Tungsten plate and preparation method thereof

Abstract

The present invention provides a tungsten plate material and a preparation method thereof, and belongs to the technical field of tungsten material processing. The preparation method of the tungsten plate material provided by the present invention comprises the following steps: the tungsten plate blank is subjected to blanking rolling, intermediate rolling and finished product rolling in sequence to obtain a rolled tungsten plate; the rolling pass of the finished product rolling is 1 pass, and the deformation of the single pass is 40-55%; the rolled tungsten plate is subjected to annealing treatment to obtain the tungsten plate material. The preparation method of the present invention effectively refines the grain size of the tungsten plate material, and at the same time adjusts the microstructure orientation, thereby improving the overall structural uniformity and performance of the tungsten plate material.

Description

Technical Field

[0001] The invention belongs to the technical field of tungsten material processing, and in particular relates to a tungsten plate and a preparation method thereof. Background Art

[0002] Tungsten is a refractory metal with a high melting point (3400°C) and high dissipation energy. Its density is as high as 19.35 g / cm 3 It not only has excellent mechanical properties such as high hardness, high creep resistance, and high elastic modulus, but also has excellent physical properties such as high thermal conductivity, low vapor pressure, and low thermal expansion coefficient. It is widely used in high-end fields such as aerospace devices, electrode materials, and medical treatment.

[0003] At present, tungsten ingots are mainly prepared by powder metallurgy or electron beam melting, and then prepared into tungsten plates by plastic processing and heat treatment such as hot forging and hot rolling. The deformation of each rolling pass is generally less than 30%. However, the grain size of the tungsten plate obtained by the above method is relatively large, generally above 50μm, and the uniformity is poor. Summary of the invention

[0004] The object of the present invention is to provide a tungsten plate material and a preparation method thereof. The preparation method of the present invention effectively refines the grain size of the tungsten plate material, makes the grain orientation uniform, and improves the overall structural uniformity and performance of the tungsten plate material.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing a tungsten plate material, comprising the following steps:

[0007] The tungsten plate blank is subjected to blanking rolling, intermediate rolling and finished product rolling in sequence to obtain a rolled tungsten plate; the rolling pass of the finished product rolling is 1 pass, and the deformation of the single pass is 40-55%;

[0008] The rolled tungsten plate is annealed to obtain the tungsten plate.

[0009] Preferably, the tungsten plate blank is a pure tungsten plate.

[0010] Preferably, the slab rolling process has one rolling pass, and the deformation amount of a single pass is 10-30%.

[0011] Preferably, the intermediate rolling has 1 to 7 rolling passes, and the deformation amount of a single pass is 5 to 35%.

[0012] Preferably, the total rolling deformation of the rolled tungsten plate is not less than 80%.

[0013] Preferably, the temperatures of the bloom rolling, intermediate rolling and finished product rolling are independently 900-1200°C.

[0014] Preferably, the tungsten plate blank is subjected to a first insulation treatment before the blanking rolling; the temperature of the first insulation treatment is 900~1200℃; based on the thickness of the tungsten plate blank, the insulation time of the first insulation treatment is 2min / mm, and the rate of heating to the temperature of the first insulation treatment is 5~15℃ / min.

[0015] Preferably, the temperature of the annealing treatment is 1300-1450° C., the holding time is 45-120 min, and the rate of heating to the annealing treatment temperature is 5-15° C. / min.

[0016] Preferably, the thickness ratio of the slab obtained after the intermediate rolling to the tungsten plate is 5-20:2-9.

[0017] The present invention provides a tungsten plate obtained by the above preparation method, wherein the average grain size is not greater than 20 μm, the (200) crystal plane accounts for 35-45%, and the (222) crystal plane accounts for not less than 15%.

[0018] The present invention provides a method for preparing a tungsten plate material, comprising the following steps: subjecting a tungsten plate blank to blank rolling, intermediate rolling and finished product rolling in sequence to obtain a rolled tungsten plate; the rolling pass of the finished product rolling is 1 pass, and the deformation of a single pass is 40-55%; the rolled tungsten plate is annealed to obtain the tungsten plate material. In the present invention, the finished product rolling is a large deformation warm rolling, which can effectively break the original coarse grain structure of the tungsten plate, reduce the deformation difference in the thickness direction, accumulate more deformation energy storage for the tungsten plate material, and have a high degree of grain breakage; on this basis, annealing treatment is performed to refine the grain size of the tungsten plate material, uniform grain orientation, and greatly improve the overall uniformity of the obtained tungsten plate material. Through the preparation method provided by the present invention, a tungsten plate material with small grain size, uniform structure and excellent mechanical properties can be obtained.

[0019] Furthermore, the present invention continuously performs slab rolling, intermediate rolling and finished product rolling on the tungsten plate blank, and by adjusting the rolling deformation, the structure of the obtained rolled tungsten plate is promoted to present a fibrous distribution, and subgrain structure appears in the crystal; on this basis, the rolled tungsten plate is annealed to obtain a tungsten plate with excellent structure and mechanical properties. Moreover, the hot rolling temperature of slab rolling, intermediate rolling and finished product rolling is lower than the recrystallization temperature, which can accumulate more deformation energy storage inside the tungsten plate. The embodiment shows that the grain size of the tungsten plate prepared by the present invention is not more than 20μm, the grain orientation (200) plane accounts for 35~45%, and the (222) crystal plane accounts for not less than 15%.

[0020] Furthermore, the preparation method of the present invention is easy to operate, does not require complicated process conditions, has low preparation cost, and has wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0022] Figure 1 The metallographic images of the rolled tungsten plates and tungsten sheets obtained in Comparative Example 1 and Example 1;

[0023] Figure 2 The average grain size result diagram of the tungsten plates obtained in Comparative Example 1 and Example 1;

[0024] Figure 3 The XRD patterns of the rolled tungsten plate and tungsten sheet obtained in Comparative Example 1 are shown in FIG.

[0025] Figure 4 The XRD patterns of the rolled tungsten plate and tungsten sheet obtained in Example 1 are shown in FIG.

[0026] Figure 5 The result diagram of the crystal surface texture coefficient of the rolled tungsten plate and the tungsten plate obtained in Comparative Example 1;

[0027] Figure 6 This is a graph showing the crystal texture coefficient results of the rolled tungsten plate and tungsten plate obtained in Example 1. DETAILED DESCRIPTION

[0028] The present invention provides a method for preparing a tungsten plate material, comprising the following steps:

[0029] The tungsten plate blank is subjected to blanking rolling, intermediate rolling and finished product rolling in sequence to obtain a rolled tungsten plate; the rolling pass of the finished product rolling is 1 pass, and the deformation of the single pass is 40-55%;

[0030] The rolled tungsten plate is annealed to obtain the tungsten plate.

[0031] In the present invention, unless otherwise specified, the raw materials used are commercially available products well known to those skilled in the art or are prepared by methods well known to those skilled in the art.

[0032] In the present invention, the tungsten plate blank is preferably a pure tungsten plate, and the purity is preferably not less than 99.95%, and more preferably 99.999%. In an embodiment of the present invention, the tungsten plate blank is a hot-rolled tungsten plate with a grain size of 70-150 μm, and the initial density of the hot-rolled tungsten plate is greater than 94% of the theoretical density.

[0033] The present invention performs blanking rolling on a tungsten plate blank to obtain a first rolled tungsten plate; performs intermediate rolling on the first rolled tungsten plate to obtain a second rolled tungsten plate; and performs finished rolling on the second rolled tungsten plate to obtain the rolled tungsten plate.

[0034] The present invention performs slab rolling on a tungsten plate billet to obtain a first rolled tungsten plate. In the present invention, the tungsten plate billet is preferably subjected to a first insulation treatment before the slab rolling. In the present invention, the temperature of the first insulation treatment is preferably 900-1200°C, more preferably 950°C; the insulation time of the first insulation treatment is proportional to the thickness of the tungsten plate billet, and the insulation time of the first insulation treatment increases by 2min for every 1mm increase in the thickness of the tungsten plate billet; that is, based on the thickness of the tungsten plate billet, the insulation time of the first insulation treatment is preferably 2min / mm; the rate of heating to the temperature of the first insulation treatment is preferably 5-15°C / min, more preferably 5-10°C / min. In the present invention, the slab rolling is preferably warm rolling; the rolling pass of the slab rolling is 1 pass; the deformation of a single pass of the slab rolling is preferably 10-30%, more preferably 15-20%. After the slab rolling is completed, the present invention preferably performs a second insulation treatment on the obtained rolled material to obtain a first rolled tungsten plate. In the present invention, the temperature of the second insulation treatment is preferably 900-1200°C, more preferably 950°C; the insulation time of the second insulation treatment is proportional to the thickness of the first rolled tungsten plate, preferably 2 min / mm.

[0035] After obtaining the first rolled tungsten plate, the present invention performs intermediate rolling on the first rolled tungsten plate to obtain a second rolled tungsten plate. In the present invention, the intermediate rolling is preferably warm rolling; the rolling passes of the intermediate rolling are preferably 1 to 7 passes, more preferably 5 passes; the deformation amount of a single pass is preferably 5 to 35%, more preferably 15 to 20%. After the blank rolling is completed, the present invention preferably performs a third insulation treatment on the obtained rolled material to obtain a second rolled tungsten plate. In the present invention, the temperature of the third insulation treatment is preferably 900 to 1200°C, more preferably 950°C; the insulation time of the third insulation treatment is proportional to the thickness of the second rolled tungsten plate, preferably 2 min / mm.

[0036] After obtaining the second rolled tungsten plate, the present invention performs finished rolling on the second rolled tungsten plate to obtain the rolled tungsten plate. In the present invention, the finished rolling is preferably warm rolling; the rolling pass of the finished rolling is 1 pass; the deformation of a single pass is 40-55%, preferably 50%. After the finished rolling is completed, the present invention preferably cools the obtained rolled material to room temperature; the cooling is preferably carried out in air. In the present invention, the total rolling deformation of the rolled tungsten plate is preferably not less than 80%, more preferably 80-90%.

[0037] After obtaining the rolled tungsten plate, the present invention anneals the rolled tungsten plate to obtain the tungsten plate material. In the present invention, the temperature of the annealing treatment is preferably 1300~1450°C, more preferably 1350°C; the holding time is preferably 45~120min, more preferably 60min; the rate of heating to the temperature of the annealing treatment is preferably 5~15°C / min, more preferably 5~10°C / min. After the annealing treatment is completed, the present invention preferably cools the obtained annealed material to room temperature to obtain the tungsten plate material. In the present invention, the thickness ratio of the slab obtained after the intermediate rolling to the tungsten plate material is preferably 5~20:2~9, more preferably 2:1.

[0038] The present invention also provides a tungsten plate obtained by the above preparation method, wherein the average grain size of the tungsten plate is not greater than 20 μm; the (200) crystal plane accounts for 35-45%, and the (222) crystal plane accounts for not less than 15%.

[0039] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] The hot-rolled tungsten plate used in the embodiment has a grain size of 70-150 μm and an initial density greater than 94% of the theoretical density. It is homemade in the laboratory and the process used is based on commercially available tungsten plates.

[0041] Example 1

[0042] (1) A hot-rolled tungsten plate with a purity of 99.999% and an initial thickness of 20 mm was placed in a heating furnace. The temperature of the heating furnace was uniformly increased from room temperature to 950°C at a rate of 5°C / min, and the hot-rolled tungsten plate was kept at 950°C for 40 minutes.

[0043] (2) The hot-rolled tungsten plate subjected to the heat preservation treatment in step (1) is taken out from the heating furnace, placed on a rolling mill, and subjected to one pass rolling (warm rolling) at a temperature of 950° C., with a rolling deformation of 25%; after the warm rolling, the rolled material is transferred into the heating furnace, and subjected to a heat preservation treatment at a temperature of 950° C. for 30 minutes, to obtain a first rolled tungsten plate.

[0044] (3) The first rolled tungsten plate is taken out from the heating furnace, placed on a twin-roll mill, and rolled (warm rolled) for 5 times at a temperature of 950°C, wherein the rolling deformation of the first and second rolling passes is 20%, and the rolling deformation of the third, fourth and fifth rolling passes is 15%. After each rolling pass, the rolled material is transferred to the heating furnace and heat-treated at 950°C for 48 minutes to obtain the second rolled tungsten plate.

[0045] (4) The second rolled tungsten plate is taken out of the heating furnace, placed on a rolling mill, and rolled for the last time at 950°C with a rolling deformation of 50%. After the rolling, the rolled material is cooled to room temperature in air to obtain a rolled tungsten plate (with a total rolling deformation of 80%).

[0046] (5) The rolled tungsten plate is placed in a vacuum furnace, the temperature of the vacuum furnace is increased from room temperature to 1350° C. at a rate of 5° C. / min, and the rolled tungsten plate is annealed at 1350° C. for 60 min. After the annealing treatment, the temperature of the vacuum furnace is lowered to room temperature to obtain a tungsten plate.

[0047] Comparative Example 1 (Conventional rolling process for preparing tungsten sheet)

[0048] (1) A hot-rolled tungsten plate with a purity of 99.999% was placed in a heating furnace and rolled (warm rolling) continuously for 9 times at 950°C. The rolling deformation of each rolling process was 20%, and the total rolling deformation was 86.57%. After the rolling process, a rolled tungsten plate was obtained.

[0049] (2) The rolled tungsten plate is annealed according to the conditions of step (5) of Example 1 to obtain a tungsten plate.

[0050] Test Example 1

[0051] The grain size and grain orientation of the rolled tungsten plate and tungsten sheet obtained in Example 1 and Comparative Example 1 were tested respectively, and the test methods and results are as follows:

[0052] The metallographic microstructures of the rolled surfaces of the tungsten plates obtained in Example 1 and Comparative Example 1 after rolling and annealing were observed using an optical microscope. The results are as follows: Figure 1 As shown, Figure 1 (a) is the metallographic image of the rolled surface of the rolled tungsten plate obtained in comparative example 1, (b) is the metallographic image of the rolled surface of the tungsten plate obtained in comparative example 1 after annealing, (c) is the metallographic image of the rolled surface of the rolled tungsten plate obtained in example 1, and (d) is the metallographic image of the rolled surface of the tungsten plate obtained in example 1 after annealing.

[0053] According to the national standard "Method for determination of average grain size of metals" (GB / T6394-2017), Figure 1 The average grain size of the tungsten plates obtained in Comparative Example 1 and Example 1 shown in the figure is statistically calculated. The results are as follows: Figure 2 shown.

[0054] Depend on Figure 2 It can be seen that the average grain size of the tungsten plate obtained by annealing in Example 1 is 19.65μm, and the grain size of the tungsten plate obtained by annealing in Comparative Example 1 is 21.62μm. After comparison, it can be seen that the average grain size of the tungsten plate obtained in Example 1 is 9.11% smaller than that of the tungsten plate obtained in Comparative Example 1.

[0055] The macro texture of the rolled tungsten plate and tungsten sheet obtained in Example 1 and Comparative Example 1 was tested by XRD analysis. The results are as follows: Figure 3~4 As shown in the figure, the crystal texture coefficient TC (Texture Coefficient) calculated by XRD is as follows Figures 5 and 6 shown.

[0056] Depend on Figure 3~4 It can be seen that the (200) crystal plane and (222) crystal plane in the rolled tungsten plate and tungsten plate obtained in Example 1 are significantly higher than those in Comparative Example 1.

[0057] Depend on Figures 5 and 6It can be seen that in the rolled tungsten plate obtained by rolling in Comparative Example 1, the TC value of the (110) crystal plane is 5%, the TC value of the (200) crystal plane is 46%, the TC value of the (211) crystal plane is 14%, the TC value of the (220) crystal plane is 3%, the TC value of the (310) crystal plane is 18%, the TC value of the (222) crystal plane is 9%, and the TC value of the (321) crystal plane is 5%; in the tungsten plate obtained by rolling and annealing in Comparative Example 1, the TC value of the (110) crystal plane is 13%, the TC value of the (200) crystal plane is 22%, the TC value of the (211) crystal plane is 18%, the TC value of the (220) crystal plane is 12%, the TC value of the (310) crystal plane is 20%, the TC value of the (222) crystal plane is 7%, and the TC value of the (321) crystal plane is 9%. In the rolled tungsten plate obtained by rolling in Example 1, the TC value of the (110) crystal plane is 4%, the TC value of the (200) crystal plane is 42%, the TC value of the (211) crystal plane is 12%, the TC value of the (220) crystal plane is 3%, the TC value of the (310) crystal plane is 13%, the TC value of the (222) crystal plane is 22%, and the TC value of the (321) crystal plane is 4%; in the tungsten plate obtained by rolling and annealing in Example 1, the TC value of the (110) crystal plane is 9%, the TC value of the (200) crystal plane is 37%, the TC value of the (211) crystal plane is 14%, the TC value of the (220) crystal plane is 6%, the TC value of the (310) crystal plane is 15%, the TC value of the (222) crystal plane is 13%, and the TC value of the (321) crystal plane is 6%. Among them, the TC value of the (200) crystal plane of the tungsten plate obtained in Example 1 is 15% higher than that of the tungsten plate obtained in Comparative Example 1, and the TC value of the (222) crystal plane of the tungsten plate obtained in Example 1 is 6% higher than that of the tungsten plate obtained in Comparative Example 1.

[0058] In summary, compared with the traditional rolling process, the present invention prepares tungsten plates by a single-pass large deformation rolling method, which can make the grains uniformly refined and the crystal plane orientation more uniform, greatly improving the structure and mechanical properties of the tungsten plates.

[0059] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing a tungsten plate, characterized in that: The following steps are involved: The tungsten plate blank is subjected to blanking rolling, intermediate rolling and finished product rolling in sequence to obtain a rolled tungsten plate; the rolling pass of the finished product rolling is 1 pass, and the deformation amount of a single pass is 50%; annealing the rolled tungsten plate to obtain the tungsten plate; The rolling pass of the slab rolling is 1 pass, and the deformation of the single pass is 20-30%; The intermediate rolling has 1 to 7 passes, and the deformation of each pass is 15 to 35%; The temperatures of the slab rolling, intermediate rolling and finished product rolling are independently 900-1200°C; The total rolling deformation of the rolled tungsten plate is not less than 80%; The annealing treatment is carried out at a temperature of 1300-1450° C. and a heat preservation time of 45-120 min.

2. The preparation method according to claim 1, characterized in that: The tungsten plate blank is a pure tungsten plate.

3. The preparation method according to claim 1, characterized in that: Before the slab rolling, the process also includes: performing a first insulation treatment on the tungsten plate blank; the temperature of the first insulation treatment is 900-1200°C; based on the thickness of the tungsten plate blank, the insulation time of the first insulation treatment is 2 min / mm, and the rate of heating to the first insulation treatment is 5-15°C / min.

4. The preparation method according to claim 1, characterized in that: The rate of heating to the annealing temperature is 5-15°C / min.

5. The preparation method according to claim 1, characterized in that: The thickness ratio of the slab obtained after the intermediate rolling to the tungsten plate is 5-20:2-9.

6. The tungsten plate material obtained by the preparation method according to any one of claims 1 to 5 has an average grain size of no more than 20 μm, a (200) crystal plane ratio of 35% to 45%, and a (222) crystal plane ratio of no less than 15%.

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