Fine-grain tungsten plate and preparation and application method thereof

Abstract

The invention discloses a fine-grain tungsten plate and a preparation and application method thereof, and belongs to the technical field of tungsten plate preparation methods. The preparation method comprises the steps that a tungsten blank with the density not smaller than 18.4 g / cm < 3 >, the average grain size being 50-70 microns and the thickness being 20-24 mm is selected as a raw material tungsten blank of the fine grain tungsten plate; the first-pass heating temperature is larger than or equal to 1300 DEG C and smaller than 1400 DEG C, and multi-pass hot rolling treatment is carried out when the rolling deformation rate of each pass is larger than 25%. Through simple raw material control and process control, specific control over the machining performance and the grain structure of the finished tungsten plate can be achieved, meanwhile, the strength of the tungsten plate is not obviously reduced, and the obtained tungsten plate is made to meet the high requirement of components for the ion implantation process.

Description

Technical Field

[0001] The invention relates to the technical field of a tungsten plate preparation method, and in particular to a fine-grained tungsten plate preparation method. Background Art

[0002] The ion implantation process needs to be applied in a high-temperature clean environment, and has very high requirements for the high-temperature performance and chemical corrosion resistance of the ionization chamber components of the equipment. Tungsten, molybdenum or graphite materials are usually used for the main components of the ionization chamber. Among them, tungsten plates have a high demand in high-temperature components such as the ion chamber of the ion implanter due to the low vapor pressure and good high-temperature performance of tungsten elements.

[0003] On the one hand, the tungsten plate used in the ion implantation process needs to meet the requirements of special-shaped processing, and on the other hand, it needs to ensure that there are no abnormal problems such as grain loss and edge collapse during processing. The key to achieving the above requirements is to control the grain structure of the tungsten plate.

[0004] However, the tungsten plates processed according to the traditional tungsten plate rolling process generally have high rolling temperatures to prevent cracking during rolling, resulting in significant recrystallization and large grain structure, which leads to serious grain loss during machining such as grinding, milling, and slow wire cutting, and cannot meet the requirements of tungsten plate processing technology for ion implantation.

[0005] According to the traditional technical processing ideas, in order to solve the problem of grain loss during machining, the finished tungsten plate or semi-finished tungsten plate is usually heat treated and recrystallized to achieve grain refinement. However, this method of heat treatment is difficult to control, and the processing cost is significantly increased. At the same time, the material is affected by recrystallization, and the strength will be significantly reduced, and the deformation resistance will be weakened.

[0006] Therefore, how to achieve good control of grains and ensure that the tungsten plate is not damaged during the rolling process without significantly increasing the cost and sacrificing the strength of the tungsten plate is an urgent problem to be solved in this field. Summary of the invention

[0007] In view of the defects of the prior art, the purpose of the present invention is to propose a method for preparing a fine-grained tungsten plate which has relatively low control difficulty, can well control the grain structure of the tungsten plate, does not significantly reduce the strength of the tungsten plate and does not increase the manufacturing cost.

[0008] The technical solution of the present invention is as follows:

[0009] A method for preparing a fine-grained tungsten plate, comprising:

[0010] Choose a density no less than 18.4g / cm 3 , a tungsten blank with an average grain size of 50-70 μm and a thickness of 20-24 mm is used as the raw material tungsten blank for fine-grained tungsten plates;

[0011] The raw tungsten billet is subjected to multiple hot rolling processes to obtain a finished fine-grained tungsten plate;

[0012] Each hot rolling process includes one heating and one rolling; the rolling deformation rate of each hot rolling process is greater than 25%; the heating temperature of the first hot rolling process is greater than or equal to 1300°C and less than 1400°C, and the heating temperature of subsequent hot rolling processes gradually decreases.

[0013] According to some preferred embodiments of the present invention, the heating temperature (ie, the blanking temperature) of the first hot rolling process is 1350°C.

[0014] According to some preferred embodiments of the present invention, it also includes: heating and leveling the tungsten plate obtained after completing the multiple hot rolling processes, the heating temperature is consistent with the heating temperature of the last hot rolling process, and the heating time is 3-5 minutes.

[0015] This preferred method can further improve the flatness of the fine-grained tungsten plate.

[0016] According to some preferred embodiments of the present invention, it further comprises: annealing the tungsten plate after the heating and leveling, wherein the annealing temperature is 1100° C. and the time is 1 hour.

[0017] This preferred embodiment can further eliminate the processing stress of the fine-grained tungsten plate and obtain a product with better machining performance.

[0018] According to some preferred embodiments of the present invention, the heating and holding time of the first hot rolling treatment is 20-30 minutes, and the heating and holding time of subsequent hot rolling treatments is gradually reduced.

[0019] According to some preferred embodiments of the present invention, the multi-pass hot rolling treatment includes eight-pass hot rolling treatment, wherein the heating temperature of the first hot rolling treatment is 1350°C, and the heating temperature of the last hot rolling treatment is 1000-1100°C.

[0020] According to some preferred embodiments of the present invention, the multi-pass hot rolling treatment includes eight-pass hot rolling treatment, wherein the heating and holding time of the first hot rolling treatment is 20 minutes, and the heating and holding time of the last hot rolling treatment is 1 minute.

[0021] According to some preferred embodiments of the present invention, the multi-pass hot rolling treatment includes eight-pass hot rolling treatment, and the respective heating temperatures and heating and holding times are: 1350°C, 20-30min; 1300-1320°C, 5-7min; 1250-1290°C, 3-5min; 1200-1240°C, 1-3min; 1150-1190°C, 1-2min; 1100-1140°C, 1-2min; 1010-1090°C, 1-2min; 1010-1090°C, 1-2min.

[0022] The inventors unexpectedly found that the fine-grained tungsten plate obtained according to the above preferred implementation not only has a significantly refined grain structure, but also has no local slight cracks or uneven grain size such as local large grains as a whole.

[0023] The present invention further provides a fine-grained tungsten plate prepared according to the above preparation method.

[0024] The microstructure of the fine-grained tungsten plate in the rolling direction is a slender fibrous processed microstructure, and the grain structure perpendicular to the rolling direction is fine short crystals. The average grain size is more than 10 times finer than that of conventional tungsten plates.

[0025] The fine-grained tungsten plate is particularly suitable for manufacturing components for ion implantation process.

[0026] The beneficial effects of the present invention include:

[0027] (1) The present invention can achieve specific control of the processing performance and grain structure of the finished tungsten plate through simple raw material control and rolling process control, and at the same time does not significantly reduce its strength (Vickers hardness can reach 470HV30), so that the obtained tungsten plate is suitable for the high requirements of components for ion implantation process;

[0028] (2) The preparation method of the present invention can not only avoid cracking of the product during processing, but also significantly refine and improve the grain structure;

[0029] (3) The hot rolling temperature required by the preparation method of the present invention is relatively low, which can significantly reduce energy consumption compared to the conventional blanking temperature of 1500°C or above, and can also avoid the cracking problem caused by low-temperature rolling. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 These are the metallographic structure images of the center and edge parts of the fine-grained tungsten plate obtained in Example 1 in the rolling direction and perpendicular to the rolling direction, wherein (a) is the metallographic structure of the center part in the rolling direction, (b) is the metallographic structure of the edge part in the rolling direction, (c) is the metallographic structure of the center part perpendicular to the rolling direction, and (d) is the metallographic structure of the edge part perpendicular to the rolling direction.

[0031] Figure 2 These are metallographic structure images of the center and edge parts of the tungsten plate obtained in Example 3 in the rolling direction and perpendicular to the rolling direction, wherein (a) is the metallographic structure of the center part in the rolling direction, (b) is the metallographic structure of the edge part in the rolling direction, (c) is the metallographic structure of the center part perpendicular to the rolling direction, and (d) is the metallographic structure of the edge part perpendicular to the rolling direction.

[0032] Figure 3 These are metallographic structure images of the center and edge parts of the tungsten plate obtained in Example 4 in the rolling direction and perpendicular to the rolling direction, wherein (a) is the metallographic structure of the center part in the rolling direction, (b) is the metallographic structure of the edge part in the rolling direction, (c) is the metallographic structure of the center part perpendicular to the rolling direction, and (d) is the metallographic structure of the edge part perpendicular to the rolling direction.

[0033] Figure 4 These are metallographic structure images of the center and edge parts of the tungsten plate obtained in Example 5 in the rolling direction and perpendicular to the rolling direction, wherein (a) is the metallographic structure of the center part in the rolling direction, (b) is the metallographic structure of the edge part in the rolling direction, (c) is the metallographic structure of the center part perpendicular to the rolling direction, and (d) is the metallographic structure of the edge part perpendicular to the rolling direction.

[0034] Figure 5 These are metallographic structure images of the center and edge parts of the tungsten plate obtained in Example 7 in the rolling direction and perpendicular to the rolling direction, wherein (a) is the metallographic structure of the center part in the rolling direction, (b) is the metallographic structure of the edge part in the rolling direction, (c) is the metallographic structure of the center part perpendicular to the rolling direction, and (d) is the metallographic structure of the edge part perpendicular to the rolling direction.

[0035] Figure 6 These are metallographic structure images of the center and edge parts of the tungsten plate obtained in Example 8 in the rolling direction and perpendicular to the rolling direction, wherein (a) is the metallographic structure of the center part in the rolling direction, (b) is the metallographic structure of the edge part in the rolling direction, (c) is the metallographic structure of the center part perpendicular to the rolling direction, and (d) is the metallographic structure of the edge part perpendicular to the rolling direction.

[0036] Figure 7 These are metallographic structure images of the center and edge parts of the tungsten plate obtained in Example 10 in the rolling direction and perpendicular to the rolling direction, wherein (a) is the metallographic structure of the center part in the rolling direction, (b) is the metallographic structure of the edge part in the rolling direction, (c) is the metallographic structure of the center part perpendicular to the rolling direction, and (d) is the metallographic structure of the edge part perpendicular to the rolling direction.

[0037] Figure 8 These are metallographic structure images of the center and edge parts of the tungsten plate obtained in Example 11 in the rolling direction and perpendicular to the rolling direction, wherein (a) is the metallographic structure of the center part in the rolling direction, (b) is the metallographic structure of the edge part in the rolling direction, (c) is the metallographic structure of the center part perpendicular to the rolling direction, and (d) is the metallographic structure of the edge part perpendicular to the rolling direction. DETAILED DESCRIPTION

[0038] The present invention is further described in detail below through specific embodiments, but this should not be construed as limiting the scope of the present invention to the following examples. Without departing from the above-mentioned method concept of the present invention, various substitutions or changes made according to common technical knowledge and conventional means in the art should be included in the scope of the present invention.

[0039] Example 1

[0040] Fine-grained tungsten plates were prepared by the following steps:

[0041] (1) Select a density of 18.4 g / cm 3 , T22 tungsten blank with an average grain size of 50-70μm and a thickness of 22mm is used as the raw material tungsten blank of fine-grained tungsten plate, and the size of the raw material tungsten blank is T22×280×255mm;

[0042] (2) The raw tungsten billet is subjected to eight hot rolling processes along its width (280 mm). Each heating process is carried out in a high-temperature furnace. The heating temperature and holding time of each process are shown in Table 1. The rolling rate of each process is 40 m / min, and the deformation rate is controlled to be 25-30%;

[0043] Table 1 Heating process table of Example 1

[0044] Lane number Heating temperature Insulation time 1 1350℃ 20min 2 1320℃ 5min 3 1290℃ 3min 4 1240℃ 2min 5 1190℃ 1min 6 1140℃ 1min 7 1090℃ 1min 8 1090℃ 1min

[0045] (3) Annealing the tungsten plate after hot rolling at a temperature of 1100°C for 1 h;

[0046] (4) The tungsten plate that has completed the annealing treatment is heated and leveled at a temperature of 1090° C. for 3 min, and then leveled by thirteen rollers to obtain a fine-grained tungsten plate.

[0047] The grain structure of the obtained fine-grained tungsten plate is a slender fiber-like processed structure in the rolling direction, and the grain structure in the vertical rolling direction is fine and short crystal. The average grain size is more than 10 times finer than the grain size of the conventional tungsten plate. There is no cracking phenomenon in single preparation and batch production, and there is no grain loss in slow wire processing, which meets the requirements of slow wire processing. Figure 1 shown.

[0048] Example 2

[0049] The fine-grained tungsten plate was prepared by the same process as in Example 1, except that the first heating temperature in the hot rolling process was 1300°C.

[0050] The results show that the grain structure of the obtained fine-grained tungsten plate in the rolling direction is a slender fibrous processed structure, the grain structure in the vertical rolling direction is fine and short crystals, the average grain size is equivalent to that in Example 1, there is no cracking phenomenon in a single preparation, but there is occasional rolling cracking in mass production, and the products without cracking have no grain loss during slow wire processing, which meets the requirements of slow wire processing.

[0051] Example 3

[0052] The tungsten plate was prepared by the same process as in Example 1, except that the first heating temperature in the hot rolling process was 1450° C. or 1400° C., and the subsequent heating temperatures were gradually reduced according to Example 1.

[0053] The results show that the grain structure of the tungsten plate obtained in the above two cases (1450℃ or 1400℃) presents a coarse and long rolled structure in the rolling direction and a wide recrystallized structure in the vertical rolling direction. Compared with the conventional method for processing tungsten plates, the grain structure refinement trend is not significant, and there is no cracking phenomenon in a single preparation. However, the products have serious grain loss in slow wire processing, which does not meet the requirements of slow wire processing. Figure 2 shown.

[0054] Example 4

[0055] The tungsten plate was processed according to the conventional method, and the process was similar to that of Example 1, except that the heating process in the hot rolling treatment was as shown in Table 2 below:

[0056] Table 2 Heating process table of Example 4

[0057] Lane number Heating temperature Insulation time 1 1500℃ 40min 2 1470℃ 10min 3 1440℃ 5min 4 1400℃ 4min 5 1350℃ 3min 6 1300℃ 2min

[0058] The grain size of the obtained tungsten plate material is significantly coarser than that of Example 1, and the product of this example has serious grain loss during slow wire processing, which does not meet the requirements of slow wire processing. Figure 3 shown.

[0059] Example 5

[0060] The tungsten plate was processed according to the same conventional method as in Example 4, except that reversing rolling was performed.

[0061] The results show that the obtained tungsten plate has no cracking during the processing, but the grain structure is significantly coarsened, and the product has serious grain loss during slow wire processing, which does not meet the requirements of slow wire processing. Figure 4 shown.

[0062] Example 6

[0063] The tungsten plate was prepared by the same process as in Example 1, except that the raw material tungsten blank used had a density of 18 g / cm 3The T36 tungsten billet with an average grain size of 60-80μm and a thickness of 36mm has an initial heating temperature of 1400℃ or 1450℃ in the hot rolling process.

[0064] The results show that both of the above two cases have cracking phenomena in single preparation and cannot meet further processing requirements.

[0065] Example 7

[0066] The tungsten plate was prepared by the same process as in Example 1, except that the thickness of the raw tungsten billet was 36 mm and the first heating temperature in the hot rolling process was 1500°C or 1550°C.

[0067] The results show that in the above two cases, there is no abnormality in the rolling process, but the grain structure is significantly coarsened. The product of this embodiment has serious grain loss during the slow wire processing and does not meet the slow wire processing requirements. Figure 5 shown.

[0068] Example 8

[0069] The tungsten plate was prepared by the same process as in Example 1, except that the thickness of the raw tungsten billet was 36 mm and the first heating temperature in the hot rolling process was 1400°C or 1450°C.

[0070] The results show that in the above two cases, the tungsten plate with the first heating temperature of 1400℃ cracked during rolling, and the tungsten plate with the first heating temperature of 1450℃ had no cracking in single preparation, but occasional cracking occurred in batch rolling. At the same time, its grain structure was coarse, and there was a serious grain loss phenomenon in slow wire processing, as shown in the attached figure. Figure 6 shown.

[0071] Example 9

[0072] The tungsten plate was prepared by the same process as in Example 6, except that the first heating temperature in the hot rolling process was 1300°C or 1350°C.

[0073] The results showed that the tungsten billets had severe cracking in the first rolling pass and could not meet further processing requirements.

[0074] Example 10

[0075] The tungsten plate was prepared by the same process as in Example 1, except that the heating process in the hot rolling process is shown in Table 3 below:

[0076] Table 3 Heating process table of embodiment 10

[0077]

[0078]

[0079] The results show that the grain structure of the tungsten plate is similar to that of Example 1, but there are local micro cracks, and the implementation effect is not as good as that of Example 1.

[0080] Embodiment 11

[0081] The tungsten plate was prepared by the same process as in Example 1, except that the heating process in the hot rolling process is shown in Table 4 below:

[0082] Table 4 Heating process table of Example 11

[0083] Lane number Heating temperature Insulation time 1 1350℃ 20min 2 1330℃ 5min 3 1310℃ 3min 4 1280℃ 2min 5 1240℃ 1min 6 1190℃ 1min 7 1140℃ 1min 8 1090℃ 1min

[0084] The results show that, relative to Example 1, the heating temperatures of the first and last passes of the above heating process are consistent, but the temperature gradient between passes is adjusted (the temperature reduction gradient for the first three passes is 20°C, the fourth pass drops by 30°C, the fifth pass drops by 40°C, and the sixth to eighth passes drops by 50°C each time). The grain structure of the tungsten plate obtained is similar to that of Example 1, but there is local growth, and the implementation effect is not as good as that of Example 1.

[0085] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0086] The above embodiments are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a fine-grained tungsten plate, characterized in that: It includes: Choose a density no less than 18.4g / cm 3 , a tungsten blank with an average grain size of 50-70 μm and a thickness of 20-24 mm is used as the raw material tungsten blank for fine-grained tungsten plates; The raw tungsten billet is subjected to multiple hot rolling processes to obtain a finished fine-grained tungsten plate; Each hot rolling process includes one heating and one rolling; the rolling deformation rate of each hot rolling process is greater than 25%; the heating temperature of the first hot rolling process is greater than or equal to 1300°C and less than 1400°C, and the heating temperature of subsequent hot rolling processes gradually decreases.

2. The preparation method according to claim 1, characterized in that: The heating temperature of the first hot rolling process is 1350°C.

3. The preparation method according to claim 1, characterized in that: The method further comprises: heating and leveling the tungsten plate obtained after the multiple hot rolling processes, wherein the heating temperature is consistent with the heating temperature of the last hot rolling process, and the heating time is 3-5 minutes.

4. The preparation method according to claim 3, characterized in that: It also includes: annealing the tungsten plate that has completed the heating and leveling, the annealing temperature is 1100° C., and the time is 1 hour.

5. The preparation method according to claim 1, characterized in that: The heating and holding time of the first hot rolling treatment is 20-30 minutes, and the heating and holding time of the subsequent hot rolling treatments is gradually reduced.

6. The preparation method according to claim 1, characterized in that: The multi-pass hot rolling treatment includes eight-pass hot rolling treatment, wherein the heating temperature of the first hot rolling treatment is 1350°C, and the heating temperature of the last hot rolling treatment is 1000-1100°C.

7. The preparation method according to claim 1, characterized in that: The multi-pass hot rolling treatment includes eight-pass hot rolling treatment, wherein the heating and holding time of the first hot rolling treatment is 20 minutes, and the heating and holding time of the last hot rolling treatment is 1 minute.

8. The preparation method according to claim 1, characterized in that: The multi-pass hot rolling treatment includes eight-pass hot rolling treatment, and the heating temperatures and heating and holding times thereof are: 1350°C, 20-30min; 1300-1320°C, 5-7min; 1250-1290°C, 3-5min; 1200-1240°C, 1-3min; 1150-1190°C, 1-2min; 1100-1140°C, 1-2min; 1010-1090°C, 1-2min; 1010-1090°C, 1-2min.

9. A fine-grained tungsten plate prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the fine-grained tungsten plate according to claim 9 in components for ion implantation processes.

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