full melting temperature is 1480°C-1500°C, the refining temperature is 1490°C-1510°C, the refining time is greater than 60 minutes, and the tapping temperature is 1510°C-1530°C.

[0019] Furthermore, the vacuum degree of the full melting is 20Pa-30Pa, and the vacuum degree of the refining is less than 5Pa.

[0020] Furthermore, in the electroslag remelting, the protective slag system is CaF2:Al2O3:CaO:MgO=60%:20%:10%:10%, and the melting speed is 3kg / min-5kg / min.

[0021] Furthermore, in the electroslag remelting, the slag amount of the slag system is 50-80 kg, the current is 5000 A-9000 A, and the voltage is 53 V-63 V.

[0022] The present invention also provides an ultra-thin foil material, which is prepared using the iron-nickel-based high-temperature alloy of the present invention. The thickness of the ultra-thin foil material is ≤0.1 mm, and the yield of the ultra-thin foil material is ≥95%.

[0023] Furthermore, the present invention also provides a method for preparing an ultra-thin foil, comprising the following steps:

[0024] Step 1: Sheet Rolling

[0025] Hot rolling the iron-nickel-based high-temperature alloy for more than four times to obtain a plate;

[0026] Step 2: Strip Rough Rolling

[0027] cold rolling the plate for two or more passes to obtain a rough strip;

[0028] Step 3: Strip finishing

[0029] cold rolling the rough strip material for more than 5 times to obtain a strip foil material;

[0030] Furthermore, in step 1, the deformation amount of each pass is 40%-60%, and the heating temperature of the hot rolling is 1050℃-1150℃; annealing heat treatment is performed between each pass, the heating temperature of the annealing heat treatment is 1100℃-1150℃, and the holding time is more than 30 minutes.

[0031] Furthermore, in step 2, the deformation amount of each pass is 60%-80%; and annealing heat treatment is performed between each pass, wherein the heating temperature of the annealing heat treatment is 1100° C.-1150° C. and the holding time is more than 30 minutes.

[0032] Furthermore, in step 3, the deformation amount of each pass is 50%-80%; a hydrogen-protected continuous annealing furnace is used for bright intermediate annealing and finished product annealing, the heating temperature of the annealing heat treatment is 1100° C.-1150° C., and the holding time is 2-4 minutes.

[0033] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0034] 1. The present invention strictly controls the contents of C, Co, W and Mo elements by adjusting the composition ratio of the iron-nickel-based high-temperature alloy, wherein the C element is controlled according to the lower limit, and the binding rate of the C element with elements such as Cr, W and Ti is reduced, so that the amount of precipitated carbides in the iron-nickel-based high-temperature alloy is effectively reduced, and the dispersion strengthening effect of the iron-nickel-based high-temperature alloy is weakened; the Co, W and Mo elements are controlled according to the middle and lower limits, and the solubility of the Co, W and Mo elements in the austenite matrix of the iron-nickel-based high-temperature alloy is reduced, thereby weakening the solid solution strengthening effect; the dispersion strengthening and solid solution strengthening effects of the iron-nickel-based high-temperature alloy are weakened, thereby significantly reducing the hardness and strength of the iron-nickel-based high-temperature alloy, and improving its deformation coordination and plasticity, and the room temperature tensile elongation of the iron-nickel-based high-temperature alloy is ≥50.4%.

[0035] 2. The present invention, on the basis of strictly controlling the contents of C, Co, W and Mo elements, adds the element B, and controls the content of the element B within the range of 0.005%-0.010%. The element B is mainly enriched at the grain boundaries and forms borides. The grain boundary borides prevent grain boundary sliding, the connection and expansion of voids, increase the grain boundary bonding force, and thus improve the high-temperature and long-term performance of the alloy. In addition, the element B easily forms boron carbide with the element C, thereby reducing the combination of C with elements such as Cr, W and Ti, reducing the amount of primary carbides precipitated between dendrites, changing the distribution of carbides, preventing the segregation of carbides, and reducing banded structure. More importantly, during the solidification process of alloy smelting, the element B can reduce the amount of eutectic structure and refine the matrix structure, reducing the probability of crack initiation caused by the high brittleness of the eutectic structure, thereby improving the plasticity of the iron-nickel-based high-temperature alloy.

[0036] 3. The present invention optimizes the composition of the iron-nickel-based high-temperature alloy by regulating and controlling the C element according to the lower limit, the Co, W and Mo elements according to the middle and lower limits, and adds the B element; then adopts a vacuum induction melting and electroslag remelting two-step smelting process, and under the action of vacuum with a slag system of CaF2:Al2O3:CaO:MgO=60%:20%:10%:10%, the content of gas elements O and N in the iron-nickel-based high-temperature alloy is reduced, as well as the content of impurity elements such as S, so that more B element combines with C element to form boron carbide, further reducing the combination of C element with elements such as Cr, W and Ti, improving the internal structure and distribution of the iron-nickel-based high-temperature alloy, thereby reducing the strength and hardness of the iron-nickel-based high-temperature alloy, and further improving the plasticity of the iron-nickel-based high-temperature alloy.

[0037] 4. The iron-nickel-based high-temperature alloy obtained by the present invention has high plasticity, that is, the elongation after break at room temperature is ≥50.4%. After hot rolling and cold rolling, the iron-nickel-based high-temperature alloy can be prepared into ultra-thin strip foil with a thickness of ≤0.1 mm, and the yield of the ultra-thin strip foil can reach more than 95%.

[0038] In the present invention, the above-mentioned technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of the present invention will be described in the following description, and some advantages will become apparent from the description or be learned through practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like parts throughout the drawings.

[0040] Figure 1 The metallographic structure of the ultra-thin foil obtained in Example 1 is shown in FIG.

[0041] Figure 2 The metallographic structure of the ultra-thin foil obtained in Example 2;

[0042] Figure 3 The metallographic structure of the ultra-thin foil obtained in Example 3;

[0043] Figure 4 The metallographic structure of the ultra-thin foil obtained in Example 4 is shown in FIG.

[0044] Figure 5 This is the metallographic structure of the ultra-thin foil obtained in Example 5;

[0045] Figure 6 The metallographic structure of the ultra-thin foil obtained in Example 6 is shown in FIG.

[0046] Figure 7 The metallographic structure of the ultra-thin foil obtained in Example 7 is shown in FIG.

[0047] Figure 8 This is the metallographic structure of the ultra-thin foil obtained in Comparative Example 1;

[0048] Figure 9 This is the metallographic structure of the ultra-thin foil obtained in Comparative Example 2;

[0049] Figure 10 This is the metallographic structure of the ultra-thin foil obtained in Comparative Example 3;

[0050] Figure 11 This is the metallographic structure of the ultra-thin foil obtained in Comparative Example 4;

[0051] Figure 12 This is a physical picture of the ultra-thin foil. DETAILED DESCRIPTION

[0052] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0053] The invention provides an iron-nickel-based high-temperature alloy. The iron-nickel-based high-temperature alloy comprises, by mass percentage, the following components: C: 0.06%-0.10%; Cr: 21.0%-22.0%; Mo: 8.5%-9.5%; W: 0.30%-0.60%; Co: 0.55%-1.50%; Fe: 17.5%-20.5%; Al≤0.40%; Ti≤0.10%; Si≤0.9%; S≤0.008%; P≤0.020%; and the balance is Ni.

[0054] Compared with the existing technology, the content of element C and solid solution strengthening elements Co, W, Mo, and impurity element S in the iron-nickel base high temperature alloy is strictly controlled, the binding rate of element C with elements such as W, Cr, Fe, Ti, and the binding rate of element S with element Fe is reduced, the amount of precipitation of carbides and sulfides is reduced, and the effects of dispersion strengthening and solid solution strengthening of the iron-nickel base high temperature alloy are weakened, thereby improving the plasticity of the iron-nickel base high temperature alloy.

[0055] Specifically, the functions of the components of the above-mentioned iron-nickel-based high-temperature alloy are as follows:

[0056] C: Carbon primarily forms carbides with Cr, W, and Ti, acting as dispersion strengthening, increasing the hardness and strength of Fe-Ni-based superalloys and helping to control grain size. However, as the C content gradually increases, excessive carbides form, and the carbides are distributed in chains at the grain boundaries, producing a banded structure that reduces the alloy's plasticity and toughness. Therefore, in order to significantly reduce the deformation resistance of Fe-Ni-based superalloys, improve the plasticity of Fe-Ni-based superalloys, and thereby improve the cold rolling performance of Fe-Ni-based superalloy strip and foil, the C content in Fe-Ni-based superalloys is preferably controlled between 0.06% and 0.10%.

[0057] For example, the content of element C in the iron-nickel-based high-temperature alloy may be 0.06%, 0.07%, 0.08%, 0.09% or 0.10%.

[0058] Co, W, and Mo: The elements Co, W, and Mo simultaneously dissolve in the austenite matrix of the Fe-Ni-based superalloy, acting as a composite solid solution strengthening agent. Co not only helps improve the high-temperature thermal strength of the Fe-Ni-based superalloy, but also has benefits for high-temperature hot corrosion resistance. W promotes the formation of carbides. The increase in W directly leads to a significant increase in the number of carbides precipitated, which inhibits grain growth. Furthermore, the increased W content significantly increases the σ phase in the TCP phase. Mo and Co have little effect on the precipitation morphology and number of carbides. However, when Mo is added in excess, it not only reduces the alloy's corrosion resistance but also promotes the formation of harmful phases, deteriorating the hot working properties.

[0059] As the overall content of Co, W, and Mo gradually increases, Co, W, and Mo gradually dissolve in the γ matrix, causing lattice distortion, thereby making the solid solution strengthening effect prominent. At the same time, a large number of fine and dispersed carbides will form in the iron-nickel-based high-temperature alloy, ultimately significantly improving the hardness and strength of the iron-nickel-based high-temperature alloy. However, while the strength and hardness of the iron-nickel-based high-temperature alloy are greatly improved, the deformation resistance of the iron-nickel-based high-temperature alloy increases, and the coordinated deformation ability and plasticity decrease, which is not conducive to the cold rolling processing of ultra-thin strip foils, and is prone to uneven deformation and cracking. Therefore, the Co, W, and Mo contents in the iron-nickel-based high-temperature alloy of the present invention are appropriately controlled according to the middle and lower limits, Co 0.55%-1.50%, W 0.30%-0.60%, and Mo 8.50%-9.50%.

[0060] For example, the content of element Co in the iron-nickel based high temperature alloy may be 0.55%, 0.65%, 0.75%, 0.85%, 0.95%, 1.05%, 1.20%, 1.30%, 1.40% or 1.50%.

[0061] For example, the content of W in the iron-nickel-based high-temperature alloy may be 0.30%, 0.35%, 0.40%, 0.45%, 0.50%, 0.55% or 0.60%.

[0062] For example, the content of element Mo in the iron-nickel based high temperature alloy may be 8.50%, 8.80%, 9.0%, 9.20% or 9.50%.

[0063] Si and S: The elements Si and S have little effect on the hardness and strength of iron-nickel-based superalloys. However, a significant increase in their content can reduce their hot and cold working plasticity and coordinated deformation capabilities, leading to a significant tendency toward deformation cracking and hindering the hot and cold rolling of ultra-thin strip. Therefore, maintaining low levels of Si and S in the present invention helps improve the purity and hot and cold working plasticity of the iron-nickel-based superalloy.

[0064] To further improve the microstructure and performance of the above-mentioned iron-nickel-based superalloy, the composition of the above-mentioned iron-nickel-based superalloy is further adjusted. For example, the composition, by mass percentage, includes: C: 0.06%-0.08%; Cr: 21.0%-22.0%; Mo: 8.5%-9.0%; W: 0.30%-0.45%; Co: 0.55%-1.0%; Fe: 17.5%-20.5%; Al≤0.40%; Ti≤0.10%; Si≤0.9%; S≤0.008%; P≤0.020%; the balance is Ni.

[0065] In order to further improve the microstructure and performance of the above-mentioned iron-nickel-based superalloy, the composition of the above-mentioned iron-nickel-based superalloy is further adjusted. For example, the composition of the above-mentioned iron-nickel-based superalloy further includes B: 0.005%-0.01% by mass.

[0066] The role of element B in the present invention is as follows:

[0067] B: B is a microalloying element that concentrates at grain boundaries, forming borides there. Borides can inhibit grain boundary slip and the connection and expansion of voids, increasing the cohesion of grain boundaries and significantly improving the alloy's creep and durability properties. The addition of B in the present invention alters the morphology and distribution of carbides, making them fine and dispersed, and reducing banding. It also improves the room-temperature and high-temperature plasticity of the iron-nickel-based superalloy, significantly increasing its elongation after fracture. However, when the B content in the alloy exceeds 0.010%, a low-melting-point eutectic structure gradually forms and segregates at and near grain boundaries. Due to the high brittleness of the eutectic structure, crack initiation is easily triggered, reducing the plasticity of the iron-nickel-based superalloy, and consequently, its elongation after fracture. Therefore, the B content in the iron-nickel-based superalloy of the present invention is controlled between 0.005% and 0.010%.

[0068] For example, the content of element B in the iron-nickel-based high-temperature alloy may be 0.005%, 0.006%, 0.007%, 0.008%, 0.009% or 0.01%.

[0069] Specifically, the iron-nickel based high temperature alloy structure includes an austenite matrix, M6C type carbides, M 23 C6 type carbide and TCP phase.

[0070] Specifically, the M6C carbide and the M 23 The content of C6 type carbide is ≤3.0%.

[0071] The present invention provides a method for preparing an iron-nickel-based high-temperature alloy, which adopts a vacuum induction melting and electroslag remelting two-step smelting process to prepare the iron-nickel-based high-temperature alloy, comprising the following steps:

[0072] S1: Vacuum induction melting: Raw materials are weighed according to the element ratio of the iron-nickel-based high-temperature alloy, added into a vacuum induction furnace, and fully melted, refined, and impurity-removed under vacuum conditions. The steel is then cast into electrode rods under argon protection.

[0073] The full melting temperature is 1480°C-1500°C, the refining temperature is 1490°C-1510°C, the refining time is greater than 60 minutes, and the tapping temperature is 1510°C-1530°C.

[0074] S2: electroslag remelting: the electrode rod is subjected to electroslag remelting in an electroslag smelting furnace to produce an iron-nickel based high temperature alloy.

[0075] The protective slag system is CaF2:Al2O3:CaO:MgO=60%:20%:10%:10%, and the melting speed is 3kg / min-5kg / min.

[0076] Compared with existing technologies, this new process optimizes the alloy composition of the iron-nickel-based high-temperature alloy and utilizes a dual-melting process of vacuum induction melting and electroslag remelting. During the vacuum induction melting stage, the alloy raw materials are completely melted at 1480°C-1500°C to produce molten steel with good fluidity. Raising the temperature to 1490°C-1510°C facilitates the thorough mixing of the various elements, achieving a uniform composition of the molten steel. The temperature is then further raised to 1510°C-1530°C for tapping and pouring. At this temperature, the molten steel exhibits good fluidity and meets the shrinkage feeding requirements during solidification.

[0077] During the electroslag remelting stage, the content of gas elements O and N in the iron-nickel base high-temperature alloy is reduced by combining the protective slag system of CaF2:Al2O3:CaO:MgO=60%:20%:10%:10% and the melting speed, and the content of impurity elements such as S is reduced, providing a high-purity iron-nickel base high-temperature alloy.

[0078] In order to facilitate understanding of the present invention, the following examples and comparative examples are provided for illustration.

[0079] Example 1

[0080] The preparation of the iron-nickel based high temperature alloy comprises the following steps:

[0081] S1: Vacuum induction melting:

[0082] (1) Raw material selection: The raw materials selected are nickel, chromium, cobalt, molybdenum, tungsten and pure iron. New metal raw materials are used and the oxide scale is removed;

[0083] (2) The element ratio of the iron-nickel based high temperature alloy is: C: 0.06%; Cr: 21.75%; Mo: 9.50%; W: 0.60%; Co: 1.50%; Fe: 18.50%; Al: 0.10%; Ti: 0.09%; Si: 0.10%; S: 0.005%; P: 0.005%; the balance is Ni;

[0084] (3) weighing raw materials according to the element ratio of the iron-nickel-based high-temperature alloy, adding the raw materials into a vacuum induction furnace, and performing full melting, refining, and impurity removal under vacuum conditions, and then casting the steel into a Φ150 mm electrode rod under argon protection;

[0085] The temperature of the full melt is 1480°C, and the vacuum degree of the full melt is 20Pa;

[0086] The refining temperature is 1490°C, the refining time is 80 min, and the refining vacuum is 3 Pa;

[0087] The tapping temperature is 1510°C;

[0088] S2: Electroslag remelting: The electrode rod is subjected to electroslag remelting in an electroslag smelting furnace to obtain an electroslag ingot of Φ280 mm, i.e., an iron-nickel-based high-temperature alloy.

[0089] The protective slag system is CaF2:Al2O3:CaO:MgO=60%:20%:10%:10%, the slag amount of the slag system is 70kg, the smelting speed is 5kg / min, the current is 9000A, and the voltage is 63V.

[0090] Example 2

[0091] The preparation method of the iron-nickel-based high-temperature alloy in Example 2 is substantially the same as that in Example 1, except that the element ratio of the iron-nickel-based high-temperature alloy in Example 2 is: C: 0.06%; Cr: 21.75%; Mo: 9.0%; W: 0.45%; Co: 1.0%; Fe: 18.50%; Al: 0.10%; Ti: 0.09%; Si: 0.10%; S: 0.005%; P: 0.005%; and the balance is Ni.

[0092] Example 3

[0093] The preparation method of the iron-nickel-based high-temperature alloy in Example 3 is substantially the same as that in Example 1, except that the element ratio of the iron-nickel-based high-temperature alloy in Example 3 is: C: 0.06%; Cr: 21.75%; Mo: 8.50%; W: 0.30%; Co: 0.55%; Fe: 18.50%; Al: 0.10%; Ti: 0.09%; Si: 0.10%; S: 0.005%; P: 0.005%; and the balance is Ni.

[0094] Example 4

[0095] The preparation method of the iron-nickel-based high-temperature alloy in Example 4 is substantially the same as that in Example 1, except that the element ratio of the iron-nickel-based high-temperature alloy in Example 4 is: C: 0.10%; Cr: 21.75%; Mo: 8.50%; W: 0.30%; Co: 0.55%; Fe: 18.50%; Al: 0.10%; Ti: 0.09%; Si: 0.10%; S: 0.005%; P: 0.005%; and the balance is Ni.

[0096] Example 5

[0097] The preparation method of the iron-nickel-based high-temperature alloy in Example 5 is substantially the same as that in Example 1, except that the element ratio of the iron-nickel-based high-temperature alloy in Example 5 is: C: 0.08%; Cr: 21.75%; Mo: 8.50%; W: 0.30%; Co: 0.55%; Fe: 18.50%; Al: 0.10%; Ti: 0.09%; Si: 0.10%; S: 0.005%; P: 0.005%; B: 0.005%; and the balance is Ni.

[0098] Example 6

[0099] The preparation method of the iron-nickel-based high-temperature alloy in Example 6 is substantially the same as that in Example 1, except that the element ratio of the iron-nickel-based high-temperature alloy in Example 6 is: C: 0.06%; Cr: 21.75%; Mo: 8.50%; W: 0.30%; Co: 0.55%; Fe: 18.50%; Al: 0.10%; Ti: 0.09%; Si: 0.10%; S: 0.005%; P: 0.005%; B: 0.005%; and the balance is Ni.

[0100] Example 7

[0101] The preparation method of the iron-nickel-based high-temperature alloy in Example 7 is substantially the same as that in Example 6, except that, in the vacuum induction melting,

[0102] The temperature of the full melt is 1500°C, and the vacuum degree of the full melt is 30Pa;

[0103] The refining temperature is 1510°C, the refining time is 80 min, and the refining vacuum is 3 Pa;

[0104] The tapping temperature is 1530°C.

[0105] Comparative Example 1

[0106] The preparation method of the iron-nickel-based high-temperature alloy in Comparative Example 1 is substantially the same as that in Example 1, except that the element ratio of the iron-nickel-based high-temperature alloy in Comparative Example 1 is: C: 0.06%; Cr: 21.75%; Mo: 10.0%; W: 0.70%; Co: 1.80%; Fe: 18.50%; Al: 0.10%; Ti: 0.09%; Si: 0.10%; S: 0.005%; P: 0.005%; and the balance is Ni.

[0107] Comparative Example 2

[0108] The preparation method of the iron-nickel-based high-temperature alloy in Comparative Example 2 is substantially the same as that in Example 1, except that the element ratio of the iron-nickel-based high-temperature alloy in Comparative Example 2 is: C: 0.15%; Cr: 21.75%; Mo: 8.50%; W: 0.30%; Co: 0.55%; Fe: 18.50%; Al: 0.10%; Ti: 0.09%; Si: 0.10%; S: 0.005%; P: 0.005%; and the balance is Ni.

[0109] Comparative Example 3

[0110] The preparation method of the iron-nickel-based high-temperature alloy in Comparative Example 3 is substantially the same as that in Example 1, except that the element ratio of the iron-nickel-based high-temperature alloy in Comparative Example 3 is: C: 0.15%; Cr: 21.75%; Mo: 10.00%; W: 1.00%; Co: 2.55%; Fe: 18.50%; Al: 0.10%; Ti: 0.09%; Si: 0.10%; S: 0.005%; P: 0.005%; and the balance is Ni.

[0111] Comparative Example 4

[0112] The preparation methods of the iron-nickel-based high-temperature alloy of Comparative Example 4 and Example 6 are substantially the same, except that, in vacuum induction melting,

[0113] The temperature of the full melt is 1470°C, and the vacuum degree of the full melt is 30Pa;

[0114] The refining temperature is 1520°C, the refining time is 80 min, and the refining vacuum is 3 Pa;

[0115] The tapping temperature is 1500°C.

[0116] The hardness and tensile strength of the iron-nickel-based high-temperature alloy obtained above were tested at room temperature. The specific test results are shown in Table 1. Figure 1-11 shown.

[0117] Table 1 Performance test results at room temperature

[0118]

[0119]

[0120] Preparation of ultra-thin foils

[0121] The Φ280 mm electroslag ingots (i.e., iron-nickel-based high-temperature alloys) obtained in Examples 1-7 and Comparative Examples 1-4 were processed into slabs with a thickness of 40 mm, and then the slabs were prepared into ultra-thin strip foils by hot rolling and cold rolling. The preparation method includes the following steps:

[0122] Step 1: Sheet Rolling

[0123] The slab with a thickness of 40 mm was placed on a four-roll hot rolling mill for hot rolling at a heating temperature of 1100° C., and a control range of the deformation of each pass was: 40 mm → 18 mm → 9 mm → 5 mm → 3 mm; an annealing heat treatment was performed between each pass at a heating temperature of 1150° C., a holding time of 30 minutes, and air cooling was performed to obtain a plate with a thickness of 3 mm;

[0124] Step 2: Strip Rough Rolling

[0125] The obtained plate was placed on a four-roll reversible cold rolling mill for cold rolling, with the pass deformation control range being: 3.0 mm → 2.0 mm → 1.5 mm, to produce a rough strip with a thickness of 1.5 mm;

[0126] Annealing heat treatment is performed between each pass, the heating temperature of the annealing heat treatment is 1150°C, and the holding time is 30 minutes;

[0127] Step 3: Strip finishing

[0128] The obtained rough strip was placed on a twenty-roll reversible cold rolling mill for cold rolling, with the deformation amount of each pass distributed as 1.5 mm → 0.85 mm → 0.65 mm → 0.45 mm → 0.25 mm → 0.15 mm → 0.09 mm → 0.05 mm, to produce a strip foil with a thickness of 0.05 mm;

[0129] A hydrogen-protected continuous annealing furnace is used for bright intermediate annealing and finished product annealing. The heating temperature of the annealing heat treatment is 1150° C. and the holding time is 4 minutes.

[0130] Using strip foil to manufacture honeycomb structures meets the demand for lightweight aviation and aerospace engines. Key requirements for strip foil include a hardness of HV ≤ 253 (equivalent to HBS 241) and a room-temperature tensile ductility δ ≥ 35%. Strip foils were prepared from the iron-nickel-based superalloys obtained in Examples 1-7 and Comparative Examples 1-4. The properties and yield of the resulting strip foils are shown in Table 2.

[0131] Table 2 Foil yield rate

[0132] Group Hardness HV Tensile plasticity / % Yield rate / % Example 1 185 50％ 95％ Example 2 178 52％ 95％ Example 3 167 55％ 96％ Example 4 194 49％ 95％ Example 5 186 50％ 95％ Example 6 168 59％ 97％ Example 7 165 61％ 98％ Comparative Example 1 210 43％ 75％ Comparative Example 2 217 40％ 72％ Comparative Example 3 225 37％ 65％ Comparative Example 4 178 45％ 82％

[0133] Reference Figure 1-7 , according to Example 1-7, the iron-nickel based high temperature alloy was prepared. From the metallographic diagram, it can be seen that a small amount of carbides are precipitated at the grain boundaries and inside the grains. The carbides mainly include M6C type carbides and M 23 C6 carbide, M6C carbide and M 23 The total content of C6 carbides is ≤3.0%. Moreover, the carbides are small in size and relatively dispersed in distribution. No carbide banding is observed. The alloy matrix has good uniformity of structure and the grain size is uniform without obvious mixed crystal phenomenon.

[0134] Reference Figure 8-11 , Iron-nickel-based high-temperature alloys were prepared according to Comparative Examples 1-4. From the metallographic images, it can be seen that a large amount of carbides are precipitated at the grain boundaries and inside the grains of the iron-nickel-based high-temperature alloys of Comparative Examples 1-3. The carbides mainly include M6C type carbides and M 23 C6 carbide, M6C carbide and M 23 The total content of C6 carbides is greater than 3.0%. Moreover, when the content of elements C, Mo, W and Co exceeds the upper limit, mixed crystal phenomenon occurs in the matrix of the iron-nickel base high-temperature alloy, the uniformity of the structure deteriorates, and the carbide strips are more obvious (see Figure 10 ).

[0135] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. An iron-nickel-based high-temperature alloy for preparing ultra-thin strip foil, characterized in that: The composition of the iron-nickel-based high-temperature alloy includes, by mass percentage, C: 0.06%-0.10%; Cr: 21.0%-22.0%; Mo: 8.5%-9.5%; W: 0.30%-0.60%; Co: 0.55%-1.50%; Fe: 17.5%-18.5%; Al≤0.40%; Ti≤0.10%; Si≤0.9%; S≤0.008%; P≤0.020%; the balance is Ni; wherein the iron-nickel-based high-temperature alloy structure includes an austenite matrix, M6C carbides, M 23 C6 type carbide and TCP phase; and the M6C type carbide and the M 23 The content of C6 carbide is ≤3.0%; The iron-nickel based high temperature alloy is prepared by vacuum induction melting and electroslag remelting two-step smelting process, including the following steps: S1: Vacuum induction melting: Raw materials are weighed according to the element ratio of the iron-nickel-based high-temperature alloy, added to a vacuum induction furnace, and fully melted, refined, and impurity-removed under vacuum conditions. The steel is then tapped and cast into electrode rods under argon protection. The fully melting temperature is 1480°C-1500°C, the refining temperature is 1490°C-1510°C, the refining time is greater than 60 minutes, and the tapping temperature is 1510°C-1530°C. S2: Electroslag remelting: The electrode rod is subjected to electroslag remelting in an electroslag smelting furnace with a protective slag system of CaF2:Al2O3:CaO:MgO = 60%:20%:10%:10%, to produce an iron-nickel based high temperature alloy for preparing ultra-thin strip foil with a thickness of ≤0.1mm. The yield of the ultra-thin strip foil can reach more than 95%.

2. The iron-nickel-based high-temperature alloy according to claim 1, characterized in that: The composition of the iron-nickel-based high-temperature alloy includes, by mass percentage, C: 0.06%-0.08%; Cr: 21.0%-22.0%; Mo: 8.5%-9.0%; W: 0.30%-0.45%; Co: 0.55%-1.0%; Fe: 17.5%-18.5%; Al≤0.40%; Ti≤0.10%; Si≤0.9%; S≤0.008%; P≤0.020%; and the balance is Ni.

3. The iron-nickel-based high-temperature alloy according to claim 1 or 2, characterized in that: Calculated by mass percentage, the composition of the iron-nickel-based high-temperature alloy also includes B: 0.005%-0.01%.

4. The iron-nickel-based high-temperature alloy according to claim 1 or 2, characterized in that: The room temperature tensile elongation after break of the iron-nickel based high temperature alloy is ≥50.4%.

5. A method for preparing the iron-nickel-based high-temperature alloy according to any one of claims 1 to 4, characterized in that: The iron-nickel-based high-temperature alloy is prepared by a vacuum induction melting and electroslag remelting two-step smelting process, which includes the following steps: S1: Vacuum induction melting: Raw materials are weighed according to the element ratio of the iron-nickel-based high-temperature alloy, added into a vacuum induction furnace, and fully melted, refined, and impurity-removed under vacuum conditions. The steel is then cast into electrode rods under argon protection. S2: Electroslag remelting: The electrode rod is electroslag remelted in an electroslag smelting furnace to obtain an iron-nickel based high temperature alloy, and the protective slag system is CaF2:Al2O3:CaO:MgO = 60%:20%:10%:10%.

6. An ultra-thin foil material, characterized in that: The ultra-thin strip foil is prepared by using the iron-nickel-based high-temperature alloy according to any one of claims 1 to 4, and the yield rate of the ultra-thin strip foil is ≥95%.

7. A method for preparing the ultra-thin foil material according to claim 6, characterized in that: The method comprises the following steps: Step 1: Sheet Rolling Hot rolling the iron-nickel-based high-temperature alloy for more than four times to obtain a plate; Step 2: Strip Rough Rolling cold rolling the plate for two or more passes to obtain a rough strip; Step 3: Strip finishing The rough strip is cold rolled for more than 5 times to obtain a strip foil.

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