JP2001342524A - Recycling equipment for forming materials and recycling process of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a forged metal product of high quality which is excellent in mechanical properties and reduce the cost, for example, aluminum alloy often used as a material at a low cost, in lightweight, and durable under-chassis foot-related components in automobile or other vehicles which reduces vehicles' fuel consumption and lowers the emission of carbon dioxide and contributes to ecological issues, including prevention of greenhouse effect or global warming. SOLUTION: This is a piece of forging metal recycling equipment in which metal burrs or other scarps 5 produce in the process of die forging are used as material. Such material may be scrap 5 alone or the mixture of scrap 5 and high purity virgin material 8 when necessary to obtain starting molten metal. The molten metal is then cleaned in filtration process 12 and cast to produce forging stock 6. The forging stock 6 is also formed into various product shapes in the equipment. This recycling equipment 1 includes an integral process for the entire recycling of burrs and other scraps as forging stock.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus and a method for recycling forging materials. More specifically, for example, unnecessary materials such as burrs generated during forging, which are used in the manufacture of vehicle suspension parts for automobiles and the like, which are manufactured through a forging process, can be used again as a raw material in the forging process. The present invention relates to a forging material recycling apparatus that can be used and a recycling method using the apparatus.

[0002]

2. Description of the Related Art In order to prevent global warming, which is one of the global environmental problems, reduction of fuel consumption of automobiles is strongly demanded worldwide. In order to reduce the fuel consumption, it is said that the technology for reducing the weight of the vehicle is the most important. This is because if the vehicle itself is reduced in weight, the load on the power source is reduced, and the fuel consumption can be reduced regardless of the power source regardless of the gasoline engine. By using an aluminum alloy material, which is one of the representative examples of the weight reduction technology, automobile parts such as an engine cylinder head and an engine cylinder block have already been widely adopted as castings which are easy to manufacture.

[0003] However, even with the same automobile parts,
It is required to have low corrosiveness and sufficient strength and elongation characteristics and to have few defects. For example, it is difficult to use cast products for undercarriage parts. Instead, forged products and squeeze cast products (low-speed injection molded products) And the like are already used, but are expensive and their application is limited. Conventional JISA
The main reasons for the high cost of an aluminum forged product using a 6061 wrought alloy or the like are the high cost of the forging material itself and the large number of manufacturing steps. Also, for example, squeeze castings using a JISAC4CH casting alloy or the like have not been able to be manufactured at a low cost because the number of manufacturing steps is large and the injection speed is slow.
On the other hand, it has been apparent that it is extremely difficult to apply general cast products to undercarriage parts, which have a severe use environment, even if efforts are made to reduce defects by cleaning the molten metal.

[0004] Therefore, there has been an increasing demand for cost reduction by reviewing the manufacturing process of a forged product having higher mechanical strength. Normally, when manufacturing an aluminum forged product, a round bar made of wrought material is purchased as a forging material, cut into lengths according to the metal product to be manufactured, and then forged, stamped out the forging material. The product and burrs (including burrs) are separated, but the burrs that do not become this product have reached about 30% of the raw material before stamping. That is, only about 70% of the forging material is used for the product, which causes a large waste. It is considered that the cost can be reduced by correcting the waste.

[0005] However, as noted above, it is standard in the art for forging materials to be supplied in round bars. If the supplier seeks a forging material having a shape close to the product shape to be produced in an attempt to reduce the amount of waste burr, if possible, such special non-standard forging material can be used. Manufacturing results in a cost that cannot be overcome by suppressing the amount of burrs, and does not solve the problem.

[0006] On the other hand, the casting process and the forging process as a material for spreading are usually performed by different companies in different factories, and the efficiency of reusing burrs is also required.
In general, it is not efficient and efficient to collect and reuse exactly the same materials, and it is not possible to distinguish between forging materials and casting materials, and also to classify alloys specified by the amount of trace metals contained. Regardless of the detailed material type, etc., a specialized recycling company collects burrs and processing waste, distinguishes them by sorting them together, for example, if they are the same aluminum alloy, and dissolves them into ingots , For castings. In this case, of course, it is difficult to use it as a raw material of a metal product by forging with higher quality, and at present, it is a raw material of a general cast product.

[0007]

Accordingly, for example, it can be applied to underbody parts for vehicles such as automobiles used under severe conditions, and is manufactured by forging and has excellent mechanical properties such as strength and elongation. However, there is a demand for a metal product that can be reduced in cost, but no suitable metal product has been proposed.

[0008] The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide excellent mechanical properties, high quality, and cost reduction.
It is to provide a metal product by a forging process. And, for example, using aluminum alloy as the metal, we supply lightweight and durable suspension parts for vehicles such as automobiles at low cost, reduce fuel consumption of automobiles etc., reduce carbon dioxide emissions, and prevent global warming. To contribute to countermeasures.

In order to solve the above-mentioned problems, the present inventors have conducted various studies on a manufacturing process and a manufacturing apparatus of a metal product manufactured by forging. As a result, it was found that unnecessary materials such as burrs generated by forging stamping were used as raw materials. As a new raw material with high purity (hereinafter also referred to as new material), for example,
Mixing with a new lump of a predetermined component, melting to obtain a molten metal, cleaning the molten metal, casting it to produce a forging material, and forging the forging material into a product shape. A manufacturing apparatus that can consistently carry out the process of reusing the unnecessary material such as burrs as a forging material as described above by a recycling apparatus and a forging material recycling method. I found what I could achieve.

[0010]

That is, according to the present invention, there is provided a forging material recycling apparatus for manufacturing a metal product from unnecessary material including burrs generated during forging, wherein at least the unnecessary material is melted and melted. Melting means for obtaining the forging material, casting means for casting the molten metal to obtain a forging material, forging means for forging the forging material to obtain a forged product, and trimming the forged product into a forged product by deburring. Means for removing the oxide film of the forging material at a stage prior to the forging means.

In the present invention, a cooling means for lowering the temperature of the forging material to a temperature suitable for the forging means is provided, and it is possible to omit means for raising the temperature of the forging material before the forging means. Further, it is preferable to provide analysis means for analyzing components of the molten metal and monitoring the composition of the molten metal. Furthermore,
It is preferable to provide a cleaning means for removing impurities in the molten metal. The forging material recycling apparatus of the present invention is suitably used when the forging material is an aluminum alloy.

According to the present invention, there is also provided a method for recycling a forging material for producing a metal product from an unnecessary material including burrs generated during forging, wherein a melting step of melting the unnecessary material to obtain a molten metal; A casting process of casting to obtain a forging material, a forging process of forging the forging material to obtain a forged product, and a trimming process of deburring the forged product into a forged product, A method for recycling a forging material is provided, in which a step of removing an oxide film of the forging material is omitted in a process preceding the forging process. In the present invention, a cooling step of lowering the temperature of the forging material to a temperature suitable for the forging step is provided, and a step of raising the temperature of the forging material in a step before the forging step can be omitted.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of a forging material recycling apparatus and a forging material recycling method of the present invention will be specifically described, but the present invention is interpreted as being limited to these embodiments. Without departing from the scope of the present invention, based on the knowledge of those skilled in the art,
Various changes, modifications, and improvements can be made. For example, in this specification, an aluminum product manufactured by forging an aluminum alloy will be described as a typical example of a metal product. However, the present invention is originally a forging material, which is an unnecessary material (burr) generated at the time of forging. Materials, burrs, rejects, etc.), melting and casting, forging, and forging to obtain a product. The present invention relates to a forging material recycling apparatus and a forging material recycling method. The metal as the forging material is not limited to the aluminum alloy, but may be another lightweight metal, for example, a magnesium alloy, or may be carbon steel or special steel, and is not limited.

According to the present invention, in addition to forging means for producing a metal product having excellent mechanical properties by forging, unnecessary burrs generated during the forging (hereinafter, also referred to as burrs) are mixed with a new material and dissolved. Forging that has a means to be cast and used as a material for forging, and enables waste materials such as burrs at the time of forging that have been reused only in cast products to be effectively reused in forged products. The present invention relates to a material recycling apparatus and a method for recycling forging materials.

In the present invention, in a forging material recycling apparatus, a dissolving means for mixing an unnecessary burr or the like and a new material, for example, a new lump of a predetermined component, to obtain a molten metal, and casting the molten metal. It is characterized by comprising casting means for obtaining a material for forging, forging means for forging the forging material to obtain a forged product, and trimming means for removing burrs from the forged product. By providing such means,
The following effects can be obtained. 1) Unnecessary burrs and the like are effectively reused inside the apparatus, not outside the apparatus, so that the burrs and the like to be reused are limited, so that the quality control of components is easy. There is no transportation cost, contributing to total cost reduction. 2) Since the forging material is forged immediately after casting, it is possible to omit means for removing an oxide film of the forging material,
Manufacturing costs can be reduced. In a usual forging process, an oxide film is formed on a round bar as a forging material. The oxide film is inevitably formed in the atmosphere, but plays a role of intentionally forming and preventing a certain level of corrosion.
Therefore, it is necessary to maintain the quality of the forging material through the distribution to the forging process.In general, means for removing the oxide film of the round bar as the forging material before forging, so-called peeling, is required. Become.

Further, in the present invention, in the forging material recycling apparatus, in addition to the above-mentioned respective means, when moving from the casting means to the forging means, the temperature of the forging material produced by the casting means is excessively lowered. It is preferable to provide a cooling means for lowering the temperature to a temperature suitable for the forging means. By providing such a means, 3) it is possible to omit means for raising the temperature of the forging material again by a heating furnace for heating the material for forging, thereby reducing equipment costs and increasing the temperature again. Heat is not required, and the manufacturing cost is reduced. In a normal forging device, the temperature of the forging material is at room temperature before forging, and therefore, in order to perform forging stamping in a certain temperature range, this temperature raising means and heat are required.

Hereinafter, a forging material recycling apparatus and a forging material recycling method of the present invention will be specifically described with reference to the drawings. FIG. 1 is a block flow diagram showing one embodiment of the constituent means in the forging material recycling apparatus of the present invention. Forging material recycling device 1 of the present invention
At least, a melting means 11 for melting a forging material to obtain a molten metal 3, a casting means 14 for casting the molten metal 3 to obtain a forged material 6 formed by casting, and a forging method for forging the forging material 6 The apparatus includes a forging means 16 for obtaining the product 4 and a trimming means 18 for removing the burr of the forged product 4 to obtain a forged product, and is a device capable of performing a casting process and a forging process consistently.

In addition to the above-described means, a cooling means 15 for lowering the temperature of the forging material 6 produced by the casting means 14 to a temperature suitable for the forging means 16 and a forging material including the unnecessary material 5 such as a burr material are used. Analyzing means 20 for confirming the components of the melt 3 obtained by melting, purifying means 12 for removing impurities of the melt 3, and improving the mechanical properties of the forged and trimmed forged product to obtain the metal product 7. It is preferable to provide a heat treatment unit 19 and the like.

In order from the top of the block flow diagram of FIG. 1, as a material for forging, Al according to JIS classification H4140 is used.
-Mg-Si heat treated aluminum alloy wrought material A60
61 (hereinafter also simply referred to as A6061 alloy) will be described as an example.

The compounding means 10 collects the unnecessary material 5 including the burr material separated from the forged product 4 in the trimming means 18 and replenishes the new material 8 with a new A6061 alloy. This is a tank where silicon, copper and chromium are weighed, mixed and supplied as raw materials.
The mixed raw material is melted by the next melting means 11 to become the molten metal 3.

The standard composition of the A6061 alloy is, in addition to pure aluminum, 1.0% by mass of magnesium and 0.6% of silicon.
It contains 0.2% by mass of copper, 0.25% by mass of copper, and 0.25% by mass of chromium. The first raw material which does not contain the waste material 5 such as a burr material is composed of only the new material 8 and the composition naturally falls within the composition range.
, For example, by reusing about 30% and continuing to include it as a raw material, the raw material composition changes little by little,
Eventually, it may be out of the standard of the A6061 alloy. Therefore, the component analysis of the molten metal 3 is performed by the analysis means 20 described later, and when any of the trace metals 9 is insufficient according to the result, the corresponding trace metal 9 is blended as necessary, and the quality becomes unstable. It is preferable to prevent this from happening. When any of trace metals 9 is large, compounding means 1
0 can be supplemented with pure aluminum (not shown) to reduce the content of the trace metal 9. Usually, the trace metal 9 and pure aluminum are mixed and used as raw materials in the mixing means 10, but may be directly charged into the next melting means 11.

Further, if the weight ratio of trace metals such as silicon, magnesium, copper, and manganese is intentionally changed, it is possible to impart properties different from those of the original alloy. For example, when it is desired to particularly improve the strength, the original forging material is A6.
061 alloy, it melts by adding a lot of copper,
It is possible to perform a refining operation such as giving characteristics close to those of a 2000-series aluminum alloy represented by a Cu-Si-based heat treatment type aluminum alloy A2011. Even by such an operation, the analyzing means 20 described later
Since the composition of the forging material is clearly recorded, even if the characteristics to be given are changed, the quality does not deteriorate or fluctuate.

The melting means 11 includes a burr material as a solid metal,
Unnecessary material 5 including burrs and defective products and new material 8
This is a furnace for heating to a liquid metal, that is, a molten metal 3.
The fuel for heating may be liquid, solid or gas depending on the material. A heat source of an electric system such as electric resistance, electric induction, and arc, or a heating method of an electronic system such as a laser or an electron beam may be used. In addition, a more preferable functional shape such as a crucible type, a groove type, and a rotary type may be adopted in accordance with the heating method. Regardless of the heating method used, it is possible to minimize the heat loss by performing preliminary heating or the like using waste heat, instead of directly putting the forging material at room temperature into the melting means 11. It is preferable for cost reduction.

The melting temperature of the A6061 alloy is preferably about 680 to 780 ° C., and the alloy is melted while being maintained in this temperature range. Next, the molten metal 3 is transferred to the cleaning means 12 to remove impurities. Since the molten metal serving as the liquid metal is handled from the melting means 11 to the casting means 14, in consideration of productivity efficiency and safety, it is preferable to provide an automatic transportation / pouring means when transporting the molten metal. It is also preferable to integrate the components up to the casting means 14 and eliminate the transport path.

The analysis means 20 is an apparatus for analyzing the components of the molten metal 3.
Preferably, it is provided before the casting means 14. For example, it is preferable that the analysis unit 20 obtains a metal component ratio by taking a sample of the molten metal 3 from the melting unit 11 and monitor and measure whether there is any problem in the quality of the molten metal 3. If there is a problem, an alarm is issued, and a means for automatically supplying a pure main metal or a trace metal is provided, and a pure main metal or a trace metal is required for the blending means 10 or the melting means 11 before a problem occurs. It is also preferable that the amount is charged and the composition is automatically adjusted so as to have a preferable component ratio. Further, if the quality of the molten metal 3 is monitored with the analysis means 20, not only the unnecessary material 5 such as the burr material generated from the inside of the apparatus as described above and the new material 8 to be replenished, but also the raw material, Waste materials such as burrs generated from other factories or manufacturing processes can be easily reused as raw materials. Of course, in that case, it is preferable to investigate the source of the waste material such as burrs and to clarify the type of the original forging material. Stability can be prevented. An apparatus constituting the analysis means 20 is, for example, an emission spectroscopy apparatus. This apparatus polishes the surface of a sample and discharges the same, disperses spectral lines of necessary elements, and obtains a% in comparison with a standard sample. To display.

The purifying means 12 recognizes that increasing the purity of the molten metal is important for preventing the occurrence of internal defects in the product and for improving the mechanical strength. A treatment, a filtration treatment, and the like are performed to remove inclusions, impurity gases, and the like. Although it is an effective means in the ordinary casting process, the forging material recycling apparatus 1 of the present invention for reusing the unnecessary material 5 such as a burr material has a partial circulation system in the apparatus, so that cleaning is performed. Means 1
It is preferable to provide the method 2 and sufficiently remove inclusions and impurity gas components.

The degassing process is a process for removing harmful gas components, mainly hydrogen, remaining in the molten metal 3 and causing defects such as pores and shrinkage cavities. In the A6061 alloy molten metal 3, for example, vacuum degassing is performed. A gas method, a method using nitrogen or chlorine gas, or the like may be used. In the means after the degassing treatment, it is preferable to perform a sealing treatment with an inert gas such as nitrogen so that hydrogen gas and the like do not dissolve in the molten metal 3 again.

The deoxidation treatment is a treatment for removing excess oxygen in the molten metal 3 that causes defects such as inclusions remaining and poor running of the molten metal. For example, the deoxidizing treatment is more oxygen than the molten metal 3 of the A6061 alloy to be deoxidized. And ferromanganese or the like which easily reacts with the mixture to appropriately reduce the oxygen in the molten metal 3.

The filtration treatment is to separate and remove solidified inclusions remaining in the molten metal 3 through, for example, a porous substance, and is preferably employed as the last treatment of cleaning. The method of the filtration treatment is not limited, but generally, a filter or the like often used in a production process of a raw material for casting, a raw material for forging, or the like may be used. The filtration accuracy of the filter is not limited, but is generally about 10 to 50 due to the size of inclusions such as slag and oxides which are generally known.
μm may be used.

The cleaning means 12 is preferably provided with a heater to maintain the temperature of the molten metal 3 and prevent deterioration due to a temperature change before the molten metal 3 is sent to the next holding means 13. Although the type of the heater is not limited, it is preferable to use an immersion heater capable of transmitting heat directly to the molten metal 3. It is also important to install a heater in the cleaning means 12 so that the heat distribution is not biased.

The holding unit 13 is a furnace that holds the temperature of the molten metal 3 that has been subjected to the cleaning treatment in the cleaning unit 12 until it is sent to the casting unit 14, and usually includes a heater. Although the type of the heater is not limited, it is preferable to use an immersion heater capable of transmitting heat directly to the molten metal 3 and install the heater so that the heat distribution is not biased.

Although there is little occurrence of inclusions in the molten metal 3 in the holding means 13, if the inclusions are present, the molten metal 3 containing the inclusions is directly cast by the casting means 14 and the forged material 6 after casting is cast. Metal products 7
Directly linked to the quality of Therefore, even if inclusions are generated in the molten metal 3, for example, the shape of the holding means 13 is provided with a slope at the bottom so as to have a function of sedimentation and separation of the inclusions so that the inclusions are not easily carried into the casting means 14. Is more preferable.

The casting means 14 injects the molten metal 3 into a mold, and after solidification, as a solid metal, a casting, that is, a forging material 6.
Is what you get. Although it is possible to obtain a forging material 6 having a complicated shape by using a mold, the balance between the effect of improving the mechanical properties of the forging means 16 and the cost reduction by simplifying the forging means 16 is balanced. Is preferably determined. In other words, it is not preferable to obtain a very complicated shape in order to increase the mechanical strength.

Although the method of the casting means 14 is not limited,
In order to enhance the mechanical properties of the final metal product 7,
It is preferable to use a so-called low pressure casting method. Low-pressure casting is generally performed by pressurizing the molten metal into the molten metal container by gas pressure or the like, or by suctioning from the mold side with a vacuum, filling the molten metal 3 into the mold at a low pressure, molding, and forming a cast product. It is a method of obtaining. This has the advantage that it can be easily integrated with the holding means 13 described above. Further, it is preferable that the inspection means 21 be provided at a stage after the casting means 14 and inspect whether there is no defect in the forging material 6. Since the wrought material, which is a forging material, is not necessarily a material having excellent castability, it is more preferable in terms of quality control to confirm that no internal defects have occurred before forging stamping. The inspection means 21 can be composed of, for example, a magnetic flaw detector, an ultrasonic flaw detector, or the like.

In the casting means 14, it is preferable that the mold be heated in advance and heated. It is desirable to raise the temperature of the A6061 alloy to approximately 230 to 270 ° C.
Further, it is preferable to use a material having higher thermal conductivity for the mold. For example, even with an A6061 alloy, an aluminum alloy can be suitably used as a mold. Aluminum alloy has high thermal conductivity, heat is radiated from the mold in a shorter time, solidification of the molten metal 3 is completed early, and throughput is improved.

However, in the forging material recycling apparatus 1 of the present invention, it is important that the forged material 6 after casting is not cooled too much. In the present invention, in order to provide the forging means 16 following the casting means 14,
The forging material 6 obtained by casting can be forged immediately, and the temperature of the forging material 6 may be reduced to a temperature suitable for the forging means 16. This is the cooling means 15. If the temperature is too low, it is difficult to achieve effects such as improvement of mechanical properties by forging, which is not preferable. The cooling means 15 is preferably configured by air cooling, water cooling with cold water or normal temperature water, or a combination thereof.

Then, when the temperature of the forging material 6 falls to a temperature suitable for the forging means 16, the material is conveyed to the forging means 16 as a forging device and stamped to obtain a forged product 4. This eliminates the need for means such as a heating furnace and heat for raising the temperature of the forging material at room temperature to a certain temperature range required for forging stamping, which is required for ordinary forging equipment, and equipment. Costs and manufacturing costs are reduced.

In the case of the A6061 alloy, the temperature of the molten metal 3 is approximately 680 to 780 ° C.
6, the temperature required for forging stamping is approximately 380
Preferably it is 520 ° C. Further, the method of the forging means 16 is not limited, but when the metal product 7 is manufactured by using A6061 alloy, for example, to manufacture a vehicle suspension part such as an automobile, a rough press is performed using a 2000-4000 ton press machine. It is preferable to configure by forging and finish forging.

After the forged product 4 is cooled by the cooling unit 17, the forged product and the burr material are separated by the trimming unit 18. The forged product is then heat treated 19
As a result, a solution aging treatment such as T3 to T6 is performed, and the mechanical properties are improved to obtain the final metal product 7. In the case of undercarriage parts for vehicles such as automobiles using A6061 alloy which requires high tensile strength and hardness, T
4 and T6 treatments are preferred.

The unnecessary material 5 such as a burr material separated by the trimming unit 18 returns to the blending unit 10 and is mixed with the new material 8 to be reused as a forging material. Normal,
Unnecessary materials 5 such as burrs reaching approximately 30% are effectively used as metal products 7 produced by forging. Therefore, it is possible to reduce the raw material cost which accounts for a large proportion of the forged product, and the product cost is reduced.

[0041]

As described above, according to the present invention, it is possible to provide a metal product by forging, which is excellent in mechanical properties, of high quality, and of which cost can be reduced.
Supplying lightweight vehicle suspension parts using, for example, aluminum alloys as metal products will reduce the fuel consumption of automobiles, etc., and contribute to the reduction of carbon dioxide emissions, a global issue, and global warming. It can contribute to environmental measures such as prevention.

[Brief description of the drawings]

FIG. 1 is a block flow diagram showing one embodiment of a configuration of a forging material recycling apparatus of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Forging material recycling apparatus, 3 ... Molten metal, 4 ... Forged product, 5 ... Unused material, 6 ... Forging material, 7 ... Metal product, 8
... new material, 9 ... trace metal, 10 ... compounding means, 11 ... dissolving means, 12 ... cleaning means, 13 ... holding means, 14 ... casting means, 15 ... cooling means, 16 ... forging means, 17 ... cooling means, 18 ... trimming means, 19 ... heat treatment means, 20 ...
Analysis means 21, inspection means.

Claims (7)

[Claims] 1. A forging material recycling apparatus for producing a metal product from unnecessary material including burrs generated during forging, wherein at least a melting means for melting the unnecessary material to obtain a molten metal, and casting the molten metal. A casting means for obtaining a material for forging, a forging means for forging the forging material to obtain a forged product, and a trimming means for removing the burr from the forged product into a forged product. A forging material recycling apparatus characterized in that a means for removing an oxide film of a forging material is omitted before the means. 2. The forging according to claim 1, further comprising cooling means for lowering the temperature of the forging material to a temperature suitable for the forging means, and omitting means for raising the temperature of the forging material before the forging means. Material recycling equipment. 3. The forging material recycling apparatus according to claim 1, further comprising an analyzing unit that analyzes a component of the molten metal and monitors a composition of the molten metal. 4. The forging material recycling apparatus according to claim 1, further comprising a cleaning unit that removes impurities in the molten metal. 5. The forging material recycling apparatus according to claim 1, wherein the forging material is an aluminum alloy. 6. A method for recycling a forging material for producing a metal product from a waste material containing burrs generated during forging, comprising: a melting step of melting the waste material to obtain a molten metal; and casting the molten metal. A casting step of obtaining a forging material by forging; a forging step of forging the forging material to obtain a forged product; and a trimming step of deburring the forged product to obtain a forged product. A method for recycling a forging material, wherein a step of removing an oxide film of the forging material is omitted in a preceding step of the step. 7. The forging according to claim 6, further comprising a cooling step of lowering the temperature of the forging material to a temperature suitable for the forging step, wherein a step of raising the temperature of the forging material is omitted in a step before the forging step. How to recycle materials.