JPH02303644A - Method and device for hot free forging - Google Patents

Abstract

PURPOSE:To eliminate an hourly and economical loss caused by intermediate heating by holding a stock temperature immediately before pressurization within a prescribed range, pressurizing locally and successively a stock by a forging tool whose pressurizing area is smaller than an area to be pressurized to the stock and working and forming the whole. CONSTITUTION:A stock (long-sized belt-like article) 3 is gripped by a handling part 4 and while heating it by the upper and the lower gas burners 51, 52, it is pressurized and formed successively by using the upper and the lower forging tools 1, 2 of a simple shape. Subsequently, a temperature of the stock 3 immediately before it is pressurized on a line of this hot free forging is measured by thermometers 61A, 62B, and while holding it within a prescribed range, the stock 3 is pressurized locally and successively by the forging tools 1, 2 having a smaller pressurizing area than an area to be pressurized of the stock 3 and the whole is worked and formed. In such a way, the quality deterioration such as a failure of the working accuracy, generation of a crack on the surface, etc., can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hot free forging method and an apparatus therefor in which a material is heated and sequentially pressurized and formed using a simple tool.

[Conventional technology]

Hot free forging work for secondary products has been automated due to a lack of skilled workers or a deteriorating working environment. However, plasticity and processing, vol25 vol. 279 (19
84-4) As described on pages 265-271,
Even in highly automated forging equipment, unexpected deformation (abnormal deformation) K during forging may require temporary interruption or manual intervention.

If the cause of the abnormality is discovered in a short time and emergency recovery measures are taken, the material can be forged within the specified temperature range, but if this procedure takes too long, the temperature of the material will drop. This is because reheating is required. Also, the shape of the workpiece (for example, if the cross section is flat and long)
In some cases, the temperature of the material may drop below the specified range in the latter half of processing, even during regular work, leading to problems such as an increase in processing force and a decrease in quality. This resulted in material loss and an increase in processing costs.

On the other hand, Japanese Patent Application Laid-Open No. 62-286638 discloses a method of processing a titanium alloy while heating it with a burner or the like. However, this technology presses the cylindrical material in the axial direction to forge the ingot after melting, and the entire pressurized surface is pressurized using a forging tool that has a larger pressurized surface than the pressurized surface of the material. Heating is applied to the area where pressure is applied,
This is done in real time when machining force is being applied. Therefore, in machining that applies pressure locally and sequentially with a forging tool that has a pressurizing surface smaller than the pressurized surface of the material, for example, when machining a stepped bar with a circular cross section,
If the pressurized surface in the longitudinal direction is completely restrained by a forging tool, the pressurized part can be directly
It is not possible to heat the material, and in the case of sequential processing, there is no guarantee that the temperature of the processed surface of the material at the time when processing force begins to be applied by the forging tool is within a predetermined range.

[Problem to be solved by the invention]

As mentioned above, the material is locally kneaded using a forging tool with a pressurized area smaller than the pressurized area of the material.

In conventional hot free forging, which is mainly used for secondary products and is sequentially pressurized to form the desired shape, it is necessary to take measures against abnormal deformation during the forging process, or to process the workpiece due to the shape of the workpiece. In response to the temperature drop in the material, no measures were taken to maintain the material within the specified temperature range during processing, resulting in an increase in processing force that could result in the inability to obtain the specified reduction amount or deterioration in the quality of the workpiece material. Alternatively, time and economic losses due to intermediate heating were unavoidable.

The purpose of the present invention is to provide a hot free forging method that is effective in terms of pressing and forming materials, thermoeconomics, and quality of molded products.
be.

Another object of the present invention is to provide a hot free forging device that is effective in terms of pressing and forming materials, thermoeconomics, and quality of molded products.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention provides (1) a hot free forging method in which a material is heated and sequentially pressurized and formed using a simple-shaped tool, immediately before being pressurized on a forging line; While maintaining the temperature of the material within a predetermined range, the material is locally and sequentially pressurized using a forging tool having a pressurizing area smaller than the pressurized area of the material to process and shape the entire material. It is characterized by

(2) In (1), the material is a titanium alloy.

(3) In (1) or (2), the temperature of the material is maintained within a predetermined temperature range by heating a portion of the material with a heating element.

(4) In (1), (2) or (3), heating for maintaining the temperature of the material within a predetermined temperature range is performed by a heating body, a part of the forging tool, the pressurizing/forming device, Or, it is characterized by extending over all.

(6) The material is maintained within a predetermined temperature range immediately after being pressurized and molded in (1), (2), (3), or (4).

(6) In a hot free forging device that sequentially pressurizes and forms a material using a simple-shaped tool while heating the material, the material, a handling part that grips the material, and two or more free axes of the material a manipulator that can be moved at a certain temperature; a heating means that heats part or all of the material; a temperature sensor that detects the temperature of the material; and a temperature sensor that determines the temperature of the material based on the measured value of the temperature sensor. and a control device that controls the amount of heat output by the heating means so that the temperature falls within a predetermined temperature range.

[Effect]

In the hot free forging method of the present invention, the heating body 1 adjusts its output according to the measured value of the temperature of the material by the temperature sensor so that its output falls within a preset temperature range for each pressurization/forming. controlled.

This makes it possible to maintain the temperature of the gin material that is pressed and formed by the forging tool at a predetermined value depending on the material, thereby preventing an increase in the pressing force and preventing a deterioration in the quality of the material.

In particular, it is OK to process titanium alloys, which require a long time to process.
It has a great effect of eliminating time and economic losses caused by intermediate heating and improving processing accuracy.

On the other hand, the temperature of the material is maintained sequentially by heating a part of the material, and the loss of thermal energy from forging tools, pressurization, and forming equipment is reduced by heating these in advance to increase their heat capacity. It can be prevented.

Furthermore, by heating the material after pressurizing and forming it, a gradual transformation of the metal structure after processing occurs, further improving processing accuracy.

〔Example〕

FIG. 1 shows one embodiment of the present invention, and is a front view of a processing device used for hot free forging of a long strip-shaped product.

In Fig. 1, 1 and 2 are upper and lower forging tools, 3 is a long strip, 4 is a handling part, 51.52 is a subvarna,
61 and 62 are two-color pyrometers. Up.

Between the upper forging tool 1 and the lower forging tool 2 which are arranged facing each other below, the elongated strip-shaped article 5 held is inserted into the handling part 4 of a manipulator (not shown) having degrees of freedom of two or more axes. , to the maniverator side, that is, to the white arrow side, sequentially,
While feeding, the upper forging tool 1 repeatedly presses the crankshaft at a rotational speed of about 30 orpm. In parallel with this pressurization, two
Color pyrometer (OA thermometer 61A, 62A near the pressure tool)
Based on the signal of the measured value of the surface temperature of the long strip-shaped product 3 measured by the remote OB thermometers 61B and 62B)K,
A heating device (not shown) and upper and lower gas burners 51D and 511 for heating are activated according to a command output from the control device.
．． 51F, 51G: 52D, 521.52F, 52GK
by adjusting the heating energy.

K was set so that the temperature of the long strip-shaped product 5 immediately before being pressurized by the lower forging tools 1 and 2 could be maintained within a predetermined range.

This will be explained in detail below.

As shown in Fig. 5, long strip products are 1,1==10006, W-1, where the total length is W, the plate width is W, and the plate thickness is T.
00-1! =50 snow.

The material is titanium alloy (Ti-6A4-4v).Here, the case where the thickness of the long strip 3 is compressed by 20 inches will be shown. (In other words, the plate thickness after pressurization is 40 mm.) One end of the long strip 5 is held by the handling part 4 of the manipulator, and the long strip is held between the upper and lower pair of forging tools 1.2. Insert it so that the first pressurizing position 5C of No. 3 is on. Titanium alloy (Ti-6A1-4V) O forging temperature range is from 700℃ to 1
At 200°C, the quality as a secondary product deteriorates. Therefore, the upper limit was set at 950° C., which is below the β-transformation point (approximately 1000° C.), and the lower limit was set at 80.0° C., at which fine cracks occur on the surface.

In the processing, the upper forging tool 1 is lowered by a predetermined stroke and pressurized while moving the manipulator sequentially at a pitch of 20 in the direction of the white arrow.

The plate thickness is made to be 45- by pressurizing the - pass and 40- by the second pass. These operations are similar to the conventional hot free forging method.

The long strip 5 is heated to 980°C in the furnace and taken out of the furnace, and when it is gripped by the handling section 4, its surface temperature drops to about 950°C. However, titanium alloy ('ri)
-bht-av) has a low thermal conductivity, so the internal temperature is maintained at about 980°C. Simultaneously with the start of pressurization, the heat of the elongated strip 3 is transmitted to the forging tool 1.2 and is also dissipated into the atmosphere, so that the surface temperature of the elongated strip 3 decreases. −
The measured values of thermometers A and B were kept at 800°C or higher for the bus. However, during the forging process, the surface temperature of the long strip-like product 50 becomes 800° C. or less when it is actually pressurized, so heating is performed in the following procedure.

That is, the surface temperature of the elongated strip-shaped product 3 is measured using B thermometers 61B and 62B, which are two-color high-temperature needles, placed at a position of about 200 mm on the opposite side of the manipulator of the forging tool 1.2 shown in FIG. The measured value is sent to the control device (201), as shown in FIG. 2 as a block diagram of the heating control system in FIG. Ru. If the measured value is less than or equal to the lower limit 1, a heating command is issued (202), and a heating gas burner equipped with a nozzle wider than the plate width W is activated. At the same time, the surface temperature of the long strip 30 immediately before pressurization was measured using the A thermometers 61A and 62A, which had two-color high-temperature needles placed near the upper and lower forging tools 1.20, and the upper limit temperature for forging was measured. 9
Compare with 50°C. When the measured value exceeds 950°C, the nozzle of the heating gas burner is throttled (203) based on the measured value signals from the A thermometers 61A and 62A (203), and the amount of heat for heating is reduced (203). is weakened.

The control device controls the manipulator (204) and the forging machine (2) depending on whether the surface temperature of the material is within a predetermined range.
05).

In this example, it was possible to forge the material while keeping the temperature within a predetermined range, and a forged product with stable quality was obtained.

In the example, the forged object is a simple long strip-like product, but it is similar to a turbine blade made of titanium alloy.

If the present invention is applied to processing complex-shaped products that require a long time to process, the effects will be significant. Further, the forged object may be a primary product that is forged from an ingot and then processed by rolling or the like.

In addition, the heating method may be any method other than those in the examples, such as high-frequency induction heating, electric heaters, lasers, etc. Instead of partial heating of the material as in the examples, forging tools,
Heating may include part or all of the pressure/forming device.

Moreover, if the material is heated even after pressing and forming, the metal structure will undergo a gradual transformation, improving quality.

In the present invention, the temperature is measured using a two-color pyrometer, but the present invention is not limited to this, and the capacity, number, and arrangement of the heating elements should be changed depending on the size and shape of the material.

Furthermore, the heating element may be placed on either side of the forging tool.

On the other hand, although the temperature of the forging tool is not mentioned in the examples, heating the tool to about 500° C. below the tempering temperature is effective in preventing a drop in the temperature of the material during forging.

Furthermore, if the material of the forging tool is selected to have a low thermal conductivity, such as a ceramic tool, it is possible to prevent the material temperature from decreasing.

〔Effect of the invention〕

According to the invention, the temporary suspension or the size of the material,
Even if heating cannot be completed within a predetermined temperature range with one heating due to the shape, processing can be completed without interrupting processing and performing intermediate heating in a furnace outside the apparatus. Therefore, time and economic losses due to intermediate heating can be eliminated.

In addition, by controlling the amount of heat supplied to the heating element based on the measured value of the surface temperature of the material being processed, highly accurate temperature control can be performed, so even titanium alloys can be processed within a predetermined temperature range. This can prevent quality deterioration such as an increase in processing force due to a decrease in temperature, poor accuracy due to a decrease in the amount of material, surface cracks, and uneven structure.

[Brief explanation of the drawing]

FIG. 1 is a front view of a processing apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram of the heating control system of FIG. 1, and FIG. 5 is a perspective view of a long strip-shaped product before processing. 1... Upper forging tool 2... Lower forging tool 5... Long strip-shaped product 4... Handling part 51... Upper gas burner 52... Lower gas burner 61A, 62A... A thermometer 61B , 62B...B thermometer. Figure 2

Claims (1)

[Claims] 1. In a hot free forging method in which a material is heated and sequentially pressurized and formed using a simple-shaped tool, the temperature of the material immediately before being pressurized on a forging line is set to a predetermined value. A heating method characterized by processing and forming the entire material by locally and sequentially applying pressure to the material using a forging tool having a pressurizing area smaller than the pressurized area of the material while maintaining the material within a range of . Free forging method. 2. The hot free forging method according to claim 1, wherein the material is a titanium alloy. 3. The hot free forging method according to claim 1 or 2, wherein the temperature of the material is maintained within a predetermined temperature range by heating a portion of the material with a heating element. 4. Claim 2 or 3, wherein the heating for maintaining the temperature of the material within a predetermined temperature range extends to a part or all of the forging tool, pressurizing/forming device, or the like by means of a heating body. Hot free forging method described. 5. The hot free forging method according to claim 1, 2, 3, or 4, wherein the material is maintained within a predetermined temperature range immediately after being pressurized and formed. 6. Using a simple tool while heating the material,
A hot free forging device that presses and forms the material, comprising: a material, a handling unit that grips the material, a manipulator that can move the material with a degree of freedom of two or more axes, and a part or all of the material. A heating means for heating, a temperature sensor for detecting the temperature of the material, and an amount of heat output by the heating means so that the temperature of the material falls within a predetermined temperature range based on the measured value of the temperature sensor. A hot free forging device comprising: a control device for controlling the hot free forging device;