A deformed high-temperature alloy bar and its preparation method

Abstract

The present invention relates to a deformed high-temperature alloy bar and its preparation method, and relates to the technical field of metal material processing and preparation. The main technical solution adopted is: a method for preparing a deformed high-temperature alloy bar, which includes the following steps: wrapping a deformed high-temperature alloy billet with an insulating material, then wrapping a bendable and foldable steel foil around the insulating material to secure the insulating material, thereby obtaining a sheathed deformed high-temperature alloy billet; and heating and extruding the sheathed deformed high-temperature alloy billet to obtain a deformed high-temperature alloy bar of target size. The present invention primarily utilizes foldable and bendable foil sheets of existing specifications to achieve sheathing, eliminating the need for mechanical processing of pipes and welding steps. The method is simple to operate, has a short production cycle, and produces a high yield rate for the bars.

Description

Technical Field

[0001] The present invention relates to the technical field of metal material processing and preparation, in particular to a deformed high-temperature alloy bar and a preparation method thereof. Background Art

[0002] Deformed superalloys are important structural materials for aircraft engines and gas turbines. They possess excellent high-temperature strength, creep resistance, and thermal corrosion resistance, enabling long-term, stable service under complex and demanding operating conditions. To meet the performance improvements of both airborne and ground-based power systems, the performance requirements for deformed superalloys are gradually increasing, along with their alloying levels, approaching those of cast superalloys. This significantly increases the difficulty of hot working these alloys, making them difficult to deform.

[0003] Currently, there are two main methods for preparing deformable high-temperature alloys: forging and extrusion. Forging involves repeatedly upsetting and drawing the deformable high-temperature alloy ingot using a hydraulic press or a fast forging machine, gradually breaking up the alloy's cast structure and forming a fine-grained structure. However, the stress state of the billet during the forging process is one-dimensional compressive stress and two-dimensional tensile stress. Due to the low thermoplasticity of the alloy, the billet is prone to cracking and failure under the action of tensile stress. Extrusion is a three-dimensional compressive stress process, which significantly improves the thermoplasticity of the alloy under three-dimensional compressive stress conditions, solving the problem of difficult-to-deform alloy forging operability.

[0004] For deformable high-temperature alloys, the alloy's hot working temperature window is narrow, so whether forging or extrusion, the billet needs to be jacketed to prevent severe cooling from contact with the die. Jacketing is categorized into soft, hard, and composite. Soft jacketing involves wrapping insulating material around the billet surface using a high-temperature adhesive. This method is only suitable for forging, as friction between the insulating material and the extrusion barrel during extrusion can cause the jacket to fall off, losing its insulating effect. Both hard and composite jacketing require steel pipes to wrap around the billet, while composite jacketing also has a layer of insulating material inserted between the steel pipe and the billet. To match the billet size, the steel ingot needs to be machined into a steel pipe, and the upper and lower surfaces of the jacket need to be welded. Consequently, the jacketing process is cumbersome and leads to a long production cycle during extrusion. Furthermore, removing the jacket after extrusion is difficult, resulting in low material utilization. Summary of the Invention

[0005] In view of this, the present invention provides a deformed high-temperature alloy bar and a preparation method thereof, the main purpose of which is to solve the problems of complicated sheathing procedures, long production cycle and low material utilization rate during the extrusion and blanking process of deformed high-temperature alloy.

[0006] To achieve the above objectives, the present invention mainly provides the following technical solutions:

[0007] In one aspect, an embodiment of the present invention provides a method for preparing a deformed high-temperature alloy bar, comprising the following steps:

[0008] The blank encapsulation step includes encapsulating the deformed high-temperature alloy blank with a heat-insulating material, and then encapsulating the heat-insulating material with a bendable and foldable steel foil to fix the heat-insulating material, thereby obtaining the encapsulated deformed high-temperature alloy blank.

[0009] Hot extrusion step: heating and extruding the sheathed deformed high-temperature alloy billet to obtain a deformed high-temperature alloy bar of target size.

[0010] Preferably, in the billet encapsulation step, before encapsulating the deformed high-temperature alloy billet with a heat-insulating material, a high-temperature adhesive is applied to the surface of the deformed high-temperature alloy billet. Preferably, the heat-insulating material is encapsulated after the high-temperature adhesive applied to the deformed high-temperature alloy billet has dried.

[0011] Preferably, the high-temperature adhesive is a glass coating, preferably a glass coating developed by Tianli Chuang Company such as GRF-37, GRF-45, TLC1350-1, G3-1, etc.; and / or the operating temperature of the glass coating is 1000-1200°C; and / or when the temperature reaches above 1000°C, the high-temperature adhesive is in a molten state.

[0012] Preferably, the thermal insulation material is asbestos blanket; and / or the thickness of the thermal insulation material is 15-30 mm.

[0013] Preferably, in the step of encapsulating the blank:

[0014] Wrapping the deformed high-temperature alloy billet with a thermal insulation material to obtain a deformed high-temperature alloy billet with the surface wrapped with the thermal insulation material;

[0015] The deformed high-temperature alloy blank with the surface wrapped with the heat-insulating material has two ends arranged opposite to each other and a side portion located between the two ends;

[0016] The steel foil includes a side fixed steel foil and an end fixed steel foil; wherein,

[0017] Placing the end fixing steel foil at the end of the deformed high temperature alloy billet with the surface wrapped with the heat insulation material;

[0018] The side fixing steel foil is wrapped around the side of the deformed high-temperature alloy billet whose surface is wrapped with the thermal insulation material; the side fixing steel foil has a first end and a second end arranged opposite to each other; the first end of the side fixing steel foil is folded at one end of the deformed high-temperature alloy billet whose surface is wrapped with the thermal insulation material, and the second end of the side fixing steel foil is folded at the other end of the deformed high-temperature alloy billet whose surface is wrapped with the thermal insulation material, so as to fix the end fixing steel foil at the end of the deformed high-temperature alloy billet whose surface is wrapped with the thermal insulation material.

[0019] Preferably, the wrapping length L of the side-fixed steel foil is 1.2-1.5 times the circumference of the extrusion cylinder; and / or the steel foil is made of stainless steel or low-carbon steel with a thickness of 0.1-0.5 mm; and / or the first end and the second end of the side-fixed steel foil are both arranged to have a serrated structure.

[0020] Preferably, in the hot extrusion step: first, the sheathed deformed high-temperature alloy billet is heated to the extrusion temperature in a heat treatment furnace and kept warm for 2-4 hours, and then the sheathed deformed high-temperature alloy billet is transferred from the heat treatment furnace to an extruder for extrusion treatment; wherein, the transfer time is 5-10s, the extrusion ratio is 3.5-12, and the extrusion temperature is 1090-1140°C; wherein, the deformed high-temperature alloy bar of the target size can be obtained by a single-step or multi-step extrusion treatment; preferably, when the deformed high-temperature alloy bar of the target size is obtained by a multi-step extrusion treatment, after each step of extrusion treatment, the sheath is removed and cut, and the obtained bar is re-sheathed as a deformed high-temperature alloy billet, and then further subjected to a hot extrusion treatment step; preferably, the extrusion ratio of the latter extrusion treatment is greater than the extrusion ratio of the previous extrusion treatment, and the extrusion temperature of the latter extrusion treatment is less than the extrusion temperature of the previous extrusion treatment.

[0021] Preferably, before the billet sheathing step, a deformed high-temperature alloy billet preparation step is also included: a deformed high-temperature alloy ingot is prepared by vacuum induction melting and electroslag remelting technology; and the deformed high-temperature alloy ingot is homogenized and surface treated to obtain a deformed high-temperature alloy billet.

[0022] Preferably, the deformed high-temperature alloy ingot comprises the following components, in weight percentage: Co10-25wt%, Cr8-15wt%, Ti 5.2-6wt%, Al 1.8-4.0wt%, W 4-6wt%, Mo 2-4wt%, Ta 0-2wt%, C<0.05wt%, Zr<0.1wt%, and Ni as the balance.

[0023] Preferably, the homogenization treatment step includes: heating the deformed high-temperature alloy ingot from a heating rate of 60-240°C / h to 1140-1170°C, keeping it warm for 20-40h, then heating it to 1180-1200°C at a heating rate of 180-300°C / h, keeping it warm for 15-24h, and then cooling it to below 100°C before taking it out of the furnace.

[0024] Preferably, the yield rate of deformed high-temperature alloy bars prepared by the method is ≥85%.

[0025] On the other hand, an embodiment of the present invention provides a deformed high-temperature alloy rod, wherein the alloy grain size of the deformed high-temperature alloy rod is 10-100 μm; preferably, the deformed high-temperature alloy rod is prepared by any of the above-mentioned methods for preparing a deformed high-temperature alloy rod.

[0026] Compared with the prior art, the deformed high-temperature alloy rod and the preparation method thereof of the present invention have at least the following beneficial effects:

[0027] The method for preparing a deformed high-temperature alloy bar proposed in an embodiment of the present invention is to prepare the deformed high-temperature alloy billet by extruding it. During the extrusion process, the embodiment of the present invention proposes a new sheathing process, that is, using a completely foldable steel foil to fix the insulation material. Compared with the steel pipe fixation in the prior art, the sheathing process of the present invention only requires the folding of foil plates of existing specifications, without the need for mechanical processing of the pipe, and the sheathing does not need to be welded and fixed. The operation is simple, the production cycle is significantly shortened, and the preparation yield rate is improved (the yield rate of bars prepared using the method of the embodiment of the present invention is greater than or equal to 85%).

[0028] Furthermore, the method for preparing a deformed high-temperature alloy bar proposed by the present invention requires applying a high-temperature adhesive to the surface of the deformed high-temperature alloy billet before wrapping the deformed high-temperature alloy billet with a thermal insulation material. This high-temperature adhesive is a glass coating, which has an operating temperature of 1000-1200°C. When the temperature reaches above 1000°C, the glass coating becomes molten. This not only acts as a high-temperature adhesive, ensuring that the thermal insulation material remains wrapped around the billet surface, ensuring good thermal insulation during extrusion deformation, but also provides high-temperature oxidation protection.

[0029] Furthermore, in the preparation method of the deformed high-temperature alloy bar proposed by the present invention, in the billet sheathing step, the steel foil used includes an end-fixed steel foil and a side-fixed steel foil. When the steel foil is used to wrap and fix the thermal insulation material, only the two end-fixed steel foils need to be respectively placed at the two ends of the deformed high-temperature alloy billet whose surface is wrapped with the thermal insulation material, and the side-fixed steel foil is wrapped around the side of the deformed high-temperature alloy billet whose surface is wrapped with the thermal insulation material, and the first end and the second end of the side-fixed steel foil are respectively folded at the two ends of the deformed high-temperature alloy billet whose surface is wrapped with the thermal insulation material. Therefore, the process operation of this method is simple.

[0030] Furthermore, in the method for preparing deformed high-temperature alloy bars proposed in the present invention, the wrapping length of the side fixed steel foil used is 1.2-1.5 times the circumference of the extrusion cylinder. This arrangement ensures that after the billet is deformed in the extrusion cylinder, the steel foil can still completely wrap the billet.

[0031] Furthermore, the present invention proposes a method for preparing a deformed superalloy bar, which utilizes vacuum induction melting and electroslag remelting to produce a deformed superalloy ingot. The deformed superalloy ingot is then homogenized to eliminate solidification segregation in the ingot. The homogenized ingot is then surface treated to polish away surface oxide scale, imparting a metallic luster to the surface and preventing surface defects from becoming crack initiation sites during deformation. Furthermore, the deformed superalloy ingot comprises the following composition, by weight percentage: Co 10-25wt%, Cr 8-15wt%, Ti 5.2-6wt%, Al 1.8-4.0wt%, W 4-6wt%, Mo 2-4wt%, Ta 0-2wt%, C <0.05wt%, Zr <0.1wt%, with Ni as the balance. This allows the deformed superalloy to have a service temperature of up to 750°C and, at 1100°C, still contain 10-25% γ′ phase.

[0032] 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 and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of a deformed high-temperature alloy billet after canning provided by an embodiment of the present invention;

[0034] Figure 2 1 is a schematic longitudinal cross-sectional view of a canned deformed high-temperature alloy billet provided by an embodiment of the present invention;

[0035] Figure 3 It is a schematic diagram of the unfolding of the side fixed steel foil;

[0036] Figure 4 It is a schematic diagram of the end-fixed steel foil. DETAILED DESCRIPTION

[0037] To further illustrate the technical means and effects employed by the present invention to achieve its intended objectives, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention is provided in conjunction with the accompanying drawings and preferred embodiments. In the following description, different references to "one embodiment" or "embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0038] The present invention provides a deformed high-temperature alloy bar and a preparation method thereof. The specific technical solution is as follows:

[0039] The following steps are used to prepare deformed high-temperature alloy billets: The deformed high-temperature alloy ingots are produced using vacuum induction melting and electroslag remelting techniques. The ingots are then homogenized to eliminate solidification segregation in the billets. The homogenized billets are then surface treated to remove any surface oxide scale, imparting a metallic sheen to the billet surface and preventing surface defects from becoming crack initiation sites during deformation.

[0040] Among them, the deformed high-temperature alloy ingot includes the following components, in terms of weight percentage: Co 10-25wt%, Cr8-15wt%, Ti 5.2-6wt%, Al 1.8-4.0wt%, W 4-6wt%, Mo 2-4wt%, Ta 0-2wt%, C<0.05wt%, Zr<0.1wt%, and Ni is the balance.

[0041] This deformable superalloy has a service temperature of up to 750°C, and even at 1100°C, it still contains 10-25% γ′ phase. The raw materials are melted in a vacuum induction melting furnace to produce electroslag remelting electrodes, which are then remelted to produce high-purity ingots. Homogenization treatment is then performed on the ingots to eliminate solidification segregation and improve the alloy's thermoplasticity. The homogenization process consists of two steps. The first step, homogenization, eliminates low-melting-point precipitates and prevents the formation of melt holes in the ingot. The temperature is raised at a rate of 60-240°C / h to 1140-1170°C and held for 20-40 hours. The second step, homogenization, dissolves as much of the high-melting-point precipitates as possible or distributes them uniformly as dispersed, fine particles. The temperature is raised at a rate of 180-300°C / h to 1180-1200°C and held for 15-24 hours. The ingot is then cooled to below 100°C before removal from the furnace to prevent excessive thermal stress from causing cracking. A grinding wheel is used to remove oxides from the ingot's surface, imparting a metallic luster and preventing surface defects from becoming crack nucleation sites during deformation.

[0042] The blank sheathing step comprises: wrapping the deformed high-temperature alloy blank with a heat-insulating material, and then wrapping a bendable and foldable steel foil around the heat-insulating material to fix the heat-insulating material, thereby obtaining the sheathed deformed high-temperature alloy blank.

[0043] Here, the deformed high-temperature alloy blank is covered with insulation material on all surfaces (sides and ends).

[0044] Before the step of wrapping the deformed high-temperature alloy billet with insulation material, a high-temperature adhesive needs to be applied to the surface of the deformed high-temperature alloy billet; preferably, after the high-temperature adhesive applied to the deformed high-temperature alloy billet is dried, the deformed high-temperature alloy billet is wrapped with insulation material.

[0045] like Figures 1 to 4 As shown, a deformed high-temperature alloy billet 1 is wrapped with a thermal insulation material 2 to obtain a deformed high-temperature alloy billet with a surface wrapped with the thermal insulation material. The deformed high-temperature alloy billet with a surface wrapped with the thermal insulation material has two oppositely arranged ends and a side located between the two ends. The steel foil includes a side-fixed steel foil 32 and an end-fixed steel foil 31; wherein the end-fixed steel foil 31 is placed at the end of the deformed high-temperature alloy billet with a surface wrapped with the thermal insulation material. The side-fixed steel foil 32 is wrapped around the side of the deformed high-temperature alloy billet with a surface wrapped with the thermal insulation material; and the two opposite ends of the side-fixed steel foil 32 (the first end and the second end set oppositely, as shown Figure 3 As shown, the first end and the second end are both arranged in a serrated structure) and are respectively folded at the two ends of the deformed high-temperature alloy billet with the surface wrapped with insulation material to fix the end fixing steel foil 31 at the end of the deformed high-temperature alloy billet with the surface wrapped with insulation material.

[0046] Preferably, the high temperature adhesive is a glass coating, and the operating temperature is 1000-1200°C.

[0047] Preferably, the thermal insulation material is an asbestos blanket with a wrapping thickness of 15-30 mm.

[0048] Preferably, the steel foil is made of stainless steel or low carbon steel, has a thickness of 0.1-0.5 mm, and can be bent and folded manually.

[0049] Preferably, if Figures 1 to 4As shown, the above steps are specifically as follows: a commercially available glass coating is applied to the surface of a deformed high-temperature alloy blank 1. After the glass coating adhesive dries, an insulating material 2 is wrapped around the surface (including the sides and ends) of the deformed high-temperature alloy blank 1. Finally, the insulating material is fixed with steel foil 3. The glass coating has an operating temperature of 1000-1200°C. When the temperature reaches above 1000°C, it becomes molten. It not only acts as a high-temperature adhesive to keep the insulating material wrapped around the blank surface, ensuring good insulation during extrusion deformation, but this molten coating also provides high-temperature oxidation protection. The insulating material 2 is an asbestos blanket with a wrapping thickness of 15-30mm. The steel foil 3 is stainless steel or low-carbon steel with a thickness of 0.1-0.5mm and can be bent and folded by hand.

[0050] like Figure 3 As shown in FIG. 1 , the wrapping length L of the side fixed steel foil 32 wrapping the side of the deformed high-temperature alloy billet is 1.2-1.5 times the circumference of the extrusion cylinder. This arrangement ensures that the steel foil can still completely wrap the billet after the billet is deformed in the extrusion cylinder. The term "wrapping length" herein refers to the length of the side fixed steel foil when it is unfolded, such as Figure 3 The length in the direction shown is perpendicular to the direction where the first end and the second end of the side fixed steel foil are located, and the two ends of the side fixed steel foil are used to fold at the end of the deformed high-temperature alloy billet with the surface wrapped with insulation material.

[0051] Hot extrusion step: heating and extruding the sheathed deformed high-temperature alloy billet to obtain a deformed high-temperature alloy rod.

[0052] In the hot extrusion step: first, the sheathed deformed high-temperature alloy billet is heated to the extrusion temperature in a heat treatment furnace and kept warm for 2-4 hours, and then the sheathed deformed high-temperature alloy billet is transferred from the heat treatment furnace to an extruder for extrusion; wherein, the transfer time is 5-10 seconds, the extrusion ratio is 3.5-12, and the extrusion temperature is 1090-1140°C. The target size of the deformed high-temperature alloy bar can be obtained by a single-step or multi-step extrusion process. Preferably, when the target size of the deformed high-temperature alloy bar can be obtained by a single-step or multi-step extrusion process, after each extrusion process, the sheath is removed and cut, and the extruded bar is re-sheathed as a deformed high-temperature alloy billet, and then further subjected to a hot extrusion process; preferably, the extrusion ratio of the latter extrusion process is greater than the extrusion ratio of the previous extrusion process, and the extrusion temperature of the latter extrusion process is lower than the extrusion temperature of the previous extrusion process.

[0053] Here, the deformed high-temperature alloy rod obtained above can reach a service temperature of 750° C. after further heat treatment.

[0054] In summary, the above-mentioned method proposed in the present invention avoids the tensile stress generated during the deformation process that causes cracking of the alloy, and improves the yield rate of blank preparation; at the same time, it solves the problems of cumbersome sheathing procedures, long production cycles, and low material utilization in the traditional extrusion deformation process.

[0055] The present invention is further described below by means of specific examples:

[0056] Example 1

[0057] This embodiment provides a method for preparing a deformed high-temperature alloy rod, comprising the following steps:

[0058] Preparation of a deformed high-temperature alloy billet: Using vacuum induction melting, a vacuum induction melting ingot with a composition of 25wt% Co, 8wt% Cr, 6wt% Ti, 4wt% Al, 5wt% W, 3wt% Mo, 2wt% Ta, 0.02wt% C, 0.015wt% Zr, and the balance Ni is obtained; the vacuum induction melting ingot is subjected to riser cutting and surface polishing, and is further electroslag remelted as an electrode ingot to prepare a high-purity deformed high-temperature alloy ingot; the deformed high-temperature ingot is subjected to homogenization treatment, and the homogenization treatment process is as follows: heating from a heating rate of 60°C / h to 1170°C, holding for 40 hours, heating at a heating rate of 180°C / h to 1200°C, holding for 24 hours, and then cooling to 100°C in the furnace before being removed from the furnace; the billet after homogenization treatment is surface treated, and the surface oxide scale is polished to give the billet surface a metallic luster, thereby obtaining a deformed high-temperature alloy billet.

[0059] Blanket encapsulation steps: Apply G3-1 glass coating evenly on the surface of the deformed high-temperature alloy billet, then wrap it with 30mm thick insulation material (asbestos blanket), and finally use 0.5mm thick steel foil to fix the insulation material. The length of the steel foil wrapped around the side of the billet is 430mm (wherein, the encapsulation method is referred to Figures 1 to 4 ) to obtain the deformed high-temperature alloy billet after sheathing.

[0060] Hot extrusion steps: Place the sheathed deformed high-temperature alloy billet in a heat treatment furnace and heat it to 1140°C, keep it warm for 4 hours, and then transfer the sheathed deformed high-temperature alloy billet to the extruder. The transfer time interval is 5 seconds, the first extrusion ratio is 3.5, the extruded rod diameter is 60 mm, remove the sheath on the rod surface, and cut it. The rod with a length of 150 mm was re-wrapped, and a high-temperature adhesive was evenly applied on the surface and both ends of the rod, and then wrapped with a 20 mm thick insulation material. Finally, the insulation material was fixed with a 0.25 mm thick steel foil, and the wrapping length of the side fixing steel foil wrapped around the side of the rod was 315 mm; then it was heated to 1090°C in a heat treatment furnace, kept warm for 3 hours, and transferred to an extruder with a transfer time of 8 seconds and an extrusion ratio of 5 to extrude a deformed high-temperature rod with a diameter of 30 mm. The deformed high-temperature alloy rod had a uniform structure and an average grain size of 100 μm (it should be noted that for extruded rods, the main evaluation indicators are grain size and structural uniformity). The yield of the alloy was 85% ((initial rod mass - mass of the extruded rod obtained) × 100% / initial rod mass).

[0061] Example 2

[0062] This embodiment provides a method for preparing a deformed high-temperature alloy rod, comprising the following steps:

[0063] Preparation of a deformed high-temperature alloy billet: Using vacuum induction melting, a vacuum induction melted ingot with a composition of Co 15wt%, Cr 10wt%, Ti 5.5wt%, Al 3wt%, W 5wt%, Mo 3wt%, Ta 1wt%, C 0.03wt%, Zr 0.02wt%, and the balance Ni is obtained; the vacuum induction melted ingot is subjected to riser cutting and surface polishing, and is further electroslag remelted as an electrode ingot to prepare a high-purity deformed high-temperature alloy ingot; the deformed high-temperature ingot is homogenized, and the homogenization process is as follows: heating from a heating rate of 150°C / h to 1160°C, holding for 30 hours, heating at a heating rate of 200°C / h to 1190°C, holding for 20 hours, and then cooling to 100°C with the furnace before being removed from the furnace; the billet after the homogenization treatment is surface treated, and the surface oxide scale is polished to give the billet surface a metallic luster, thereby obtaining a deformed high-temperature alloy billet.

[0064] Blanket encapsulation steps: Apply TLC1350-1 glass coating evenly on the surface of the deformed high-temperature alloy billet, then wrap it with 20mm thick insulation material (asbestos blanket), and finally use 0.2mm thick steel foil to fix the insulation material. The length of the steel foil wrapped around the side of the billet is 440mm (wherein, the encapsulation method is referred to Figures 1 to 4 ) to obtain the deformed high-temperature alloy billet after sheathing.

[0065] Hot extrusion step: The sheathed deformed high-temperature alloy billet is placed in a heat treatment furnace and heated to 1130°C, kept warm for 3 hours, and then transferred to an extruder with a transfer time interval of 8 seconds and an extrusion ratio of 8.2 to extrude a deformed high-temperature alloy rod with a diameter of 35 mm. The deformed high-temperature alloy rod has a uniform structure, an average grain size of 50 μm, and an alloy yield of 95%.

[0066] Example 3

[0067] This embodiment provides a method for preparing a deformed high-temperature alloy rod, comprising the following steps:

[0068] Preparation of a deformed high-temperature alloy billet: Using vacuum induction melting, a vacuum induction melted ingot with a composition of Co 10wt%, Cr 12wt%, Ti 5.2wt%, Al 2wt%, W 4wt%, Mo 2wt%, Ta 1wt%, C 0.02wt%, Zr 0.01wt%, and the balance Ni is obtained; the vacuum induction melted ingot is subjected to riser cutting and surface polishing, and is further electroslag remelted as an electrode ingot to prepare a high-purity deformed high-temperature alloy ingot; the deformed high-temperature ingot is homogenized, and the homogenization process is as follows: heating from a heating rate of 240°C / h to 1140°C, holding for 20 hours, heating at a heating rate of 300°C / h to 1180°C, holding for 15 hours, and then cooling to 100°C with the furnace and removing from the furnace; the billet after homogenization is surface treated, and the surface oxide scale is polished to give the billet surface a metallic luster, thereby obtaining a deformed high-temperature alloy billet.

[0069] Blanket encapsulation steps: Apply GRF-45 glass coating evenly on the surface of the deformed high-temperature alloy billet, then wrap it with 15mm thick insulation material, and finally fix the insulation material with 0.1mm thick steel foil. The length of the steel foil wrapped around the side of the billet is 470mm (see the encapsulation method for details). Figures 1 to 4 ) to obtain the deformed high-temperature alloy billet after sheathing.

[0070] Hot extrusion step: The sheathed deformed high-temperature alloy billet is placed in a heat treatment furnace and heated to 1110°C, kept warm for 2 hours, and then transferred to an extruder with a transfer time interval of 10 seconds and an extrusion ratio of 12 to extrude a deformed high-temperature alloy rod with a diameter of 28 mm. The deformed high-temperature alloy rod has a uniform structure, an average grain size of 10 μm, and an alloy yield of 92%.

[0071] Comparative Example 1

[0072] Preparation of a deformed high-temperature alloy billet: Using vacuum induction melting, a vacuum induction melting ingot with a composition of 25wt% Co, 8wt% Cr, 6wt% Ti, 4wt% Al, 5wt% W, 3wt% Mo, 2wt% Ta, 0.02wt% C, 0.015wt% Zr, and the balance Ni is obtained; the vacuum induction melting ingot is subjected to riser cutting and surface polishing, and is further electroslag remelted as an electrode ingot to prepare a high-purity deformed high-temperature alloy ingot; the deformed high-temperature ingot is subjected to homogenization treatment, and the homogenization treatment process is as follows: heating from a heating rate of 60°C / h to 1170°C, holding for 40 hours, heating at a heating rate of 180°C / h to 1200°C, holding for 24 hours, and then cooling to 100°C in the furnace before being removed from the furnace; the billet after homogenization treatment is surface treated, and the surface oxide scale is polished to give the billet surface a metallic luster, thereby obtaining a deformed high-temperature alloy billet.

[0073] The billet encapsulation process involves chipping a stainless steel round bar with a diameter 30mm greater than the high-temperature alloy billet and a uniform height to remove the core material, forming a 15mm-thick stainless steel sheath. Two 15mm-thick stainless steel discs with a diameter equal to the stainless steel sheath are then processed, and a gas outlet is cut into one of the discs using wire cutting. A stainless steel disc is then arc welded to the end of the stainless steel sheath. Brushed asbestos is inserted into the sheath, followed by the high-temperature alloy billet. The gap between the billet and the sheath is then filled with asbestos, which is then pushed down with a needle-like tool. Finally, a stainless steel disc is welded to the other end of the sheath, completing the high-temperature alloy composite encapsulation.

[0074] Hot extrusion steps: Place the sheathed deformed high-temperature alloy billet in a heat treatment furnace and heat it to 1140°C, keep it warm for 4 hours, then transfer the sheathed deformed high-temperature alloy billet to an extruder with a transfer time interval of 5 seconds. The first extrusion ratio is 3.5, and the extruded bar diameter is 60mm. The surface sheath of the bar is removed by lathe turning, and the length is cut. The 150mm long bar is sheathed again, and stainless steel sleeves and discs of corresponding sizes are machined, welded, and filled with brushed insulation asbestos; then heat it to 1090°C in a heat treatment furnace and keep it warm for 3 hours. Transfer it to an extruder with a transfer time of 8 seconds and an extrusion ratio of 5 to extrude a deformed high-temperature alloy bar with a diameter of 30mm. The bar is turned to remove the sheath. The average grain size of the deformed high-temperature alloy bar is 120μm, and the alloy yield is 65%.

[0075] Compared with Comparative Example 1, it is obvious that the method for preparing a deformed high-temperature alloy rod proposed in the embodiment of the present invention can be achieved by simply folding a foil plate of existing specifications, without the need for mechanical processing of pipes or welding and fixing, simple operation, significantly shortening the production cycle, improving the uniformity of the structure, making the grains fine, and achieving a high material utilization rate, without having to cut a large amount of waste when removing the sheath.

[0076] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiment based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a deformed high-temperature alloy bar, characterized in that: It includes the following steps: The blank encapsulation step includes encapsulating the deformed high-temperature alloy blank with a heat-insulating material, and then encapsulating the heat-insulating material with a bendable and foldable steel foil to fix the heat-insulating material, thereby obtaining the encapsulated deformed high-temperature alloy blank. Hot extrusion step: heating and extruding the canned deformed high-temperature alloy billet to obtain a deformed high-temperature alloy bar of target size; Wherein, in the step of encapsulating the blank: Wrapping the deformed high-temperature alloy billet with a thermal insulation material to obtain a deformed high-temperature alloy billet with the surface wrapped with the thermal insulation material; The deformed high-temperature alloy blank with the surface wrapped with the heat-insulating material has two ends arranged opposite to each other and a side portion located between the two ends; The steel foil includes a side fixed steel foil and an end fixed steel foil; wherein, Placing the end fixing steel foil at the end of the deformed high temperature alloy billet with the surface wrapped with the heat insulation material; The side fixing steel foil is wrapped around the side of the deformed high-temperature alloy billet whose surface is wrapped with the thermal insulation material; the side fixing steel foil has a first end and a second end arranged opposite to each other; the first end of the side fixing steel foil is folded at one end of the deformed high-temperature alloy billet whose surface is wrapped with the thermal insulation material, and the second end of the side fixing steel foil is folded at the other end of the deformed high-temperature alloy billet whose surface is wrapped with the thermal insulation material, so as to fix the end fixing steel foil at the end of the deformed high-temperature alloy billet whose surface is wrapped with the thermal insulation material.

2. The method for preparing a deformed high-temperature alloy bar according to claim 1, characterized in that: In the blank covering step: Before the step of wrapping the deformed high-temperature alloy blank with a heat-insulating material, a high-temperature adhesive needs to be applied to the surface of the deformed high-temperature alloy blank.

3. The method for preparing a deformed high-temperature alloy bar according to claim 2, characterized in that: After the high-temperature adhesive applied on the deformed high-temperature alloy blank is dried, the deformed high-temperature alloy blank is wrapped with a heat-insulating material.

4. The method for preparing a deformed high-temperature alloy bar according to claim 2, wherein: The high temperature adhesive is a glass coating.

5. The method for preparing a deformed high-temperature alloy bar according to claim 4, characterized in that: The high temperature adhesive is selected from glass coatings of GRF-37, GRF-45, TLC1350-1, and G3-1 models.

6. The method for preparing a deformed high-temperature alloy bar according to claim 2, characterized in that: The operating temperature of the glass coating is 1000-1200°C; and / or When the temperature reaches above 1000° C., the high-temperature adhesive is in a molten state.

7. The method for preparing a deformed high-temperature alloy bar according to claim 1, characterized in that: The thermal insulation material is asbestos blanket; and / or The thickness of the thermal insulation material is 15-30 mm.

8. The method for preparing a deformed high-temperature alloy bar according to claim 1, wherein: The wrapping length L of the side fixed steel foil is 1.2-1.5 times the circumference of the extrusion cylinder; and / or The steel foil is made of stainless steel or low carbon steel, with a thickness of 0.1-0.5 mm; and / or The first end and the second end of the side fixed steel foil are both arranged in a zigzag structure.

9. The method for preparing a deformed high-temperature alloy bar according to any one of claims 1 to 8, characterized in that: In the hot extrusion step: First, the canned deformed high-temperature alloy billet is heated to the extrusion temperature in a heat treatment furnace and kept at this temperature for 2-4 hours. Then, the canned deformed high-temperature alloy billet is transferred from the heat treatment furnace to an extruder for extrusion treatment. The transfer time is 5-10 seconds, the extrusion ratio is 3.5-12, and the extrusion temperature is 1090-1140°C. The deformed high-temperature alloy rod of the target size can be obtained through a single-step or multi-step extrusion process.

10. The method for preparing a deformed high-temperature alloy bar according to claim 9, characterized in that: When the target-sized deformed high-temperature alloy rod is obtained through a multi-step extrusion process, after each extrusion process, the sheath is removed and cut, and the obtained rod is re-sheathed as a deformed high-temperature alloy billet and then further subjected to a hot extrusion process.

11. The method for preparing a deformed high-temperature alloy bar according to claim 10, characterized in that: The extrusion ratio of the latter extrusion process is greater than the extrusion ratio of the former extrusion process, and the extrusion temperature of the latter extrusion process is lower than the extrusion temperature of the former extrusion process.

12. The method for preparing a deformed high-temperature alloy bar according to claim 1, wherein: Before the blank covering step, the method further comprises: The preparation steps of the deformed high-temperature alloy billet are as follows: a deformed high-temperature alloy ingot is prepared by using vacuum induction melting and electroslag remelting technology; and the deformed high-temperature alloy ingot is homogenized and surface treated to obtain the deformed high-temperature alloy billet.

13. The method for preparing a deformed high-temperature alloy bar according to claim 12, characterized in that: The deformed high-temperature alloy ingot includes the following components in weight percentage: Co 10-25wt%, Cr 8-15wt%, Ti 5.2-6wt%, Al1.8-4.0wt%, W 4-6wt%, Mo 2-4wt%, Ta 0-2wt%, C<0.05 wt%, Zr<0.1wt%, and Ni as the balance.

14. The method for preparing a deformed high-temperature alloy bar according to claim 12, wherein: The homogenization treatment step includes: heating the deformed high-temperature alloy ingot from a heating rate of 60-240°C / h to 1140-1170°C, keeping it warm for 20-40h, then heating it to 1180-1200°C at a heating rate of 180-300°C / h, keeping it warm for 15-24h, and then cooling it to below 100°C before taking it out of the furnace.

15. The method for preparing a deformed high-temperature alloy bar according to claim 1, wherein: The yield rate of deformed high-temperature alloy bars prepared by the method is ≥85%.

16. The method for preparing a deformed high-temperature alloy bar according to claim 1, wherein: The alloy grain size of the deformed high-temperature alloy rod is 10-100 μm.

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