Alloy material, heat treatment method of alloy, and production method of alloy product

Abstract

The application provides an alloy material, a heat treatment method of the alloy and a production method of the alloy product. The alloy comprises a tantalum-tungsten alloy or a niobium alloy, the tantalum-tungsten alloy comprises any one or more of Ta2.5W, Ta5W, Ta7.5W and a high-tungsten tantalum alloy, the niobium alloy comprises any one or more of Nb521, NbW5-1, Nb752, Cb752, and the production method comprises the following steps: preheating an alloy ingot by using a medium-frequency heating furnace to obtain a preheated ingot; setting an oxidation-resistant layer on the surface of the preheated ingot to obtain an oxidation-resistant ingot; and performing a staged heating treatment on the oxidation-resistant ingot by using the medium-frequency heating furnace to obtain a heat-treated ingot, wherein the staged heating treatment comprises increasing the heating power of the medium-frequency heating furnace in a gradient in the range of 40KW-145KW to increase the temperature to 1500±50 DEG C. The processing plasticity of the ingot is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of alloy, in particular to an alloy material, a heat treatment method of alloy and a production method of alloy product. BACKGROUND

[0002] With the development of aerospace, weapon equipment power technology, the material use temperature requirement of engine combustion chamber, thrust chamber, structural parts and fasteners is higher and higher, and the size requirement is larger and larger. At present, the highest use temperature of niobium tungsten alloy is 1550℃, and the long-term service temperature is about 1250-1300℃, so a material with higher use temperature needs to be sought. Since Ta10W and Ta12W alloys have higher material melting point, recrystallization temperature and high temperature strength, the use temperature can be increased to 1700-1900℃, so they are applied to the thrust chamber, structural parts and fasteners of super-high speed and hypersonic aircraft engine.

[0003] Tantalum tungsten alloy is a typical solid solution strengthening tantalum alloy, tungsten is infinitely dissolved in tantalum in the form of substitutional solid solution. With the increase of tungsten content, the room temperature strength and high temperature strength of tantalum tungsten alloy increases nearly linearly. Typical tantalum tungsten alloys include Ta2.5W, Ta5W, Ta7.5W, Ta10W, Ta12W, Ta15W and Ta20W. With the increase of tungsten content, the room temperature and high temperature strength of the material gradually increases. Ta10W and Ta12W alloys have excellent corrosion resistance, high temperature strength, high temperature toughness and creep properties, and are suitable for high temperature, high pressure, corrosion resistant and other working environments. Since they can solve the problem of insufficient high temperature performance of structural materials caused by the performance improvement of aerospace engine, they are the preferred materials for space vehicles, missile engine nose cone, nozzle, exhaust pipe and other components. The melting points of Ta10W alloy and Ta12W alloy are close to 3080 and 3100℃, and the densities are 16.85-16.90 and 16.95-17.1 g / cm 3 . Since Ta12W alloy has a higher tungsten content than Ta10W alloy, its room temperature performance and high temperature performance are relatively higher than that of Ta10W.

[0004] However, the increase of tungsten content leads to the increase of strength, the sharp decrease of processing plasticity and toughness, and theoretically, the tungsten content of 13% is the limit of the processable material (also the upper limit of the tungsten content of Ta12W alloy), and exceeding this tungsten content leads to the poor plasticity and thus the inability to be processed by traditional pressure processing means. Therefore, Ta12W alloy is the highest-tungsten-content and highest-strength tantalum-tungsten alloy that can be processed by pressure processing. The tungsten content of 13% or more can only be increased by alloying with Hf, Re and other elements to improve the processing plasticity of the alloy, but the effect is limited. Therefore, in the commercial binary component tantalum-tungsten alloy, Ta12W is the highest-tungsten-content and highest-strength alloy. Compared with the most mature Ta10W commercial alloy, Ta12W alloy has higher room temperature and high temperature strength and is more valuable in application, and the difficulties are how to ensure the uniformity and narrow range control of the tungsten content by smelting and casting technology, and how to process the Ta12W ingot into plate and rod products that can be applied by pressure processing and meet the performance requirements of application. SUMMARY

[0005] The present application provides an alloy material, a heat treatment method of the alloy and a production method of the alloy product to solve the problem of difficult pressure processing of the alloy.

[0006] The first aspect of the present application provides a heat treatment method of an alloy, the alloy comprising a tantalum-tungsten alloy or a niobium alloy, the tantalum-tungsten alloy comprising any one or more of Ta2.5W, Ta5W, Ta7.5W and a high-tungsten-content tantalum alloy, the niobium alloy comprising any one or more of Nb521, NbW5-1, Nb752 and Cb752, and the production method comprising: preheating the alloy ingot by using a medium-frequency heating furnace to obtain a preheated ingot; setting an oxidation-resistant layer on the surface of the preheated ingot to obtain an oxidation-resistant ingot; and performing a staged heating treatment on the oxidation-resistant ingot by using the medium-frequency heating furnace to obtain a heat-treated ingot, wherein the staged heating treatment comprises increasing the heating power of the medium-frequency heating furnace in a gradient in the range of 40KW-145KW to increase the temperature to 1500±50℃.

[0007] In any embodiment of the first aspect, the preheating step comprises: setting the power of the medium-frequency induction furnace to 30KW-50KW to start timing, and keeping the temperature at 80℃-120℃ for 20-30 seconds.

[0008] In any embodiment of the first aspect, the staged heating treatment step comprises the following steps performed in sequence: adjusting the heating power of the medium-frequency heating furnace to 40KW-50KW and keeping for 1min-3min; adjusting the heating power of the medium-frequency heating furnace to 70KW-145KW and keeping for 15min-35min; and adjusting the heating power of the medium-frequency heating furnace to 120±10KW and keeping for 1min-3min.

[0009] In any embodiment of the first aspect, the gradient of the heating power of the step of the hierarchical heating treatment is 10KW-30KW, optionally 15KW-25KW, further optionally 20KW.

[0010] In any embodiment of the first aspect, the step of the hierarchical heating treatment comprises the following steps in sequence: adjusting the heating power of the intermediate frequency heating furnace to 40KW-50KW and keeping for 1min-3min; adjusting the heating power of the intermediate frequency heating furnace to 80±10KW and keeping for 5min-10min; adjusting the heating power of the intermediate frequency heating furnace to 100±10KW and keeping for 3min-6min; adjusting the heating power of the intermediate frequency heating furnace to 120±10KW and keeping for 2min-5min; adjusting the heating power of the intermediate frequency heating furnace to 130KW-145KW and keeping for 5min-10min; adjusting the heating power of the intermediate frequency heating furnace to 120±10KW and keeping for 1min-3min.

[0011] In any embodiment of the first aspect, the step of the hierarchical heating treatment comprises the following steps in sequence: adjusting the heating power of the intermediate frequency heating furnace to 40KW-50KW and keeping for 1min-3min to raise the temperature of the anti-oxidation ingot to 550℃-650℃; adjusting the heating power of the intermediate frequency heating furnace to 80±10KW and keeping for 5min-10min to raise the temperature of the anti-oxidation ingot to 1000℃-1200℃; adjusting the heating power of the intermediate frequency heating furnace to 100±10KW and keeping for 3min-6min to raise the temperature of the anti-oxidation ingot to 1100℃-1300℃; adjusting the heating power of the intermediate frequency heating furnace to 120±10KW and keeping for 2min-5min to raise the temperature of the anti-oxidation ingot to 1250℃-1300℃; adjusting the heating power of the intermediate frequency heating furnace to 130KW-145KW and keeping for 5min-10min to raise the temperature of the anti-oxidation ingot to 1350℃-1550℃; adjusting the heating power of the intermediate frequency heating furnace to 120±10KW and keeping for 1min-3min to raise the temperature of the anti-oxidation ingot to 1450℃-1500℃.

[0012] In any embodiment of the first aspect, the high-tungsten tantalum alloy includes any one of Ta10W, Ta12W, Ta15W, Ta20W; optionally, the alloy ingot includes Ta10W ingot with a specification of Ф(110-115mm) x (220-305mm), Ta10W ingot with a specification of Ф(150-155mm) x (220-300mm), Ta12W ingot with a specification of Ф(110-115mm) x (220-305mm), or Ta12W ingot with a specification of Ф(150-155mm) x (220-300mm).

[0013] In any embodiment of the first aspect, the intermediate frequency heating furnace is a tube furnace.

[0014] The second aspect of the present application provides an alloy material including a tantalum-tungsten alloy or a niobium alloy, the tantalum-tungsten alloy including any one or more of Ta2.5W, Ta5W, Ta7.5W, and a high-tungsten tantalum alloy, the niobium alloy including any one or more of Nb521, NbW5-1, Nb752, Cb752, optionally the high-tungsten tantalum alloy being selected from any one of Ta10W, Ta12W, Ta15W, Ta20W; the alloy material having a tensile strength of 470-700 MPa, a yield strength of 490-750 MPa, an elongation of 25-30%, and / or the alloy material being obtained by the heat treatment method provided in any embodiment of the first aspect.

[0015] The third aspect of the present application provides a production method of an alloy product, the production method including sequentially performing heat treatment and forging treatment on an alloy ingot, the heat treatment being implemented by the heat treatment method provided in any embodiment of the first aspect; optionally, the alloy product being any one of a bar, a plate, a cake, and a pipe.

[0016] The heat treatment method of the present application performs waste heat and step heating treatment by using an intermediate frequency heating furnace, and performs magnetic induction heating by using a high-frequency and high-power induction coil, and the maximum heating temperature can reach 1450-1550°C according to the heat melting and volume of the material, so that the best plasticity of the material for pressure processing can reach 25-30%, the plasticity of the material at this temperature is excellent, and the cracking problem in subsequent pressure processing can be greatly reduced. At the same time, the radiation heating efficiency of the intermediate frequency heating furnace is improved by at least 10 times compared with the box furnace, the oxidation time of the material in the atmosphere is shortened, the problems of surface oxidation, thermal cracking, embrittlement, and powdering are greatly reduced, the thickness of the surface hardening layer is reduced, and the generation of surface thermal cracks in the subsequent pressure processing and the possibility of thermal cracking and crack propagation in the pressure processing process are greatly reduced. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments of the present application will be briefly introduced as follows. Obviously, the drawings described below only represent some of the embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of the drawings.

[0018] Figure 1 The ingot heat treatment flowchart of the embodiment 1 of the present application is shown. DETAILED DESCRIPTION

[0019] The embodiments of the present application will be further described in detail below in combination with the drawings and the embodiments. The detailed description of the following embodiments is used to exemplarily illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0020] Term explanation:

[0021] Tantalum tungsten alloy: general term of solid solution strengthening tantalum tungsten alloy.

[0022] Tantalum high tungsten alloy: general term of tantalum tungsten alloy with tungsten content reaching nominal composition and measured composition W%≥9% or more.

[0023] Ta10W alloy: (Ta10W): tantalum tungsten alloy with tungsten content nominal composition 9%≤W%≤11%.

[0024] Ta12W alloy: (Ta12W). Tantalum tungsten alloy with tungsten content nominal composition 11%≤W%≤13%.

[0025] The tungsten content in other tantalum tungsten alloys is sequentially extended.

[0026] As analyzed in the background of the present application, the tantalum tungsten alloy belongs to the solid solution strengthening tantalum-based alloy, and with the increase of the tungsten content, the solid solution strengthening effect is significant, and the room temperature mechanical properties and high temperature mechanical properties of the material are strengthened with the increase of the tungsten content. However, with the increase of the tungsten content and the solid solution strengthening effect, the processing performance, plasticity and toughness of the alloy will be sharply reduced. It causes that the Ta10W alloy and the Ta12W alloy are extremely difficult to be formed by pressure processing, and the increase of the tungsten content increases the degree of segregation in the alloy, and the alloy is extremely easy to crack and be scrapped by the traditional extrusion, forging, rolling and other methods.

[0027] Since the tantalum tungsten alloy material is a high-temperature refractory metal alloy, the material cannot be processed at room temperature, and the elongation rate of the as-cast state at room temperature is only less than 10%, and the as-cast axial is coarse columnar crystal organization, the room temperature strength (the as-cast room temperature tensile strength≥450MPa or more) is high and the brittleness is strong.

[0028] The existing alloy ingot heat treatment technology is generally a box-type resistance furnace radiation heating method. The box-type resistance furnace heating has the following shortcomings:

[0029] 1) The heating temperature of the general alloy resistance wire box-type resistance furnace can only reach below 1000℃ due to the material limitation of the heating body. The highest temperature of the high-temperature resistance wire can only reach 1150℃. The highest temperature of the carbon-silicon rod heating body is below 1350℃, which has reached the upper limit of heating. The best plastic temperature of Ta10W and Ta12W needs to be 1400-1600℃. The existing box-type resistance furnace heating equipment cannot meet the target process requirements.

[0030] 2) Most of the box-type resistance furnaces are heated in the atmospheric environment. The combustion gas furnace is a combustion atmosphere containing C, H and O. Ta10W and Ta12W alloy has strong chemical activity and is easily oxidized in the air. When the temperature is above 500-600℃, a destructive oxidation film will be formed. The surface is oxidized, hardened and embrittled. With the extension of time, the surface oxidation falls off, powders, increases the invisible loss of the material and forms the surface hardening thermal cracks, which is not conducive to the subsequent pressure processing. The surface hardening layer is hard and brittle. The surface cracks during the stress process and forms thermal cracks, which affects the tensile strength and yield strength. Under the pressure, the cracks expand and the material cracks and is scrapped.

[0031] 3) The box-type furnace heating method is radiation heating. The heating method determines that the heating efficiency is low. Under the premise of ensuring that the material is fully heated and the internal and external temperatures are uniform, a long heating time is needed. The diameter of the general alloy ingot is The ingot heating time needs 1-3 hours. The diameter of the large alloy ingot is The ingot heating time needs 2-5 hours. The surface is seriously oxidized and powdered by long-time heating, which has a very negative impact on the comprehensive utilization of the material and the subsequent pressure processing.

[0032] In order to solve the problem, the present application provides an alloy material, an alloy heat treatment method and an alloy product production method.

[0033] In the first embodiment of the present application, a heat treatment method of an alloy is provided. The alloy includes a tantalum-tungsten alloy or a niobium alloy. The tantalum-tungsten alloy includes any one or more of Ta2.5W, Ta5W, Ta7.5W and a high-tungsten tantalum alloy. The niobium alloy includes any one or more of Nb521, NbW5-1, Nb752 and Cb752. The production method includes: preheating the alloy ingot by using a medium-frequency heating furnace to obtain a preheated ingot; setting an oxidation-resistant layer on the surface of the preheated ingot to obtain an oxidation-resistant ingot; and performing a graded heating treatment on the oxidation-resistant ingot by using the medium-frequency heating furnace to obtain a heat-treated ingot. The graded heating treatment includes increasing the heating power of the medium-frequency heating furnace in the range of 40KW-145KW to increase the temperature to 1500±50℃.

[0034] The heat treatment method of the present application adopts a medium-frequency heating furnace for waste heat and staged heating treatment, and a high-frequency and high-power induction coil is used for magnetic induction heating. According to the thermal melting and volume of the material, the maximum heating temperature can reach 1450-1550℃, which can reach the best pressure processing plasticity of the material to 25%-30%. The plasticity of the material at this temperature is excellent, which can greatly reduce the cracking problem in subsequent pressure processing. At the same time, the radiation heating efficiency of the medium-frequency heating furnace is at least 10 times higher than that of the box furnace, which shortens the oxidation time of the material in the atmosphere, greatly reduces the problems of surface oxidation, thermal cracking, embrittlement, and powdering and falling, and reduces the thickness of the surface hardening layer, thereby greatly reducing the generation of surface thermal cracks in the subsequent pressure processing process and the possibility of thermal cracking and crack propagation during the pressure processing process, which is beneficial to the plastic processing into plates or rods.

[0035] If there are impurities on the surface of the alloy ingot, the surface can be cleaned before preheating, such as using conventional tap water to rinse the surface to remove surface contamination and air dry.

[0036] The preheating in the heat treatment process is beneficial to the combination of the subsequently arranged antioxidant layer and the alloy ingot. In some embodiments, the step of preheating treatment includes setting the power of the medium-frequency induction furnace to 30KW-50KW to start timing, and keeping warm for 20-30 seconds to heat the alloy ingot to 80℃-120℃. The above preheating treatment is beneficial to the uniform heating of the surface of the alloy ingot, and thus is beneficial to improving the surface bonding strength of the antioxidant layer and the surface of the ingot.

[0037] After preheating, an antioxidant layer is arranged on the surface of the preheated ingot. The arrangement method and composition of the antioxidant layer can refer to the conventional arrangement method and composition of the antioxidant layer, such as adding hydrated sodium silicate liquid to sodium silicate and calcium silicate powder, stirring thoroughly, and then uniformly brushing the ingot surface after the powder is fully mixed and presents a gelatinous liquid, and then air drying to form an antioxidant layer.

[0038] The staged heating treatment of the present application gradually heats the antioxidant ingot, thereby improving the uniformity of heating. In some embodiments, the step of the above staged heating treatment includes adjusting the heating power of the medium-frequency heating furnace to 40KW-50KW and keeping for 1min-3min; adjusting the heating power of the medium-frequency heating furnace to 70KW-145KW and keeping for 15min-35min; adjusting the heating power of the medium-frequency heating furnace to 120±10KW and keeping for 1min-3min.

[0039] First, the relatively low frequency of 40KW-50KW is used to heat the anti-oxidation ingot in the first stage, then the heating power is increased to further heat and warm up, and the temperature is homogenized at the high frequency of 120±10KW, which effectively reduces the heating internal stress and reduces the temperature deviation of the anti-oxidation ingot in the axial and radial directions, thereby improving the temperature consistency. Therefore, the stress uniformity and consistency during the subsequent forging pressure processing are high, the stress is uniform at different positions, the anisotropy degree at different positions caused by uneven temperature and the material organization and stress inconsistency caused by uneven stress are reduced, and the cracking caused by uneven final rolling organization, uneven performance and uneven stress during pressure processing is effectively inhibited.

[0040] In some embodiments, in order to further improve the heating uniformity of the anti-oxidation ingot in the staged heating treatment, the gradient change of the heating power of the above staged heating treatment is 10KW-30KW, which can be selected as 15KW-25KW, and further selected as 20KW.

[0041] In some embodiments, the step of the staged heating treatment includes the following steps in sequence: adjusting the heating power of the intermediate frequency heating furnace to 40KW-50KW and keeping for 1min-3min; adjusting the heating power of the intermediate frequency heating furnace to 80±10KW and keeping for 5min-10min; adjusting the heating power of the intermediate frequency heating furnace to 100±10KW and keeping for 3min-6min; adjusting the heating power of the intermediate frequency heating furnace to 120±10KW and keeping for 2min-5min; adjusting the heating power of the intermediate frequency heating furnace to 130KW-145KW and keeping for 5min-10min; adjusting the heating power of the intermediate frequency heating furnace to 120±10KW and keeping for 1min-3min. The anti-oxidation ingot can be heated to 1500±50℃ by using the above step-by-step heating power, and the anti-oxidation ingot after heating presents a dazzling bright white light, and there is no difference between the center and the edge of the ingot (explanation: the temperature is uniform without difference in the axial direction and the radial edge to the center).

[0042] In some embodiments, the step of the above hierarchical heat treatment comprises the following steps in sequence: adjusting the heating power of the intermediate frequency heating furnace to 40-50 KW and keeping for 1-3 min to raise the temperature of the anti-oxidation ingot to 550-650 ℃; adjusting the heating power of the intermediate frequency heating furnace to 80±10 KW and keeping for 5-10 min to raise the temperature of the anti-oxidation ingot to 1000-1200 ℃; adjusting the heating power of the intermediate frequency heating furnace to 100±10 KW and keeping for 3-6 min to raise the temperature of the anti-oxidation ingot to 1100-1300 ℃; adjusting the heating power of the intermediate frequency heating furnace to 120±10 KW and keeping for 2-5 min to raise the temperature of the anti-oxidation ingot to 1250-1300 ℃; adjusting the heating power of the intermediate frequency heating furnace to 130-145 KW and keeping for 5-10 min to raise the temperature of the anti-oxidation ingot to 1350-1550 ℃; adjusting the heating power of the intermediate frequency heating furnace to 120±10 KW and keeping for 1-3 min to raise the temperature of the anti-oxidation ingot to 1450-1500 ℃.

[0043] The application does not have special requirements for the structure of the intermediate frequency heating furnace, and the intermediate frequency heating furnace meeting the above power requirements can be considered for application in the application. In some embodiments, the above intermediate frequency heating furnace is a tubular furnace. The heating sealed space of the tubular furnace has reduced material oxygen contact and reduced heat dissipation, which is more conducive to the heat preservation and overall temperature uniformity and consistency of material heating.

[0044] The above heat treatment method of the application is not only suitable for the above alloy, and the advantage is more obvious when treating a tantalum high-tungsten alloy. In some embodiments, the above tantalum high-tungsten alloy includes but is not limited to any one or more of Ta10W, Ta12W, Ta15W, and Ta20W.

[0045] In some embodiments, the above alloy ingot includes a Ta10W ingot with a specification of Ф(110-115 mm)×(220-305 mm), a Ta10W ingot with a specification of Ф(150-155 mm)×(220-300 mm), a Ta12W ingot with a specification of Ф(110-115 mm)×(220-305 mm), or a Ta12W ingot with a specification of Ф(150-155 mm)×(220-300 mm).

[0046] The tensile strength, yield strength, and elongation of the alloy material treated by the heat treatment method of the application are obviously improved, wherein the tensile strength of the alloy material is 500-1100 MPa, the yield strength is 450-800 MPa, and the elongation is 15%-40%.

[0047] In the second embodiment of the present application, an alloy material is provided, the alloy material comprising a tantalum-tungsten alloy or a niobium alloy, the tantalum-tungsten alloy comprising any one or more of Ta2.5W, Ta5W, Ta7.5W and a high-tungsten tantalum alloy, the niobium alloy comprising any one or more of Nb521, NbW5-1, Nb752, Cb752, the tantalum-tungsten alloy material having a tensile strength of 470-700 MPa, a yield strength of 490-750 MPa and an elongation of 25-30%.

[0048] In some embodiments, the alloy material described above can be obtained by using the heat treatment method of any one of the first embodiment described above.

[0049] The high-tungsten tantalum alloy described above includes, but is not limited to, Ta10W, Ta12W, Ta15W and Ta20W.

[0050] In the third embodiment of the present application, a production method of an alloy product is provided, the production method comprising sequentially performing heat treatment and forging treatment on an alloy ingot, wherein the heat treatment is achieved by using any one of the heat treatment methods described above. The forging process can be selected according to the actual product requirements, which will not be described herein. Since the heat treatment method of the present application improves the plasticity of the alloy ingot, the forging requirements can be met in the pressure processing of forging without the problem of cracking and scrapping.

[0051] In some embodiments, optionally, the alloy product is any one of a bar, a plate, a cake and a pipe.

[0052] The beneficial effects of the present application will be further illustrated below in combination with examples and comparative examples, but the scope of the present application is not limited to these examples.

[0053] Example 1

[0054] The ingot used is a Ф110mm x 220mm (diameter x length) Ta10W ingot, and the element composition of the ingot is W% = 9.0-11.0%.

[0055] The heat treatment process of the ingot is referred to the flowchart of Figure 1 , and the details are as follows:

[0056] 1) Clean the surface, use conventional tap water to rinse the surface, remove the surface contamination, and air dry naturally.

[0057] 2) Ingot preheating, the ingot is lifted to the inside of the crucible coil of the medium-frequency heating furnace by the wire sling lifting platform, the medium-frequency power supply is turned on, the power is set to 40 KW, the timing is started, the temperature is maintained for 20-30 seconds, and the lifting platform is lowered for coating;

[0058] 3) Surface coating, using sodium silicate, calcium silicate powder, adding hydrated sodium silicate liquid, stirring well, stirring until the powder is fully melted into a gelatinous liquid, then evenly applying it to the surface of the ingot with a woodworking brush and air drying, resulting in an antioxidant layer with a thickness of about 0.5-1 mm.

[0059] 4) The ingot with the antioxidant layer is again put into the coil of the intermediate frequency heating furnace through the lifting platform, the heating power is adjusted to 40 KW and kept for 2 min, at this time the temperature rises to about 600°C; the heating power is adjusted to 80 KW and kept for 7 min, at this time the temperature rises to about 1100°C; the heating power is adjusted to 100 KW and kept for 4 min, at this time the temperature rises to about 1200°C; the heating power is adjusted to 120 KW and kept for 4 min, at this time the temperature rises to about 1300°C; the heating power is adjusted to 140 KW and kept for 8 min, at this time the temperature rises to about 1450°C. The temperature of the ingot is evenly heated to a bright white color, with no difference between the center and the edge, and the temperature is about 1450°C; the heating power is adjusted back to 120 KW and kept for 2 min, the temperature is evenly cooled, and the ingot is removed at 1450-1500°C, obtaining the ingot after heat treatment of Example 1.

[0060] Example 2

[0061] The ingot used is a Ta10W ingot with a diameter of Ф150mm and a length of 300mm. The element composition of the ingot is W% = 9.0-11.0%.

[0062] The heat treatment process of the ingot is as follows:

[0063] 1) Surface cleaning, using conventional tap water to rinse the surface, removing surface contamination, and air drying naturally.

[0064] 2) Ingot preheating, the ingot is lifted by the wire holder lifting platform into the coil of the intermediate frequency heating furnace, the intermediate frequency power supply is turned on, the power is set to 40 KW, the timer is started, and the temperature is kept for 20-30 seconds, then the lifting platform is lowered for coating.

[0065] 3) Surface coating, using sodium silicate, calcium silicate powder, adding hydrated sodium silicate liquid, stirring well, stirring until the powder is fully melted into a gelatinous liquid, then evenly applying it to the surface of the ingot with a woodworking brush and air drying, resulting in an antioxidant layer with a thickness of about 0.5-1 mm.

[0066] 4) again put the ingot with the anti-oxidation layer into the coil of the intermediate frequency heating furnace through the lifting platform, adjust the heating power to 40 KW and keep for 2 min, at this time the temperature rises to about 600°C; adjust the heating power to 80 KW and keep for 7 min, at this time the temperature rises to about 1100°C; adjust the heating power to 100 KW and keep for 4 min, at this time the temperature rises to about 1200°C; adjust the heating power to 130 KW and keep for 5 min, at this time the temperature rises to about 1250°C; adjust the heating power to 145 KW and keep for 9 min, at this time the temperature rises to about 1450°C. The ingot is bright white and the temperature is about 1450°C; adjust the heating power to 120 KW and keep for 2 min, then heat and cool down, and the ingot is taken out at 1450-1500°C, thus obtaining the ingot after heat treatment of Example 2.

[0067] Example 3

[0068] The ingot used is a Ta12W ingot with a diameter of 110 mm and a length of 220 mm, and the W content in the ingot is 11.0-13.0%.

[0069] The heat treatment process of the ingot is as follows:

[0070] 1) clean the surface, wash the surface with conventional tap water to remove impurities, and dry naturally.

[0071] 2) preheat the ingot, put the ingot into the coil of the intermediate frequency heating furnace through the lifting platform, turn on the intermediate frequency power supply, set the power to 40 KW, start timing, keep for 20-30 seconds, and then lower the lifting platform for coating;

[0072] 3) surface coating, use sodium silicate and calcium silicate powder, add hydrated sodium silicate liquid, stir well, and then evenly apply the paste on the surface of the ingot using a woodworking brush, and dry naturally, thus obtaining an anti-oxidation layer with a thickness of about 0.5-1 mm.

[0073] 4) Again put the ingot with the anti-oxidation layer into the coil of the intermediate frequency heating furnace through the lifting platform, adjust the heating power to 40 KW and keep for 2 min, at this time the temperature rises to about 600°C; adjust the heating power to 80 KW and keep for 7 min, at this time the temperature rises to about 1100°C; adjust the heating power to 100 KW and keep for 4 min, at this time the temperature rises to about 1200°C; adjust the heating power to 130 KW and keep for 6 min, at this time the temperature rises to about 1300°C; adjust the heating power to 145 KW and keep for 10 min, at this time the temperature rises to about 1450°C. The ingot is bright white and the temperature is about 1450°C; adjust the heating power to 120 KW and keep for 2 min, then heat and cool down, and take out the ingot at 1450-1500°C to obtain the ingot after heat treatment of Example 3.

[0074] Example 4

[0075] The ingot used is a Ta12W ingot with a diameter of 150 mm and a length of 300 mm, and the W content in the element composition of the ingot is 11.0-13.0%.

[0076] The heat treatment process of the ingot is as follows:

[0077] 1) Clean the surface, use conventional tap water to rinse the surface to remove surface contamination, and air dry naturally.

[0078] 2) Preheat the ingot, put the ingot into the coil of the intermediate frequency heating furnace through the wire lifting platform, turn on the intermediate frequency power supply, set the power to 40 KW, start timing, keep for 20-30 seconds, and then lower the lifting platform for coating;

[0079] 3) Surface coating, use sodium silicate and calcium silicate powder, add hydrated sodium silicate liquid, stir well, and then evenly apply the paste on the surface of the ingot using a woodworking brush, and dry naturally to obtain an anti-oxidation layer with a thickness of about 0.5-1 mm.

[0080] 4) Again put the ingot with the anti-oxidation layer into the coil of the intermediate frequency heating furnace through the lifting platform, adjust the heating power to 40 KW and keep for 3 min, at this time the temperature rises to about 600°C; adjust the heating power to 80 KW and keep for 9 min, at this time the temperature rises to about 1100°C; adjust the heating power to 100 KW and keep for 5 min, at this time the temperature rises to about 1200°C; adjust the heating power to 130 KW and keep for 5 min, at this time the temperature rises to about 1300°C; adjust the heating power to 145 KW and keep for 7 min, at this time the temperature rises to about 1450°C. The ingot is bright white and the temperature is about 1450°C; adjust the heating power to 120 KW and keep for 2 min, then heat and cool down, and take out the ingot at 1450-1500°C to obtain the ingot after heat treatment of Example 4.

[0081] Example 5

[0082] The ingot used is a Ta12W ingot with a diameter of 110 mm and a length of 220 mm, and the W content in the element composition of the ingot is 11.0-13.0%.

[0083] The heat treatment process of the ingot is as follows:

[0084] 1) Clean the surface, wash the surface with conventional tap water to remove surface contamination, and air dry naturally.

[0085] 2) Preheat the ingot, put the ingot into the coil of the intermediate frequency heating furnace through the wire lifting platform, turn on the intermediate frequency power supply, set the power to 40 KW and start timing, keep for 20-30 seconds, then lower the lifting platform for coating;

[0086] 3) Surface coating, use sodium silicate and calcium silicate powder, add hydrated sodium silicate liquid and stir well, then evenly apply the paste on the surface of the ingot after the powder is fully mixed into a paste, and dry to obtain an anti-oxidation layer with a thickness of about 0.5-1 mm.

[0087] 4) again put the ingot with the anti-oxidation layer into the coil of the intermediate frequency heating furnace through the lifting platform, adjust the heating power to 40 KW and keep for 2 min, at this time the temperature rises to about 600°C; adjust the heating power to 70 KW and keep for 7 min, at this time the temperature rises to about 1050°C; adjust the heating power to 90 KW and keep for 6 min, at this time the temperature rises to about 1200°C; adjust the heating power to 110 KW and keep for 5 min, at this time the temperature rises to about 1300°C; adjust the heating power to 130 KW and keep for 10 min, at this time the temperature rises to about 1450°C. The ingot is bright white and the temperature is about 1450°C; adjust the heating power to 120 KW and keep for 2 min, then heat and cool down, and the ingot is taken out at 1450-1500°C, thus obtaining the ingot after heat treatment of Example 3.

[0088] Example 6

[0089] The ingot used is a Ta12W ingot with a diameter of 110 mm and a length of 220 mm, and the W content in the ingot is 11.0-13.0%.

[0090] The heat treatment process of the ingot is as follows:

[0091] 1) clean the surface, wash the surface with conventional tap water to remove impurities, and air dry naturally.

[0092] 2) preheat the ingot, put the ingot into the coil of the intermediate frequency heating furnace through the lifting platform, turn on the intermediate frequency power supply, set the power to 40 KW, start timing, keep for 20-30 seconds, and then lower the lifting platform for coating;

[0093] 3) surface coating, use sodium silicate and calcium silicate powder, add hydrated sodium silicate liquid, stir well, and then evenly apply the paste on the surface of the ingot using a woodworking brush, and dry naturally, thus obtaining an anti-oxidation layer with a thickness of about 0.5-1 mm.

[0094] 4) Again put the ingot with the anti-oxidation layer into the coil of the intermediate frequency heating furnace through the lifting platform, adjust the heating power to 50 KW and keep for 2 min, at this time the temperature rises to about 630°C; adjust the heating power to 90 KW and keep for 7 min, at this time the temperature rises to about 1150°C; adjust the heating power to 110 KW and keep for 4 min, at this time the temperature rises to about 1250°C; adjust the heating power to 130 KW and keep for 4 min, at this time the temperature rises to about 1300°C; adjust the heating power to 140 KW and keep for 10 min, at this time the temperature rises to about 1450°C. The ingot is bright white and the temperature is about 1450°C; adjust the heating power to 110 KW and keep for 2 min, then heat and cool down, and the ingot is taken out at 1450-1500°C, thus obtaining the ingot after heat treatment of Example 6.

[0095] Example 7

[0096] The ingot used is a Ta12W ingot with a diameter of 110 mm and a length of 220 mm, and the W content in the element composition of the ingot is 11.0-13.0%.

[0097] The heat treatment process of the ingot is as follows:

[0098] 1) Clean the surface, wash the surface with conventional tap water to remove surface contamination, and air dry naturally.

[0099] 2) Preheat the ingot, put the ingot into the coil of the intermediate frequency heating furnace through the lifting platform, turn on the intermediate frequency power supply, set the power to 40 KW, start timing, keep for 20-30 seconds, and then lower the lifting platform for coating;

[0100] 3) Surface coating, use sodium silicate and calcium silicate powder, add hydrated sodium silicate liquid, stir well, and then evenly apply the paste on the surface of the ingot using a woodworking brush, and dry naturally, thus obtaining an anti-oxidation layer with a thickness of about 0.5-1 mm.

[0101] 4) again put the ingot with the anti-oxidation layer into the coil of the intermediate frequency heating furnace through the lifting platform, adjust the heating power to 40 KW and keep for 2 min, at this time the temperature rises to about 600°C; adjust the heating power to 70 KW and keep for 7 min, at this time the temperature rises to about 1050°C; adjust the heating power to 110 KW and keep for 4 min, at this time the temperature rises to about 1250°C; adjust the heating power to 140 KW and keep for 10 min, at this time the temperature rises to about 1450°C. The ingot presents a dazzling bright white light, and there is no difference between the center and the edge, and the temperature is about 1450°C; adjust the heating power to 120 KW and keep for 2 min, and then the ingot is cooled, and the ingot is taken out of the furnace at 1450-1500°C, and the ingot after heat treatment of example 7 is obtained.

[0102] Example 8

[0103] The ingot used is a NbW5-1 ingot with a diameter of Ф110 mm and a length of 220 mm.

[0104] The heat treatment process of the ingot is as follows:

[0105] 1) clean the surface, use conventional tap water to wash the surface, remove the surface contamination, and air dry naturally.

[0106] 2) preheat the ingot, put the ingot into the coil of the intermediate frequency heating furnace through the wire lifting platform, turn on the intermediate frequency power supply, set the power to 40 KW, start timing, keep for 20-30 seconds, and then lower the lifting platform for coating;

[0107] 3) surface coating, use sodium silicate and calcium silicate powder, add hydrated sodium silicate liquid, stir well, and then evenly apply the paste on the surface of the ingot after drying, and the obtained anti-oxidation layer has a thickness of about 0.5-1 mm.

[0108] 4) again put the ingot with the anti-oxidation layer into the coil of the intermediate frequency heating furnace through the lifting platform, adjust the heating power to 40 KW and keep for 2 min, at this time the temperature rises to about 600°C; adjust the heating power to 80 KW and keep for 7 min, at this time the temperature rises to about 1150°C; adjust the heating power to 100 KW and keep for 4 min, at this time the temperature rises to about 1250°C; adjust the heating power to 120 KW and keep for 4 min, at this time the temperature rises to about 1350°C; adjust the heating power to 140 KW and keep for 6 min, at this time the temperature rises to about 1450°C. The ingot presents a dazzling bright white light, and there is no difference between the center and the edge, and the temperature is about 1450°C; adjust the heating power to 120 KW and keep for 2 min, and then the ingot is cooled, and the ingot is taken out of the furnace at 1450-1500°C, and the ingot after heat treatment of example 8 is obtained.

[0109] Example 9

[0110] The ingot used was a Ф110mm x 220mm (diameter x length) Nb752 ingot.

[0111] The heat treatment process of the ingot was as follows:

[0112] 1) Clean the surface, use conventional tap water to rinse the surface, remove surface contamination, and air dry naturally.

[0113] 2) Preheat the ingot, raise the ingot to the inside of the crucible coil of the intermediate frequency heating furnace through the wire cantilever lifting platform, turn on the intermediate frequency power supply, set the power to 40KW, start timing, and keep warm for 20-30 seconds. Lower the lifting platform for coating;

[0114] 3) Surface coating, use sodium silicate and calcium silicate powder, add hydrated sodium silicate liquid, stir well, and then evenly apply the paste-like liquid to the surface of the ingot using a woodworking brush and air dry. The obtained antioxidant layer is about 0.5-1mm thick.

[0115] 4) Put the ingot with the antioxidant layer into the coil inside the intermediate frequency heating furnace again through the lifting platform, adjust the heating power to 40KW, and keep for 2min, at which time the temperature rises to about 600℃; adjust the heating power to 80KW, and keep for 7min, at which time the temperature rises to about 1100℃; adjust the heating power to 100KW, and keep for 4min, at which time the temperature rises to about 1200℃; adjust the heating power to 120KW, and keep for 4min, at which time the temperature rises to about 1300℃; adjust the heating power to 140KW, and keep for 8min, at which time the temperature rises to about 1450℃. The ingot is evenly heated and presents a dazzling white light, with no difference between the center and the edge, and the temperature is about 1450℃; adjust the heating power to 120KW, and keep for 2min, and then heat and cool down, and take out the ingot at 1450-1500℃ to obtain the ingot after heat treatment of Example 9.

[0116] Comparative Example 1

[0117] The difference from Example 1 is that step 4) uses a box-type resistance furnace for heat treatment, and the specific heat treatment process is as follows: heat the box-type resistance furnace, load the furnace at a temperature of about 1050℃, and keep warm for 2.5 hours.

[0118] Comparative Example 2

[0119] The difference from Example 2 is that step 4) uses a box-type resistance furnace for heat treatment, and the specific heat treatment process is as follows: heat the box-type resistance furnace, load the furnace at a temperature of about 1050℃, and keep warm for 2.5 hours.

[0120] Comparative Example 3

[0121] The difference from Example 3 is that step 4) is heat treated by a box resistance furnace, and the specific heat treatment process is as follows: the box resistance furnace is heated to the warm loading furnace, and is kept at 1050℃ for 2.5 hours.

[0122] Comparative Example 4

[0123] The difference from Example 4 is that step 4) is heat treated by a box resistance furnace, and the specific heat treatment process is as follows: the box resistance furnace is heated to the warm loading furnace, and is kept at 1050℃ for 2.5 hours.

[0124] Comparative Example 5

[0125] The difference from Example 1 is that the ingot preheating in step 2) is preheated by a box resistance furnace, and the box resistance furnace is heated to the warm loading furnace, and is kept at 300℃ for 20min.

[0126] Comparative Example 6

[0127] The difference from Comparative Example 5 is that step 4) is that the ingot with the antioxidant layer is again put into the coil of the intermediate frequency heating furnace through the lifting platform, the heating power is adjusted to 20KW, and is kept for 6min, at this time the temperature rises to about 590℃; the heating power is adjusted to 40KW, and is kept for 6min, at this time the temperature rises to about 790℃; the heating power is adjusted to 60KW, and is kept for 10min, at this time the temperature rises to about 1050℃; the heating power is adjusted to 80KW, and is kept for 12min, at this time the temperature rises to about 1375℃.

[0128] Comparative Example 7

[0129] The difference from Example 8 is that step 4) is heat treated by a box resistance furnace, and the specific heat treatment process is as follows: the box resistance furnace is heated to the warm loading furnace, and is kept at about 1050℃ for 2.5 hours.

[0130] Comparative Example 8

[0131] The difference from Example 9 is that step 4) is heat treated by a box resistance furnace, and the specific heat treatment process is as follows: the box resistance furnace is heated to the warm loading furnace, and is kept at about 1050℃ for 2.5 hours.

[0132] The tensile strength, yield strength and elongation of the ingots obtained in each example and comparative example are tested, wherein the test method of the tensile strength is GB / T228.1-2021; the test method of the yield strength is GB / T228.1-2021; and the test method of the elongation is GB / T228.1-2021. The test results are recorded in Table 1.

[0133] Table 1

[0134]

[0135]

[0136] Note: In general, plastic processing of metal requires an elongation of 25% or more to achieve plastic processing, 15-25% elongation shows poor plasticity, and 10% or less elongation is difficult to plastic process.

[0137] Comparative Examples 1-4 were heat treated using a box-type resistance furnace, which is difficult to achieve higher heat treatment temperatures, and the surface of the ingot absorbs oxygen during the heat treatment process, resulting in insufficient strength and elongation of the ingot.

[0138] Comparative Example 5 used a combination of preheating with a box-type resistance furnace and heat treatment with a medium-frequency heating furnace, resulting in excessive tensile strength and yield strength of the ingot, and insufficient elongation.

[0139] Comparative Example 6 still has insufficient heat treatment temperature, although it can improve the strength of the ingot, but the plasticity is insufficient.

[0140] According to the comparison, the elongation of the alloy ingot of each embodiment obtained by using the heat treatment process of the present application is more than 25%, so that the product can be plastic processed into a plate or a rod.

[0141] It should be noted that the present application is not limited to the above embodiments. The above embodiments are only examples, and embodiments having the same technical idea and the same effect as the technical idea within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, within the scope of the main idea of the present application, various modifications that can be thought of by those skilled in the art, other ways constructed by combining part of the elements in the embodiments are also included in the scope of the present application.

Claims

1. A heat treatment method of an alloy, characterized by, The alloy includes tantalum-tungsten alloy or niobium alloy, the tantalum-tungsten alloy includes any one or more of Ta2.5W, Ta5W, Ta7.5W and tantalum high-tungsten alloy, the niobium alloy includes any one or more of Nb521, NbW5-1, Nb752, Cb752, the tantalum high-tungsten alloy is selected from any one of Ta10W, Ta12W, Ta15W, Ta20W;The heat treatment method comprises: The alloy ingot is preheated by using a medium-frequency heating furnace to obtain a preheated ingot; An oxidation-resistant layer is arranged on the surface of the preheated ingot to obtain an oxidation-resistant ingot; The oxidation-resistant ingot is subjected to a staged heating treatment by using a medium-frequency heating furnace to obtain a heat-treated ingot, and the staged heating treatment comprises the following steps in sequence: The heating power of the medium-frequency heating furnace is adjusted to 40-50 kW and kept for 1-3 min to raise the temperature of the oxidation-resistant ingot to 550-650 DEG C; The heating power of the medium-frequency heating furnace is adjusted to 80±10 kW and kept for 5-10 min to raise the temperature of the oxidation-resistant ingot to 1000-1150 DEG C; The heating power of the medium-frequency heating furnace is adjusted to 100±10 kW and kept for 3-6 min to raise the temperature of the oxidation-resistant ingot to 1200-1250 DEG C; The heating power of the medium-frequency heating furnace is adjusted to 120±10 kW and kept for 2-5 min to raise the temperature of the oxidation-resistant ingot to 1250-1300 DEG C; The heating power of the medium-frequency heating furnace is adjusted to 130-145 kW and kept for 5-10 min to raise the temperature of the oxidation-resistant ingot to 1350-1450 DEG C; The heating power of the medium-frequency heating furnace is adjusted to 120±10 kW and kept for 1-3 min to raise the temperature of the oxidation-resistant ingot to 1450-1500 DEG C.

2. The heat treatment method according to claim 1, characterized by, The preheating step comprises: setting the power of the medium-frequency induction furnace to 30-50 kW and starting timing, and keeping for 20-30 seconds to heat the alloy ingot to 80-120 DEG C.

3. The heat treatment method according to any one of claims 1 to 2, characterized in that, The alloy ingot includes Ta10W ingot with a specification of Ф(110-115 mm) x (220-305 mm), Ta10W ingot with a specification of Ф(150-155 mm) x (220-300 mm), Ta12W ingot with a specification of Ф(110-115 mm) x (220-305 mm) or Ta12W ingot with a specification of Ф(150-155 mm) x (220-300 mm).

4. The heat treatment method according to any one of claims 1 to 2, characterized in that, The medium-frequency heating furnace is a tube furnace.

5. An alloy material, characterized by comprising: The alloy material includes tantalum-tungsten alloy or niobium alloy, the tantalum-tungsten alloy includes any one or more of Ta2.5W, Ta5W, Ta7.5W and high-tungsten tantalum alloy selected from any one of Ta10W, Ta12W, Ta15W, Ta20W; the alloy material has a tensile strength of 470 MPa-700 MPa, a yield strength of 490 MPa-750 MPa and an elongation of 25%-30%, and is obtained by the heat treatment method in any one of claims 1-4.

6. A method for producing an alloy product, the method employing a process comprising sequentially subjecting an alloy ingot to a heat treatment and a forging treatment, characterized by, The heat treatment is achieved by the heat treatment method in any one of claims 1-4.

7. The production method according to claim 6, wherein, The alloy product is any one of a bar, a plate, a cake and a pipe.

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