KR101065357B1 - A forging device for titanium alloy bolt and a manufacturing method of forging for titanium alloy bolt and titanium alloy bolt using it - Google Patents

Abstract

The forging device for titanium alloy bolt according to the present invention includes a forcing unit forcing the transfer of a titanium alloy material as a bar, and a stopper for selectively limiting the transfer distance of the titanium alloy material to be conveyed by the forcing unit; Pressing the outer surface of the titanium alloy material stopped by the stopper to limit the movement, the rapid heating portion for rapidly heating the portion projecting out of the holder of the titanium alloy material, and pressurized the heated titanium alloy material It characterized in that it comprises a punch to form a forged product for titanium alloy bolts.

Description

Forging device for titanium alloy bolt and a manufacturing method of forging for titanium alloy bolt and titanium alloy bolt using it}

The present invention relates to a titanium alloy bolt forging device capable of producing a titanium alloy bolt forging in a low temperature forging process of 400 ℃ or less, and a method for producing a titanium alloy bolt forging using the same and a method for producing a titanium alloy bolt.

Titanium alloy has higher strength, corrosion resistance and light weight than ordinary carbon steel, stainless steel and special alloy steel, and is the second most abundant metal after aluminum, iron and magnesium among the various metals that can be mined on the earth.

Therefore, the existing materials as structural materials and functional materials are being replaced with titanium, and the demand for military equipment and civil industry is rapidly increasing, and is being actively used for aircraft and ships.

In addition, a lot of research is being conducted on the manufacture of bolts made of titanium alloy.

That is, titanium alloy bolts are generally poor in formability, so a cold forging process is required to be carried out a plurality of times, and in particular, the occurrence frequency of cracks is high, and productivity is lowered.

In addition, the titanium alloy bolt manufactured by hot forging has a problem that surface cracks are frequently generated by the surface oxide layer generation, such surface oxide layer has a problem of lowering the machinability.

Therefore, many studies have been conducted on forging dies and process designs in consideration of formability and machinability of titanium alloy bolts.

However, the titanium alloy bolts formed by a plurality of cold and hot forgings have the following problems.

That is, defects such as cracks are frequently generated during forging molding, which causes difficulty in mass production.

In addition, since the forging die is caused due to friction with the inside of the mold and the characteristic of the material during the forging using the forging die, there is a problem in that the management cost due to the forging die is rapidly increased.

In addition, the forged-molded titanium alloy has a high hardness and a surface oxide layer, and the amount of tool wear of the molding machine increases rapidly during post-processing, so that the frequent replacement of the titanium alloy bolt has a problem of increasing the manufacturing cost of the titanium alloy bolt.

In addition, Korean Patent No. 0628030 discloses a 'titanium bolt and its manufacturing method' which is completed by forming a cut titanium alloy material by hot forging, spraying a small particle into the titanium alloy and shortening the thread after machining. have.

However, such a prior art requires a shot peening step for imparting compressive stress to a forged molded forging. That is, as the hot forging is performed, a thick oxide layer is formed on the surface of the titanium alloy material when it is heated, and the oxide layer is a main cause of problems such as causing thread cracking during surface rolling and post-processing.

An object of the present invention for solving the above problems is to move the titanium alloy material by a set length, and then only a part of the rapid heating and low temperature forging molding to block the generation of oxide layer in advance, to minimize the molding time and contact with the mold The present invention provides a forging device for titanium alloy bolts which allows forging molding without precoating to prevent seizure.

Another object of the present invention is to manufacture a forging for titanium alloy bolt using a forging device for the titanium alloy bolt that allows the continuous production of the forging by cutting a titanium alloy material forged molded by a predetermined length in the forging device for titanium alloy bolt. To provide a method.

Still another object of the present invention is to provide a method of manufacturing a titanium alloy bolt, which is performed by performing the forging product heat treatment step, the forging product processing step, the forging step, and the aftertreatment step in the manufacturing method of the forging product for titanium alloy bolt as described above.

The forging device for titanium alloy bolt according to the present invention includes a forcing unit forcing the transfer of a titanium alloy material as a bar, and a stopper for selectively limiting the transfer distance of the titanium alloy material to be conveyed by the forcing unit; Pressing the outer surface of the titanium alloy material stopped by the stopper to limit the movement, the rapid heating portion for rapidly heating the portion projecting out of the holder of the titanium alloy material, and pressurized the heated titanium alloy material It characterized in that it comprises a punch to form a forged product for titanium alloy bolts.

The punch is characterized in that the material is selectively stopped by contacting the forged article for titanium alloy bolt which is forcibly conveyed by the conveying forcing unit after returning to its original position after forming the forged article for titanium alloy bolt.

The stopper is characterized in that forging the titanium alloy bolt forging from the material by the linear motion when the punch and the forging for titanium alloy bolt is in contact.

The rapid heating unit is characterized in that for heating the titanium alloy material by any one of the heating method of direct current, induction heating, reflection furnace heating.

The holder is characterized in that the heat radiation to the outside of a portion of the heat provided by the rapid heating unit.

The method for manufacturing a titanium alloy bolt forging using the titanium alloy bolt forging device according to the present invention includes a material setting step of setting a titanium alloy material, which is a bar material, in a forging device for titanium alloy bolts, and transferring the titanium alloy material to a transfer steel part and The material transfer step of limiting the movement of the titanium alloy material using the holder after the transfer using a stopper for a predetermined distance, and the material heating to rapidly heat a portion of the titanium alloy material protruding outside the holder to a temperature of 400 ℃ or less And a forging molding step of forging the titanium alloy material protruding outside the holder with a punch, and transferring the titanium alloy material by a predetermined length and cutting the length by a length including a forged portion. It consists of forging part cutting step.

In the material heating step, the holder is characterized in that to release a part of the heat provided to the titanium alloy material to the outside.

The material heating step is a process of heating a portion of the titanium alloy material by a rapid heating unit for heating by any one of the direct current, induction heating, reflection furnace heating.

The forging part cutting step is characterized in that the process of cutting using the stopper after stopping the titanium alloy material to be transported with a punch.

The material heating step is characterized in that the part of the titanium alloy material is heated to a temperature of 400 ℃ or less.

The method for manufacturing a titanium alloy bolt according to the present invention includes a material setting step of setting a titanium alloy material, which is a bar, in a forging device for titanium alloy bolts, and transferring the titanium alloy material by a predetermined distance using a feed force and a stopper. After the material transfer step of limiting the movement of the titanium alloy material using the holder, the material heating step of rapidly heating a portion of the titanium alloy material protruding outside the holder to a temperature of 400 ℃ or less, protruding outside the holder A forging molding step of forging a titanium alloy material by punching it with a punch, and a forging cutting step of transferring the titanium alloy material by a predetermined length and cutting the length by a length including a forged molded part to form a forging product, and the forging product. Forging heat treatment step for heat treatment, Pickling treatment step for pickling the heat treatment forged product And that comprising the preceding step of the forging process step of processing the pickling process the forging, and machining the thread on the outer surface of the machined titanium alloy forging forming the bolt characterized.

The forged product heat treatment step is characterized in that the forged product is maintained at 927 ° C. for 1 hour, cooled to 850 to 900 ° C., immersed in water, and quenched at 480 ° C. for 24 hours.

After the precursor step, a post-treatment step consisting of an anodizing process for forming a film on the surface of the titanium alloy bolt, and a lubricant coating process for applying a lubricant is carried out.

The pickling step is characterized in that the process of removing the oxide scale by immersing the titanium alloy bolt for 5 to 10 minutes in a pickling solution containing 15% HNO ₃ , 3% HF, 82% H ₂ O by weight.

According to the present invention as described above, after the titanium alloy material is moved by a set length, only a portion of the titanium alloy material is rapidly heated and forged to block the generation of oxide scales.

Further, minimization of forging time and contact with a mold prevents quenching during forging, thereby improving quality and preventing damage to the device.

In addition, since the forged product can be continuously manufactured by cutting the forged-molded titanium alloy material by a predetermined length, there is an advantage of improving productivity and reducing manufacturing costs.

1 is a schematic view showing the configuration of a forging apparatus for titanium alloy bolt according to the present invention.
Figure 2 is a process flow chart showing a method for producing a titanium alloy bolt forging using the titanium alloy bolt forging apparatus according to the present invention.
Figure 3 is a process flow chart showing a method for producing a titanium alloy bolt according to the present invention.
Figure 4 is a schematic diagram showing a material transfer step as one step in the titanium alloy bolt forging manufacturing method using the forging device for titanium alloy bolt according to the present invention.
5 is a schematic view showing a material heating step as one step in the method for manufacturing a titanium alloy bolt forging using the forging device for titanium alloy bolt according to the present invention.
Figure 6 is a schematic view showing a forging step in one step in the method for manufacturing a forging for titanium alloy bolt using the forging device for titanium alloy bolt according to the present invention.
Figure 7 is a schematic diagram showing a state in which the titanium alloy material is transferred before the forging step cutting step in the titanium alloy bolt forging manufacturing method using the forging device for titanium alloy bolt according to the present invention.
Figure 8 is a schematic view showing a state in which the forging part cutting step, which is a step in the titanium alloy bolt forging manufacturing method using the forging device for titanium alloy bolt according to the present invention is completed.
9 is a process flowchart showing in detail a post-treatment step which is one step in the method of manufacturing a titanium alloy bolt according to the present invention.
10 is a data showing the measurement of the diameter change with the pickling treatment time change for the titanium alloy bolt prepared according to the method for producing a titanium alloy bolt according to the present invention.

With reference to the accompanying Figure 1 looks at the configuration of the forging device for titanium alloy bolt according to the present invention.

Figure 1 is a schematic view showing the configuration of the forging device for titanium alloy bolt according to the present invention.

As shown in the accompanying drawings, the forging device for titanium alloy bolt according to the present invention (hereinafter referred to as "forging device 100") transfer and stop the rod-shaped titanium alloy material (B) by a predetermined length, limiting the movement A device for manufacturing a forged article for titanium alloy bolt (reference F in Fig. 8) by making a head of the bolt by forging molding after partly rapid heating in one state, and after cutting the titanium alloy material (B) by a certain distance. to be.

To this end, the forging device 100 is a transfer forcing portion 110 for transferring the titanium alloy material (B) without cutting, and the transfer of the titanium alloy material (B) transferred by the transfer forcing portion (110) Stopper 120 for selectively limiting the distance, holder 130 for limiting movement by pressing one side of the outer surface of the titanium alloy material (B) stopped by the stopper 120, and the titanium alloy material (B) A punch 150 for rapidly heating a portion protruding out of the holder 130 of the holder 130 and the forged article for titanium alloy bolts by pressing the heated titanium alloy material (B) (150) It is configured to include.

The conveying forcing part 110 is configured to convey a predetermined distance in the left direction by rotating in contact with the titanium alloy material (B), the movement of the long titanium alloy material (B) consisting of a plurality of rollers By forcing it helps to continuously manufacture the forging (F) for titanium alloy bolts.

A stopper 120 is provided on the left side of the conveyance forcing part 110. The stopper 120 is configured to selectively contact and stop the titanium alloy material (B) conveyed in the left direction by the transfer forcing unit 110, it is configured to linearly reciprocate in the up / down direction.

In addition, the stopper 120 also performs a role for simultaneously cutting the forged article F for the titanium alloy bolt in which the forging molding is completed by the punch 150 from the titanium alloy material B.

Therefore, the lower end of the stopper 120 is preferably formed sharply.

The holder 130 is provided between the stopper 120 and the transfer force unit 110. The holder 130 is composed of two blocks having a symmetrical shape to each other, thereby limiting the movement of the titanium alloy material (B) by providing pressure to the titanium alloy material (B) in close proximity to each other.

Therefore, the holder 130 has a groove corresponding to the longitudinal cross-sectional shape of the titanium alloy material (B) therein, and the left side of the holder 130 has a shape to be molded during forging molding to perform a mold role. .

A rapid heating unit 140 is provided between the holder 130 and the stopper 120. The rapid heating unit 140 is configured to rapidly heat the titanium alloy material (B), it is to heat the portion exposed in the left direction from the holder 130.

The rapid heating unit 140 is to heat the titanium alloy material (B) by any one of the direct current, induction heating, reflection furnace heating method, wherein the holder 130 is provided by the rapid heating unit 140 The heat conducting to the titanium alloy material (B) that is contacted and accommodated inside the heat is radiated to the outside.

Therefore, the titanium alloy material (B) is locally heated rapidly by the rapid heating unit 140, even if the heat is conducted in the longitudinal direction by minimizing the heating by the holder 130, the generation of oxide scale can be controlled. .

The punch 150 is provided on the left side of the stopper 120. The punch 150 is a configuration for performing forging molding by linearly reciprocating in the left / right direction by selectively hitting the left side of the titanium alloy material (B).

That is, when the punch 150 moves in the right direction, the right side hits the left end of the titanium alloy material B in the right direction. At this time, the titanium alloy material B is restricted by the holder 130. Therefore, forging is formed into a shape corresponding to the shape formed on the left side of the holder 130.

Hereinafter, a method of manufacturing the forging product F for a titanum alloy bolt using the forging device 100 configured as described above will be described in detail with reference to FIGS. 2 and 4 to 8.

2 is a flowchart showing a method for manufacturing a titanium alloy bolt forging (F) using the titanium alloy bolt forging device 100 according to the present invention, and FIGS. 4 to 8 show the titanium alloy bolt according to the present invention. Schematic diagram showing the state of the forging device 100 for each step in the method for manufacturing a titanium alloy bolt forging using the forging device 100 for.

As shown in these figures, the method for manufacturing the forging (F), the material setting step (S100) for setting the titanium alloy material (B) in the forging device for titanium alloy bolts (S100), and the titanium alloy material (B) A material transfer step (S200) for limiting the movement of the titanium alloy material (B) after transferring a predetermined distance by using the transfer forcing unit 110 and the stopper 120, and the titanium protruding outside the holder 130 Material forging step (S300) of rapid heating a portion of the alloy material (B), and forging molding step of forging by hitting the titanium alloy material (B) protruding outside the holder 130 with a punch 150 (S400) ), And the forging part cutting step (S500) of transferring the titanium alloy material (B) by a predetermined length and then cutting by the length including the forged molded portion to form the forging (F).

The material setting step (S100) is a state in which the titanium alloy material (B) is positioned between the transfer forcing portions 110 to allow forced transfer by the transfer forcing portion 110, and the titanium alloy material (B) is It is in a state where no heat treatment or surface treatment is performed.

After the material setting step (S100) is carried out a material transfer step (S200). The material transfer step (S200) is a process of transferring the titanium alloy material (B) to the left direction by rotating the transfer forcing unit 110, the stopper 120 is a linear movement to the lower side of the titanium alloy material (B) By blocking the path when moving in the left direction, the left end of the titanium alloy material (B) as shown in FIG. 4 is restricted to be placed in a set position.

At this time, the holder 130 is close to each other to receive a portion of the titanium alloy material (B) and at the same time to limit the left / right movement of the titanium alloy material (B) (see Figure 4).

After the material transfer step (S200), the material heating step (S300) is carried out. The material heating step (S300) is a titanium alloy material (B) protruding to the left side of the holder 130 using the rapid heating unit 140 in a state in which the titanium alloy material (B) is constrained by the holder (130). It is a process of rapid heating.

At this time, the titanium alloy material (B) in contact with the inner surface of the holder 130 is radiated by the holder 130 even if the heat provided from the heating unit is conducted, so that rapid heating is blocked beforehand. (See FIG. 5).

In addition, the rapid heating unit 140 may be variously changed to heat the titanium alloy material (B) by any one of a heating method, such as direct current, induction heating, and reflection furnace heating, and the titanium alloy material (B) It is rapidly heated to a temperature of 400 ° C. or lower.

After the material heating step (S300), forging molding step (S400) is carried out. The forging molding step (S400) is a process of forging the titanium alloy material (B) rapidly heated by the rapid heating unit 140 and exposed to the left side of the holder 130 with a punch 150, the titanium The left end of the alloy material B is molded to have a shape corresponding to the opened left side of the holder 130 (see Fig. 6).

After the forging step (S400), the forging part cutting step (S500) is performed. The forging part cutting step (S500) is a process of completing the forging (F) by cutting the left portion of the forged-molded titanium alloy material (B) by a predetermined length, as shown in FIG. Move (B) to the left direction and the punch 150 limits the leftward conveying range of the titanium alloy material (B), in this state the stopper 120 moves downward to complete the forging (F). (See Fig. 8).

By sequentially performing the steps described above, the production of the forged product (F) is completed, and after a plurality of steps to perform the production of titanium bolts.

Hereinafter, a method of manufacturing titanium bolt will be described with reference to FIG. 3.

Among the methods for manufacturing the titanium bolt, the above-described method of manufacturing the forged product F is performed in the same manner, and the forged product heat treatment step S600 is performed after the forged product cutting step S500.

The forging product heat treatment step (S600) is a process of maintaining the forging (F) at 927 ℃ for 1 hour and then cooled to 850 to 900 ℃, immersed in water and quenched at 480 ℃ for 24 hours.

The forging heat treatment step (S600) is a process of adding a high strength and elongation of the forging (F), the microstructure to represent a double structure of isotropic α and transformed β.

After the forging product heat treatment step (S600), a pickling treatment step (S700) is performed. The pickling treatment step (S700) is a process of removing oxide scale by dipping a titanium alloy bolt in a pickling solution containing 15% HNO ₃ , 3% HF, and 82% H ₂ O by weight% as shown in FIG. 10. It is preferably carried out for 10 minutes.

That is, when the pickling process step (S700) is less than 5 minutes, the scale of oxidation remains on the surface of the bolt, and when more than 10 minutes, the oxidation scale is completely removed, but the etching amount is increased to increase the dimensional accuracy. Can cause falling problems.

Therefore, the pickling step (S700) is preferably carried out for 5 to 10 minutes in consideration of the effective removal of the oxide scale and the dimensional accuracy of the bolt.

After the pickling treatment step (S700), forging processing step (S800) is carried out. The forging product processing step (S700) is a process for finishing the outer surface of the forging (F).

After the forging step (S800), the forging step (S900) is carried out. The forging step (S900) is a forging molding immediately after the titanium alloy material (B) is heated rapidly in the material heating step (S300) and forging molding step (S400), so that the heat is not applied to the area to be subjected to the forging process Since there is no state, cold or low temperature rolling molding is possible within a temperature range of 400 ° C. or less. When the rolling step S900 is completed, the forging F has a shape of a titanium alloy bolt.

After the precursor step (S900), a post-processing step (S1000) is optionally carried out. The post-treatment step (S1000) is a process for surface treatment of the titanium alloy bolt, the post-treatment step (S1000) may be made of a plurality of processes.

That is, the post-treatment step (S1000), an anodizing process (S1050) to form a film using an anodizing process on the surface of the titanium alloy bolt, as shown in Figure 9 attached, and a lubricant coating process for applying a lubricant ( S1010).

Through the above steps, the production of the titanium alloy bolt is completed.

The scope of the present invention is not limited to the above-described embodiments, and many other modifications based on the present invention will be possible to those skilled in the art within the scope of the present invention.

100. Forging device for titanium alloy bolt 110. Feeding steel part
120. Stopper 130. Holder
140. Rapid heating 150. Punch
B. Titanium alloy material F. Forging
S100. Material setting step S200. Creative transfer step
S300. Material heating step S400. Forging Molding Step
S500. Forging part cutting step S600. Forging Heat Treatment Step
S700. Pickling treatment step S800. Forging Process
S900. Rolling step S1000. Post-Processing Step
S1050. Anodizing Process S1100. Lubrication application process

Claims (14)

A transfer force part forcing the transfer of the titanium alloy material, which is a bar,
A stopper for selectively limiting a transfer distance of the titanium alloy material conveyed by the transfer forcing unit;
A holder for limiting movement by pressing one side of the outer surface of the titanium alloy material stopped by the stopper;
A rapid heating part for rapidly heating a part of the titanium alloy material protruding to the outside of the holder;
The forging device for titanium alloy bolts, characterized in that it comprises a punch for pressurizing the heated titanium alloy material to form a forging for titanium alloy bolts. The titanium alloy according to claim 1, wherein the punch selectively stops the material by contacting the forged product for the titanium alloy bolt which is returned to its original position after forming the forged product for the titanium alloy bolt and forcedly conveyed by the conveying forcing part. Forging device for bolts. The forging device for titanium alloy bolts according to claim 2, wherein the stopper cuts the titanium alloy bolt forging from the material by linearly moving when the punch and the forging for the titanium alloy bolt are in contact. The forging device for titanium alloy bolt according to claim 3, wherein the rapid heating unit heats the titanium alloy material by any one of a direct current, induction heating, and reflection furnace heating. 5. The forging device for titanium alloy bolt according to claim 4, wherein the holder radiates part of the heat provided by the rapid heating unit to the outside. A material setting step of setting the titanium alloy material, which is a bar, in the forging device for the titanium alloy bolt;
A material transfer step of transferring the titanium alloy material by a predetermined distance using a transfer force part and a stopper, and restricting the movement of the titanium alloy material by using a holder;
A material heating step of rapidly heating a portion of the titanium alloy material protruding from the holder to a temperature of 400 ° C. or less;
A forging molding step of forging a titanium alloy material protruding from the holder by punching;
Titanium alloy bolt forgings manufacturing method using the forging device for titanium alloy bolts, characterized in that the forging product for transferring the titanium alloy material by a predetermined length and then cut by a length including a forged molded portion to form a forging product . 7. The method of claim 6, wherein in the material heating step, the holder releases a part of the heat provided to the titanium alloy material to the outside. The forging of the titanium alloy bolt according to claim 6, wherein the material heating step is a process of heating a part of the titanium alloy material by a rapid heating part which heats any one of direct current, induction heating, and reflection furnace heating. Method of manufacturing forged products for titanium alloy bolts using a device. 7. The method of claim 6, wherein the forging part cutting step is a process of cutting the titanium alloy material to be transferred using a stopper after stopping the titanium alloy material to be punched. delete A material setting step of setting the titanium alloy material, which is a bar, in the forging device for the titanium alloy bolt;
A material transfer step of transferring the titanium alloy material by a predetermined distance using a transfer force part and a stopper, and then limiting the movement of the titanium alloy material by using a holder;
A material heating step of rapidly heating a portion of the titanium alloy material protruding from the holder to a temperature of 400 ° C. or less;
A forging molding step of forging a titanium alloy material protruding from the holder by punching;
A forging part cutting step of transferring the titanium alloy material by a predetermined length and cutting the length by a length including a forged molded part to form a forging product;
A forging product heat treatment step of heat-treating the forging product;
Pickling treatment step of pickling the heat-treated forged product,
A forging product processing step of processing the pickled forged product;
Method for producing a titanium alloy bolt, characterized in that the forging step of forming a titanium alloy bolt by processing a thread on the outer surface of the forged product. The method of claim 11, wherein the forging heat treatment step is a process of maintaining the forging for 1 hour at 927 ℃ and then cooled to 850 to 900 ℃, immersed in water and then aged at 480 ℃ for 24 hours Titanium alloy bolt manufacturing method. The method of claim 12, wherein after the precursor step,
And a post-treatment step comprising an anodizing process for forming a film on the surface of the titanium alloy bolt and a lubricating application process for applying a lubricant. 12. The method of claim 11, wherein the pickling step is a process of removing oxide scale by immersing a titanium alloy bolt for 5 to 10 minutes in a pickling solution containing 15% HNO ₃ , 3% HF, and 82% H ₂ O by weight. Method for producing a titanium alloy bolt, characterized in that.

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