JP6108258B2 - Die for hot forging and hot forging method - Google Patents

Description

  The present invention relates to a hot forging die and a hot forging method.

For example, when manufacturing a turbine blade, the root portion of the turbine blade is formed by forging a round bar-shaped hot forging material to a desired diameter, and further forming a near-net shape turbine blade material by stamping forging. In order to secure the volume of the part that becomes the wing part, a desired round bar-shaped rough ground is formed. Regarding the shape of this wasteland, for example, in FIG. 2 of Japanese Patent Laid-Open No. 63-238942 (Patent Document 1), the root portion is thick (the volume is large) and gradually narrows toward the wing tip. Wasteland is shown.
As a specific method for producing this wasteland, for example, a round bar-like hot forging material is radially forged to a desired diameter to obtain a long round bar, cut into a predetermined size, and further free forging. It is forged into the desired wasteland shape with the equipment.

When turbine blades are stamped and forged, roots, wings, and protrusions called bosses may be provided on the blades of turbine blades, and volume and dimensional adjustments are important in turbine blade waste. It becomes. If the volume and dimensions are not adjusted sufficiently, the rough surface will not be fully filled in the die carved surface during die forging, and part of the turbine blade material of the near net shape after die forging will be missing. A problem arises. Moreover, since the material of the turbine blade is an Ni-based super heat-resistant alloy or an expensive alloy such as a Ti alloy, a defect occurs in which a part of the turbine blade material of the near net shape after die-cut forging is missing. And the damage is not small.
Therefore, it is preferable to provide a processing groove called “segiri” at the time of manufacturing the wasteland, and to perform the processing at the time of the rough ground forming so that the die carved surface at the time of stamping forging is fully filled. However, as shown in, for example, Japanese Patent Application Laid-Open No. 60-250843 (Patent Document 2), a special jig is prepared and a processing device is sequentially provided with a processing groove in a round bar-shaped material by a press device. Become.

JP-A-63-233892 JP-A-60-250843

The shape of the jig for performing the margin shown in Patent Document 2 has a flat pressing portion and the same width, and is not suitable for forming a desired groove in a difficult-to-work material. Further, the groove formed by the margin is narrow and narrow in the vertical direction. When grooves perpendicular to the depth direction of the material are formed, the occurrence of fogging becomes a problem during hot forging in which the forging material is extended to the turbine blade length.
An object of the present invention is to provide a hot forging die and a hot forging method that can be easily scored using a radial forging machine even for difficult-to-work materials used for turbine blades. That is.

The present invention has been made in view of the above-described problems.
That is, the present invention is a hot forging die for hot forging a rod-like forging material by radial forging,
The hot forging die has a pair of halved pressing parts for sandwiching the forging material,
Each of the halved pressing parts is continuous so as to surround the forging material , and the cross section perpendicular to the continuous direction has a substantially semicircular convex shape,
Each of the half-shaped pressing portions is a hot forging die having a rough processed portion and a convex finished processed portion having a radius of curvature larger than that of the rough processed portion.
Preferably, each of the half-shaped pressing portions is a hot forging die having a gradually changing portion in which the radius of curvature of the half-shaped pressing portion gradually increases from the rough processing portion to the finishing processing portion. .
More preferably, it is a hot forging die in which the curvature radius of the substantially semicircular convex shape of the finishing portion is 10 mm or more larger than the curvature radius of the substantially semicircular convex shape of the roughing portion.
Each of the half-shaped pressing portions is a hot forging die that is used for barring.
It is a hot forging die in which a plurality of pressing portions for staking processing are formed in the longitudinal direction of the forging material.

Further, the present invention is a hot forging method for hot forging a rod-like forging material by radial forging,
Hot forging dies used in the hot forging, has a pair of half-shaped pressing portion for sandwiching the forging material,
Each of the halved pressing parts is continuous so as to surround the forging material , and the cross section perpendicular to the continuous direction has a substantially semicircular convex shape,
Each of the half-shaped pressing parts has a roughened part and a convex finished processed part having a larger radius of curvature than the roughened part,
A forging material heating step for heating the forging material to a hot forging temperature;
Hot forging forcing a forging material by rotating the heated forging material while pressing the forging material with each of the halved pressing portions of the two hot forging dies arranged opposite to each other. Process,
Is a hot forging method.
Preferably, it is a hot forging method in which the rod-like forging material is a Ni-base superalloy or Ti alloy.
The hot forging method of the present invention is suitable for manufacturing rough land for turbine blades.

  According to the present invention, even a difficult-to-work material used for a turbine blade can be easily scored using a radial forging machine.

It is a schematic diagram which shows an example of the metal mold | die for hot forging of this invention. It is a schematic diagram which shows an example of the metal mold | die for hot forging of this invention. It is a schematic diagram which shows an example of an expansion | 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 a forge raw material when performing hot forging using the metal mold | die for hot forging of this invention. It is a schematic diagram which shows an example of the place which presses a forge raw material when performing hot forging using the metal mold | die for hot forging of this invention. It is a schematic diagram which shows an example of an expansion | extension part.

In the above-mentioned Patent Document 2, the object to be squeezed is a small product called a connecting rod. On the other hand, turbine blades are becoming larger and larger in the future, and their materials are Ni-based super heat-resistant alloys and Ti alloys, which are also known as difficult-to-work materials. In particular, some of these alloys have only a small range of temperatures that can be hot forged, and if forging is performed using a jig for staking, the temperature of the forging material will decrease. . Therefore, depending on the weight of the material, for example, in the case of a 40 to 60 inch turbine blade, 7 to 10 times of reheating must be performed. As the size of the turbine blade increases, the number of times of reheating further increases.
For this problem, it is very effective if it can be squeezed using a radial forging machine, but the radial forging machine usually uses a mold called a anvil with a flat pressing part. For this reason, it has been impossible to squeeze with a radial forging machine using a conventional anvil.
The present invention enables this, and the greatest feature is an unprecedented shape that can be applied to rough ground forming for large turbine blades using a radial forging machine. The hot forging die used in the present invention will be described below.

  FIG. 1 is a schematic side view of a hot forging die 1 according to the present invention, a cross-sectional view of a finishing portion of the hot forging die 1 (AA cross-sectional view), and a cross-sectional view of rough working surface (CC cross-sectional view). ) And a cross-sectional view (BB cross-sectional view) located between the finish processed portion and the rough processed portion. In addition, in this invention, the radial forging machine pressed from two opposing directions is used. In FIG. 1, 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 half-shaped pressing portion shown in the cross-sectional view gradually increases, and from the BB cross-sectional view to A The radius of curvature up to the position (bottom) shown in the -A sectional view is substantially the same. In addition, the "finishing part" said by this invention makes the place which has the same curvature radius including the position (bottom part) shown by said AA sectional drawing as a finishing part.

The hot forging die 1 shown in FIG. 1 is paired with two, for example, as shown in FIG. 4, the hot forging die 1 is disposed so as to sandwich the forging material 21, and a pair of two Two hot forging dies 1 work together to perform the margin. Specifically, the hot forging molds shown in FIG. 1 are in pairs (pairs) and have a half-shaped pressing portion 2 for sandwiching a forging material (not shown in FIG. 1). The forging material is pressed so as to be sandwiched by the half-shaped pressing portion. The forging material is gripped by the gripping mechanism provided in the radial forging machine, and the forging material is intermittently rotated.
As shown in the schematic side view of FIG. 1, each halved pressing portion 2 has a convex shape having a substantially semicircular cross section that is continuous so as to surround the forging material. The forging material is sandwiched between the pressing portions of the two hot forging dies that work together in a halved shape. Further, “continuous so as to surround the forging material” means a shape in which the periphery of the forging material 21 is surrounded by the roughing portion and the finishing portion as shown in FIG. 4. The half-shaped pressing portion 2 is formed such that a flat surface is formed in a concave shape, and the pressing portion looks like an arc when viewed from the side (a schematic side view of FIG. 1). The half-shaped pressing part 2 has a finishing part 4 and a roughing part 3. The finishing portion 4 is formed around the bottom of the concave shape (arc shape), and the rough processing portion 3 is formed on both sides of the finishing portion (both ends of the concave shape (arc shape)). Then, the distance between the roughing parts widens from the bottom of the finishing part 4 toward the ends of both roughing parts 3, and when the two hot forging dies press the forging material, the forging material Is a shape that can be pressed by a substantially semi-convex convex shape. When the hot forging material is hot forged with the hot forging die 1 having this shape, it contacts the forging material from the convex roughened portion formed in the hot forging die, and is necessary for the margin. Grooves can be formed sequentially. Therefore, the “convex shape having a substantially semicircular cross section” referred to in the present invention refers to a shape when viewed from the direction of each of the above sectional views. That is, it is a cross section when viewed from a direction perpendicular to the longitudinal direction of the forging material.

Each of the half-shaped pressing portions 2 includes a roughing portion 3 and a convex finishing portion 4 having a larger curvature radius than that of the roughing portion. This is because the contact area is reduced in the initial stage of forging so that a groove with a predetermined depth can be formed even when the forging material starts forging from the roughened portion, even if it is difficult to forge. Therefore, the groove can be efficiently processed. Then, as forging progresses, it is gradually pressed toward the finished part, increasing the width of the groove and adjusting the shape of the edge. However, even hot forging at the finished part may not reach the depth of the edge, so the finished part also forms a press part with a substantially semicircular cross-section and contacts as much as possible. By making the area small, it is possible to efficiently adjust the edge shape.
That is, in the present invention, first, the rough machining portion 3 having a small radius of curvature is efficiently grooved first, and then the final shape is efficiently obtained by the finishing portion 4 having a radius of curvature larger than that of the rough machining portion 3. It will be molded. For this reason, the curvature radius is gradually increased from the substantially semicircular pressing portion formed in the rough machining portion 3, and the finish machining portion 4 gradually changes to a convex finish machining portion having a larger curvature radius than the rough machining portion. A gradual change portion will be formed.
In addition, since the actual pressing part may form a substantially semicircular convex part by, for example, overlay welding, or after that, the shape may be machined manually, the convex part having the same curvature radius is not necessarily required. May not be formed. Therefore, the “substantially semicircular shape” in the present invention may be a convex shape having a curvature including an error due to overlay welding or machining, and the curvature may be obtained from an approximate shape. Moreover, what is necessary is just to comprise the curvature of the part to press the forging raw material according to this invention if it is convex shape with the curvature.

  The curvature radius of the substantially semicircular convex shape of the finishing portion 4 of the present invention is preferably 10 mm or more larger than the curvature radius of the substantially semicircular convex shape of the roughing portion 3. This is because the forged material of the present invention becomes a wasteland for large turbine blades, and it is better to increase the contact area between the roughened part and the finished part as a large (long) turbine blade wasteland. This is because it becomes suitable. As another reason, when the curvature radius of the substantially semicircular convex shape of the finished processed portion is large, formation of a wide processed groove is facilitated. This is because it is desirable to widen the width of the processing groove formed by the margin in order to prevent fogging at the location where the margin has been performed during forging where the forging material is elongated after forging. In any case, if the difference in the radius of curvature between the finished portion and the rough portion is less than 10 mm, the effect may not be sufficiently obtained. Therefore, the curvature radius of the substantially semicircular convex shape of the finished portion 4 is The radius of curvature of the substantially semicircular convex shape of the roughened portion is 10 mm or more. Preferably, it is formed with a difference of 15 mm or more.

As described above, the hot forging die 1 of the present invention is suitable for staking processing. In addition, as shown in FIG. 2, you may form two or more half-pressing parts 2 for a barge process in the longitudinal direction of a forge raw material. This is because, for example, in the case of forming machining grooves by cutting at two locations at the same time, it is advantageous to improve productivity by forming a plurality of half-pressing portions 2 for cutting processing in one mold. Because there is. In particular, the material of the alloy used for the turbine blade is a difficult-to-work material, and therefore it is preferable to complete the forging in as short a time as possible within a temperature range where hot forging is possible. It is effective to use this simultaneous cutting process at a plurality of locations on a portion that becomes a boss portion provided on a blade portion of the turbine blade.
In addition, the simultaneous forging at a plurality of locations is possible because the contact area of the pressing portion formed on the hot forging die of the present invention is gradually increased from a small area to a radial area. This could only be realized in combination with a forging machine.
Also in the hot forging die having the structure shown in FIG. 2, the position having the same radius of curvature including the position (bottom part) shown in the EE sectional view (the EE sectional view from the position in the FF sectional view). (Up to the position shown in the figure) is the finishing part.

In addition, after the forging is completed, the forging material is extended to have a predetermined wasteland shape. The hot forging die 11 used in that case is provided with an extending portion 7 that extends the forging material. As shown in FIG. 3, the press portion for forging provided in the extension portion 7 has a flat shape (a flat shape along the longitudinal direction of the forging material 2 and is bent so as to sandwich the forging material 2. Formed). The extending portion 7 for forging has a pair of half-pressing portions 12 for sandwiching the forging material, and each half-pressing portion 12 has a continuous convex shape so as to surround the forging material. The split pressing portion 12 includes a substantially flat rough processing portion 13 and a finishing processing portion 14. The basic configuration is the same as that of the hot forging die suitable for the above-described barring process, and the hot forging die 11 for forging shown in FIG. 3 is a pair (a pair). Forging of the forging material is 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 forging material is gripped and the forging material is rotated. Further, with the rotation of the forging material, the gripped forging material moves in the longitudinal direction, and the longitudinal direction of the forging material is also extended.
In addition, the flat pressing portion of the hot forging die for forging can be efficiently forged by reducing the contact area at the initial stage of forging, and then adjusted to a predetermined shape. In order to facilitate, the surface width of the substantially flat pressing portion formed in the roughing portion 13 is narrowed, and the surface width of the pressing portion formed in the finishing portion 14 is larger than that of the roughing portion 13. It is preferable to make it wide.
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 pressing portion is flat. If the width of the flat pressing portion (the width in the longitudinal direction of the forging material) is excessively widened, the pressure required for forging may increase. For this reason, it is preferable to select a width suitable for the forging machine in consideration of the contact area as the width of the flat pressing portion so that the forge can be efficiently forged by one impact.

Next, as an example, a method for hot forging of rough land for 50-inch turbine blades using the hot forging die of the present invention will be described.
FIG. 4 is a schematic view showing an example of a radial forging machine. A 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 to sandwich 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 differs depending on the material of the forging material. For example, the heating temperature is 950 to 1150 ° C. for a Ni-based super heat resistant alloy, and 800 to 1000 ° C. for a Ti alloy. In addition, it is 900-1200 degreeC in precipitation strengthening type stainless steel. The forging material has a rod shape. The rod-shaped forging material may be any material that has been adjusted to a predetermined shape by a forging device or a pressing device. It is preferable that it is equivalent to the width between each other.
Of the forging materials described above, a predetermined round bar-like forging material is attached to a radial forging machine.

In the hot forging, while rotating the heated forging material 21, two hot forging dies 1 arranged opposite to each other are made into one set (a pair), and the forging material is pressed by the halved pressing portions. As a result, a forging process is performed on the forging material. The shape of the hot forging die for performing the setting is shown in FIG. At the time of this margin processing, first, hot forging is started from the roughened portion 3 of the hot forging die 1. In the hot forging die according to the present invention, when the interval between the roughing portions widens from the finishing portion 4 toward the roughing portion 3 and the two hot forging dies press the forging material, The forging material is continuous and has a substantially semicircular convex shape that can be pressed. Further, in the first margin processing, the forging material rotates on the spot (the forging material does not move in the longitudinal direction).
There are two types of processing methods for this margin processing. The first method will be described from a method emphasizing the shape after finishing the barring process.
When hot forging from two opposing directions is started, first, pressing of the forging material at a predetermined position is started from the roughing portion 3 as shown in FIG. The contact (forging) position between the forging material 21 and the hot forging die during rough machining is indicated by an arrow. Then, although it is hot forging from the two opposite directions, the rough-processed part formed in the two hot forging molds that cooperate and forge at the beginning of forging starts pressing, so at the start of forging There are four places where the forging material is pressed. When these four places start cutting at the same time, since the contact area is small, grooving is performed efficiently. Then, hot forging is sequentially performed toward the finish processing portion, and the finish processing portion formed in the pair of hot forging dies is arranged into a predetermined shape. In the final stage of finishing, as shown in FIG. 6B, when hot forging the forging material 21 at the bottom of the finishing portion, there are two pressing locations. In other words, at the initial stage of the forging process, a pair of hot forging dies are used to perform forging at four locations (forging process), and the final shape adjustment is performed using a pair of hot forging dies. The shape can be adjusted by forging at several locations. Moreover, it can shape | mold efficiently in the final shape by the convex finishing process part 4 with a larger curvature radius than a rough process part. In addition, since it is possible to adjust the final shape with the shape of the bottom of the finished portion indicated by the arrow, it is convenient when the final finished shape is important.

Another method is a method applied when the processing time is short.
When hot forging from two opposing directions is started, as shown in FIG. 7A, first, pressing of the forging material at a predetermined position is started from the rough processed portion 3. The contact (forging) position between the forging material 21 and the hot forging die during rough machining is indicated by an arrow. Then, although it is hot forging from the two opposite directions, the rough-processed part formed in the two hot forging molds that cooperate and forge at the beginning of forging starts pressing, so at the start of forging There are four places where the forging material is pressed. When these four places start cutting at the same time, since the contact area is small, grooving is performed efficiently. Then, hot forging is sequentially performed toward the finishing portion, and the finishing portion 4 formed in the pair of hot forging dies is arranged into a predetermined shape.
As described above, since the radius of curvature from the BB cross-sectional view to the position (bottom portion) shown in the AA cross-sectional view is substantially the same, the finishing process used to the bottom part of the finishing part is not performed. As shown in (B), the finishing process is terminated with four places to be pressed even during the finishing process. Even in this case, it is possible to efficiently form the final shape with the convex finished processed portion 4 having a larger radius of curvature than the rough processed portion, and it is possible to shorten the time by using four pressing points. Gripping can be performed. Therefore, it is convenient when it is desired to shorten the forging time.
In addition, when using this forging time-oriented method, the radius of curvature of the bottom portion (position shown in the AA cross-sectional view) of the finished portion (the radius of curvature when viewed from the direction perpendicular to the longitudinal direction of the forging material shown in FIG. 7). It is important to make it smaller than the radius of curvature of the diameter after processing. However, it is preferable that the bottom portion of the finished processed portion has a curved surface shape so as to avoid excessive stress concentration during hot forging.

When the staking process is completed, the hot forging die 1 is replaced with a hot forging die 11 having a forging press portion. At the time of exchanging the hot forging die, the forging material is reheated to a predetermined forging temperature again.
The exchanged hot forging die 11 is provided with an extension portion 7 having a forging press portion for extending the forging material. The forging press part has the shape shown in FIG. The shape of the pressing portion of the hot forging die 11 having the forging press portion viewed from the longitudinal direction of the forging material is also the hot forging die subjected to the staking shown in FIG. Since it is the same as the mold 1, when hot forging from two opposite directions is started, first, pressing of the forging material at a predetermined position is started from the roughing portion 13. Then, although it is hot forging from two opposing directions, the roughened portion formed on two (a pair) hot forging dies that cooperate and forge in the initial stage of forging (forging) presses. Since it starts, there are four places where the forging material is pressed at the start of forging. When these four locations start forging at the same time, the forging 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 a radial forging machine, sequentially performing hot forging toward the finishing portion, and finishing formed in a pair of hot forging dies. It will be trimmed into a predetermined shape at the processing section.
That is, at the final stage of the finishing process, as shown in FIG. 6B, when hot forging is performed in the finishing part 14, there are two pressing points. This method of adjusting to the final shape with the shape of the bottom of the finished portion is advantageous when the final finished shape is important.
Also, in the hot forging by this forging press section, in order to shorten the hot forging time, as shown in FIG. 7, the number of pressing points from the initial stage of hot forging to the final stage of hot forging is four. By doing so, the forging material can be extended in a short time.

Further, in the hot forging die having the forging and pressing portion, the shape shown in FIG. 8 can be obtained. The hot forging die 11 shown in FIG. 8 is formed with a recess 8 from the bottom in the width of the finish processing portion 14 (width in the longitudinal direction of the forging material) toward the rough processing portion. The pressing part of the finishing part is divided into two parts. By forming one or more recesses within the width of the finish processing portion 14 and using two or more pressing portions of the finish processing portion, bending of the forging material during forging can be more reliably prevented. When hot forging is performed using the hot forging die shown in FIG. 8, the final stage of forging can be performed at the bottom of the finished portion shown by the AA cross section. At the moment when the forging material is pressed, a portion pressed by the finishing portion and a portion adjacent to the portion pressed by the finishing portion are not pressed. When the pressed portion of the meat flows into the non-pressed portion and the meat flows, the cross-section of the forging material may become an ellipse. The forged material that has become an ellipse tends to bend during forging. However, according to the structure of the hot forging die in FIG. 8, since the pressing portion (finishing portion) is divided by the concave portion, the forging material is intermittently rotated by radial forging at the place where the pressing is first performed. Then, the finish is forged by the next pressing part. At this time, in the structure shown in FIG. 8, since the pressure is pressed at a total of four places, as described above, the bending can be corrected while correcting the ellipse by the next pressing portion. In addition, the formation part of a recessed part can exhibit the effect of prevention of bending to the maximum by forming so that the bottom part (part where the straight line shown by AA in FIG. 8 is in contact) is included.
In this way, since the forging material can be hot-forged into a predetermined wasteland shape continuously using the same radial forging machine from squeezing to forging, after using a jig for staking as in the past It is possible to omit the complicated process of forging again with another forging machine. Therefore, although the number of reheating times can be reduced, it is possible to manufacture a highly accurate waste for turbine blades.

  According to the present invention, even a difficult-to-work material used for a turbine blade can be easily scored using a radial forging machine. Further, according to the unprecedented hot forging method using a radial forging machine, the number of reheatings of the forged material can be drastically reduced, productivity is improved, and energy saving is extremely effective.

Example 1
A hot forging die 1 of the present invention shown in FIG. 2 was prepared.
The gap portion 5 of the prepared forging die 1 for hot forging has a pair of half-pressing portions for sandwiching the forging material, and each of the half-pressing portions is made of the forging material. Consecutively surrounding, the cut portion has a substantially semicircular convex shape, and each of the half-shaped pressing portions includes a roughened portion and a convex finished processed portion having a larger radius of curvature than the roughened portion. It is what has. The curvature radius of the substantially semicircular convex shape of the rough processed portion 13 was 30 mm, and the curvature radius of the substantially semicircular convex shape of the finished processed portion 14 gradually changed to 50 mm.
In addition, the forging press portion provided in the extending portion 7 of the hot forging die 11 that extends the forging material after the staking process is formed by pressing the pressing portion in a flat shape. This is shown in FIG. The extending portion 7 for forging has a pair of half-pressing portions 12 for sandwiching the forging material, and each half-pressing portion 12 has a continuous convex shape so as to surround the forging material. The split pressing portion 12 includes a substantially flat rough processing portion 13 and a finishing processing portion 14. The width of the pressing portion for forging is such that the roughened portion 13 is 50 mm and the finished portion 14 is changed to 100 mm, and a hot forging die having a shape focusing on the final shape is used.
The above-mentioned hot forging molds were attached to a radial forging machine as a pair in pairs, and preparation for hot forging was performed.

A forging material for a 50 inch turbine blade was heated in a heating furnace heated to 950 ° C. The forging material was a titanium alloy, and the dimensions were a diameter of 200 mm and a length of 1100 mm.
The forging material was taken out of the heating furnace and hot forging was started with a radial forging machine. The forging material was manipulated by gripping with a manipulator.
In the hot forging, first, the forging material is pressed by pressing each of the half-shaped pressing portions of the two hot forging dies 1 arranged opposite to each other while rotating the heated forging material 21. The sashimi processing was performed. In the first cutting process, the forging material was hot forged into a predetermined shape while rotating the forging material on the spot (without moving the forging material in the longitudinal direction). As shown in FIG. 2, a mold in which a plurality of half-pressing portions 2 for slicing was formed on one mold was used to perform squeezing at two locations simultaneously.
After the staking process was completed, the hot forging die 11 having a forging press part was replaced. At this time, the forging material was removed from the radial forging machine and reheated again to a predetermined forging temperature. After completion of the exchange for the hot forging die 11 having the forging press part, the forging material was again attached to the radial forging machine, and hot forging by the forging press part was performed. The forging material was sequentially moved in the longitudinal direction while intermittently rotating with a radial forging machine, adjusted to a predetermined shape, and hot forged into a rough land shape. The waste land 22 after hot forging had a shape as shown in FIG. 7 suitable for forming the root portion, the wing portion, and the boss portion. In the wasteland after hot forging, there were no problems such as fogging.

(Example 2)
As Example 2, the effect of the hot forging die in FIG. 8 was confirmed. The hot forging die used for the setting was 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 extending portion 7 for forging has a pair of half-shaped pressing portions 12 for sandwiching the forging material, and each of the half-shaped pressing portions 12 is made of a forging material. Each of the halved pressing parts 12 has a substantially flat roughened part 13 and a finished processed part 14. The width of the pressing portion for forging is 50 mm for the rough processed portion 13 and 100 mm for the finished processed portion 14, and a recess having a width of 80 mm is formed at the center of the finished processed portion. There are two pressing parts. In addition, the width | variety of the press part divided into two was 270 mm, respectively. Further, the hot forging die used for staking was the same as that in Example 1 described above.

A forging material for a 50 inch turbine blade was heated in a heating furnace heated to 950 ° C. The forging material was a titanium alloy, and the dimensions were a diameter of 200 mm and a length of 1100 mm.
The forging material was taken out of the heating furnace and hot forging was started with a radial forging machine. The forging material was manipulated by gripping with a manipulator.
In the hot forging, first, the forging material is pressed by pressing each of the half-shaped pressing portions of the two hot forging dies 1 arranged opposite to each other while rotating the heated forging material 21. The sashimi processing was performed. In the first cutting process, the forging material was hot forged into a predetermined shape while rotating the forging material on the spot (without moving the forging material in the longitudinal direction). As shown in FIG. 3, a die having a plurality of half-pressing portions 12 for cutting processing formed on one die was used, and two locations were simultaneously cut.
After the staking process was completed, the hot forging die 11 shown in FIG. At this time, the forging material was removed from the radial forging machine and reheated again to a predetermined forging temperature. After completion of the exchange for the hot forging die 11 having the forging press part, the forging material was again attached to the radial forging machine, and hot forging by the forging press part was performed. The forging material was sequentially moved in the longitudinal direction while intermittently rotating with a radial forging machine, adjusted to a predetermined shape, and hot forged into a rough land shape. Finally, the hot forging die 11 shown in FIG. 8 was replaced, and the forging material was finished by 10-pass radial forging. The waste land 22 after hot forging had a shape as shown in FIG. 5 suitable for forming the root portion, the wing portion, and the boss portion. In the wasteland after hot forging, there were no problems such as fogging. About the bending of the wasteland whose total length is about 1500 mm, compared with the wasteland obtained in Example 1, suppression of the bending of about 5 mm was confirmed.
According to the manufacturing method of the present invention, even a difficult-to-work material used for a turbine blade or the like can be easily forged using a radial forging machine. Further, since the forging process can be hot forged into a predetermined rough ground shape using a radial forging machine, a complicated process such as using a jig for staking as in the prior art can be omitted. For this reason, it has become possible to manufacture a highly accurate waste for turbine blades even though the number of times of reheating can be reduced.

DESCRIPTION OF SYMBOLS 1 Hot forging die 2 Half-shaped press part 3 Roughing part 4 Finishing part 5 Edge part 7 Elongation part 8 Recessed part 11 Hot forging die (for forging)
12 Half-pressing part (for forging)
13 Roughly processed part (For forging)
14 Finishing part (for forging)
21 Forging material 22 Wasteland 31 Hot forging die

Claims (8)

A hot forging die for hot forging a rod-like forging material by radial forging,
The hot forging die has a pair of halved pressing parts for sandwiching the forging material,
Each of the halved pressing parts is continuous so as to surround the forging material , and the cross section perpendicular to the continuous direction has a substantially semicircular convex shape,
Each of the halved pressing parts includes a roughing part and a convex finishing part having a larger curvature radius than the roughing part.   Each said half-shaped press part has a gradual change part from which a curvature radius of the said half-shaped press part becomes large gradually toward a finishing process part from a rough processing part. Hot forging die.   The curvature radius of the substantially semicircular convex shape of the finishing portion is 10 mm or more larger than the curvature radius of the substantially semicircular convex shape of the rough portion. Hot forging die.   The hot forging die according to any one of claims 1 to 3, wherein each of the half-shaped pressing portions is used for a barring process.   5. The hot forging die according to claim 4, wherein a plurality of pressing portions for squeezing are formed in a longitudinal direction of the forging material. A hot forging method in which a rod-like forging material is hot forged by radial forging,
Hot forging dies used in the hot forging, has a pair of half-shaped pressing portion for sandwiching the forging material,
Each of the halved pressing parts is continuous so as to surround the forging material , and the cross section perpendicular to the continuous direction has a substantially semicircular convex shape,
Each of the half-shaped pressing parts has a roughened part and a convex finished processed part having a larger radius of curvature than the roughened part,
A forging material heating step for heating the forging material to a hot forging temperature;
Hot forging forcing a forging material by rotating the heated forging material while pressing the forging material with each of the halved pressing portions of the two hot forging dies arranged opposite to each other. Process,
A hot forging method comprising:   The hot forging method according to claim 6, wherein the bar-like forging material is a Ni-base superalloy or Ti alloy. Hot forging method according to claim 6 or 7, hot forging how to characterized in that it is used in the manufacture of wasteland for a turbine blade.

Images