What is metal stamping

Hot stamping and cold stamping of sheet metal parts

Hot die forging is a process of deliberate deformation of a heated workpiece made of various types of metal to change its size and configuration.

Moreover, the geometric characteristics of the product change in several dimensions, and not in one plane. The technology has found application in many industries and has very broad prospects for further development and improvement.

In what areas of industry has the technology found application?

Hot die forging is a type of processing of metal workpieces using pressure, which involves the use of a special tool, a stamp, to form a forging from a heated workpiece.

The surfaces of the cavities and protrusions of individual parts of the die limit the flow of metal, so as a result of the operation, a single closed cavity is formed according to the configuration of the forging. Such a cavity is called a stream.

For this type of processing, special stamping blanks are required. They are made using rolled profiles of various shapes by cutting the rods into individual products using crank press shears, mechanical saws, gas cutting, etc.

Hot stamping.

The advantages of this technology when compared with forging are as follows:

• high performance indicators;
• higher precision in manufacturing parts: tolerances when stamping forgings are 3 times smaller than when forging.

The main disadvantages of the technology are the high cost of the tool and its narrow focus: a specific stamping machine is suitable for creating a forging of one shape and size.

In addition, to carry out volumetric hot stamping of forgings, several times more deformation forces will be required than for forging similar forgings.

The technology is actively used at manufacturing enterprises in the metalworking industry that deal with aluminum alloys and brass.

Using hot stamping with a press, blanks are produced for parts of cars, tractors and other types of agricultural machines, airplanes, railway cars, machine tools, etc.

Taking into account the trend towards increasing serial production in mechanical engineering, stamping will become even more popular and developed in the future.

Types of volumetric stamping

There are different types of volumetric stamping: cold and hot. The first technology is less common than hot technology, since it does not require very powerful equipment.

In addition, it is worth noting the tendency of most steels and alloys to be processed in a hot state. Therefore, it is the hot type of stamping and forging that is preferable for many enterprises in the metallurgical industry that involve the manufacture of products from metal sheets.

But the cold technology of creating metal forgings also has its advantages:

• the metal does not heat up during operation;
• the metal surface does not oxidize upon contact with oxygen;
• it is possible to manufacture products with more precise parameters;
• low metal surface roughness;
• low metal consumption;
• low labor intensity of product production.

The hot stamping method for forgings is different:

• high performance indicators;
• excellent uniformity and strength of finished forgings;
• the ability to produce forgings of complex shapes;
• high automation of work processes.

Hot stamping process.

There are different methods of hot die forging, depending on the type of dies used:

• open;
• closed;
• extrusion;
• firmware;
• in split matrices.

It is this classification that is considered the main one, because the type of die used in the work is the determining factor for the nature of the metal flow during the formation of the forging.

Thanks to the use of metal processing technology using this method, it is possible to produce forgings of various geometric parameters:

1. Elongated parts: levers, connecting rods.
   To produce them you will need a stamping press. The original workpiece is drawn and processed flat. At the end of the work, the part is shaped using forging.
2. Disk parts of square, round shape and short length: hubs, gears, flanges, covers.
   Manufactured using the technology of upsetting into the end of the workpiece. And their use is carried out using stamping transitions.

It is extremely difficult to produce forgings that are absolutely accurate in size by stamping; for this reason, there is such a thing as tolerances. They take into account under-stamping of the product in height, wear of the die groove, the risk of the dies shifting during use, etc.

If the tolerances determine the cleanliness of the surface and the accuracy of the forging, which satisfies the general requirements for the final results of the work, then no other allowances are required in the future.

If the previously assumed tolerances or the cleanliness of the metal surface turn out to be unsatisfactory, it is worth considering the possibility of obtaining more accurate parameters of forgings through calibration, coining, improving the quality of the process itself and heating.

If this solution does not resolve the issue, then allowances are assigned for subsequent processing by cutting.

Technological diagrams of stamping

The hot metal stamping machine operates using special working schemes. They are used to forge and stamp various metal products. Based on the characteristics of the applied working scheme, it is possible to determine the future parameters of the finished forging.

Such schemes can be classified according to the type of stamps involved in the work:

In closed stamps

The die cavity is closed during deformation, so the gap between the moving and stationary zones is minimal. The design features of a closed stamp determine the type of stamping machine.

In most cases, the upper part of the die is characterized by a protrusion, and the lower part is a cavity. The opposite situation can also be encountered.

The use of such products in practice must be carried out with careful preparation and strict control over the identity of the volumes of the forging and the workpiece.

Problems may also arise with the height of the forging when working with the hot method: if there is too much metal, the height of the forging will be greater than planned. In order for stamping to take place according to the optimal pattern, it is important to cut the workpieces with maximum precision.

In open dies with variable clearance

A certain volume of metal flows into it, which makes it possible to fill the working cavity of the forging completely. In addition, the flash will be filled with excess metal at the final stage of work, which will reduce the requirement for the accuracy of workpieces by weight.

Cold and hot stamping using such products is carried out in four stages: upsetting the workpiece, aligning the walls of the product with the workpiece, excess metal flowing into the groove during compression, and removing excess metal from the cavity.

The advantage of hot stamping dies is the ability to produce any type of forgings.

Closed dies also have certain advantages:

1. More favorable forging structure.
   In this case, there is no cutting of the fibers into a flash at the point of metal leakage. They flow around the forging contour, which makes it possible to achieve unique surface precision of parts without any types of grinding;
2. No flash with this scheme.
   This allows you to significantly reduce metal consumption.
3. The ability to work with low-plasticity alloys characterized by a high level of deformation under high stress of uneven all-round compression.

Tools and equipment

Stamping production using cold and hot methods requires a number of tools and devices. The equipment used for stamping is conventionally divided into main and auxiliary.

The first group of tools includes dies, which in turn are divided into forging dies for making products and trimming dies for eliminating burrs after stamping.

All of them are intended to create exclusively a given part, but sometimes you can also find options with removable parts and blocks that allow reconfiguration.

Stamping tools for hot technology are made from high-quality alloy tool steel, because the products are subject to high mechanical pressure and thermal load during operation.

But this is a rather expensive material, so to save money, stamps are made with inserts made of cheaper metals.

Cold metal stamping involves the use of equipment that operates under high specific loads and ensures high accuracy of product shapes and sizes. It is characterized by high productivity and increased stroke, as it has high structural rigidity.

The process of obtaining volumetric stamps.

The second group of tools and devices for stamping includes:

• devices that allow the delivery and loading of metal into the furnace, its supply from the furnace to the hammer and the transfer of blanks from one hammer to the next;
• equipment for feeding blanks under the stamping press with their subsequent transfer from one die strand to another;
• tools for removing forgings from dies after production;
• measuring instruments and templates for periodic inspection of stamped forgings.

To process metal parts using hot stamping, you will need the following equipment:

• hammer dies;
• hot stamping crank presses;
• horizontal forging units.

The most common options today are double-action steam-air hammers and simple friction driven hammers. They work due to the shock-deforming effect on the metal workpiece.

High-quality redistribution of metal can be ensured by simultaneous regulation of the stroke of moving parts and impact force in combination with tilting the workpiece. Note that hammers are classified as fairly inexpensive stamping equipment.

Also, when hot stamping, crank presses with a rigid drive are often used, which does not allow changing the direction of the slide.

Forgings made using presses are distinguished by greater accuracy due to their rigid motion. This reduces the risk of machining allowances to a minimum.

The disadvantage of such equipment is the need to pre-clean the workpiece from scale, otherwise it will be pressed into the body of the forging.

When the heated metal comes into contact with the walls of the press, the workpiece cools down due to the large amount of time spent on the deformation process.

Summarize

Hot and cold stamping are technologies actively used at enterprises of the metallurgical industry, in mechanical and aircraft construction and in other production areas in the manufacture of various types of parts from steel and non-ferrous metals.

At the same time, hot sheet stamping is more common than cold stamping, since it allows you to work with almost all metals, including low-melting metals.

Source: https://tutsvarka.ru/oborudovanie/goryachaya-obemnaya-shtampovka

Stamping is a metal processing process. Types of stamping and equipment

The technological process in which workpieces are processed to produce flat or three-dimensional finished products of various shapes and sizes is stamping. The working tool for this purpose is a stamp, which is attached to a press or other equipment. Stamping is two types of technology, which, depending on the conditions, are performed hot or cold, and therefore both the equipment and technological standards differ from each other.

Categories

In addition to dividing technology into cold and hot methods, stamping is a whole series of categories into which methods of processing materials are divided. The chosen method most often depends on the purpose of the product, but technological conditions also influence it.

For example, there is a method in which part of the workpiece is separated, and this is separation stamping. This also includes punching, chopping, and cutting parts. There is a category of operations when hot stamping is used, through which a sheet of metal changes shape. They are also called molding.

As a result, the parts are subjected to bending, drawing and other procedures.

Cold and hot stamping are implemented using the same principle, which involves deformation of the material, but otherwise the production of products by these methods has many differences.

Preheating of parts to certain (and quite high) temperatures is assumed mainly in large industrial enterprises, such as, for example, a metalworking plant.

This is due to the complexity of such a technological process, a large number of operations, which can be performed efficiently only with accurate preliminary calculations and high accuracy of the degree of heating of the workpiece.

Hot way

Stamped parts processed using hot technology must have excellent quality, since, for example, important things such as boiler bottoms and other hemispherical products, including critical elements in shipbuilding, are made from sheet metal of different thicknesses. To heat a metal part, equipment is used that provides the correct temperature conditions.

These devices and ovens can be plasma, electric or others; there are many types of them. Before submitting a hot part to a stamping press, it is necessary not only to calculate the heating rate, but also to develop a detailed drawing of the finished product, which must take into account the shrinkage of the metal after cooling.

Cold stamping

Cold stamping involves the formation of a product through the pressure that the working elements of the press exert on the workpiece. Such products are not subject to shrinkage because they are not preheated. Such products also do not need further mechanical modification after stamping is completed. Stamping methods can be different, but cold stamping is both more convenient and economical.

Materials that lend themselves well to cold forming are not limited to carbon or alloy steels. Stamping production works successfully on both aluminum and copper alloys. The cold method is carried out mainly using hydraulic presses, and their production is regulated by GOST.

Serial models are very diverse, and therefore it becomes possible to choose a suitable machine for the production of any configurations and sizes of products.

Dies for stamping metals are very different in their equipment from those that work with materials such as leather, rubber, cardboard, polymer alloys and the like.

Separation stamping

One of the most common technological operations is separation stamping, which separates part of the metal from the workpiece. This method is used in almost all manufacturing plants.

The stamping press is equipped with special tools that cut, punch and punch the material. Thanks to this process, it is possible to separate metal parts either along a curve or along a straight cutting line.

Cutting is performed by a variety of devices: guillotine shears, vibrating and disc machines, and the like. Cutting is used to cut workpieces for further processing.

Cutting is another technological operation. For example, a stainless steel sheet needs to be turned into parts with closed contours. Using punching, sheet metal is provided with holes of any configuration.

It must be said that this technological process also requires careful preliminary preparation and a detailed plan, with calculation of the geometric parameters of the tool that is used. Otherwise, you may not get a quality product.

There are a lot of technological operations related to stamping, because it is necessary to change the initial configuration of parts. These are bending, forming, flanging, drawing and crimping.

Technological operations

The most common operation that changes the shape of a part is bending, which forms planned bending areas on the surface of a metal workpiece. Drawing is called volumetric stamping. This is an operation by which a three-dimensional product is obtained from a flat metal surface, such as, for example, a stainless steel sheet.

It is with the help of a hood that it turns into a cylinder, cone, hemisphere or takes on a box-shaped configuration. Sheet metal products must have a bead around the edge and around the holes if they are made inside the workpiece. For example, a flange must complete the end of a pipe in order to install a flange on it. This operation requires a special tool.

With crimping, the opposite effect occurs. Flanging widens the ends of sheet metal blanks, and crimping narrows them. The same ends of the pipes or the edge of the cavity require such an operation, which is carried out externally by means of a conical matrix.

Forming is also one of the main operations related to stamping. It helps change the shape of individual elements of the stamped part, while leaving the outer contour unchanged.

Volumetric stamping requires special equipment and complex preliminary drawings, and therefore is almost never implemented at home.

Press selection

For processing metals, even the softest (for example, for stamping aluminum), special equipment is required: a hydraulic or crank press or guillotine shears. And of course, a lot of knowledge is needed. For example, how to calculate material consumption and make technical drawings. The requirements of GOST must be taken into account.

To choose the right stamping press, you first need to clearly imagine the problem that it has to solve. Performing operations such as punching or blanking requires the use of simple-action stamping equipment, with a small stroke of the slide and washers during processing. But for drawing, completely different, more powerful equipment is needed, where the slider and washers make a much wider stroke. Double-action equipment has this ability.

Depending on the conditions of the task, stamping can be performed on the following types of equipment: one-, two- and four-crank. The latter involves installing large-sized sliders. However, equipping a stamping press with a die does not depend on the design.

The main work through movement is performed by a slider connected by its lower part to a movable stamp.

And in order for the press slide to move, the drive electric motor is equipped with elements of a kinematic chain: a V-belt drive, a starting clutch, washers, a crank shaft, and a connecting rod that regulates the stroke of the slide.

The slider is launched using a foot press pedal, which is connected to the starting clutch, after which its reciprocating movements begin, directed towards the working table of the press. The four-rod press has a different operating principle. Its working bodies direct all the force to the middle of the quadrangle, which is formed by four connecting rods. Such a device is successfully used for the manufacture of products of the most complex configuration: asymmetrical or dimensional.

For complex products

To obtain high-quality products of complex configurations, a pneumatic press with two or three sliders is very widely used. A double-action press operates with two sliders simultaneously: the outer one fixes the workpiece, and the inner one stretches the surface of the metal sheet. Thin sheets of metal are stamped with special friction presses, and thick ones with hydraulic presses, which have more reliable washers.

A separate category of stamping equipment is explosion-controlled stamping. Such devices direct the power of the explosion to individual sections of a metal workpiece (usually of considerable thickness). This is innovative equipment, the operation of which even on video looks very impressive. Bends and the overall configuration of a complex product are processed using built-in vibrating shears.

Sheet stamping

Sheet stamping (for example, making a punched sheet) involves the process of punching sheet metal. All other stamping is volumetric. The equipment used for stamping equipment is divided into types. It can be instrumental, pulsed (explosion, magnetic or hydraulic pulse), roller or stamping with elastic media.

Sheet stamping can produce spatial and flat parts of various masses - from fractions of a gram, and various sizes - from fractions of a millimeter (here you can look at the second hand of a wristwatch).

Sheet stamping also produces parts weighing many tens of kilograms and several meters in size (car cladding, rockets and airplanes).

For this purpose, they mainly use low-carbon steel, as well as alloy steel - with special ductility, brass, copper, aluminum and magnesium with alloys, titanium and much more. Sheet stamping covers almost all industries: rocket, aircraft, tractor, auto, instrument making, electrical industry and so on, you can list everything. Its advantages are great.

Volume stamping

Volumetric stamping can be performed using both cold and hot methods. Hot - pressure processing, where the forging is formed using a stamp. The blanks are rolled rectangular, round, square profiles, which are cut into dimensional blanks (sometimes they are not cut, but stamped directly from the rod, and then the forging is separated directly by a stamping machine).

Volume stamping is used in mass and serial production, which increases labor productivity and reduces metal waste. The quality of the products also meets high standards. This stamping produces products that are extremely complex in shape and cannot be produced even by free forging.

Open and closed stamps

Open dies allow you to observe the gap between the stationary and moving parts of the machine. During hot stamping, flash flows into the gap - metal that closes the exit from the cavity and forces the rest of the mass to fill the cavity completely. During the deformation process, excess metal gets into the flash. But removing the burr is difficult.

Closed stamps do not allow you to look inside and observe the process - the cavity is closed. The flash is also not provided. The design of such a stamp depends on the type of machine. Here it is necessary to very strictly observe the accuracy of volumes and their equality in blanks and forgings: a lack of metal will leave the corners of the cavity empty, and an excess of it will make the forging larger than the required height.

Source: https://FB.ru/article/339436/shtampovka---eto-protsess-obrabotki-metallov-vidyi-shtampovki-i-oborudovanie

Technology of stamping parts from sheet metal. Equipment

The production of parts using stamping occupies a leading place in metal forming technology and is used in various industries.

Of particular importance is the stamping of metal products from rolled sheets. It is based on plastic deformation of metal without heating it using special stamps. This method of plastic deformation of parts is widely used for the manufacture of parts of different sizes and complex shapes with great accuracy, which cannot be achieved using other processing methods.

They are used for assembling large-sized products in the engineering industry, in the automotive and shipbuilding industries, as well as in the instrument-making industry and everyday life, where various miniature parts are often required.

Technology of stamping parts from metal sheets and its types

Stamping is the process of giving parts the desired shape and obtaining the size specified by documents by mechanically acting on them using pressure. The main direction of stamping is the production of parts from blanks, which are used as rolled sheets. Under the action of a compressive force, the workpiece undergoes deformation and acquires the desired configuration.

There is a distinction between stamping performed by the hot method with heating of the workpiece and the cold method without preheating it. Stamping of sheet metal parts is carried out without preheating them.

Pressure deformation with heating of a workpiece is used in the manufacture of parts from metal that does not have sufficient ductility, and is mainly used in the production of small batches of volumetric products from metal sheets with a thickness of within 5 millimeters.

The technological process of hot metal stamping largely coincides with the sequence of operations for cold processing of workpieces. The difference lies in the preheating of the initial blanks in furnaces to a temperature that ensures the plasticity of the metal.

This takes into account the degree of warping of the part during cooling, as well as its shrinkage during deformation processing, which affects its size. To eliminate deviations from the required dimensions for parts obtained by hot stamping, large tolerances are made.

In the production of stamped sheet metal parts, the cold stamping method is mainly used.

Cold stamping of sheet metal

The technology of cold deformation of rolled sheets using stamps involves changing the shape and dimensions of the product while maintaining their original thickness.

As a material for producing cold stamped products, strips, sheets or thin tape are used mainly from low-carbon and alloyed ductile steels, as well as copper, brass (containing over 60% copper), aluminum, magnesium, titanium and other ductile alloys. The use of alloys with good ductility for stamping is due to the fact that they are easily subject to deformation changes.

To carry out cold stamping of sheet metal, various operations are used, which depend on the task of achieving a certain shape of the workpiece. They are divided into separation and shape-changing effects.

1. During separation deformations, the workpiece material is partially separated along a given contour. Separation is carried out by shifting part of the metal in relation to the main workpiece. Such operations are cutting, cutting, punching and others.

Let's consider how some separation operations are carried out.

cutting

When cutting, a certain part is separated from a part by cutting it along a curly or straight line. This separation operation is performed using a press made in the form of scissors of different designs.

This operation is intended mainly to prepare the workpiece for other processing methods.

Punching

An operation called punching is used to create holes of different shapes in a workpiece. During punching, part of the metal is completely removed from the workpiece, and its weight decreases.

The figure shows a diagram of the punching process.

Felling

Using the process of cutting out a metal part, a finished product has a closed contour.

The figure shows a diagram for manufacturing a part using cutting.

2. Form-forming deformations include changes in the shape and size of a product when its individual areas are moved, without leading to its general destruction. These include drawing, bending, relief molding, twisting, crimping and other operations.

Let's consider some types of operations that do not lead to physical destruction of the form.

Hood

Using drawing, hollow volumetric products are obtained from flat sheet blanks. For example, in this way parts are made in the shape of a hemisphere, cylinder, cone, cube and other types. The figure shows different hood options.

Bending

Using the bending operation, a sheet product is given a given bending shape. Depending on the type of bending, this operation makes it possible to obtain curved products of different configurations. Some of them are shown in the figure.

Relief molding

This type of operation involves modification of local parts of the product, its external configuration remains unchanged. The figure shows diagrams of some molding operations:

It is also possible to use combined operations, including separation and shaping of one part.

The technological process of cold stamping consists of stages that are associated with the nature of the deformation operation and depend on the type of stamping equipment used.

The development of the technical process is carried out in the following sequence:

• The structure of the main operations is indicated, including their nature, quantity and sequence of execution.
• The initial, intermediate and finished dimensions of the part are calculated, as well as the necessary deformation forces to achieve the desired result.
• Documentation of the technological process is carried out.

Additional operations can be introduced into the technical process, with the help of which the workpiece is brought to a form convenient for processing. These include cleaning, straightening sheets, applying lubricants and other operations.

Metal stamping press

All cold stamping operations can be carried out with special equipment, the main one of which is a stamping press. Its device can be based on mechanics or using hydraulics.

Mechanical types include:

• eccentric presses;
• presses using a crank mechanism.

A crank-type stamping press is used to carry out punching, punching and drawing operations.

Design and principle of operation of a crank-type press

Any press intended for stamping products includes main components, which include: a mechanism that drives it and a device that carries out direct stamping.

The operating mechanism is a crank shaft, which is driven by an electric drive. To do this, the electric motor, when the flywheel rotates, transmits rotation to the crank mechanism using a gear transmission.

Performing reciprocating actions, the crank slide drives a stamping device, which, with a pressure force, produces plastic deformation.

The main parts of such a press are made of high-strength steels and are additionally strengthened in order to impart the necessary rigidity.

Hydraulic press device

A hydraulic metal stamping press is used to create three-dimensional shapes by pressing metal.

The principle of operation of such a mechanism is based on the pressure of a liquid placed in two reservoirs, which are equipped with pistons. The tanks are connected by pipeline. As a result of the pressure in the liquid that arises at the moment it is pumped into the cylinder from another reservoir, it is transmitted to the slide and sets it in motion. When moving, the slider presses the workpiece with great force.

Making dies for cold metal stamping

The working device of any pressing machine is the stamp itself. It includes two working parts called a die and a punch. During operation, only the upper part of the stamp is movable - the punch attached to the slide. The matrix is ​​located below and remains motionless.

The sheet is deformed when the punch is pressed against the matrix with the workpiece located on it.

The development of drawings and the manufacture of dies for the press are subject to increased requirements, since the correct formation of the product depends on their accuracy.

Such work is carried out step by step in the following sequence:

• a sketch of the stamp is drawn up;
• using a computer diagram of the stamp, compiled using a special program, the rational cutting of the material is checked;
• if necessary, the sketch is adjusted and the dimensions of the stamp are specified;
• the locations of the holes and their sizes are indicated, which will then be applied to the surface of the stamp;
• After final approval of the drawings, the production of the stamp itself begins.

Modern machines for stamping products are equipped with dies made with great precision using computer technological programs.

(2 5,00 out of 5)

Source: https://plavitmetall.ru/obrabotka/shtampovka-detalej-iz-listovogo-metalla.html

Basic nuances and technology of metal stamping

Metal stamping is the shaping of a material under the influence of an external force in order to obtain the desired part. Processing a workpiece in this way requires a lot of force. For this purpose, there is equipment that is produced with a force of 16 to 500 tons. The equipment installed in the press is called a stamp. In it there is direct contact of the working tool with the metal. In 1 stroke of the machine, a part with a high degree of accuracy is obtained.

Metal stamping process

History of the process

Stamping of metal products first began in the 16th century. This was due to the development of weapons production, which required the production of a large number of identical parts. In the 19th century, the rapid development of stamping production began. Household items are produced. There is a need to manufacture high-quality serial products.

With the advent of the automotive and shipbuilding industries, metal forming has taken a key position in the development of these industries. Dimensional parts began to be produced using stamping.

Areas of use

Industrial production is not complete without cold and hot stamping. Using these methods, you can create both small and large parts in a short period of time. Hot stamping is used where three-dimensional parts are needed.

When stamping flanges, 2 methods are used:

1. Hydraulic presses are used in the forging process. Here, under the influence of pressure, the metal flows into the cavity, which is made in the striker. This space corresponds to the shape of the resulting part.
2. When using sheet metal as a workpiece, crank presses are used. A stamp is inserted into them and sheet metal is fed. The flange is drawn out under pressure.

Punching technology

The technology for manufacturing parts by stamping, both hot and cold, requires the presence of tooling. For both types, stamps are made, which have certain differences. They are used for metal that has varying degrees of thickness.

Large sized workpieces are preheated and then the forging process takes place. When cold, the sheet thickness rarely exceeds 1 mm. Various operations are carried out with such material, for example, stamping badges.

Stamping technology

Hot stamping

In the process of manufacturing metal parts by hot pressing, the workpieces enter a heating chamber. Hot metal stamping begins after they reach a temperature of 1200°C. Heated products are placed in a stamp, where there are special grooves for preliminary and final stamping.

If you need to upset a heated forging, then it is placed in the space between two flat strikers.
The equipment starts up and the workpiece is settled to the required size. Hot metal stamping, automated lines

Alternative stamping methods

Metal stamping can also occur under the influence of other forces:

1. Explosion. The process is carried out in water. The material is placed on a matrix in which a recess of the desired shape is made. There is an explosion from above. As a result, the workpiece fills the stream and takes on the desired shape.
2. Electrohydraulic. Voltage is applied in the aquatic environment. The water is heating up. Under the influence of high temperature, a shock wave occurs, which forms the workpiece.
3. Pulling metal through rolls. This method allows you to give the workpiece the desired shape.

Stamped badges are made in a die, where enamel is placed in the recess of the punch.

Making metal stamps

To make stampings from a workpiece, metal dies are constructed.
At the first stage, drawings with specifications and details are developed. Homemade matrix and punch (stamp)
Stamps consist of the following parts:

1. The working parts are a punch and a matrix. Manufactured from tool steel U8a, U10a, X12M. After heat treatment, they are hardened to 60 Rockwell units.
2. Punch holder. Material - Art. 3
3. Gaskets. Manufactured from structural steel with a hardening grade of 45 Rockwell.
4. Puller. Made from Art. 3
5. Top and bottom plates. Their thickness depends on the force expended on stamping.
6. Columns and bushings. The material is Steel 20. The surface is carburized to a depth of 1–1.5 mm. This layer is then hardened.
7. Shank. Inserted into the press slide.

Parts for making a stamp

Equipment and tools

To form metal products, dies are made and inserted into presses, which are of 2 types:

1. Crank-rod. The main element in them is a slider moving along guides. An electric motor is located on top, which gives impetus to the movement of the crank mechanism. There is a plate at the bottom on which the stamp is placed. The equipment is high-speed. The disadvantages include the high impact force when the punch comes into contact with the metal. As a result, the tool becomes chipped.
2. Hydraulic presses. They have great power. The advantages include the smooth movement of the slider. Thanks to this, there is no mechanical shock during operation, which leads to long service life of the tool. The amount of travel of the slider provides a large open height of the press space. This makes it possible to perform deep drawing or bending operations on workpieces with high sides. PV-100 is a vertical hydraulic press with a force of up to 100 tons

Metal forming allows you to produce a large number of parts in a short time. In this case, they will all have the same shape. The accuracy of their manufacture is regulated by GOST.

Basic nuances and technology of metal stamping Link to main publication

Source: https://metalloy.ru/obrabotka/shtampovka/metalla

What is metal stamping - Metalworker's Handbook

Hot stamping of a metal workpiece promotes its deformation in a heated state in order to give the appropriate shape to the product. These technologies are used in heavy engineering, and they are unique in their own way.

The essence of technology

Hot metal stamping involves heating a product and using the pressure of a given stamp to form a part. In this case, the temperature regime is changed to the state that would be formed during forging.

To prevent metal leakage, special cavities in the form of protrusions are provided in the stamp design. This is how a surface in the form of a stream is formed, corresponding to a closed type, and the configuration of the completed product corresponds to its shape.

Hot stamping is made from multi-profile bars of cross-section: rectangular, square or round.

In exceptional cases, the technological process of stamping products is performed from rods. First, a forging is produced with specified dimensions, and then it is divided into parts.

Blanks for stamps are usually made of metal rod.

The efficiency of the technological process lies in the fact that it can be used in the production of serial workpieces.

When using this technology, enterprises have many advantages:

1. The percentage of metal waste generation is reduced.
2. Labor productivity is growing.
3. Ability to perform complex structural elements.
4. Ensuring accuracy of geometric dimensions.
5. The workpieces have a high surface quality.

The technology for manufacturing a part by volumetric stamping is as follows:

• cutting the workpiece to size;
• heating in an oven;
• 1 transition;
• 2 transition;
• 3 transition;
• flash removal and metal processing.

According to stamping technology, a huge list of actions is performed from loading the blank into the processed area, ending with removal from the furnace. The algorithm involves performing the following work:

1. Dies are used with closed or open streams.
2. Execute design documentation for the development of forgings.
3. Think about how many transitions it takes to complete the workpiece.
4. Choose the appropriate equipment, think about which stamps to use.
5. Heat the forging, choosing the method of heating the die and operating modes of the equipment.
6. Based on the quality requirements for processing the part, evaluate which final operations to carry out.
7. Calculate the technical and economic indicators of a given technical process.

In relation to forging, the hot stamping method has its advantages and disadvantages:

No.	Advantages	Flaws
1.	High productivity of the labor process	Limits on the mass of received parts and blanks, no more than 3.5 tons
2.	The quality of the processed surface, tolerances and allowances are almost 4 times less; When performing calibration, the resulting tolerances are 0.05 mm, so only the interfaces with adjacent products are subjected to machining, while the remaining surfaces have sufficient roughness and accuracy	The deformation is higher, based on this, powerful equipment is used, this happens because the workpiece is completely subject to deformation, while the flow of metal is subject to the resistance created by the walls of the die
3.	Possibility of obtaining structural elements of complex configuration	The price of the equipment is quite high, since it is complex and made of high-quality material, and is used only for the manufacture of one type of product
4.	Simplicity of the operations performed, for this it is not necessary to have extensive work experience, the training program for a stamper is simple

Several well-known technologies are used for hot metal stamping, depending on the following parameters:

• selection of equipment;
• geometric dimensions;
• workpiece material.

Technology selection

Using the chosen technology, you can produce several types of parts:

► Extended – these include levers, shafts, knobs and others. Processing is done flat using a stamping press. The last stage of this work is shaping, performed in the preparation rollers for forging.

► Disk – these include rings, disks, gears, covers and other products. When performing this operation, the method of upsetting is used, which is carried out at the end of the workpiece. For this process, stamping transitions are used.

Table of typical products for different shapes of forgings with a detailed description:

No.	Brief description of characteristics	Standard products
Extended configuration products
1.	Straight axis	Beams, shafts, bushings, connecting rods
2.	Axially curved	Steering levers
Symmetrical
1.	Round products	Flanges, gears and hubs
2.	Square and polygonal	Nuts, flange connections and hubs
3.	Products with extensions	Fork and cross type
Other products
1.	Combined form	Crankshafts, rotary cams
2.	With a larger number of untreated surfaces	Shift linkages, towing hooks and parallel axle beams
3.	With internal holes and recesses	Cavity Shafts, Gear Blocks and Flange Connections

► Stamping lines, which in turn are divided into:

1. Lengthy (the length of individual elements on the workpiece increases; it is on this part that blows are applied with tilting of the part).
2. Procurement (shaping a part or uniformly redistributing the metal mass with minimal losses).
3. Pinch (at the same time the height decreases and the width of the workpiece increases).
4. Rollable (the diameter of individual sections increases as the metal is distributed along the axis of the workpiece).
5. Bending (a forging of a workpiece is formed with an axial bend at 90 0).

► Varieties of stamping strands:

• Roughing - the configuration of the processed material is more close to the shape of the forging. Features include increased depth, radii and slopes in relation to the parameters of the finished product.
• Finishing - when acquiring the required shape, the dimensions increase by the amount by which the shrinkage of the metal workpiece increases. The rolled metal is placed in the central axis of the die, since maximum forces are exerted on it.

About die patterns

► Two hot stamping schemes are used in the production process:

1. Closed type - according to the given technology, small gaps are visible between the stationary and movable parts of the stamp and are minimal. To produce products, presses are used with a protrusion at the top of the working tool, and a cavity at the bottom. Or, on the contrary, on hammers with a protrusion from below, in a cavity in the upper part of the tool used. This method is used when the volumes of the finished product and the forging correspond to the parameters. Stamps of this type simultaneously have two cavities for the connector, located at an angle of 900 relative to each other.
2. Open type - the principle of their operation is based on the fact that a gap is provided between the fixed and moving parts into which excess metal is poured. They can be used for forgings of any size.

► Advantages of production using open type dies:

• Impeccable surface quality.
• Homogeneous material structure.
• Metal saving.
• The possibility of using materials with low ductility, as high stress is applied and unevenness during compression is ensured.

Equipment used

Even if the material being processed has a soft structure, the use of equipment to give it a given shape is mandatory. This equipment includes:

1. Hydraulic presses.
2. Guillotines.
3. Crank mechanisms.

You also need to correctly calculate the consumption of materials and make drawings, taking into account the requirements of state standards.

If we consider a stamping machine, then it includes the following structural elements:

• an actuator corresponding to the type of machine;
• motor for driving equipment;
• transmission that provides movement from one mechanism to another.

: hot metal stamping - automated lines.

About the operation of mechanisms

► Crank - connecting rod presses. Its principle of operation is to rotate the drive, which, in turn, converts the movement into reciprocating movement on an installed slider. Parts of the technical device are made of steel with a strong structure with stiffening ribs.

The slider moves according to a given mode, while a force of 8000 tons acts on it. Crank-type installations used in production reduce the cost of parts and also simplify their production. The savings are about 30%. Machines are divided into: simple, double action or triple action.

Using a technical device, you can perform the following technological solutions:

1. Production of stamped parts with open or closed dies.
2. Execution of a hangnail.
3. Extruding blanks.
4. Firmware.
5. Processing simultaneously in several ways.

Under the influence of one shock load, mechanical presses produce work, but with a lower impact force, a hydraulic press produces better results. In this regard, hydraulics are used for large-sized and thick-walled parts.

► Hydraulic presses. The manufacturing plant produces equipment for forging, creating punching forces and stamping the surface. Recycling metal waste with their help is also effective. The principle of operation is to increase the force of pressure on the product several times.

The press looks like this: these are two cylinders filled with water and a pipe is located between them. Each cylinder contains pistons, and the operating principle is based on Pascal's law.

  CNC drilling machines for metal

► Radial forging mechanisms. The workpiece is located in a module in which heating is carried out using the induction principle.

After the material becomes soft, it is fed to the gripper through a conveyor mechanism directly into the processing zone.

In the process of acquiring the desired shape, the workpiece rotates, which ensures its uniform processing. Forging of the part is carried out with strikers.

The press operates from a motor connected to V-belt drives. Their vertical placement transmits movement to the firing pin and connecting rod mechanism.

To ensure synchronized operation, the device contains copying drums. Worm gears drive the holder with an electric motor.

Slowing down of movements is carried out by a spring clutch.

Source: https://ssk2121.com/chto-takoe-shtampovka-metalla/

Sheet stamping

Since ancient times, people have made thin-walled products, vessels and jewelry from metal.

They were made from a sheet of metal by hammering - giving shape to a cold or heated sheet of ductile metal by tapping it with a hammer around a wooden model of the future product. The seams were soldered or embossed.

Copper was most often subjected to this treatment, less often silver or gold. The products obtained in this way were extremely highly valued, since all operations were manual and it took the craftsman more than one day to make one jug.

Sheet stamping

The inquisitive human mind was looking for ways to speed up and reduce the cost of production until the mid-19th century, when such a powerful source of energy as steam appeared. Since then, the technology for producing thin-walled metal sheet products by deforming it under pressure, or sheet stamping, has improved significantly. Today, billions of different parts are produced using this method, from phone parts to car bodies.

Cold sheet stamping is a guarantee of high-precision parts

Sheet metal stamping from sheet metal at room temperature is called cold stamping. It is used for small sheet thicknesses and in the case of ductile alloys. If they are stamped from a thick sheet (from 5 mm) or from alloys with low fluidity, then the workpiece sheet is heated to increase ductility.

Sheet stamping guarantees the production of a large number of parts that are absolutely identical in shape and size with high accuracy.

Cold die forging makes it possible to produce high-precision thin-walled parts of almost any shape at a cost significantly lower than in the case of casting or machining. The metal utilization rate is also much higher. In addition, cold die forging guarantees not only strength, but also uniformity of the material properties of the part, which is especially important in critical structures.

Both die stamping and sheet metal stamping are cost effective for large production runs. This is due to the high costs of preparing production.

Characteristics of sheet stamping

Cold sheet stamping is today one of the most widespread technologies for processing metals, plastics and some other materials. The range of application of the technology is from large structures in shipbuilding to thin-walled parts of household appliances

The technology is characterized by the following undeniable advantages:

• Exceptional opportunities for mechanization and automation of production processes.
• Reducing the cost of manufacturing mass products.
• High utilization rate of sheet metal.
• The ability to accurately manufacture thin-walled but durable products of almost any shape.
• Minimal need for subsequent machining.

However, in addition to obvious advantages, cold sheet metal stamping also has disadvantages. This is, first of all:

• High complexity of technological process design.
• High cost of preparation for production of molds.
• Highly qualified press equipment debuggers.

Sheet metal stamping

It should be noted that with large series of manufactured products, these disadvantages are leveled out due to the economies of scale known from economics, and the cost of manufactured products turns out to be lower than with alternative methods of metal processing.

A wide range of equipment is used for different types of sheet metal stamping operations.

Thus, vibration or guillotine shears are used for cutting operations.

To perform forming operations, the main stamping equipment is used - a sheet stamping machine or a press. By type they differ in:

• Crank-rod.
• Hydraulic.
• Radial forging.
• electromagnetic.

The simplest to set up and maintain is a press with a crank drive. It is suitable for simple sheet stamping—thin-walled, small and medium-sized parts of simple shape.

Press with crank drive

Hydraulic presses allow you to develop much greater force (up to 2 thousand tons) and more accurately regulate the press stroke. This type of equipment is used for bending or die stamping operations from thick sheets.

Radial forging complexes are used for sheet stamping of parts having the shape of a body of rotation.

Electromagnetic presses are a fairly new type of equipment. The pressure on the workpiece is produced by the mass of the electromagnetic core, directed to the punch by an electromagnetic pulse. A pulse of opposite polarity returns the core to its original position. Such a drive is much simpler to manufacture and maintain than a hydraulic one, but does not yet reach its power.

Principle of operation

The physical principle of operation of stamping equipment is the plastic deformation of a sheet blank under pressure. The shape of the future part is determined by two parts - a matrix and a punch, which are pressed against the sheet blank from both sides under great pressure. Where there is a convexity at the matrix, the punch has a depression corresponding to it in shape and size. When deformed, the sheet blank repeats the shape of the matrix and punch.

Along with this, holes can be drilled and individual parts can be cut out of the sheet material. When designing a technological process for cold stamping of sheet metal parts, the tooling designer and technologist combine and, if possible, combine form-changing separation operations in order to make do with a minimum number of workers passing the die and thus reduce the cost of manufacturing the product.

In the case of thin sheets, cold sheet stamping is carried out. When working with thick sheets or low-ductility alloys, the workpiece is preheated to increase its ductility.

What operations does cold stamping involve?

All working operations of cold sheet stamping are divided into two large groups: separation and forming.

Sheet stamping separation operations

Separation operations of sheet stamping include operations associated with violating the integrity of the sheet material. The most common of them are

• Cutting is the separation of part of a workpiece along a straight or curved line. It is used both for obtaining finished products and for dividing sheets into blanks of the required size for the purpose of further processing.
• Cutting-separation of part of the workpiece along a closed contour. A piece of metal can also be cut out inside the contour.
• Punching is the production of round or arbitrary shaped holes in a workpiece.

Form-changing operations of sheet metal stamping

Shape-changing operations of sheet stamping include operations that change the spatial shape of the sheet without violating its integrity, such as:

• Bending - giving a flat workpiece a curved shape along the longitudinal axis. There are V-shaped, U-shaped and more complex bending forms.
• Drawing is the transformation of a flat workpiece into a hollow spatial form. When drawing, the thickness of the workpiece may change.
• Beading is the creation of edges along the outer or inner contour of a product.
• Crimping is the compression of the workpiece material in a conical die in order to reduce the size of the end part of the part.
• Molding - Changing the shape of a part of a part while maintaining the outer contour line.

When designing sheet metal stamping technology, the technologist combines operations from both groups.

Process technology

The process of cold sheet stamping begins with the joint work of the technologist and the tooling designer.

They consider all the changes that must occur with a flat workpiece on its way to the finished product, plan and group separating and forming operations.

After such grouping, the operations performed during each pass of the press are determined (if the part cannot be stamped in one pass). For this specific list of operations, a matrix-punch pair is designed.

Matrices and punches are usually produced by milling on multi-axis machining centers. The accuracy of the stamping dimensions and the final quality of the product directly depend on the accuracy of manufacturing. The materials used are high-alloy steel - the mold must withstand hundreds, or even millions of stamping cycles without changing in size. Often molds are made consisting of several parts, which are then securely connected.

Sometimes an insert made of a stronger material is installed in the mold, for example, in the part where cutting or drawing will be carried out and which will be subject to significantly greater stresses than the rest of the mold.

An extremely important stage of the technology is setting up presses for sheet stamping. Each working pass of the press requires strict adherence to the force prescribed by the technology in order, on the one hand, to accurately shape the workpiece, and, on the other hand, not to damage it.

Progressive methods of sheet metal stamping

Rubber stamping. Used for workpieces of small thickness and high ductility. The role of the matrix or punch is performed by hard rubber. It simplifies the production of the punch and is suitable for small series of stampings.

Sheet stamping schemes using elastic media

Liquid stamping. The role of the punch is played by liquid supplied under pressure. It presses the workpiece against the die and forces the sheet to exactly follow its shape. The method is used for drawing products of complex spatial shape.

Explosion stamping. A small explosive charge is detonated in a protected chamber. The resulting high pressure forces the workpiece into the die. The method is used for large parts and intricate configurations that are difficult to manufacture otherwise. Significant savings in equipment costs are achieved.

Electrohydraulic sheet metal stamping

Electrohydraulic stamping. The role of mechanical pressure is played by a shock wave in the liquid, which is caused by a high voltage discharge. The method is highly accurate and cost-effective.

Scheme of magnetic pulse stamping of sheet metal

Magnetic pulse stamping. High-intensity magnetic pulses generate a high-energy magnetic field that impacts the workpiece, inducing eddy currents in it and forcing it into a given shape. In this way, pipes are compressed and complex reliefs are formed.

Liquid stamping

Unlike previous methods related to cold die forging, this method is a combination of two technologies: stamping and casting. First, the required volume of molten metal is poured into the matrix, after which the punch is lowered into it.

Liquid stamping

Liquid metal is extruded into the gap between the matrix and the punch, which is the shape of the future product. The method is used in the manufacture of large thin-walled housing parts made of low-melting and ductile alloys.

Source: https://stankiexpert.ru/spravochnik/obrabotka-davleniem/listovaya-shtampovka.html

Types of metal stamping

Metal stamping is a process of controlled deformation in which a body changes its shape under the influence of excess pressure. Thanks to this processing, metal products are given a wide variety of shapes that they need to fulfill their functional duties. Parts of small thickness can be stamped, since bending thick products is very problematic.

Cold metal stamping

There are two types of metal stamping: cold and hot. The first option involves processing the workpiece without preheating it. This method is cheaper from the point of view of industrial production, since it does not require energy to bring the metal to a certain temperature. This method is used to process mainly thin sheets, which can be easily treated even without heating.

The process of cold stamping of sheet metal is divided into several stages, each of which plays an important role in obtaining the final result. At the initial stage, a compaction process is performed, which reduces the ductility of the metal so that the product better holds the shape obtained as a result of stamping. Technologically, the process involves pressing a metal blank under high pressure.

At the second stage, the products are annealed at temperatures of 550-620 degrees Celsius in special furnaces.

This makes it possible to carry out the procedure of recrystallization of the metal lattice and the introduction of carbon atoms into it at the molecular level, which can significantly increase the strength of the metal.

The annealing time depends on the composition of the alloy and the size of the parts being processed. When the preparation is completed, the product is sent to a press for cold metal stamping, which will give it the desired shape.

The procedure takes just a few seconds and does not require human intervention. Presses use special dies made of hard steel, and less often of other alloys. They are designed for long-term use, during which they retain their original shape to the nearest millimeter.

This is very important, since cold stamping of metal is carried out for specific needs, and deviations in the shape of the finished product are unacceptable, as this can lead to inconsistencies with other parts. This method is harmless to working personnel, since they do not have to be in an area with high temperatures.

In addition, the absence of the need for preheating makes it quite easy to automate the workflow.

Hot metal stamping

Hot stamping of metal makes it possible to process thicker workpieces, since the intermolecular bonds in the hot alloy are much weaker, and it is easier to bend. Before starting the procedure, metal products undergo the same preparatory steps as in the case of cold stamping.

But equipment for metal stamping is already significantly different. It consists of two main parts: a furnace and a press. The furnace is used to preheat the workpiece to a red-hot temperature.

In this form, the alloy lends itself well to physical impact and there is absolutely no risk of burning it out.

To create optimal conditions inside the furnace, modern machines are equipped with a high-precision automated control system. It only requires setting the initial parameters, which depend on the type of part being processed. The computer will take care of the rest.

Presses for hot metal stamping are made from hard, high-alloy steel grades, which undergo additional processing to increase resistance to thermal stress.

They must withstand a certain number of technological operations without losing their original characteristics, so it is very important to use the highest quality material for their production.

Hot stamping requires direct human participation in the production process. The workpiece cools quickly under normal conditions, so it must be quickly delivered from the furnace to the metal stamping machine. This is done by a worker who, using blacksmith pliers, transfers the product to the desired place.

Working in an environment with constantly high temperatures has a negative impact on the body, so it is necessary to correctly calculate the duration of shifts in order to minimize the harmful effects of the conditions on workers.

Automation of the process also faces great difficulties and requires high costs, so it is practically not used anywhere.

No additional equipment is used to cool the parts; they cool naturally. In most cases, no additional processing of parts is required after stamping. The exception is products for the automotive industry that undergo galvanizing. Sometimes when stamping sheet metal it becomes necessary to trim off excess elements. For this purpose, a special machine with a high-precision cutter is used.

Liquid metal stamping

In addition to the two listed methods, there is one more, which is used much less frequently.

It involves liquid stamping of metal or the so-called injection molding, when the alloy is poured into a closed die in a liquid state, and the final formation of the product occurs in solid form.

This allows you to obtain ideally shaped parts with improved mechanical properties. The wide dissemination of the method at this stage is hampered by the high cost and complexity of the technological process.

Metal stamping technology is used to produce a wide range of products for various industries. In this way, automobile body parts, various panels and finishing materials, and housings for household appliances are obtained. Stamping is one of the oldest metal processing methods that has survived to this day. The technology has changed, but the principle remains the same as many years ago.

Using metal stamping, products of a wide variety of shapes are produced. These include special angles that are used in anchor supports, and various elements for equipment, and parts used in the production of instruments, components and assemblies for all industries.

Stamping of metal products allows you to obtain a part of almost any shape, which cannot be achieved with other types of processing. This is successfully used in steel plants, which can quickly adapt to new market needs. You just need to make a stamp of the required shape and you can start producing new products.

Source: https://promplace.ru/obrabotka-metallov-staty/shtampovka-metalla-1537.htm