阅读说明：本技术 减少高温合金涡轮叶片锻件飞边开裂的坯料设计方法 (Blank design method for reducing flash cracking of high-temperature alloy turbine blade forging ) 是由 魏丽 封嗣虎 苏化冰 孙正力 孙凤军 郝艳雄 康炯 于 2021-09-18 设计创作，主要内容包括：本发明公开了一种减少高温合金涡轮叶片锻件飞边开裂的坯料设计方法,具体是采用制坯工装进行镦头,制坯工装包括镦头模和约束模,镦头模中设置有成型叶身和一部分叶根的型腔,约束模设置于型腔的端部,约束模中设置有变截面腔,用于对坯料剩余部分叶根形状进行外廓形状约束,使坯料的叶根同锻件叶根的截面积变化趋势相同,再对坯料叶身拔长,完成制坯。或者,对下料体积进行控制,使镦头模的型腔达到自然未充满状态,根据镦头成型规律,叶根镦粗部位自然形成变截面,与锻件叶根截面积变化趋势相近或相同,再对坯料叶身拔长,完成制坯。上述坯料设计方法可得到叶根变截面坯料,有效改善了模锻时叶根飞边开裂的情况,提高了锻件合格率。(The invention discloses a blank design method for reducing flash cracking of a high-temperature alloy turbine blade forging, which particularly comprises the step of upsetting by using a blank manufacturing tool, wherein the blank manufacturing tool comprises a heading die and a restraining die, the heading die is provided with a forming blade body and a cavity of a part of blade root, the restraining die is arranged at the end part of the cavity, and the restraining die is provided with a variable cross-section cavity for carrying out outline shape restraint on the shape of the rest blade root of a blank so that the blade root of the blank has the same change trend with the cross-section area of the blade root of the forging, and then the blade body of the blank is drawn out to finish blank manufacturing. Or controlling the blanking volume to ensure that the cavity of the heading die is in a natural unfilled state, naturally forming a variable cross section at the upsetting part of the blade root according to the heading forming rule, wherein the variable cross section is similar or identical to the variation trend of the sectional area of the blade root of the forged piece, and then drawing out the blade body of the blank to finish blank manufacturing. The blank design method can obtain the blank with the variable cross section of the blade root, effectively improves the condition that the flash of the blade root is cracked during die forging, and improves the qualified rate of forgings.)

1. The blank design method for reducing the flash cracking of the high-temperature alloy turbine blade forging is characterized in that a blank making tool is adopted for heading, the blank making tool comprises a heading die and a restraining die, a die cavity for forming a blade body and a part of blade root is arranged in the heading die, the restraining die is arranged at the end part of the die cavity, a variable cross-section cavity is arranged in the restraining die and used for carrying out outline shape restraint on the shape of the rest blade root of the blank, the blade root of the blank has the same change trend with the sectional area of the blade root of the forging, and then the blade body of the blank is drawn out to finish blank making.

2. The blank design method for reducing flashing cracking of a high temperature alloy turbine blade forging as set forth in claim 1, wherein: the blanking volume is equal to the sum of the volume of the cavity and the volume of the variable cross-section cavity.

3. The blank design method for reducing flashing cracking of a high temperature alloy turbine blade forging as set forth in claim 1, wherein: the end part of the heading die is provided with a mounting cavity, and the restraint die is embedded into the mounting cavity to align and connect the variable cross-section cavity with the die cavity.

4. A blank design method for reducing flash cracking of a high-temperature alloy turbine blade forging is characterized in that blanking volume is controlled, a cavity of a heading die is naturally in an unfilled state, a blade root upsetting portion naturally forms a variable cross section according to heading forming rules, the variable cross section is close to or identical to the variation trend of the cross section of a blade root of a forging, and then a blank is manufactured by lengthening a blade body of the blank.

5. The blank design method for reducing flashing cracking of a high temperature alloy turbine blade forging as set forth in claim 4, wherein: and (4) blanking according to 0.8-1 of the volume of the cavity of the heading model.

Technical Field

The invention relates to the technical field of blade forging manufacturing, in particular to a blank design method for reducing flash cracking of a high-temperature alloy turbine blade forging.

Background

The gas turbine blade is mostly fir type blade root shape, and the blade shape is as shown in figure 1, and the blade root of this type of forging is variable cross section, and blade root bottom sectional area is less than the sectional area that the blade root is close to the blade body promptly, and the forging shape is as shown in figure 2.

When the blade forging is manufactured, a blank manufacturing and die forging mode is generally adopted for manufacturing and forming, a blank manufacturing design generally adopts an upset method for gathering materials at a blade root, then a blade body is drawn out, as shown in fig. 3, and a corresponding upset tool is shown in fig. 4. At present, turbine blade forgings of steam turbines are usually stainless steel blades, when a fir-shaped blade root forging heading is designed, blanks after heading are usually designed to be equal in diameter, and the stainless steel materials have good plastic deformation capacity, so that the phenomenon of blade root flash sharp corner cracking cannot occur when the blanks in the shape are subjected to subsequent die forging.

However, in order to adapt to the high-temperature working environment of the combustor, the turbine blade of the gas turbine is usually made of high-temperature alloy materials. For the high-temperature alloy forge piece, if the blank is designed to have the same diameter according to the stainless steel blade after heading, the high-temperature alloy is sensitive to deformation temperature, deformation degree and the like, the sharp corner of the blade root is easy to crack in the die forging forming process, the crack is easy to extend to the forge piece body, and then the polishing damage of the forge piece is increased, and even the forge piece is scrapped.

Therefore, the blank design method needs to be changed for different forging materials.

Disclosure of Invention

The invention aims to provide a blank design method for reducing flash cracking of a high-temperature alloy turbine blade forging, so that the blade root cracking condition of a die forging is reduced in the die forging process, the polishing and damage removing cost caused by cracking is reduced, the forging scrapping caused by serious cracking is avoided, and the forging qualified rate is improved.

In order to achieve the purpose, the invention adopts the following technical scheme:

a blank design method for reducing flash cracking of a high-temperature alloy turbine blade forging is characterized in that a blank making tool is adopted for heading, the blank making tool comprises a heading die and a restraining die, a forming blade body and a cavity of a part of blade root are arranged in the heading die, the restraining die is arranged at the end part of the cavity, a variable cross-section cavity is arranged in the restraining die and used for carrying out outline shape restraint on the shape of the rest blade root of a blank, the blade root of the blank has the same trend with the change trend of the cross-section of the blade root of a forging, then the blade body of the blank is drawn out, and blank making is completed.

In particular, the blanking volume is equal to the sum of the cavity volume and the variable cross-section cavity volume.

Particularly, the end part of the heading head die is provided with a mounting cavity, and the constraint die is embedded into the mounting cavity to align and connect the variable cross-section cavity with the die cavity.

Or, a blank design method for reducing flash cracking of a high-temperature alloy turbine blade forging, which is characterized in that the blanking volume is controlled, so that a cavity of a heading die is in a natural unfilled state, a blade root upsetting part naturally forms a variable cross section according to the heading forming rule, the variable cross section is similar or identical to the variation trend of the blade root cross section of a forging, and then the blade body of the blank is drawn out to finish blank making.

Particularly, blanking is carried out according to 0.8-1 of the volume of the cavity of the heading model.

In conclusion, compared with the prior art, the blank design method for reducing the flash cracking of the high-temperature alloy turbine blade forging has the advantages that the blade root restraining die is added to the existing heading die or the blanking volume is controlled according to the forming requirement of the fir-shaped blade root forging of the high-temperature alloy turbine blade, so that the blade root variable-section blank is obtained, the flash cracking condition of the blade root during die forging is effectively improved, and the qualified rate of the forging is improved.

Drawings

FIG. 1 is a schematic view of a gas turbine high temperature alloy turbine bucket fir-tree root blade provided in accordance with the present invention;

FIG. 2 is a schematic view of a gas turbine high temperature alloy turbine bucket fir tree root forging provided in accordance with the present invention;

FIG. 3 is a schematic illustration of a prior art blank design method provided by the present invention;

FIG. 4 is a schematic structural view of a prior art heading die provided by the present invention;

FIG. 5 is a schematic structural diagram of a blank manufacturing tool in the blank design method for reducing flash cracking of a high-temperature alloy turbine blade forging provided by embodiment 1 of the invention;

FIG. 6 is a schematic diagram of the shape of the blank obtained by the blank design method for reducing the flash cracking of the high-temperature alloy turbine blade forging provided by the embodiment 1 of the invention;

FIG. 7 is a first schematic forming diagram of a blank design method for reducing flash cracking of a high-temperature alloy turbine blade forging provided by embodiment 2 of the invention;

FIG. 8 is a second schematic forming diagram of the blank design method for reducing flash cracking of the high-temperature alloy turbine blade forging provided by embodiment 2 of the invention.

Detailed Description

Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar parts throughout or parts having the same or similar functions. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning a fixed connection, a removable connection, a mechanical connection, an electrical connection, an indirect connection via an intermediary, a communication between two elements, or an interaction between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description of the present invention, unless otherwise expressly specified or limited, the first feature "on" or "under" the second feature may include the first feature and the second feature being in direct contact, or may include the first feature and the second feature being in contact not directly but with another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature. The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

Example 1:

the preferred embodiment provides a blank design method for reducing flash cracking of a high-temperature alloy turbine blade forging, which comprises the following steps:

1) upsetting is carried out by adopting a blank making tool, so that a blank a with the shape of a blade root being a variable cross section is obtained, and the blank a is shown in figure 6.

As shown in fig. 5, the blank making tool comprises an upsetting die 1 and a restraining die 2, wherein a cavity 3 for forming a blade body and a part of a blade root is formed in the upsetting die 1, the restraining die 2 is arranged at the end part of the cavity 3, and a variable cross-section cavity 4 is formed in the restraining die 2 and is used for carrying out outline shape restraint on the shape of the rest blade root of the blank so that the blade root of the blank has the same variation trend with the sectional area of the blade root of the forged piece. Specifically, the end of the heading die 1 is provided with a mounting cavity 5, the restraint die 2 is embedded into the mounting cavity 5, the variable cross-section cavity 4 is aligned and connected with the die cavity 3, and the blanking volume is equal to the sum of the volume of the die cavity 3 and the volume of the variable cross-section cavity 4.

2) And (5) drawing out the leaf body of the blank a to obtain the final blank.

3) And die forging the blank to obtain the final forged piece.

Example 2:

the preferred embodiment provides a blank design method for reducing flash cracking of a high-temperature alloy turbine blade forging, please refer to fig. 7 and 8, which includes the steps of:

1) and controlling the blanking volume, preferably blanking according to 0.8-1 of the volume of the cavity of the heading die, so that the cavity of the heading die is naturally not filled, and the heading die obtains a formed blank b.

It should be noted that, according to the heading forming rule, the heading portion of the blade root will naturally form a variable cross section, which is similar to or the same as the variation trend of the sectional area of the blade root of the forged piece.

2) And (5) drawing out the leaf body of the blank b to obtain the final blank.

3) And die forging the blank to obtain the final forged piece.

In conclusion, the two blank design methods for reducing the flash cracking of the high-temperature alloy turbine blade forging are based on the forming requirement of the fir-type blade root forging of the high-temperature alloy turbine blade, and a blade root restraining die or the blanking volume is controlled for the existing heading die, so that the blade root variable-section blank is obtained, the situation of the flash cracking of the blade root during die forging is effectively improved, and the qualified rate of the forging is increased.

The foregoing embodiments are merely illustrative of the principles and features of this invention, which is not limited to the above-described embodiments, but is capable of various modifications and changes without departing from the spirit and scope of the invention, which are intended to be within the scope of the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.