JP6761576B2 - Bending mold and bending method and manufacturing method of wasteland for turbine blades - Google Patents

Description

The present invention relates to a die and a method for bending a hot forging material for a turbine blade using a radial forging machine, and a method for manufacturing a wasteland for a turbine blade.

For example, in manufacturing a turbine blade, a round bar-shaped hot forging material is forged to a desired diameter, and then the root of the turbine blade is formed so that it becomes a near-net-shaped turbine blade material in the subsequent stamping forging. A desired round bar-shaped wasteland is formed in order to secure the volume of the portion to be the blade or the wing. Regarding the shape of this wasteland, for example, in FIG. 2 of JP-A-63-238942 (Patent Document 1), the root portion is thick (large in volume) and gradually becomes thinner toward the tip of the wing portion. Wasteland is shown.
As a specific manufacturing method of this wasteland, for example, a round bar-shaped hot forging material is radial forged to a desired diameter to obtain a long round bar, cut to a predetermined size, and further free forged. The device forges into the desired wasteland shape.

When stamping and forging turbine blades, roots, blades, and protrusions called bosses may be provided inside the turbine blade blades, so it is important to adjust the volume and dimensions in rough terrain for turbine blades. It becomes. If the volume and dimensions are not adjusted sufficiently, the rough ground will not be sufficiently filled in the carved surface during stamping and forging, and a part of the near net-shaped turbine blade material after stamping and forging will be missing. There is a problem of size. In addition, since the material of the turbine blade is an expensive alloy such as a nickel-based super heat-resistant alloy or a titanium alloy, defects such as a part of the near-net-shaped turbine blade material after stamping and forging may be missing. And the loss is not small.
Therefore, it is preferable to provide a processing groove called "segiri" at the time of manufacturing the wasteland and perform the processing at the time of roughland molding so that the inside of the die carved surface at the time of stamping forging is sufficiently filled. However, for example, as shown in Japanese Patent Application Laid-Open No. 60-250843 (Patent Document 2), in order to form the shavings, a special jig is prepared and a processing groove is sequentially provided in the round bar-shaped material by a press device. Become.
Then, the forged material after the forging is hot-forged by stretching the forging material (hereinafter referred to as forging) so that the forged material has a predetermined wasteland shape again by another forging device.

Japanese Unexamined Patent Publication No. 63-238942 Japanese Unexamined Patent Publication No. 60-250843

As shown in Patent Document 2, conventionally, only the jig for performing the cutting has been improved, and there is no proposal for a mold suitable for forging and bending performed after the cutting. Further, the alloy used for the turbine blade is a difficult-to-process material such as a titanium alloy or a nickel-based super heat-resistant alloy, and contains a large amount of expensive alloying elements. As described above, the wasteland for turbine blades has a special shape having both a large diameter portion and a small diameter portion. This turbine blade is expected to become larger and larger in the future, and if the shape of the wasteland is uneven, it will cause shape defects such as lack of meat during subsequent blade-shaped forging, and if shape defects occur, the loss will be large. Become.
An object of the present invention is to manufacture a bending die and a bending method, and a wasteland for a turbine blade, which can easily correct the shape of a difficult-to-process material used for a turbine blade by using a radial forging machine. To provide a method.

The present invention has been made in view of the above-mentioned problems.
That is, the present invention is a bending die for correcting the shape of a rod-shaped hot forging material for turbine blades by radial forging.
The bending die has a pressing portion for correcting the bending of the hot forging material for turbine blades.
The hot forging material for turbine blades has a large diameter portion and a small diameter portion having different outer diameters.
The pressing portion has a first pressing portion and a second pressing portion that simultaneously press the large diameter portion and the small diameter portion of the hot forging material for turbine blades.
The first pressing portion and the second pressing portion are bending dies formed so as to surround the outer peripheral surface of the hot forging material for turbine blades along the circumferential direction.
Further, in the present invention, the radial forging machine is used to bend the hot forging material for turbine blades by using a pair of bending dies arranged to face each other toward the central axis of the hot forging material for turbine blades. It ’s a way to bend
The bending die has a pressing portion for correcting the bending of the hot forging material for turbine blades.
The hot forging material for turbine blades has a large diameter portion and a small diameter portion having different outer diameters.
The pressing portion has a first pressing portion and a second pressing portion that simultaneously press the large diameter portion and the small diameter portion of the hot forging material for turbine blades.
The first pressing portion and the second pressing portion are a bending method characterized in that they are formed so as to surround the outer peripheral surface of the hot forging material for turbine blades along the circumferential direction.
Preferably, the rod-shaped hot forging material for turbine blades is a nickel-based superheat-resistant alloy or a titanium alloy.
The present invention also includes a first step of obtaining a rod-shaped hot forging material for a turbine blade by hot forging.
A second method for bending the hot forging material for turbine blades by using a radial forging machine and using a pair of bending dies arranged to face each other toward the central axis of the hot forging material for turbine blades. It is a method of manufacturing a wasteland for a turbine blade having a process.
The bending die has a pressing portion for correcting the bending of the hot forging material for turbine blades.
The hot forging material for turbine blades has a large diameter portion and a small diameter portion having different outer diameters.
The pressing portion has a first pressing portion and a second pressing portion that simultaneously press the large diameter portion and the small diameter portion of the hot forging material for turbine blades.
The first pressing portion and the second pressing portion are a method for manufacturing a wasteland for turbine blades, characterized in that the outer peripheral surface of the hot forging material for turbine blades is formed so as to surround the outer peripheral surface along the circumferential direction. is there.

According to the present invention, even if it is a difficult-to-process material used for a turbine blade or the like, the shape of the hot forged material can be easily corrected by using a radial forging machine.

It is a schematic diagram which shows an example of a die for hot forging. It is a schematic diagram which shows an example of a die for hot forging. It is a schematic diagram which shows an example of the extension part. It is a schematic diagram of a radial forging machine. It is a schematic diagram which shows an example of the shape of a wasteland. It is a schematic diagram which shows an example of the place which presses the forging material at the time of performing hot forging. It is a schematic diagram which shows an example of the place which presses the forging material at the time of performing hot forging. It is a schematic diagram which shows an example of the extension part. It is a schematic diagram which shows an example of the hot forging die used in this invention. It is a schematic diagram which shows an example of the bending die used in this invention. It is a schematic diagram which shows an example at the time of performing the bending which concerns on this invention using the hot forging die.

The present invention relates to wasteland forming of a material for turbine blades using a radial forging machine that presses from two opposite directions. Wasteland molding will be described below. The order of the description is the order of the steps for producing the wasteland for the turbine blades, in the order of cutting, forging, and bending.
First, the mold used for the cutting process will be described. The feature of this die is that one die has a roughened and finished roughened part, and another feature is that the roughened and finished roughened part is formed around the forged material. It was arranged side by side in the direction.
FIG. 1 is a front view and a cross-sectional view of the hot forging die 1 for cutting. The "front" is when the forged material is forged and is viewed from the direction in which the forged material extends (longitudinal direction), and the "cross section" is the position shown in the front view in the above-mentioned longitudinal direction (longitudinal direction). This is when viewed from the direction perpendicular to the direction in which the forged material extends). It should be noted that the "front" and "cross section" of the "forging" and "forging" hot forging dies and "curving" dies described below are also when viewed from the same direction as described above. It shows the morphology.
As shown in the front view of FIG. 1 and the right figure of FIG. 4 (the view when the forging material is viewed from the extending direction), the hot forging die 1 for shaving is forged by pressing the forging material. The squeeze pressing portion 2 (squeeze portion 5) is formed so as to surround the outer peripheral surface of the forged material in the circumferential direction when the forged material is forged. As shown in the front view of FIG. 1, the pressing portion 2 to be squeezed has a shape such that the distance between the pressing portions on both sides thereof increases from the bottom portion recessed in an arc shape. Such a shape is also included in the category of "surrounding the outer peripheral surface of the forged material in the circumferential direction".

Further, the squeezing pressing portion (sometimes referred to as a substantially semicircular pressing portion) 2 to be squeezed becomes the shaving portion 5, and the pressing portion is the shaving roughing processing portion 3 and the shaving finishing processing portion 4. The rough-cut portion and the finish-cut portion are continuously formed. FIG. 1 shows a cross-sectional view (AA cross-sectional view) of a hot forging die 1 for shaving, a cross-sectional view of a rough-cut part (CC cross-sectional view), and the shaving finishing process. A cross-sectional view (BB cross-sectional view) of a portion located between the portion and the roughened portion is shown. As shown in the cross-sectional view of FIG. 1, the squeezing pressing portion has a convex shape having a substantially semicircular cross section, from the position shown in the CC cross-sectional view to the position shown in the BB cross-sectional view. , The radius of curvature of the pressing portion gradually increases, and the radius of curvature from the BB cross-sectional view to the position (bottom) shown in the AA cross-sectional view is made to be substantially the same. In addition, the "cutting finish processing part" includes a position (bottom part) shown in the above-mentioned AA cross-sectional view, and a place having the same radius of curvature is defined as a cutting finish processing part. Then, the ridgeline portion 9 of the above-mentioned roughened and finished portion is continuously formed, and is formed so as to surround the circumferential direction of the outer peripheral surface of the forged material. This ridge line is a line that continuously connects the vertices of the substantially semicircular convex portion of the pressing portion. The finish processing portion and the rough processing portion have a convex shape so that the forged material can be pressed.

In the hot forging die 1 for cutting, the radius of curvature of the substantially semicircular convex shape of the cutting finishing portion 4 is larger than the radius of curvature of the substantially semicircular convex shape of the cutting rough processing portion 3. It is preferably larger than 10 mm. This is because the forged material is processed into a wasteland for large turbine blades, and it is better to increase the contact area of the shaving finish processing part than for the shaving rough processing part for large (long) turbine blades. This is because it is convenient for molding into a wasteland shape. Further, as another reason, if the radius of curvature of the substantially semicircular convex shape of the shaving finish processed portion is large, it becomes easy to form a wide processed groove. This is because it is desirable to widen the width of the processing groove formed by the forging in order to prevent fog flaws at the place where the forging was performed during forging, in which the forged material is stretched after the forging of the forging. In either case, if the difference in radius of curvature between the shaving finish processing portion and the shaving rough processing portion is less than 10 mm, the effect may not be sufficiently obtained. Therefore, the substantially semicircular protrusion of the shaving finish processing portion 4 The radius of curvature of the shape is preferably 10 mm or more larger than the radius of curvature of the substantially semicircular convex shape of the roughened portion. It is more preferable to form with a difference of 15 mm or more.

The two hot forging dies 1 for shaving shown in FIG. 1 form a pair. For example, as shown in FIG. 4, the central shaft of the forging material is such that the hot forging dies 1 sandwich the forging material 21. A pair of two hot forging dies 1 cooperate with each other to perform shaving.
Specifically, the hot forging dies for forging shown in FIG. 1 form a pair (pair), and a convex semicircular pressing that sandwiches the forging material (not shown in FIG. 1). It has a portion 2 and presses the forged material so as to be sandwiched between the pressing portion 2 for cutting. The forging material is gripped and the forging material is intermittently rotated by the gripping mechanism provided in the radial forging machine. At the start of shaving, the forged material is squeezed from the ridgeline at the tip of the convex roughened portion shown in the BB cross section from the CC cross section, and gradually A from the BB cross section. -A The convex ridge pressing portion is continuously formed so that the ridge processing can be sequentially performed on the convex finish processing portion shown in the cross-sectional view. Further, the ridge line portion is continuously formed so as to surround the outer peripheral surface of the forging material in the circumferential direction, so that the forging material is sandwiched between the pressing portions of the two cooperating hot forging dies. It can be processed.

Explaining the above-mentioned forging in detail, when forging is started from the rough-processed portion of the forged material, the forging is performed so that a groove having a predetermined depth can be formed even if the forged material is difficult to process. At the initial stage, the groove processing can be efficiently performed in the roughed portion where the contact area is reduced. Then, as the forging progresses, the pressed portion gradually moves toward the finishing portion, widens the width of the groove, and adjusts the shape of the forging. However, even in the case of hot forging in the shaving finish processing part, it is possible that the depth of the shaving is not reached. Therefore, the shaving finishing processing part also forms a pressing part having a substantially semicircular cross section. By making the contact area as small as possible, the shape of the forging is efficiently adjusted.
That is, in the shaving process for using the hot forging material for turbine blades used in the present invention, first, the shaving rough processing section 3 having a small radius of curvature is efficiently grooved, and then the shaving rough machining section 3 The forging portion 4 having a radius of curvature larger than the radius of curvature efficiently forms the final shape of the forging. Therefore, a gradual change portion in which the radius of curvature gradually increases is formed from the substantially semicircular pressing portion in the shaving rough processing portion 3, and the shaving finishing processing portion 4 forms the final shape of the shaving. ..
It should be noted that the actual pressing portion may form a substantially semicircular convex portion by, for example, overlay welding, or the shape may be manually machined after that, so that the convex portion having the same radius of curvature is not necessarily present. May not be formed. Therefore, the above-mentioned "substantially semicircular shape" may be a convex shape having a curvature including an error due to overlay welding or machining, and the radius of curvature may be obtained from an approximate shape. For example, the radius of curvature can be obtained from the width of the curved surface portion forming the convex portion in the longitudinal direction of the forging material and the height of the curved surface portion in the direction perpendicular to the longitudinal direction of the forging. Further, the portion that presses the forging material may be convex with a curvature, and the radius of curvature of the pressing portion may be configured as described above.

When the forging material is hot forged with the hot forging die 1 for hot forging having this shape, the convex roughened portion formed in the hot forging die comes into contact with the forging material. , The pressed portion gradually moves to the forging finished portion, and the groove required for forging can be sequentially formed. In the present invention, the "convex shape in which the shaving finish processing portion has a larger radius of curvature than the shaving rough processing portion" refers to the shape of each of the above cross-sectional views. That is, when the forged material is forged, it is a cross section when viewed from a direction perpendicular to the direction corresponding to the longitudinal direction of the forged material.

The above-mentioned hot forging die 1 is suitable for cutting. In addition, like the hot forging die for hot forging of another example shown in FIG. 2 (the same reference numerals are used for the same parts as in FIG. 1), the substantially semicircular pressing portion 2 for cutting is provided. When forging a forged material, a plurality of forged materials may be formed along a direction corresponding to the longitudinal direction of the forged material. For example, when forming a machining groove by cutting at two places at the same time, it is advantageous to form a plurality of cutting pressing portions 2 for cutting in one mold, which is advantageous for improving productivity. Because there is. In particular, since the alloy material used for the turbine blade is a difficult-to-process material, it is preferable to finish the forging in the shortest possible time within the temperature range where hot forging is possible. It is effective to use this simultaneous cutting to a plurality of places for a portion to be a boss portion provided on the blade portion of the turbine blade.
It should be noted that the reason why the simultaneous forging at a plurality of places is possible is that the contact area of the pressing portion formed in the hot forging die is gradually increased from a small area as described above. This was only possible in combination with a radial forging machine.
Also in the hot forging die having the structure shown in FIG. 2, a place having the same radius of curvature (from the position of the FF cross section to the EE cross section) including the position (bottom) shown in the EE cross section. (Up to the position shown in the figure) is used as the finishing part.

After the above-mentioned forging is completed, the forging material is stretched to form a predetermined hot forging material (rough ground) shape for turbine blades. FIG. 3 shows a hot forging die 11 for forging.
Even in the case of this stretching (forging), a radial forging machine that presses from two opposite directions is used. The basic configuration is the same as the hot forging die suitable for cutting, and the characteristics of this die are also forged into one die, similar to the hot forging die for cutting described above. It has a roughing and forging finishing part, and another feature is that the roughening and forging part and the forging and finishing part are arranged side by side in the circumferential direction of the forging material. The hot forging dies 11 for forging also form a set (pair) of two.
The hot forging die 11 for forging is stretched by pressing the forging material as shown in the front view of FIG. 3 and the right view of FIG. 4 (viewed from the direction in which the forging material is stretched). The forging pressing portion 12 (extending portion 7) to be forged is formed so as to surround the outer peripheral surface of the forging material in the circumferential direction. As shown in the front view of FIG. 3, the forging pressing portion 12 to be forged has a shape such that the distance between the pressing portions on both sides thereof increases from the bottom portion recessed in an arc shape.
Further, the forging and stretching pressing portion (sometimes referred to as a substantially trapezoidal pressing portion) 12 serves as an extending portion 7, and the pressing portion has a forging roughing processing portion and a forging finish processing portion, and forging and stretching. The roughed portion and the forged finish processed portion are continuously formed. The cross-sectional view of FIG. 3 includes a cross-sectional view of a forged finish-processed portion (DD cross-sectional view) of a hot forging die 11 for forging, a cross-sectional view of a rough-forged surface (FF cross-sectional view), and A cross-sectional view (EE cross-sectional view) located between the forging finish processing portion and the forging rough processing portion is shown. As shown in the cross-sectional view of FIG. 3, the cross-sectional shape of the forging pressing portion is a substantially trapezoidal convex shape, and the working surface (pressing surface) of the forging pressing portion is substantially flat in its cross-sectional shape. It has become. Further, the working surface (pressing surface) of the forging pressing portion has a curved shape as a whole.
Then, from the surface width W1 at the position shown in the FF sectional view to the surface width W2 at the position shown in the EE sectional view, the width (width in the longitudinal direction of the forged material) gradually increases, and E- The width of the pressing surface from the E sectional view to the position (bottom) shown in the DD sectional view is almost the same. The "forging finish processing portion" referred to in the present invention is defined as a forging finish processing portion including a position (bottom portion) shown in the DD cross-sectional view and having the same width of the pressing surface. Then, the forged roughing processed portion and the forging finishing processed portion described above are continuously formed, and are formed so as to surround the circumferential direction of the outer peripheral surface of the forging material. The forged finish processed portion and the forged rough processed portion have a convex shape so that the forged material can be pressed. Further, as will be described later, a concave portion may be provided in a part of the convex pressing portion.

In the hot forging die 11 for forging, the flat forging pressing portion having a specific width is also efficiently forged by reducing the contact area at the initial stage of forging, and then predetermined. The surface width of the substantially flat forging pressing portion formed in the forging roughing processing portion 13 is narrowed so that the shape can be easily adjusted to the above shape, and the forging formed in the forging finishing processing portion 14 is performed. The surface width of the stretching pressing portion is made wider than that of the forging and roughing processing portion 13.
As described above, since the hot forging die 11 for forging is for adjusting the shape while extending the forging material in the longitudinal direction, the forging pressing portion is flat. The width in the direction corresponding to the width in the central axis direction of the forging material when forging the forging material of the flat forging pressing portion (the width in the longitudinal direction of the forging material when forging the forging material) is excessively set. When unfolded, the pressure required for forging may increase. Therefore, it is preferable to select a width suitable for the forging machine in consideration of the contact area for the width of the flat forging pressing portion so that it can be forged efficiently with one striking.
Further, the width of the pressing portion of the forging finish processing portion 14 is preferably 10 mm or more wider than the width of the pressing portion of the forging rough processing portion 13. This is because by increasing the difference in contact area, it is possible to increase the amount of processing in the initial stage of forging and to accurately finish the shape into a predetermined shape in the later stage of forging. If the difference in width between the forged finish processed portion and the forged rough processed portion is less than 10 mm, the effect may not be sufficiently obtained. Therefore, the difference is preferably 10 mm or more. It is more preferable to form with a difference of 15 mm or more.
It should be noted that the actual pressing part for forging may not always have a flat shape with almost no unevenness because it may be repaired by overlay welding or the like and then the shape may be manually machined. is there. Therefore, "flat" may be any one that includes errors due to overlay welding and machining and does not have excessive unevenness. At least, it is not curved in the longitudinal direction and is parallel to the longitudinal direction, and the shape may be obtained from an approximate shape.

The two hot forging dies 11 for forging shown in FIG. 3 form a pair. For example, as shown in FIG. 4, the center of the forging material is such that the hot forging dies 11 sandwich the forging material 21. Two pairs of hot forging dies 11 are arranged so as to face each other toward the shaft, and forging is performed in cooperation with each other.
Specifically, the hot forging dies for forging shown in FIG. 3 form a pair (pair), and press the convex substantially trapezoidal shape that sandwiches the forging material (not shown in FIG. 1). It has a portion 12, and the forging material is pressed so as to be sandwiched between the forging and stretching pressing portions. Forging of the forging material is performed by a gripping mechanism provided in the radial forging machine so that a set of hot forging dies 11 for forging work together to reduce the diameter of the forging material (not shown). As a result, the forged material is gripped and the forged material is rotated. Further, the intermittent rotation of the forging material and the gripped forging material move in the longitudinal direction thereof and extend in the longitudinal direction of the forging material.
At the start stage of forging, forging of the forging material is started by the convex pressing portion shown in the EE cross-sectional view from the FE cross-sectional view, and gradually from the EE cross-sectional view to the DD cross-sectional view. The convex pressing portion is continuously formed so that the forging process can be sequentially performed in the convex finishing processed portion shown. Further, the work surface is flat and the convex pressing portion is continuously formed so as to surround the outer peripheral surface of the forging material in the circumferential direction, thereby pressing the two cooperating hot forging dies. By sandwiching the forging material in the portion, the diameter of the forging material can be reduced, and by moving the forging material in the longitudinal direction, the longitudinal direction of the forging material can also be extended.

Further, in the hot forging die for forging, it is preferable that a flank surface is formed at a portion continuous with the finishing processed portion 14 as shown in FIG. The inclination θ of the flank preferably has an inclination of 15 ° to 35 °. The flank is the surface formed on the side where the forged material is sent. The flank is transferred to the forging material at the time of forging, and the portion transferred at the time of the next forging ((part A) in FIG. 9) is forged. As a result, it is possible to prevent the forged material from being fogged. In FIG. 3, flanks are formed on both sides of the finished portion. When a hot forging die having this structure is used, the forging material can be forged while reciprocating. For example, when forging is performed from only one direction, as shown in FIG. 9, the flank surface may be formed only on the side to which the forged material is sent.

When the forging material is hot forged with the hot forging die 11 for forging having this shape, the convex rough-processed portion formed on the hot forging die comes into contact with the forging material. The forged material can be sequentially elongated and its diameter can be reduced. The "convex shape in which the width of the finishing processed portion in the direction corresponding to the central axis direction of the forged material is wider than the width of the rough processed portion" refers to the shape of each of the above cross-sectional views. That is, it is a cross section when viewed from a direction perpendicular to the longitudinal direction of the forged material when the forged material is forged.
The forging process and the forging process are performed to complete the forging process, and one or more large diameter portions and small diameter portions having different outer diameters can be formed at one or more locations to obtain a hot forging material for turbine blades.

Next, after the forging step, the bending step of bending the hot forging material by a pair of bending dies arranged to face each other toward the central axis of the hot forging material will be described.
As described above, since the material of the turbine blade is an expensive alloy such as a nickel-based super heat-resistant alloy or a titanium alloy, the shape of the hot forging material used for hot die forging does not vary as much as possible. Better. This is because if the material shape varies, defects such as lack of meat are likely to occur during hot die-forging. Therefore, bending (shape correction) is performed in order to reduce the variation in shape. The hot forging material to be bent is formed by forming one or more large diameter portions 23 and small diameter portions 24 having different outer diameters as shown in FIG. 5 after the above-mentioned cutting and forging. Is. Of these, the place where bending is particularly likely to occur is, for example, a place (neck 25) where the cutting process is performed, which is located between the large diameter portion at both ends of FIG. 5 and the small diameter portion adjacent thereto.
Therefore, as the bending die (hot forging die) 31 used in this bending process, for example, as shown in FIG. 10, the large diameter portion and the small diameter portion of the hot forging material are pressed at the same time. It has a first pressing portion 32 and a second pressing portion 33, and each pressing portion has a shape formed so as to surround the outer peripheral surface of the hot forged material along the circumferential direction. The first pressing portion 32 is a portion for correcting the shape of the large diameter portion, the second pressing portion 33 is a portion for correcting the shape of the small diameter portion, and the first pressing portion 32 and the second pressing portion 33 The third pressing portion 34 in between is a portion that corrects the shape of the neck portion 25.
The first pressing portion 32 and the second pressing portion 33 used in the present invention have substantially the same shape on the outer peripheral surface of the hot forging material for turbine blades to be pressed. The portion having substantially the same shape is around the bottom portion 35 of each pressing portion (corresponding to the place where the straight line showing the AA cross section of FIG. 10 passes). It is preferable that the third pressing portion also has substantially the same shape on the outer peripheral surface of the forging material to be pressed in the same manner as the first and second pressing portions.

In the bending using the bending die 31 used in the bending step, for example, as shown by the arrow in FIG. 11, the bending is started from the small diameter portion of the forging material while the forging material is intermittently rotated. In the final stage, the large-diameter portion and the small-diameter portion are simultaneously pressed by the hot forging die 31 to correct the shape. At the final stage of bending (shape correction), the forged material is not moved and is formed into a final shape only by intermittent rotation to make a wasteland. It should be noted that this bending process is not a process for further forging the forged material. Of course, the forged material may be forged inevitably.

Next, as an example, a hot forging method for wasteland for a 50-inch turbine blade will be described.
FIG. 4 is a schematic view showing an example of a radial forging machine. The hot forging die 1 shown in FIG. 1 is attached to the radial forging machine. One hot forging die 1 is provided on each side of the forging material in order to sandwich and forge the forging material 21. In FIG. 4, the forging material 21 is already gripped by the radial forging machine, but the forging material is heated to a predetermined hot forging temperature in a heating furnace (not shown) and attached to the radial forging machine. ..
The heating temperature varies depending on the material of the forged material, and is, for example, 950 to 1150 ° C. for a nickel-based superheat-resistant alloy and 800 to 1000 ° C. for a titanium alloy. In addition, the temperature is 900 to 1200 ° C. for precipitation reinforced stainless steel. The shape of the forged material is rod-shaped. The rod-shaped forging material may be a rod-shaped forging material that has been adjusted to a predetermined shape by a forging device or a pressing device, and if it is a round bar-shaped material, the roughing portion of the hot forging die 1 whose diameter can be cut. It is preferable that the distance between the two is about the same.
Then, among the above-mentioned forging materials, a predetermined round bar-shaped forging material is attached to the radial forging machine.

In the hot forging, while rotating the heated forging material 21, two hot forging dies 1 arranged to face each other toward the central axis of the forging material are made into one set (pair), and each pressing portion is used. By pressing the forged material, the forged material is squeezed. In the following description, forging using the roughing portion is roughing forging, and forging using the finishing portion is finish forging.
The shape of the hot forging die for shaving is shown in FIG. At the time of this cutting, hot forging is first started from the roughing portion 3 of the hot forging die 1 for cutting. The hot forging die 1 used in the present invention has a shaving rough processing portion 3 inclined toward the bottom of the shaving finishing processing portion 4 on both sides of the shaving finishing processing portion 4. When the gap between the roughing parts is widened from the finishing part 4 toward the roughing part 3, and the two hot forging dies 1 press the outer peripheral surface of the forging material, they are continuous. It is possible to form a predetermined shape by a substantially semicircular convex pressing portion having a substantially semicircular shape. In addition, the forged material is intermittently rotated on the spot in the first cutting process (the forged material is not moved in the longitudinal direction).
There are two processing methods at the time of this cutting. As the first method, a method of emphasizing the shape after finishing the cutting process will be described.
When hot forging (grinding) is started from two opposite directions using a pair of hot forging dies, first, as shown in FIG. 6 (A), the rough forging portion 3 is used. Pressing of the forged material at a predetermined position is started. The contact (forging) position between the forging material 21 and the hot forging die during roughing is indicated by an arrow. Then, although hot forging is performed from two opposite directions, the rough forging portion 3 formed in the two hot forging dies that are forged in cooperation at the initial stage of forging starts pressing. There are four places where the forging material is pressed at the start, including a pair of hot forging dies. When these four locations start the cutting process at the same time, the groove processing is performed efficiently because the contact area is small. Then, the pressed portions are sequentially directed to the shaving finish processing portion, and the shaving finishing processing portion 4 formed in the pair of hot forging dies is adjusted to a predetermined shape. At the final stage of the finishing process, as shown in FIG. 6 (B), when the forging material 21 is hot-forged at the bottom of the finishing processing section 4, the pressing points are a pair of hot forging dies. There are two places. In other words, at the initial stage of shaving, forging (forging) is performed at four locations using a pair of hot forging dies, and at the final shape adjustment, using a pair of hot forging dies 2 The shape can be adjusted by forging in several places. In addition, the convex finishing processing portion 4 having a radius of curvature larger than that of the rough processing portion 3 can efficiently form the final shape. Moreover, since the shape of the bottom of the finishing portion indicated by the arrow can be adjusted to the final shape, it is convenient when the final finishing shape is emphasized.

The other method is a method applied when the processing time is short.
When hot forging is started from two opposite directions using a pair of hot forging dies, first, as shown in FIG. 7 (A), a predetermined forging material is first determined from the roughened portion 3. Position pressing is started. The contact (forging) position between the forging material 21 and the hot forging die during roughing is indicated by an arrow. Then, although hot forging is performed from two opposite directions, the rough forging portion 3 formed in the two hot forging dies that are forged in cooperation at the initial stage of forging starts pressing. There are four places where the forging material is pressed at the start, including a pair of hot forging dies. When these four locations start the cutting process at the same time, the groove processing is performed efficiently because the contact area is small. Then, hot forging is sequentially performed toward the finishing processing portion, and the shaving finishing processing portion 4 formed in the pair of hot forging dies is adjusted to a predetermined shape.
As described above, since the radius of curvature from the BB cross-sectional view to the position (bottom) shown in the AA cross-sectional view is almost the same, the finishing process to be used up to the bottom of the shaving finishing processing section 4 is not performed. , As shown in FIG. 7B, the finishing process is completed with four points to be pressed during the finishing process. Even in this case, it is possible to efficiently form the final shape in the convex finish processing portion 4 having a radius of curvature larger than that of the rough processing portion 3, and by setting the number of pressing points to four. Curvature processing can be performed in a short time. Therefore, it is convenient when the forging time is desired to be short.
When this method of emphasizing the forging time is used, the radius of curvature of the bottom portion (position shown in the AA cross-sectional view) of the forging finish processing portion (when viewed from the direction perpendicular to the longitudinal direction of the forged material shown in FIG. 7). It is important that the radius of curvature) be smaller than the radius of curvature of the diameter of the forged material after it has been trimmed. However, it is advisable to keep the bottom of the shaving finish processed portion in a curved shape so as to avoid excessive stress concentration during hot forging.

When the cutting process is completed, the hot forging die 1 is replaced with a hot forging die 11 having a forging pressing portion. When the hot forging die is replaced, the forging material can be reheated to a predetermined forging temperature.
The replaced hot forging die 11 is provided with an extension portion 7 having a forging pressing portion for extending the forging material. The forging pressing portion has the shape shown in FIG. The shape of the pressing portion of the hot forging die 11 having the forging pressing portion as seen from the longitudinal direction of the forging material is also the shape of the hot forging die subjected to the cutting process shown in FIG. 6 (A). Since it is the same as the die 1, when hot forging is started from two opposing directions, first, the forging roughing processing portion 13 starts pressing the forging material at a predetermined position. Then, although the hot forging is performed from two opposite directions, the forging rough processing portion 13 formed on the two (pair) hot forging dies that are forged in cooperation at the initial stage of forging (forging). Starts pressing, so there are four locations where the forging material is pressed at the start of forging, including a pair of hot forging dies. When these four locations start forging at the same time, the forged material is efficiently stretched because the contact area is small. Then, the forging material is sequentially moved in the longitudinal direction of the forging material while intermittently rotating by the radial forging machine, and hot forging is performed so that the pressing points are sequentially directed to the forging finish processing portion, and a pair of hot forging dies. The forged finish processed portion formed in the mold is adjusted to the shape of a predetermined hot forging material for turbine blades.
That is, at the final stage of the finishing process, as shown in FIG. 6B, when the forging finishing processing section 14 performs hot forging, there are two pressing points including the pair of hot forging dies. .. This method of adjusting the shape of the bottom of the forged finish processed portion to the final shape is convenient when the final finish shape is emphasized.
Further, even in the hot forging by the forging pressing portion, in order to shorten the hot forging time, as shown in FIG. 7, four pressing points are provided from the initial stage of the hot forging to the final stage of the hot forging. By doing so, the forged material can be stretched in a short time.

Further, in the hot forging die having the forging pressing portion, the shape shown in FIG. 8 can be obtained. The hot forging die 11 shown in FIG. 8 (the same reference numerals are used for the same parts as those in FIG. 3) is the width of the finishing portion 14 (the width in the longitudinal direction of the forging material when the forging material is forged). A recess 8 is formed from the bottom of the) toward the forged roughing processed portion, and the pressing portion of the forged finishing processed portion is divided into two places in the longitudinal direction of the forging material by the recess 8. By forming one or more recesses within the width of the forging finish processing portion 14 and dividing the pressing portion of the finish processing portion into two or more, it is possible to more reliably prevent bending of the forging material during forging. .. When hot forging is carried out using the hot forging die shown in FIG. 8, the final stage forging can be performed at the bottom of the forging finish processing portion shown in the AA cross section. At the moment when the forging material is pressed, there is a portion pressed by the forging finish processing portion and a non-pressed portion adjacent to the portion pressed by the forging finishing processing portion. The flesh of the pressed portion flows to the unpressed portion, and the flesh flows, so that the cross section of the forging material may be slightly elliptical. The elliptical forged material is likely to bend during forging. However, according to the structure of the hot forging die of FIG. 8, since the pressing portion (finishing portion) is divided by the recess, the forging material is intermittently rotated by radial forging at the first pressed portion. Then, finish forging is performed by the next pressing portion. At this time, in the structure of FIG. 8, since the pressing is performed at a total of four places, the ellipse can be corrected and the bending can be corrected by the following pressing portions as described above. It should be noted that the effect of preventing bending can be maximized by forming the recessed portion so as to include the bottom portion of the finished portion (the portion where the straight line shown by AA in FIG. 8 is in contact).

The hot forged material for turbine blades obtained by performing the above-mentioned shaving and forging processing is bent (shape-corrected). As shown in FIG. 10, the bending (shape correction) has a first pressing portion and a second pressing portion that simultaneously press the large diameter portion and the small diameter portion of the hot forging material for turbine blades, and each of the above-mentioned The pressing portion has a shape formed so as to surround the outer peripheral surface of the forged material along the circumferential direction. The first pressing portion and the second pressing portion are pressed surfaces having substantially the same shape on the outer peripheral surface of the hot forging material for turbine blades to be pressed, and are bent (shape-corrected) to remove rough terrain with little bending. It can be obtained with good reproducibility.
In this way, the forging material can be continuously hot forged into a predetermined wasteland shape using the same radial forging machine from cutting to forging and bending to make a wasteland. After using such a jig for forging, it is possible to omit the complicated process of forging again with another forging machine. Therefore, although the number of reheatings can be reduced, it is possible to manufacture a wasteland for turbine blades with high accuracy.

According to the present invention, even a difficult-to-process material used for a turbine blade can be easily bent by using a radial forging machine. In addition, since the shape of the bend is corrected after the forging process, it is possible to obtain a wasteland with little variation in shape with good reproducibility. Further, according to the hot forging method using an unprecedented radial forging machine, the number of times of reheating of the forged material can be dramatically reduced, the productivity is improved, and the energy saving is extremely effective.

(Example 1)
A pair of hot forging dies 1 shown in FIG. 2 were prepared. The forging using the roughing portion is roughing forging, and the forging using the finishing portion is finish forging.
The prepared cutting portion 5 of the hot forging die 1 for cutting has a pair of pressing portions for cutting for sandwiching the forging material, and the pressing portions for cutting are continuous so as to surround the forging material. , The cross section has a substantially semicircular convex shape, and the forging pressing portion has a forging roughing portion and a convex forging finishing portion having a radius of curvature larger than that of the forging roughing portion. Is. The radius of curvature of the substantially semicircular convex shape of the shaving rough processing portion 13 is 30 mm, and the radius of curvature of the substantially semicircular convex shape of the shaving finishing processing portion 14 is 50 mm, and the radius of curvature is gradually changed during that period. It was.
Further, the forging pressing portion provided in the extending portion 7 of the hot forging die 11 for extending the forging material after the cutting process has the pressing portion formed flat, and the shape thereof is shown in FIG. It is shown in 3. The forging extension portion 7 has a pair of pressing portions 12 for sandwiching the forging material, and the pressing portion 12 has a substantially trapezoidal convex cross section so as to surround the forging material and forging. The pressing portion 12 has a forging and roughing processing portion 13 having a substantially flat work surface and a finishing processing portion 14. The width of the forging pressing portion is 50 mm for the roughing portion 13 and 100 mm for the finishing processing portion 14, and the width is displaced between them. Using a hot forging die having a shape that emphasizes the final shape. went.
The hot forging dies were attached to the radial forging machine as a pair in pairs to prepare for hot forging.

The forged material for the 50-inch turbine blade was heated in a heating furnace heated to 950 ° C. The forged material was a titanium alloy, the dimensions of which were φ200 mm in diameter and 1100 mm in length.
The forging material was taken out of the heating furnace and hot forging was started with a radial forging machine. The forged material was gripped and operated by a manipulator.
In hot forging, first, the heated forging material 21 is intermittently rotated, and the outer peripheral surface of the forging material is repeatedly pressed by the pressing portions of the two hot forging dies 1 arranged opposite to each other. The material was forged. In the first forging process, the forged material was hot-forged into a predetermined shape while rotating on the spot (the forged material was not moved in the longitudinal direction). As shown in FIG. 2, a die in which a plurality of pressing portions 2 for cutting was formed in one die was used, and cutting was performed at two locations at the same time. At the time of shaving, the pressing location of the forged material was gradually moved from the roughing portion to the finishing portion.
After the completion of the cutting process, the die was replaced with a hot forging die 11 shown in FIG. 3 having a forging pressing portion. At this time, the forging material was removed from the radial forging machine and reheated to a predetermined forging temperature. After the replacement was completed with the hot forging die 11 having the forging pressing portion, the forging material was attached to the radial forging machine again and hot forging was performed by the forging pressing portion. The forged material was hot-forged into a wasteland shape by adjusting it to a predetermined shape while repeating intermittent rotation, sequential movement in the longitudinal direction, and pressing with a radial forging machine. In this forging process, the pressing location of the forged material was gradually moved from the rough processed portion to the finished processed portion. The hot forged material for turbine blades after hot forging had a shape as shown in FIG. 5, which is suitable for forming roots, blades, and bosses. The hot forged material for turbine blades after hot forging did not have any problems such as fog defects.
Finally, the bending (shape correction) step was performed using the bending mold shown in FIG. For the first pressing part and the second pressing part of the bending die, a pressing surface having substantially the same shape is prepared on the outer peripheral surface of the hot forging material for the turbine blade to be pressed, and a radial forging machine is used. Intermittent pressing was repeated to perform bending (shape correction). At this time, as shown in FIG. 11, the third pressing portion and the neck portion come into contact with each other while starting bending (shape correction) from the small diameter portion of the hot forging material for turbine blades and sequentially performing bending (shape correction). At that point, the movement of the hot forging material for the turbine blade was stopped, and bending was performed by the first, second, and third pressing portions only for intermittent rotation, and the shape was adjusted to the final shape to make a wasteland. The diameters of the small and large diameter parts of the wasteland after bending were almost unchanged as compared with the diameters before bending. There was almost no shape defect such as bending in the wasteland for turbine blades after bending (shape correction).

(Example 2)
As Example 2, the effect of the hot forging die shown in FIG. 8 was confirmed. The hot forging die used for cutting is the same as in Example 1 above.
As Example 2, the effect of the hot forging die 11 of FIG. 8 was confirmed. In the hot forging die shown in FIG. 8, the forging extension portion 7 has a pair of forging pressing portions 12 for sandwiching the forging material, and the forging pressing portion 12 surrounds the forging material. As described above, the forging pressing portion 12 having a substantially trapezoidal convex shape in cross section has a forging roughing portion 13 having a substantially flat work surface and a forging finishing machining portion 14. is there. The width of the forging pressing portion is 50 mm for the roughing portion 13 and 120 mm for the finishing processed portion 14, and the width is displaced between them. A recess having a width of 50 mm is formed in the center of the finishing processed portion for finishing. It has two pressing parts of the processed part. The width of the pressing portion divided into two was 35 mm, respectively. Further, the hot forging die used for cutting is the same as that of the first embodiment described above.

The forged material for the 50-inch turbine blade was heated in a heating furnace heated to 950 ° C. The forged material was a titanium alloy, the dimensions of which were φ200 mm in diameter and 1100 mm in length.
The forging material was taken out of the heating furnace and hot forging was started with a radial forging machine. The forged material was gripped and operated by a manipulator.
In hot forging, first, the heated forging material 21 is intermittently rotated, and the outer peripheral surface of the forging material is repeatedly pressed by the pressing portions of the two hot forging dies 1 arranged opposite to each other. The material was forged. In the first forging process, the forged material was hot-forged into a predetermined shape while rotating on the spot (the forged material was not moved in the longitudinal direction). As shown in FIG. 3, a die in which a plurality of pressing portions 12 for cutting was formed in one die was used, and cutting was performed at two locations at the same time. At the time of shaving, the pressing location of the forged material was gradually moved from the roughing portion to the finishing portion.
After the completion of the cutting process, the die was replaced with the hot forging die 11 of FIG. 3 having a forging pressing portion. At this time, the forging material was removed from the radial forging machine and reheated to a predetermined forging temperature. After the replacement was completed with the hot forging die 11 having the forging pressing portion, the forging material was attached to the radial forging machine again and hot forging was performed by the forging pressing portion. The forged material was hot-forged into a wasteland shape by adjusting it to a predetermined shape while repeating intermittent rotation, sequential movement in the longitudinal direction, and pressing with a radial forging machine. Next, the forging material was replaced with the hot forging die 11 shown in FIG. 8 and finished by 10-pass radial forging. In this forging process, the pressing location of the forged material was gradually moved from the rough processed portion to the finished processed portion. The hot forged material for turbine blades after hot forging had a shape as shown in FIG. 5, which is suitable for forming roots, blades, and bosses. The hot forged material for turbine blades after hot forging did not have any problems such as fog defects. Regarding the bending of the hot forged material for turbine blades having a total length of about 1500 mm, it was confirmed that the bending was suppressed by about 5 mm as compared with the wasteland obtained in Example 1.
Finally, the bending (shape correction) step was performed using the bending mold shown in FIG. As the first pressing portion and the second pressing portion of the bending die, a pressing surface having substantially the same shape is prepared on the outer peripheral surface of the hot forging material for the turbine blade to be pressed, and a radial forging machine is used. The intermittent pressing was repeated to remove the bend (shape correction). At this time, as shown in FIG. 11, the third pressing portion and the neck portion come into contact with each other while starting bending (shape correction) from the small diameter portion of the hot forging material for turbine blades and sequentially performing bending (shape correction). At that point, the movement of the hot forging material for the turbine blade was stopped, and bending was performed by the first, second, and third pressing portions only for intermittent rotation, and the shape was adjusted to the final shape to make a wasteland. The diameters of the small and large diameter parts of the wasteland after bending were almost unchanged as compared with the diameters before bending. There was almost no shape defect such as bending in the wasteland for turbine blades after bending (shape correction).

1 Hot forging die (hot forging die for shaving)
2 Approximately semi-circular pressing part (pressing part for cutting)
3 Roughing part 4 Roughing part 5 Cutting part 7 Extension part 8 Recession 9 Ridge part 11 Hot forging die (Hot forging die for forging)
12 Approximately trapezoidal pressing part (pressing part for forging and stretching)
13 Forging rough processing part 14 Forging finishing processing part 21 Forging material 22 Rough ground 23 Large diameter part 24 Small diameter part 25 Neck 31 Bending die (hot forging die)
32 First pressing part 33 Second pressing part 34 Third pressing part

Claims (4)

It is a bending die for correcting the shape of a rod-shaped hot forging material for turbine blades by radial forging.
The bending die has a pressing portion for correcting the bending of the hot forging material for turbine blades.
The hot forging material for turbine blades has a large diameter portion and a small diameter portion having different outer diameters.
The pressing portion has a first pressing portion and a second pressing portion that simultaneously press the large diameter portion and the small diameter portion of the hot forging material for turbine blades.
The bending die for bending, wherein the first pressing portion and the second pressing portion are formed so as to surround the outer peripheral surface of the hot forging material for turbine blades along the circumferential direction. A bending method in which the hot forging material for turbine blades is bent by a pair of bending dies arranged opposite to the central axis of the hot forging material for turbine blades using a radial forging machine. There,
The bending die has a pressing portion for correcting the bending of the hot forging material for turbine blades.
The hot forging material for turbine blades has a large diameter portion and a small diameter portion having different outer diameters.
The pressing portion has a first pressing portion and a second pressing portion that simultaneously press the large diameter portion and the small diameter portion of the hot forging material for turbine blades.
The bending method, wherein the first pressing portion and the second pressing portion are formed so as to surround the outer peripheral surface of the hot forging material for turbine blades along the circumferential direction. The bending method according to claim 1 or 2, wherein the hot forging material for turbine blades is a nickel-based superheat-resistant alloy or a titanium alloy. The first step of obtaining a rod-shaped hot forging material for turbine blades by hot forging, and
A second method for bending the hot forging material for turbine blades by using a radial forging machine and using a pair of bending dies arranged to face each other toward the central axis of the hot forging material for turbine blades. It is a method of manufacturing a wasteland for a turbine blade having a process.
The bending die has a pressing portion for correcting the bending of the hot forging material for turbine blades.
The hot forging material for turbine blades has a large diameter portion and a small diameter portion having different outer diameters.
The pressing portion has a first pressing portion and a second pressing portion that simultaneously press the large diameter portion and the small diameter portion of the hot forging material for turbine blades.
A method for manufacturing a wasteland for turbine blades, wherein the first pressing portion and the second pressing portion are formed so as to surround an outer peripheral surface of the hot forging material for turbine blades along a circumferential direction.