KR100856097B1 - Production method by means of liquid forging and hot shaping - Google Patents

Abstract

TECHNICAL FIELD The present invention relates to casting engineering, and is used to improve physical and performance characteristics of complex shaped products such as automobile wheels or parts thereof. Intricately shaped products, especially hot forged car wheels, are not economically efficient. Therefore, at this stage, casting is mainly used worldwide for the continuous production of parts of the same type as automobile wheels. However, since no clear and modern casting method exists, the parts produced by hot forging far outperform the products produced by the casting method in quality. Therefore, when manufacturing by casting, the problem of improving the physical and performance characteristics of the product is a challenge. To solve this problem, a hydraulic press operation combined with pressure treatment was used. The object of the invention is to produce a complex shaped product with a large difference in the cross-sectional height of various parts, in particular a central part and a relatively thin peripheral shape, such as an automobile wheel, or a hydraulic press operation and thermal deformation coupling. This is to improve the quality of the product, which is high and low away from the melt pouring point. This approach can at least improve the quality of critical components to the level of hot forging operations. It is also an object of the invention to improve the quality of the product by introducing additional methods. An additional task of the invention is to increase the economics of the method by simplifying the technical process. These challenges are achieved with hydraulic press operations and product manufacturing methods using thermal deformation, including crystallization and thermal plastic deformation of metals or alloys under pressure. Such methods differ in the following ways: in the manufacture of complex shaped products with variable cross-sectional areas of the part or with peripheral parts away from the metal or alloy pouring point. The crystallization pressure value at is determined by P, and the strain rate and temperature are ε and T, respectively. Where P, ε and T-are the plastic deformation process parameters in the superplasticity state for a given metal or alloy. The pressure up to the value P here is the part with the smallest cross section and / or further away from the melt pouring point from the moment of providing an upper punch to the mirror's reflector. At time t until crystallization appears. At this time, the temperature of the press is selected from two conditions. First, there are conditions to ensure plastic deformation in the superplastic state, and secondly, to consider the temperature of the melt to ensure the preservation of the metal or alloy in the liquid state for a time t.

Forging, Hot Forming, Rolling, Squeeze Forging, Automobile Wheel

Description

Manufacturing method by molten metal forging and hot forming {PRODUCTION METHOD BY MEANS OF LIQUID FORGING AND HOT SHAPING}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to casting engineering, and to improve physical properties and productivity in the production of complex shaped parts such as automobile wheels or parts thereof. The production of complex shaped products, in particular hot forgings such as automobile wheels, is not economically efficient. Therefore, parts such as automobile wheels are currently produced mainly by casting methods. However, there is no casting method that satisfies all, and the parts produced by hot forging are excellent in quality. Therefore, the problem of improving the physical characteristics and the performance level of the part in the casting process of the part is very important. In order to solve this problem, a molten metal forging method which is combined with a hot forming method is used.

Putting molten metal into a mold, cooling the molten metal until it solidifies, and a combination of pressure casting and plastic working are well known [1]. At this time, the metal is processed with ultrasonic waves while controlling the wave speed of ultrasonic waves passing through the metal during the cooling process. Pressurization occurs when the propagation of the ultrasonic waves to a given metal at room temperature reaches a rate of about 0.85-0.95.

The processing of the metal by pressure occurs when the strain force is minimal, which is determined by the speed of passage of the ultrasonic waves through the metal. In this method, the physical effect of the change of the ultrasonic propagation velocity with the density of the substance is used. However, the density depends on the temperature of the material. Upon cooling of the molten metal, the liquid phase continuously changes to a solid phase and crystal structures begin to form. The density of the material increases, and the passage speed of the ultrasonic wave increases.

The optimal time for thermoplastic semifinished products is when the pass rate of the ultrasonic wave is 0.85-0.95 at room temperature.

The slow speed of the solid phase is not enough, which makes it impossible to produce a given type of product. At high speeds, the material is close to being completely hardened, resulting in casting defects and degradation of product quality.

The advantage of the proposed method is that it has a high degree of accuracy and can determine the grain formation time of the metal structure by the change of the properties and the stress of the whole crystal structure in the solid state and the liquid state of more technical plasticity.

In addition, when the crystal structure of the cast semifinished product fails to obtain the strength of the cooled object, the thermal deformation of the cast semifinished product, the liquefaction process, and the formation of grain boundary shapes of brittle metal alloys and nonmetal phases and Separation is not complete, and consequently, there are no existing differences in the firing of the whole grain, and the grain boundaries need to be considered as active interference during the crystallization process. There is also a need to improve the properties of processed products.

This conclusion is based on the fact that, firstly, the necessary conversion of the liquid phase is made, which leads to the destruction of the primary and secondary branches of the dendrite in the metal which is crystallized under the influence of external pressure, which in itself promotes the formation of a uniform microstructure. do.

Secondly, pushing the liquid phase needed for dendritic structure helps to speed up the growth by injecting vesicle solvents and promotes the ability to form microstructures while eliminating the causes of pinhole shrinkage.

However, this method differs in the complexity of the implementation, and in addition, it cannot be used in the manufacture of products having large widths in the cross-sectional area, that is, products having different cooling rates in different regions.

At the same time, even without considering the formation of microstructures, elimination of gas holes and the cause of shrinkage, the product does not improve physical properties as much as the properties of hot forged parts.

Known methods of forging include [2] injecting molten metal into the mold, solidifying the molten metal under pressure, and forming the final form under elevated pressure.

In addition to pressing the metal into the solidification zone of the casting until the plastic strain reaches ε ≥ 0.7... 0.8, the elevated pressure causes the crystallization of the previously solidified metal to become a local part.

This method takes the following form: Add a fixed amount of solution to the mold. Pressure is applied to the four phases and under this pressure the parts are held for a time sufficient to form a 75 to 80% solid phase. Then, with increasing pressure on one glyph, a subsequent positional shift occurs under that pressure to the size of hε of the given glyph. Other pictographs are then forcibly reduced to their original state. In the region under this phase, plastic deformation ε ≥ 0.7 ... 0.8 is observed.

Improvements in mechanical properties have significant implications in areas where minor plastic deformation occurs in parts of components.

This method is intended for the fabrication of frame-type parts with bosses and ribs, but has a large width in the cross-sectional area, so that it can be used in the manufacture of parts with different cure rates in different parts. Can not. In particular, such a shape corresponds to an automobile wheel having a thick central portion and having a thin outer flange.

It is well known to manufacture a product by pressurizing a hydraulic press simultaneously with crystallization and plastic deformation during coagulation [3] .

When high pressure and fast cooling are applied in the metal mold, dissolved gases in the alloy remain in the solid and liquid, and as the developmental stage of the liquefaction process is shortened, the integrity of the alloy is increased. Shrink steam is filled by the liquid alloy. As a result, the casting has a fine crystallization structure and is also dense with high physical mechanism properties.

The structure of the casting depends on the technical parameters of the process. When pouring molten metal into the mold in critical steps, the temperature of the press-mould determines the crystallization rate during casting, which in turn determines the average size and shape of the grains. When poured into a cooled press-mould, a dendritic structure is formed that can spread to all cross sections of the casting.

As a result of changing the heat exchange conditions and cooling parameters of the grains, and also as a result of the physical compression of the upper mold against the grains, an increase in press pressure (others under the same conditions) changes the casting structure. In the press working of the solidified crystals, it is partially broken, forming additional new grains of crystallization, and this phenomenon is stronger in the area of intensive deformation.

This method consists of two steps. In the first step, the melt is added to a mold of graphite, a mold of ceramic, or a cast iron mold made of heat-resistant steel or alloy. Here, the molten metal is cooled until the outer shell is formed throughout. It also transports solid-liquid semi-finished products, formed from solids and liquids, not one type of binder in this mold, to the crimping position. In the second step, the solid-liquid semifinished product is placed in a press and shaped.

The temperature of the outer layer of the solid-liquid semifinished product corresponds to the temperature of the hot mold for the alloy, while the temperature of the solid shell and the liquid core portion is consistent with the solidification temperature of the alloy. The rate of movement of the crystal front depends on the concentration of heat transfer that takes place through the shell and casting mold to the surrounding environment and the temperature of the melt during injection.

This method is made with a very simple process in product structure. It is not possible to obtain intermediate solid liquid semifinished products for complex cross-section products such as automobile wheels, and due to crystallization in very thin peripheral parts, the subsequent plastic deformation proceeds very fast and spans the entire peripheral part, i.e. outer flange part, for a short time. . If the car wheel type is more heavily loaded, it is necessary to improve the physical characteristics of the outer flange part.

An object of the present invention is to inject a car wheel or molten metal having a relatively outer flange portion shape with an excessively wide cross section, particularly a thick central portion, when manufactured by a method in which molten forging and hot forming are combined. To improve product quality of complex shape with parts far away from the point. At this time, the quality can be improved to the level of hot forging, and at least the quality of important parts of the product can be improved.

In addition, the problem of the present invention is the improvement of product quality obtained by additionally using this method.

An additional object of the present invention is to improve the economics of this method by simplifying the technical application.

This problem is solved by a method of manufacturing a product using hot forging and hot forging that includes crystallization and thermoplastic deformation of a metal or alloy under pressure. It differs in the following points: In the manufacture of complex shaped products with large cross sections or with outer flanges away from metal or alloy injection points, the crystallization pressure value is determined to be approximately P, The temperatures are ε and T, respectively. Where P, ε and T are the plastic deformation process parameters in the superplastic state for a given metal or alloy. The pressure up to the value P here occurs from the moment punching the surface of the melt to the time t until crystallization occurs at the part with the smallest cross section and / or further away from the melt injection point. At this time, the temperature of forging is selected from two conditions. Firstly, there are conditions that ensure plastic deformation in the superplastic state, and secondly, conditions that take into account the temperature of the melt in which the metal or alloy remains liquid for a time t.

The task given is determined as follows:

In the realization of the method, use a hydraulic press to guarantee deformation and speed at intervals 10 ^{-4-10 -2} sc ^-1 . The greater the velocity at a given interval, the higher the pressure above the strain temperature.

Pressure is maintained for at least 60 seconds, which ensures plastic deformation, which is necessary to eliminate anomalies such as discontinuity and deformation after recrystallization at a given speed.

-In the manufacture of products with wide cross-sections, the melting temperature is lowered so that the crystallization time of the metal or alloy is minimal.

-The back extrusion method is used to produce cup-shaped products with periphery or outer flanges that extend along the area in the axial direction. Here, the backward extrusion method (Backward Extrusion) means that the molding of the material is molded in the opposite direction of the upper mold pressing when the upper mold is pressed on the material as is widely known.

In the manufacture of products with a central hole, such as a car wheel, a technical connector is left in the hole, which will later be removed by mechanical machining when the central hole is finished.

Additional partial plastic deformation of the core in the superplastic state. The thickness of the core is then chosen to ensure that such deformation is possible.

-Use pictograph directly as core. That is, in the present invention, the mold is composed of an upper mold for pressing and a lower mold containing molten metal, and the upper mold is used as the core by forming and pressing a core on the upper mold.

-The connecting material is made of an aluminum alloy (insert: melt-blocking element which prevents the melt from entering to make the center hole of the wheel) as the core.

-Inserts made of steel are used as cores.

In the manufacture of products with peripheral flanges such as automobile wheels, i.e., outer flanges, additional spinning is performed on the outer flange portion with a rolling roller tool in a superplastic state.

Perform plastic deformation immediately after forging without additional heating.

The component ratios of the release agent are as follows: paraffin-20%, graphite-10%, kerosene-70%

-In the manufacture of products with developed circumferential parts with undercuts, split molds are used, and the finished product is removed from the press after removing the surface of the marked part of the product.

As mentioned above, in the analysis of well-known technical grades in products with large cross-sections or away from the place of pouring, with the periphery, ie the outer flange, or when these two factors have important implications, The progress of crystallization is inconsistent in time. In addition, the crystallization proceeds very quickly in the parts mentioned.

By using the proposed technical method, in the case of parts of a product having a large cross section or located close to the place where the metal or alloy is poured, when a liquid phase is present in the part of a product having a relatively small cross section or far from the injection site, pure The plastic deformation process combined with crystallization under pressure proceeds to the plastic deformation process.

[3] In analogy to look at it analogy to [3] under the action of rapid cooling takes place in the high pressure P with the template, the speed results of the liquefaction process development step, the gas that is propagated in the alloy is left in the solution, the integrity of the alloy Is improved. The contracted vapors are forced to fill by the molten alloy. The casting results in a dense product with a small crystal structure and high physical properties.

Changes in heat exchange conditions and changes in thermodynamic parameters of crystallization, as well as the physical action of the phases on the crystals, and the high pressure of the press operation, make the casting structure densified microstructure. Upon compaction of the solidified casting, the crystals crumble partially, forming additional new grains of crystallization;

On the other hand, unlike the [3] paper, in contrast to the superplastic mode, but unlike the [3] paper on the invention of certain parameters of pressure P, strain rate ε and temperature T, New unexpected results, including improvement and subsequent grinding, result in more integral Si for each state of superplasticity. It ensures the allocation and recrystallization process of fine particles and metal alloys. New unexpected results relate to the combination of process unit technology cycles of casting and deformation in the superplastic state. Traditionally, superplastic deformation requires sufficient labor-intensive structural preparation in the first semifinished product, in particular in cast semifinished products. When the constant P, ε, T and the structure are good, plastic deformation in the superplastic state completely eliminates the cause of gas shrinkage.

As a result, in most of the products, the improvement in the level of physical properties and the level of performance characteristics occur until the original level is achieved for hot forged products.

These advantages apply to all products. However, there are products that need to calculate the height difference of the cross section in advance. In this case, the shortcomings of the gas shrinkage source cannot be completely eliminated where the largest cross section and the largest particle size typical of the casting (due to longer crystallization) are eliminated. The technical method of removing them is shown below.

According to the present invention as described above, when manufactured by the method of combining hot forging and hot forming, an automobile wheel or a molten metal having a relatively outer flange portion having a particularly large central section with an excessively wide cross section, To improve the quality of complex shaped products with parts far away from the injection point. At this time, the quality can be improved to the level of hot forging, and at least there is an effect of improving the quality of an important part of the product.

The core of the present invention is further described below and is embodied and evolved.

The essential speed of deformation and the possibility of deformation by speed ensure the use of hydraulic presses in the manufacture of various products made of different metals and alloys.

The doubling strain rate over strain time (under pressure) ensures the degree of strain needed to compensate for the shrinkage process.

However, it is not possible to directly give the strain squared value because of the complexity of the cross-section of the product and the crystallization time of the different parts. Therefore, it is reasonable to set the pressure time to 60 seconds or more. Due to the complementary plastic deformation and shrinkage of metals and alloys, the excitation is converted to some value during this time.

In the manufacture of products with largely different cross-sections, it is recommended to lower the melt temperature to a value that ensures a minimum difference during the crystallization time of the metal or alloy. Of course, the metal or alloy is preserved in the liquid state for a pressure t while taking into account the compression temperature. Examples of specific implementations of the invention are described, particularly in the manufacture of automotive wheels with a diameter of 12 inches.

The temperature of the melt is 690-720 ° C. When the molten metal is at a higher temperature, cracking of the hub, which is the wheel center, is observed. At this time, the temperature of the stamp should be more than 390 ℃. During the time t when the stamp temperature is lower, the metal cannot retain the liquid phase.

In the back extrusion process, molten metal forging has several advantages.

The path of metal injected is several times shorter than casting under pressure. This results in a much smaller loss of fluidity of the metal itself.

There is no condition to take air when compression molding metals. This is because the metal is poured into an open mold, pushing out the amount of air equal to the total amount of metal injected.

When the mold is made by the compression method, there are no vortexing conditions and the resulting loss of hydrodynamic pressure, i.e. the cause that prevents the metal from filling the outside of the mold. That is, in a deep and thin space, the metal moves upwards parallel to the wall of the mold without frontal impact.

In the manufacture of products with a central hole, it is necessary to achieve the purpose to leave the core where the hole is to be removed later by mechanical machining in a hole, including the back extrusion process. The use of metal as the core is beneficial. In other words, it can be used for the purpose of removing pores in the central part of the product to be in the most adverse conditions during the crystallization process to improve the structure of the metal or alloy. In this case, the core may be used as an upper mold. In other words, a core is formed on the upper mold. Particularly effective, however, is to press the connecting material past the intermediate insert. In this case, the inserted material is pressed in the central portion while the main metal or alloy is generated during discontinuous determination. The insert was then removed using physical processing. Inserts are made of aluminum alloy or steel.

The use of a rolling tool in the form of a roller can cause additional local deformation of the periphery, ie the outer flange. At this time, it is economical to cold-roll with a tool for rolling immediately after major deformation without additional heating. Cold calcination affects not only future structural improvements but also future shape formation. The main method is used to obtain intermediate semifinished products in a simpler form.

In order to clean the surface of the mold, it is necessary to apply oil, ie a release agent, to the mold. Applying the release agent protects the surface of the mold from welding of the metal, slows the cooling of the ingot, and most of all additionally promotes the formation of a coaxial structure. In addition, the relatively slow ingot cooling rate facilitates the implementation of crystallization studies under pressure. The component of the release agent used is optimally selected in consideration of the aggregate state of the metal or alloy.

Difficulties arise when taking the product out of the mold in the manufacture of products with complex shaped surfaces. In such a case, it is easy to take out a part mold, for example, a partition insert type that directly enters the mold.

Embodiment of the invention:

An example is a method for manufacturing automotive wheels 12, 17 and 22.5 inches in diameter made of alloy A356.2. As automotive wheels have a great difference in cross-sectional width and are complex shaped products with a periphery, i.e., an outer flange portion, these methods show the possibility of the invention more clearly. The examples presented are not intended to illustrate all cases of implementation of the invention, such as methods for producing other complex products using other metals and alloys.

 Outline for example:

Use of facilities. In operation, the following equipment was used: hydraulic presses, furnaces

Press

Characteristics of the press:

Manufacturer-Russia

Maximum load-630 tons

Knock-out Maximum load-63 tons

Knock-out diameter-320mm

Open height (maximum distance from top to bottom of press)-1775mm, (width of crosswood)

Shut height (minimum spacing above and below the press)-975 mm,

Boulster size-1250 × 1250mm

Melting furnace.

It is preliminarily maintained for the dissolution of the aluminum alloy, and a sunshade with a fan is installed. The furnace has a capacity of 250 kg, power 90 kbps and productivity 75 kg / h.

material. Aluminum alloy A356.2 (6.5-7.5)% Si, (0.2-0.4)% Mg, 0.15% Ti, 0.08% Fe, 0.01-0.04% Sr, the remainder is Al. Supply of A356.2-cast iron bars weighing 16 kg. One part of the alloy is produced at the Kamensk-Ural Aluminum Plant (Russia) and the other part is a product of the ASA. The structure of alloy A356.2 consists of a solution of alloying components distributed along dendrite grain boundaries based on a portion of aluminum and eutectic mixture silicon in the feed state (FIG. 2).

Preparation of lysates . Prior to dissolving 16 kilograms of cast iron, the cast iron was ground to place it more densely in the furnace crucible. The metal was purified after the metal changed to the liquid state. To this end, the temperature of the melt is raised to a purification temperature of 730 ° C. The temperature is controlled by nickel chromium-alumel thermal steam that has settled into the melt. The alloy is left in the crucible for 4-5 hours beforehand. At this time, a thin film of up to 1 mm is formed on the surface of which is removed by a skimmer. The alloy is then purified with clean, dry zinc chloride GOST 4529-78. The calculated amount of salt is placed in a paper bag in a “bell-shaped” glass with a diameter of 75 mm, a length of 100 mm and 40 holes of 8 mm in diameter in the cylindrical part. At this time, no special dye is applied to the working part of the “bell shaped glass”. Then put the “bell shaped glass” into the melt and place it on the bottom of the crucible.

The "boiling" process of intensive gas separation and debris formation begins. Purification ends after the intensive separation of gases has ceased. Purification time is 10 minutes. After purification, the lysate is left in the furnace for 30 minutes before splitting. The dregs formed are removed from the melt surface by a skimmer and the surface of the melt remains clean.

After five dissolutions the following facts were demonstrated: Holes in the “bell shaped” cups increased. After 10 dissolutions, many of the holes increased from 10 mm in diameter to 8 mm in diameter. The use of aluminum alloys on the cover of the tool- “bell cup”, skimmer and thermal vapor was observed. At the end of every dissolution, they are immersed in a 70% NaOH solution at 70 ° C for the purpose of removing the stuck metal.

In order to prevent the aluminum alloy from sticking to the tool, the mold was changed to the following release agent. :

Graphite-25%

Liquid glass-5%,

Water-70%.

After the change, sticking was observed only in the "bell shaped cup."

During purification, zinc chloride was added to the melt in varying amounts depending on the purity of the alloy in the melting furnace. If the cast iron consists of an alloy, the amount of salt is 0.1% of the alloy capacity. If 50% cast iron and 50% melt processing, it is 0.15%, and when using 100% melting processing, the amount of salt in the melt is sufficient to 0.2%.

The processed lysate was taken out of the melting furnace crucible using the brine gourd. The working part of the melt was made of titanium alloy. The salt gourd was pre-painted with a dye of the abovementioned ingredients. The capacity of the melt in the salt gourd is 17 kg.

Release agent . Application of a release agent to the mold is essential to obtain a clean surface of the product.

Components of Mold Release Agent: Graphite-20%, Paraffin-10%, Kerosene-70%.

Apply release agent using sprayer, soft brush or rag, slightly soaked greaser.

Deposition of the coating agent in all excesses and corners of the release agent can create bubble pores outside the product.

Painting on the metal took place after the complete disappearance of the liquid foam.

Method used- Back extrusion with core . The press mechanism (FIG. 1) is located with a reinforced upper mold (1), insert (3; inset) and ejector (4) located through the bottom slab in the upper partition of the casting press (not shown in FIG. 1). It consists of the holder 2. The shape of the spoke and rim outer part of the wheel is formed by the lower mold, the rib is made by the cutting insert and the mold, and the spoke and the rim of the wheel The interior is made by pictographs.

Removal of the processed product takes place through the dislocation of the insert towards the side and top, and the next action takes place in the lower mold.

Example 1. Preparation of wheels 12 inches in diameter.

The method was performed when the pressing force was 400 tons. At this time, the pressure P is 4.4 kg / mm ² .

A brazed tubular electric circular heater (TEN) was used for mold preheating.

The temperature T of the mold was maintained at 450-460 ° C.

Sequence of movement.

Elevation of the upper mold, opening of the insert. Visual control of the mold inner surface when no material is present.

7 release of release agent. The release agent was applied to the mold surface using a brush. Loss of release agent.

Cleaning of the mold by air.

Fill the melt. The temperature of the molten metal is 690 degreeC.

The molten metal was removed from the furnace and the molten metal was manually filled into the mold using a salt bar bag made of titanium alloy BT6.

The time interval between pouring the molten metal into the mold and starting the pressure is 20 seconds.

The upper part is removed in two steps without interruption: 200 mm in the empty space, then about 470 mm in the process until the mold is joined. Total travel time to the bottom is 11 seconds. After joining the mold, pressures of up to 400 tons occurred for 4 seconds.

Leave for 60 seconds under the added 400 tons of force.

Solidification rate considering the cross-sectional area of the various components is ^10-2 - ^10-4 is changed during the preparation time in the sc ^-1 intervals. Where the unit of sc ^-1 is Refers to the rate of solidification per temperature (s / c).

The quality of the part is determined by visually assessing the presence of cracks and vapors on the outer surface and cross-sectional area.

The appearance of a wheel 12 inches in diameter is in FIG. 3.

The microstructure of the wheel in the cross section is in FIG. 4.

At the hub and rim of a wheel 12 inches in diameter, the microstructure of alloy A356.2 varies, with the Si component at the rim being more evenly distributed.

The physical properties of wheels made without inserts are shown in Table 1.

Sampling site Tensile Strength, MPa Yield strength, MPa Elongation, (%) Hardness (HB), MPa Wheel spoke hub rim 288 298 298 229 216 212 7.1 9.8 10.4 941 956 963

Sample cross-sectional schematics are shown in FIG. 6 to study the microstructure and physical properties. In FIG. 6, Nos. 1 to 5 show sampling portions of the sample.

When the rim of the wheel is compared to the hub, it has a finer structure with a smaller single particle. This results in higher durability levels and plastic properties at the rim.

Example 2. Preparation of wheels 17 inches in diameter.

The sequence and state of movement are the same as in Example 1. The difference between Example 1 and Example 2 is as follows:

The pressing force is 400 tons.

The holding time under pressure is 80 seconds.

The temperature of the melt-700-710 ° C.

Temperature of the stamp-410-420 ° C.

A manufactured wheel figure 17 inches in diameter is shown in FIG. 7.

The microstructure of the A356.2 alloy from the rim, wheel spokes and hub is shown in FIG. 8.

The mechanical properties of wheels made without inserts are shown in Table 2.

In order to study the microstructure and mechanical properties, the sampling region of the sample is shown in FIG. 6.

Example 3.

The sequence and state of movement are the same as in Example 1. The difference lies in the fact that the transformation of the central part of the wheel-technical connection was carried out with the help of inserts made of steel.

Deformation of the central part took place at a temperature of 420 ° C, a press force of 160 tons, and an average speed of 10 ^-2 sc ^-1 . The wheel appearance after the end of the mentioned operation is shown in FIG. 9. As can be seen from this, the ball is pressurized to the center portion of the wheel. The ball with the core was completely removed through physical processing.

Physical properties of a 17 inch diameter wheel made with steel inserts are shown in Table 3.

Sample Collection Department Tensile Strength, MPa Yield strength, MPa Elongation, (%) 1 2 3 4 5 294 291 285 259 283 216 215 210 206 202 12.7 15.0 14.0 4.2 14.6

Sample Collection Department Tensile Strength, MPa Yield strength, MPa Elongation, (%) 4 270 210 8

Note: The physical properties of the different parts of the wheel are shown in Table 1.

Example 4 Preparation of a 22.5 Inch Wheel Diameter. The sequence and state of movement are the same as in Example 1. The difference between Example 1 and Example 4 is as follows:

The pressing force is 1600 tons.

The holding time under pressure is 150 seconds.

Temperature-710-720 ° C.

Mold temperature-390-420 ° C.

At this point, an intermediate semifinished product can be obtained, in which a hub and a spoke part, which are the central part of the wheel, are formed, and a protrusion is formed below the rest of the rim.

Subsequently, partial deformation of the hot rolling tool protrusion was made with extraction of the rim. The semifinished product also entered the finishing process without cooling and no additional heating. With a strain rate of 10 ⁻¹ −10 ⁻² sc ⁻¹ , the tool for rolling is made from one side to the outside.

Key References:

1. A.c. CCCP 445522, B22D 27/12, 1974

2. A.c. SU219242, B22D 18/02, 1986

3. A.c. SU 1577916, B22D 18/02, 1990

4. Schivakoff V.G., Jugulev I.O., Marashinski A.N. "Pressing the product when it is crystallized under pressure". "Forging Press Production" Magazine, No6, 2002

1. External view (photo) of a press for carrying out the method of the invention

      (1: upper type, 2: lower type, 3: insert insert, 4: ejector)

Figure 2 shows the microstructure of alloy A356.2 in the (ingot) transport state (150x magnification).

a) Russian

b) Mount Dubai

3. Exterior view (photo) of a 12 inch diameter wheel made in the manner described above

4. Cross-sectional microstructure before mechanical machining of a 12 inch diameter wheel

5. Microstructure of Alloy A356.2 on a 12 inch diameter wheel (150x magnification)

a) at the rim of the casting

b) in the hub section

Figure 6. Sample collection site for structural studies and mechanical experiments

      (No 1, 2, 3, 4, 5 indicates the body odor of the specimen)

7. Exterior view (photo) of a 17 inch diameter wheel processed according to the method described before mechanical machining.

8.Aluminum A356.2 microstructure on 17 inch diameter wheels (150x magnification)

a) at the rim of the casting

b) on wheel spokes

c) on the hub

9. Cross-sectional microstructure before mechanical machining of 17 inch diameter wheels machined using alloy inserts.

Claims (3)

delete As a product manufacturing method using molten forging and hot forming, The crystallization pressure value is determined as P in the manufacture of complex shaped products with areas with cross-sectional changes in the part or with outer flange portions away from the metal or alloy pouring point. Where the strain rate and temperature are ε and T, respectively, where P, ε and T are the plastic deformation process parameters in a superplasticity state for a given metal or alloy, where the pressure to the value P is melt From the moment punching the surface into a punch, from time to time until crystallization occurs at the part with the smallest cross-section and furthest from the melt pouring point, where The temperature of the mold is, firstly, a condition that guarantees plastic deformation in the superplastic state, but secondly, the molten state of the metal or alloy in the molten state for time t. Choose from the conditions considering the temperature of the molten metal to ensure preservation, In the manufacture of products with outer flanges, such as automobile wheels, after performing additional plastic deformation of the peripheral parts with a press in a superplastic state, A method for producing a product using hot forging and hot forming, characterized in that the plastic deformation treatment is carried out immediately by pressing rollers without additional heating. delete

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