JPS62158505A - Production of thin metallic sheet - Google Patents

Abstract

PURPOSE:To decrease the cut off at both ends and to improve yield by subjecting the cut edges of plural thin sheet pieces formed by rolling a thin intermediate sheet stretched in one direction in the direction perpendicular to one direction and cutting the same in the direction perpendicular to one direction to butt welding and rolling the same in the longitudinal direction. CONSTITUTION:A sheet-shaped metallic stock 10 is stretched in one direction by forging, rolling, etc., to form the thin intermediate sheet 12. The sheet is then cut in the direction approximately perpendicular to one direction X to form the plural thin intermediate sheet pieces 14. The end edges in the perpendicular direction are butted and joined by welding. Electron beam welding which provides the weld zone of a narrow width with high energy density is preferable for welding of the pieces 14 and TIG welding can be adopted as well. The end edges 16 of the pieces 14 are irregularly shaped and are, therefore, cut off. Initial pass rolling of the metallic material having particularly lower workability after welding is executed hot at the recrystallization temp. or above to prevent the crack or fissure.

Description

Detailed Description of the Invention Technical Field The present invention involves stretching a plate-shaped material in one direction to produce an intermediate thin plate, and then rolling the intermediate thin plate in a direction substantially perpendicular to the one direction to obtain a predetermined shape. The present invention relates to a method of manufacturing a thick metal thin plate, and particularly relates to a technique for efficiently manufacturing such a metal thin plate.

BACKGROUND ART When manufacturing a thin metal plate such as a band plate from a plate-shaped material, it is common to stretch the plate-shaped material to a desired thickness by forging or rolling. However, the thin metal sheet obtained in this way usually has a Mi weave with long fibers in the stretching direction, so when attempting to perform secondary processing such as punching or bending on this thin sheet, it is difficult to perform secondary processing in the stretching direction. Cracks or fractures occurred along a direction parallel to the For this reason, prior to such secondary processing, annealing treatment is performed to recrystallize the metal and adjust the crystal 11N to improve workability. For example, W (tungsten) .

Metals such as Mo (molybdenum) have the disadvantage that their crystal grains become coarse due to recrystallization and become extremely brittle, making it impossible to process them at room temperature.

On the other hand, in order to eliminate the orientation of the fiber structure, a method is known in which the stretching direction is changed during the stretching process. this is,
Generally referred to as a cross roll, the plate-shaped material is stretched in one direction to produce an intermediate thin plate, and then the intermediate thin plate is rolled in a direction approximately perpendicular to the one direction to form a predetermined plate. This is a method for manufacturing thick metal sheets. According to this method, even with metal materials such as tungsten and molybdenum to which the above-mentioned annealing treatment cannot be applied, it becomes possible to produce a good metal thin plate with excellent workability.

Problems to be Solved by the Invention However, in such conventional cross rolls, the width dimension of the intermediate thin plate obtained by stretching the plate material in one direction, that is, the width dimension in the direction perpendicular to the stretching direction, is limited due to the limitations of the rolling mill etc. The dimensions are relatively narrow, and therefore, when this intermediate thin plate is rolled in a direction perpendicular to one direction, the dimension in the rolling direction becomes short, resulting in extremely poor processing efficiency. In particular, when rolling a highly hard metal material such as tungsten, the rolling rate per pass is small, so it is necessary to repeat the rolling process many times, and this inconvenience has become significant.

In addition, since the width of the intermediate thin plate is narrow, the length of the thin metal sheet manufactured by rolling the intermediate thin plate in the width direction is restricted, and the rolling process is performed by applying tension in the rolling direction. Since strip rolling was difficult, the thickness of the thin metal sheet was also restricted.

Furthermore, both ends of the thin metal sheet obtained in this way in the rolling direction must be finally cut off, so the shorter the length, the lower the yield, and the longer the cutting process takes. This was one of the causes of further lowering the processing efficiency.

Means for Solving the Problems The present invention has been made to solve the above problems, and its gist is to stretch a plate-shaped material in one direction to form an intermediate thin plate, as described above. A method of manufacturing a thin metal plate having a predetermined thickness by rolling the intermediate thin plate in a direction substantially perpendicular to the one direction, the method comprising: (a) rolling the intermediate thin plate in a direction substantially perpendicular to the one direction; (b) welding the plurality of intermediate thin plate pieces by butting their ◇:h edges in a direction substantially perpendicular to the one direction; The present invention includes a welding process of manufacturing a long longitudinal welded plate material in a perpendicular direction, and the rolling process is performed in the longitudinal direction of the welded plate material to produce a thin metal plate of a target thickness.

That is, first, a predetermined sheet metal material is forged.

The intermediate thin plate is manufactured by stretching in one direction by rolling, etc., and the rolling rate at this time should be approximately the same as the rolling rate used to obtain the desired metal thin plate from the intermediate thin plate. is desirable.

Next, this intermediate thin plate is cut in a direction substantially perpendicular to the one direction to produce a plurality of intermediate thin plate pieces, and the edges of the intermediate thin plate pieces in the direction perpendicular to the one direction are butted and welded together. . When welding this intermediate thin plate piece, it is desirable to use electron beam welding, which has a high energy density and a narrow welded area, but other welding methods such as TIG welding can also be employed. In particular, when welding high-melting point metals such as tungsten, it is necessary to use such electron beams. By using receptive welding, good welding can be achieved. Incidentally, since the edge portion of the intermediate thin plate piece has an irregular shape due to the stretching process, it is desirable to cut it off prior to the welding process or the cutting process.

In addition, when welding this intermediate thin plate piece, the crystal grains become coarse due to recrystallization accompanying welding, so when manufacturing a filler metal, such as a tungsten thin plate, to prevent such coarsening of the crystal grains, It is also possible to use Mo (molybdenum), Ta (tantalum), Re (rhenium), etc., which form a solid solution in tungsten to form an alloy, and filler materials for other purposes such as increasing welding strength can also be used. It can also be used. In that case, since the composition of the welded part changes, the welded part must be removed as necessary after manufacturing the thin plate.

The welded plate material with the intermediate thin plate pieces welded in this way is then rolled in its longitudinal direction.
As mentioned above, the metal in the welded part recrystallizes and the crystal grains become coarse, so workability is low, and depending on the metal material, cracks or cracks may occur during rolling. When rolling such a metal material with particularly low workability, it is desirable to perform at least the first bus rolling after welding at a temperature higher than the recrystallization temperature. In this case, if the thickness of the welded plate material is too thin, the cooling drop due to contact with the rolling rolls will be significant, so when performing hot rolling, the thickness of the welded plate material, that is, the thickness of the intermediate thin plate, is 0.4 It is desirable to set it higher than Tsuru.

In addition, when manufacturing particularly thin metal sheets, winding rolls are installed before and after the rolling mill, and a welded sheet material is wound between both rolls to apply strong tension while rolling. For example, a foil-like thin metal plate having a thickness of about 25 μm can also be manufactured.

The method for manufacturing a thin metal sheet according to the present invention is particularly effective when manufacturing a thin sheet made of tungsten, molybdenum, or an alloy whose base material is either tungsten, molybdenum, or any one of them, to which the annealing treatment cannot be applied. However, it can be similarly applied to manufacturing thin plates from other metal materials.

Effects of the Invention According to such a method of manufacturing a thin metal sheet, the length of the welded sheet material to be rolled increases in the longitudinal direction, that is, the rolling direction, so a thin metal sheet with no directional fiber structure can be efficiently rolled by cross-rolling. It becomes possible to manufacture. especially,
For high-hardness metal materials that require a small rolling rate per pass and must be rolled many times, the processing efficiency can be greatly improved.

In addition, it has become possible to manufacture long objects such as strips by rolling a long welded plate material to produce a thin metal plate. Since it is also possible to manufacture extremely thin metal sheets using this method, restrictions regarding the length and thickness of the metal thin sheets to be manufactured are completely eliminated.

Furthermore, since the thin metal sheet obtained in this way has a long length, the amount of cutting at both ends in the length direction that is removed after rolling is smaller than that of a large number of metals with short lengths as in the past. Compared to the case where both ends of each thin sheet are cut off, the number of steps is significantly reduced, and the yield when manufacturing thin metal sheets is greatly improved. In addition, since the number of cutting points is reduced, the time required for the cutting operation is significantly reduced, and in this sense, the processing efficiency of the thin metal sheet is improved.

EXAMPLE Next, in order to further clarify the method of the present invention, an example in which the method of the present invention is applied to the manufacture of a tungsten thin plate will be described in comparison with a conventional manufacturing method.

First, FIG. 1 is a perspective view, not showing a tungsten plate-like material 1o, which is a material of a thin metal plate to be manufactured. This plate-shaped material 1o is made by cold isostatic pressing pure tungsten powder (purity ≧99.9%), and has a thickness of 23 mm and a width of 105 mm.
A green compact with a length of 170 mm and a density of 63% (compared to the theoretical density of tungsten, 19.3 g/c+!, the same applies hereinafter) was pre-sintered at 1700°C in a hydrogen atmosphere, and then further sintered by electrical heating. The board thickness is 2ON2, the width is 93mm, and the length is 150mm.

The density is 92%. Such a plate-like material 10 is
Two sheets were prepared for the test described below. In addition to such a sintered material, it is also possible to use a melted material obtained by melt casting as a plate-like material for manufacturing a tungsten metal thin plate.

Then, the intermediate thin plate 12 is manufactured by stretching these two plate-like materials 1o in the longitudinal direction indicated by the arrow X in FIG. In this drawing process, the plate-shaped material 1o was repeatedly heated to 1700°C in a hydrogen atmosphere furnace and was forged by hammer forging in the atmosphere to form a plate with a thickness of 71 m, a width IQ of 5 m, and a length of 375 cranes. Further, while repeatedly heating to 1500"C in a hydrogen atmosphere furnace, rolling was performed using a two-high rolling mill. The dimensions of the intermediate thin plate 12 manufactured by this stretching process were +F x thickness 21 m 1 width 107 Kasumi Sushi. ,
The length is 12801■.

One of the two intermediate thin plates 12 manufactured in this way was left as it is as sample A, and the other one was crossed at intervals of 1151 in the longitudinal direction (X direction), and the third
Ten intermediate thin plate pieces 14 as shown in the figure were manufactured (only three pieces are shown in the figure). This crossing is the cutting process.

Next, the ten intermediate thin plate pieces 14 obtained in this way
One of the sheets is left as sample B, and the other nine sheets are drawn in the Y direction perpendicular to the X direction, which has an irregular shape due to the stretching process, as shown in FIG. Both end edge portions 16 are cut out respectively, and the width is 103■l.
After cutting into an intermediate thin plate piece 18, the edges in the Y direction were butted against each other and welded and joined as shown in FIG. This process is a welding process, and as a result, a long welded plate material 20 that is long in the Y direction perpendicular to the stretching direction is
is obtained. The dimensions of this welded plate material 20 are a plate thickness of 2tm,
It is 115m+ wide and 927fi long. Although FIG. 5 shows a state in which three cut intermediate thin plate pieces 18 are welded together, the remaining six pieces are also welded together successively.

Here, since the melting point of the cut intermediate thin plate piece 18 made of tungsten is very high, in this example, electron beam welding with high energy density was employed as the welding means, and the welding was performed in a vacuum chamber.

In addition, during this welding, Mo, Ta, R,
To use filler metal such as e, or to increase welding strength, W-R
A filler metal such as e-alloy can be used.

The welded plate material 20 manufactured in this way is designated as a sample C, and while repeatedly heated to 1500 to 1300'C in a hydrogen atmosphere furnace together with the sample A and the sample B, the sample A is heated in the X direction. B and sample C were each rolled in the Y direction using a 4-high rolling mill to a plate thickness of 0.5 fins, and then further rolled using the same rolling machine at a heating temperature of 1200 to 800°C to obtain a plate thickness of 0.3 fins. It was made into a fin. As a result, sample A has a plate thickness of 0.3 am and a width of 107 mm.
, length 8m, sample B has a plate thickness of 0.3mm, width 115vw,
Length 0.7 m, sample C has plate thickness 0.3 mm, width 115B
, the length was 6m.

After that, samples A and C were further rolled using a 20-high rolling mill with a work roll diameter of LOAM at room temperature while applying tension in the rolling direction (rear tension and front tension 6:4). , the plate is rolled to a thickness of 0.025 mm, and in the intermediate process the plate thickness is reduced to 0.20 mm, 0.15 mm, 0.
．． 101 members, 0.0511 ring.

I went to the ring. Regarding sample B, since it is not possible to apply tension in the rolling direction due to its short length, it was rolled to a thickness of 0.15 as without tension using a 4-high rolling mill with a work roll diameter of 50 mm. , a plate thickness of 0.20 am was sampled in an intermediate process. FIG. 6 is a diagram showing a thin metal plate 22 obtained by subjecting Sample C (welded plate material 20) to such rolling processing.

Each sample piece thus obtained was bent up to 180 degrees along the X and Y directions, and the occurrence of cracks was measured. The results are shown in Table 1. In Table 1, the number 180 means that no cracks occurred even when the bending process was performed up to 180 degrees, and the number less than 180 means that no cracks were produced at that angle. This means that a crack has occurred.

Table 1 As is clear from Table 1, in sample C according to the method of the present invention, the direction of bending in the It can be seen that the characteristics have become extremely small. The same is true for Sample B produced by conventional cross-rolling, but in the case of Sample B, the short length makes it impossible to apply tension in the rolling direction and perform firm rolling. There is a disadvantage that the thickness dimension is restricted.

Furthermore, even when producing thin plates of the same thickness, tungsten has high hardness and the rolling rate per bath is low, so it is necessary to repeat the rolling process many times. Compared to the case of manufacturing a thin plate from the welded plate material 20, the processing efficiency when manufacturing a thin plate directly from the short intermediate thin plate piece 14 is extremely low. Incidentally, the actual rolling efficiency is (kg/
Figure 7 shows the results of the investigation. In Fig. 7, the ◯ marks indicate the case where sample C was subjected to rolling, and the x marks indicate the case where sample B was subjected to rolling.

Further, since the long welded plate material 20 is rolled to produce the thin metal plate 22, the long thin metal plate 22 such as a strip plate etc.
2 can be manufactured. Furthermore, since the metal thin plate 22 obtained in this way has a long length, the amount of cut off at both ends in the length direction (Y direction) after rolling is reduced by directly rolling a large number of intermediate thin plate pieces 14. Compared to the case where a thin metal plate is manufactured by processing, the amount is significantly reduced, and the product yield is improved, and the time required for the cutting operation is reduced, and processing efficiency is also improved in this respect.

Although one embodiment of the method of the present invention and the test results have been described above in detail, these are just one specific example, and the method of the present invention can be modified in various ways based on the knowledge of those skilled in the art.
It can be implemented in an improved manner.

[Brief explanation of drawings]

FIGS. 1 to 6 are diagrams illustrating an example of manufacturing a tungsten thin plate according to the method of the present invention.
The figure is a perspective view showing a plate-like material forming the material of a tungsten thin plate. FIG. 2 is a perspective view showing an intermediate thin plate obtained by stretching the plate-like material shown in FIG. 1. FIG. 3 is a perspective view showing a plurality of intermediate thin plate pieces obtained by cutting the intermediate thin plate shown in FIG. 2. FIG. FIG. 4 is a perspective view showing a state in which the edge portion of the intermediate thin plate piece shown in FIG. 3 has been cut away. FIG. 5 is a perspective view showing a welded plate material in which the cut intermediate thin plate pieces of FIG. 4 are welded together. 6th
The figure is a front view showing a thin metal plate obtained by rolling the welded plate material of FIG. 5. FIG. 7 is a graph showing the actual rolling efficiency when manufacturing a thin metal plate by the method of the present invention in comparison with a conventional cross roll. 10: Plate material 12: Intermediate thin plate 14: Intermediate thin plate piece 20; Welding plate material 22: Metal thin plate

Claims (7)

[Claims] (1) A method in which a plate-shaped material is stretched in one direction to produce an intermediate thin plate, and then the intermediate thin plate is rolled in a direction substantially perpendicular to the one direction to produce a thin metal plate of a predetermined thickness. a cutting step of cutting the intermediate thin plate in a direction substantially perpendicular to the one direction to produce a plurality of intermediate thin plate pieces; and cutting each of the plurality of intermediate thin plate pieces at an end in a direction substantially perpendicular to the one direction. a welding step of welding the edges together to produce a long longitudinal welded plate material in the perpendicular direction, and perform the rolling process in the longitudinal direction of the welded plate material to produce a thin metal plate of the desired thickness. A method for manufacturing a thin metal sheet, characterized in that: (2) The method for manufacturing a thin metal plate according to claim 1, wherein the plate-like material is tungsten, molybdenum, or an alloy having either of them as a base material. (3) The method for manufacturing a thin metal plate according to claim 1 or 2, wherein the welding step is performed by electron beam welding. (4) The thin metal sheet according to any one of claims 1 to 3, wherein the welding step is performed using a filler metal that reduces recrystallized crystal grains during welding. Production method. (5) The method for manufacturing a thin metal sheet according to any one of claims 1 to 4, wherein the rolling process includes hot rolling process. (6) The method for manufacturing a thin metal plate according to claim 5, wherein the intermediate thin plate has a thickness of 0.4 mm or more. (7) Claims 1 to 6, wherein the rolling process is performed by applying tension in the longitudinal direction of the welded plate material.
A method for producing a thin metal plate according to any of the above.