A forge is an indispensable attribute of workshops engaged in the production of various products using the manual method. artistic forging. Only a few forged elements can be made plastic deformation metals at room temperatures. In most cases, heating is required. For steel, in particular, the range of optimal forging temperatures is (depending on the steel grade) from 800...900 0 C to 1100...1200 0 C. A forge is the simplest type of heating device, which is quite suitable for these purposes.
Invented by the ancient Khalibs for forging copper knives and scrapers (Middle East, 6th millennium BC), the first forge was made in the form of a primitive depression in the ground measuring about 700 mm. The pit was surrounded stone wall, in which a hole was provided for air injection. Air injection (which is necessary for stable combustion of fuel) was carried out using blacksmith bellows. They were a cavity made of goat skins, where levers through air valve air was blown in. The reverse movement of the lever was ensured by a stone, which was installed on the top plate of the bellows, and the operation of the valve was carried out due to the difference in pressure of cold and hot air.
Existing structures blacksmith's forges determined by the following factors:
- Fuel, on which the device operates: coke, fuel oil, coal or gas.
- Design fuel burning device.
- Required sizes workspace.
- Purpose, since, in addition to heating for forging, forges are also used for some heat treatment operations of finished forgings - carburizing, tempering and even hardening.
For safety reasons, forges are often fired with coal.
Coke is expensive, fuel oil has unsatisfactory environmental operating conditions, and gas furnaces require particularly careful routine maintenance. At the same time gas furnaces are characterized by higher efficiency, and also allow for fairly convenient mechanization of some heating control processes - in particular, ignition of gas in the burner or burners.
Common disadvantages blacksmith forges are considered:
- Uneven heating metal placed on the surface;
- Impossibility practical temperature control heated workpiece;
- Undesirable saturation of surface layers heated metal sulfur compounds, resulting in increased fragility of the workpiece.
However, an experienced blacksmith is able to estimate the temperature of a metal by the color of its surface, and the problem of sulfurization is solved by using more quality type fuel.
Fuel consumption during the operation of forges is 40...150% of the mass of the heated metal, with its surface loss of 4...7% (depending on the duration of heating). Modern forges are predominantly of the closed type, since otherwise the efficiency of the heating device drops to 5...10%.
Coal fired forges
The design of a heating device of this type includes:
- Arch and side walls, which are laid out from refractory bricks (fireclay or dinas).
- Horn nest, formed by the upper surface of the arch, where the workpieces are heated.
- Umbrella, equipped with folding curtains, and designed to improve natural traction in the workspace.
- Rear wall (firewall), which provides openings for supplying source air.
- Air valve, designed to turn on the air supply to the forge socket.
- Protective box made of heat-resistant steel, which connects the inlet cavity at the air supply valve with the forge socket.
- Quenching tank(it can be steel or brick), designed to cool the workpieces during heat treatment or to cool the forge itself from overheating and subsequent formation of temperature cracks.
- Chimney, through which fuel combustion products are removed.
- Coal storage tanks and various blacksmith tools.
Schematic diagram of operation blacksmith's forge
A solid fuel forge is a rather capricious heating device, and heating it requires a certain amount of effort from the blacksmith. practical experience. It is especially difficult to ignite a forge that has not been used for a long time, and also if the external temperatures and air pressure are quite low. Coal, which is used in such forges, must comply requirements of GOST 8180.
Preparing the forge for heating metal is done in the following sequence:
- Their furnace nest removes waste, leftovers forged metal, ash and scale (this should be done even when the surface has been thoroughly cleaned after completion of work);
- Chimneys and air supply channels are purged compressed air (for small forges you can use a vacuum cleaner);
- A small layer of coal is poured onto the surface of the forge nest., and the opening of the protective box should not be completely blocked;
- Top on coal place the rags, soaked in flammable liquid or sawdust;
- After ignition when combustion becomes stable, add the next portion of coal(the fraction may have an increased size compared to the original);
- The air supply valve opens, and is installed in the middle position;
- As it burns out, the blast intensity is gradually increased.
The required quality of heating the workpiece for forging in an open forge is ensured formation of a superficial crust, which is formed during fuel combustion.
The temperature inside the crust is always higher, so the workpiece is placed inside and covered with another dose of coal on top. At the same time, they try not to destroy the upper surface of the crust, since otherwise heating will be slower, and metal waste and scaling will increase. Sometimes, to weaken the processes of carburization of the metal, the crust is sprayed with water.
In open forges, the least intense heating of the metal occurs at the periphery of the forge nest, therefore fresh coal is poured precisely along the perimeter of the heated workpiece. If the crust layer becomes too thick (more than 5...10 mm), it is broken, because in this case, the thermal conductivity to the workpiece decreases.
The workpiece is periodically heated during heating. turn to provide all its parts with the same heating conditions. The flame when burning coal should have a uniform color with a minimum of soot.
Colors of heated steel at different temperatures are:
- Dark cherry colors – 700...750 0 C;
- Cherry red – 750...800 0 C;
- Red – 800…850 0 C;
- Light red – 850…900 0 C;
- Orange – 900…1050 0 C;
- Dark yellow – 1050...1150 0 C;
- Light yellow – 1150…1250 0 C.
Overheating of the metal above the specified temperatures is unacceptable. Overheated metal is characterized by a coarse-grained structure, which is less susceptible to forging, especially when forming complex forged elements.
Gas-powered forges
Gas furnaces are brought to the design mode much easier, and this is their advantage over solid fuel heating devices. Typical design such a forge is next:
- Camera, made of fire-resistant material, and externally lined with thick sheet heat-resistant steel.
- Front flap, opening with hinges or a counterweight, and equipped with a viewing window.
- Under, made of heat-resistant fireclay bricks.
- Burner. The type of burner is determined by the calorific value of the gas used. For example, for a propane-butane mixture, diffusion combustion burners are effective, in which mixing of air and gas occurs only after the gas and air leave the device, and mixing of the components occurs due to diffusion processes. Such burners provide the most uniform heating of workpieces (especially long ones), and minimal metal waste is achieved due to the fact that there is always a protective layer above its surface.
- Mixing reducer, providing mixing of air and gas (included in the structure of the liquefied gas cylinder).
- Nozzle, the configuration of which is determined by the shape of the billets heated in the forge.
- Grate, designed to improve traction and collect scale.
- Fan, ensuring the injection of air in the required volume with its subsequent supply to the burner coverage area.
To operate such forges, a stationary source of electricity is required. It is advisable to use gas forges for heating parts of long workpieces for forging: heating occurs much faster, and therefore, scaling is less.
Using gas forge The following safety requirements must be strictly observed:
- Thoroughly ventilate the forge room. Avoiding stagnant zones where flammable gas can accumulate;
- Do not use oxygen or oxygen-containing mixtures that are prone to spontaneous combustion and self-ignition near the operating device;
- Provide for complete afterburning of gas in the working space of the furnace (determined by a gas analyzer, which is required when trial run gas forge);
- Thoroughly clean the grate after turning off the gas supply to the device.
In order to reduce scale formation, they are also used to heat workpieces for forging. and electric resistance heaters, But similar devices It’s a stretch to call them “horns.”
Forged products, if desired, can be made with your own hands at home, but for this you need to purchase or make them yourself necessary equipment for heating metal - forge. Exist various designs forges, they differ mainly only in the type of fuel used.
Despite its high cost, blacksmiths give the greatest preference to coke; when working, it requires several times less than ordinary coal. In addition, coke provides high temperature, less waste is produced. To save time, craftsmen use “coke” - fine coke, because it does not need to be crushed. Gas and liquid fuel furnaces are used mainly in large enterprises.
So, you have decided to master artistic forging, and you naturally immediately have main question- how to make a blacksmith's forge? The manufacture of the forge, of course, can be ordered at the factory, but if you have the ability and desire, you can make the forge yourself.
First you need to decide what type of forge suits you, closed or open.
Open and closed type
A closed-type forge has a special chamber in which the workpiece is heated. In terms of energy costs, this type of forge is the most economical, but the size of the workpieces processed is limited by the size of the heating chamber. Perfect option closed type forge, forge using gas as fuel.
When using an open, traditional type of forge, fuel is poured onto the grate from above, and air is supplied from below. In such a forge, the workpiece is placed directly on the fuel. This type of forge allows you to process large-sized workpieces.
Making a forge
The table is the basis of the forge, it working surface, where the fireplace with fuel is located, on which metal workpieces are heated. The table top is usually made of clay-based fire bricks, but this design is very heavy. You can make a metal cover from 4 mm steel sheet, or make a metal frame using refractory bricks. The grate is usually made of cast iron and is located in the center.
You can make a grate from a cast iron frying pan and an 8 mm steel plate by drilling holes in them with a diameter of up to 10 mm; you can also use a wheel rim.
The manufactured lattice must be inserted into the hole of the table, with a tight fit, so that the fit is really tight, the brick is carefully cut out. Bricks pre-soaked in water are easier to process. The height of the table is arbitrary, it all depends on the height of the blacksmith, usually at the level of the master’s belt. The surface of the table can also be made arbitrary, at your discretion.
Options for using the forge and their impact on the design
Air blowing can be mechanical (foot), but it is better, of course, to use a fan. You can fit a vacuum cleaner, etc., under the fan, the main thing is that there is a speed controller and it doesn’t make a lot of noise, you can install a valve that regulates the air supply.
Forging begins with pouring fuel onto the grate. Most blacksmiths place the workpiece directly on the coals, and add another layer on top. A small dome is formed inside the coal and extremely high temperatures are created, sufficient to melt the metal.
The preferred fuel, as we said, is coke, but even wood waste can be used.
example of a homemade forge made in 1 hour
To do this, a steel ring with a height of 150 mm and a diameter of 200 mm is installed on top of the forge. To position the workpieces inside the ring and control the combustion process, a vertical cutout is made on the wall of the ring, and another one is made on the opposite side - it is made in case the dimensions of the workpiece are large enough.
Upon combustion wood waste go down. In the lower part of the ring used, under a layer of charcoal, a high temperature sufficient for working with metal is created.
When processing large workpieces, it makes sense to increase the table area; for this purpose, a removable table is made from corners and metal plates of arbitrary size.
A necessary device installed above the forge is an exhaust duct; it can be purchased as a hood, or made from thin-walled metal yourself.
The forge is made with your own hands, now you can start working.
Construction of industrial furnaces
To better understand the process of functioning of the furnace, you can study it using the example of the design of an industrial product.
The figure on the right indicates:
- nozzle (tuyere) - air is supplied through it into the chamber;
- refractory bricks that maintain the temperature in the furnace;
- grate bars or hearth board holding fuel above the air chamber;
- a furnace socket into which solid fuel is loaded;
- bricks forming the frame;
- fan for supplying air to the furnace;
- holding frame made of metal;
- air chamber;
- ash pan;
- air duct;
- casing
In blacksmithing, a forge is used to heat and preheat metal blanks before heat treatment. The operating temperature in this device rises to 1200 degrees. By design, the device can be stationary and mobile (that is, placed directly in a specially equipped forge or transported to a place convenient for work). For industry, equipment is equipped with various devices, for household use The forge is produced in its simplest form.
Features of a household forge
Because of high cost melting plants, not every user can buy such equipment special purpose. For household needs, it is not difficult to assemble a gas forge with your own hands. subject to the correct determination of the shape, power and design of the supercharging system. A simple household forge for artistic forging or casting of non-ferrous metal can be assembled from several fireclay bricks and sheet steel.
Making a forge at home for working with ferrous metal is not difficult. Make the simplest design possible from metal container, in the side of which it is necessary to make a hole for gas burner. The fuel supply system can be assembled from a piece of pipe and coupling, for supporting structure Long bolts will fit under the container. The lining of a gas fireplace is carried out by filling a solution of alabaster or gypsum, sand and water.
The forge must be equipped protective casing, ceramic tube or suitable sized bottle. After lining and drilling a hole for the gas supply, the device is installed in convenient location, but at a distance from flammable materials. The advantages of the design include the ability to move the furnace and regulate the degree of heating of the workpiece, which is especially convenient when working with different forging materials.
Operating principle of the installation
Before you begin assembling the thermal unit, you need to understand the principles of operation of a homemade forge for forging metal to simplify the design of the furnace for home use. The operation of the device is based on the energy output when burning a mixture of carbon and oxygen, the percentage of metal released in molten form. During the smelting process, carbon stops the oxidation reaction of the metal; constant injection of gas into the fuel quickly increases the temperature in the forge.
The process of heating metal requires certain skills and specific knowledge. It is not enough to assemble a mini-forge with your own hands; you need to learn how to control the supply of oxygen to the fuel, the volume of which should be no more than 95%. If the workpiece overheats, carburization of the metal occurs, the steel becomes brittle, turning into cast iron.
While developing a drawing of the future forging device, Special attention should be given to the type of energetic substance influencing the design of the focus. By type, fuel for the forge is:
- gas (butane, propane);
- liquid (diesel oil, fuel oil);
- hard ( charcoal, coke);
- mixed (gas-liquid).
Depending on the planned work and the size of the workpiece, a thermal furnace can have an open or closed hearth zone. For the home handyman it should be remembered that domestic gas can be used in a furnace only after preliminary purification from sulfur using the method of “driving” through liquid naphthalene. Products made from metal heated by a gas burner cannot be used as loaded parts.
The main requirement for ensuring the security of the master is the installation of a powerful forced ventilation system, even if a household soldering apparatus running on bottled gas is used to construct the forge. The device will allow you to manufacture decorative elements of the interior and exterior in own garage.
Making a stove from a blowtorch
When making a forge for forging with your own hands, the blowtorch must be installed in a recess, around the perimeter of which fireclay bricks with a grate must be laid. When laying refractory bricks, it is necessary to maintain the distance between the enclosing elements in order to ensure the flow of air masses into the combustion chamber. The angle of the blocks relative to each other building material determined by the master.
Charcoal or coke is poured into a recess made of bricks on a grate, and a pipe is put on the blowtorch, which is fed under the grate. The blank for forging is placed in the gap between brickwork, the coal concentrate is ignited from below. To remove smoke, a probe, tent or chimney is installed above the grate.
Solid fuel device for forge
The simplest model of a solid fuel device for a private forge is an outdoor open stove, which does not require the installation of a ventilation system. The construction of the structure involves pouring reinforced concrete base, at the base of the structure it is necessary to lay wall brick. The table is installed at a convenient height, a hole is left in one wall for the blower.
The mountain pit is laid out of fireclay bricks supported on steel corners; a cavity for the grate is left in the middle part of the structure. A chimney or probe will help ensure sufficient draft in the fireplace; the air supply system is installed at the final stage construction work. Installing an electric fan in the chimney or installing blacksmith bellows will help increase the draft.
In a home forge, the tank for hardening parts and the gas-air chamber are not mandatory elements. They can be useful in cases where thermal or shock hardening is required when working with damask steel. In the gas-air chamber the following is carried out:
- drying and heating oxygen;
- filtering oxygen from condensate and foreign impurities;
- mixing air with additives for alloying steel.
To melt precious metals and create an alloy of non-ferrous metals, it is necessary to make a crucible from a heat-resistant material. The device, made in the form of a cap, allows you to increase the operating temperature in the furnace without the risk of overheating the workpiece and the formation of soot.
Home gas forge
To make a simple home gas forge, you can use parts from an old bicycle. If on lathe grind the sprocket from the gearbox; the device can operate on butane or propane and heat closed furnaces of small volume. An important condition When using a portable design, it is prohibited to operate the burner with acetylene, since the high temperature of the flame can burn the former “star” and the stove will simply explode.
It is not difficult to assemble such a device, and homemade horn for forging is not much inferior to industrial ones, but is much cheaper. The main thing is to follow safety rules during manufacture and use.
The word "horn" comes from the German horn. It's essentially a "horn". They made an ancient forge with their own hands to obtain screaming iron. His appearance resembles an inverted trumpet made of horn, which was the basis for calling it a bugle. From him came the blacksmith's forge.
Note: In a forge, the device is used as a tool for heating metal before processing it. Therefore, forges are items that are needed by everyone who works in metal. With its help you can achieve high temperatures - over 1000 degrees. Consequently, he can allow himself to produce various metal structures. In our case, these could be boilers, pipes, decorative elements fireplaces and other metal products.
There are two main types of equipment:
- stationary;
- desktop
An important feature of forges is that you can make them yourself. Of course, if you build a unit that runs on natural gas, you won’t be able to get a serious product like a Damascus blade, but you can make the structure in just a few minutes. This will require some fire bricks and pieces of steel. Such a device will be sufficient for melting or forging.
Homemade portable tabletop forge
Compound
Let's look at the design of traditional equipment for a forge:
- fireproof table;
- hearth;
- lattice;
- air drain and chamber;
- umbrella;
- valve;
- air duct;
- hardening bath;
- removable furnace;
- window for long products;
- chimney.
Operating principle
Let's figure out how to make a forge with your own hands. After all, the traditional design for home use can be simplified without compromising the quality of the process.
Functioning basis – chemical reaction carbon combustion, which is effectively used for working with metal. It combines with oxygen, and the metal is released in free form. The forge also uses the calorific value of carbon. By adding air to the fuel, combustion will occur much faster, given enough carbon. As a result, the temperature will increase and more heat will be generated.
The flame of a handmade forge The air supply to the forges is organized in such a way as to ensure a slight lack of oxygen to prevent metal oxidation. If the workpiece is left in the device for longer than the recommended period, the properties of the metal will be impaired. For example, steel sheets may become brittle with increased hardness. This means that its properties will be closer to those of cast iron.
Fuel
Note: A regular forge runs on coal. However, you can also use firewood. To do this, they are heated to coals. You can simplify the device if you use, for example, butane or propane.
Their composition includes hydrogen and carbon, which, when combined with oxygen, release a lot of heat. Moreover, such mixing can occur in advance, for example, in a burner.
However, it must be understood that it will be almost impossible to manage natural gas for such purposes, since it consists of different hydrocarbons that require different quantities oxygen. Therefore, it will not be possible to organize optimal air supply. In addition, natural gas contains sulfur, which negatively affects the properties of the metal. Therefore, the mixture requires pre-cleaning or can be used to process non-critical parts.
Kinds
Let's look at what forges can be like. They are the main tool of the forge. Thanks to development and improvement, many varieties have appeared:
- electric or fuel;
Portable electric forge blue - on liquid, gaseous or solid fuel;
Blacksmith's forge on coals in action - closed or open type;
- with a central lance or with a side nozzle;
Homemade forge of simple design with a side nozzle 
Open forge with central tuyere in action - stationary or portable.
Stationary forge in action Let's look at the most popular types.
Gas
Making such a forge with your own hands is quite difficult, but possible. The homemade version, like the purchased one, traditionally has a camera and bellows. Operates on propane-butane. The gas is supplied to the mixing reducer, after which it goes to the gas burner. The latter in some cases may be located on the side. This format is quite often used in homemade options, used in forges.
You can make a gas furnace yourself to heat the ends of small-sized products. Can be used to create decorative solutions in artistic forging.
Portable
These forges are easy to use. The design uses a steel frame, on top of which there is a recess made of. At its bottom there is a tuyere, with the help of which the air supply is organized (a compressor or fan is used). The tuyere has small slots through which air is forced, but no coal or slag passes through.
Portable gas models of forges This type of forge is used for processing small items. It can be carried or transported, so the place of work can be ad hoc.
Stationary
Can be open or closed.
Device open version execution - a frame with a table in the form of a trough about 70 cm high. The hearth is made of fireclay brick, inside there is a tuyere. To cool the device, there is a water tank located at the front. The fan creates pressure to supply air through a duct.
Stationary tabletop forge in action The lever allows you to adjust the volume, which makes it possible to change the temperature in the fireplace. The damper protects the tuyere from pieces of ash and coal getting into it. Removal flue gases carried out through an umbrella and an exhaust pipe. The fuel can be charcoal or coke.
The closed type device has the following advantages:
- rapid achievement of maximum temperature;
- high efficiency;
- increased fire safety.
The only problem if you make such a forge with your own hands is that it is difficult to work with large or long products, especially if you need to warm up their middle part.
The chamber is made of fireclay bricks located in metal frame. It has a tuyere, a grate, a window and a firebox hatch.
Creating a stationary device
Let's look at how to make a forge with your own hands of a simple design. To do this you will need six fire bricks. Of course, it is impossible to obtain a very high temperature under such conditions, but it is quite possible to heat the metal, say, for forging or bending.
To make grate bars, you can take steel strips about 5 mm thick. Shelves can be made from pipe scraps. Charcoal or coke can be used as fuel. Blowtorch used for ignition. However, when exposed to heat from the forge, it may not withstand it, so an asbestos partition must be placed between them. You can also use a burner (gasoline or gas). Since there is no umbrella with a chimney, the homemade device is used outdoors.
Simple DIY outdoor blacksmith's kit Creating a portable device
For greater versatility, you can make a portable version with your own hands. It can be built from a goose barn. You can make a homemade boost using a fan from a hand siren or a corrugated pipe.
Making your own forge
Of course she is homemade design has more features than described stationary option, however, there are also disadvantages:
- the temperature is not very high - up to 900 degrees;
- expensive to operate, given the cost of carbon;
- because in such homemade device There is no space for burning, it operates on charcoal or coke.
Forge made from pipe Summary
Forges are quite common today, despite consumerism towards things that are easier to buy than to make. However, if you are not too lazy, make a device with your own hands, build a small forge, you can create original metal products that can be used to decorate private property, create devices for heating rooms, etc. Therefore, making a forge with your own hands is the right decision .
Tips for making your own forge
A forge furnace (in other words, a forge) is necessary for welding or forging metal in any forge, since this work is usually carried out at fairly high temperatures, not counting “cold forging”.
A forge (forge) is necessary for forging metal. It tolerates very high temperatures and should be in every forge.
If you wish, you can make forged items yourself and at home. To do this, you will need to construct a forging furnace with your own hands. There is a wide variety of such forges; they differ only in the type of fuel used.
Some features
There are several types of fuel - solid fuel, wood or coal, firewood and coke. Experienced blacksmiths prefer fuel such as coke, but it costs much more than regular coal. Although its consumption is much less than coal, about 5 times.
If we talk about metal forging artistic style, then this is the best fuel to use. Coke will give a fairly high hearth temperature. And because of all this, forging will be performed well, and there will not be a lot of soot and waste in the form of slag.
If you have decided on coke, then it is best to purchase coke. This is the same coke, only much smaller. If you take a large one, you will still need to split it into small pieces. This will take a lot of time, which you can spend usefully.
There are also furnaces that run on gas or liquid fuel, but this fuel option is usually used in larger-scale production.
The forge furnace is quite simple to operate.
The working surface is the place where the main forging work is done. Coal burns on it, which will heat the steel blanks. At the moment, there is a wide variety of structures and designs of such forges. They have their differences due to the fuel that is used on them.
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DIY forge furnace
Let's talk about how to make a forging furnace yourself, and if you don't have the time or desire, you can order it from specialized factories. There are 2 types of ovens: closed and open.
The closed type of the stove is equipped with a special-purpose chamber; it is intended for preheating a metal workpiece. This type is the most economical, since its use requires minimum costs electricity.
However, there are restrictions on the size of the workpiece; only those that match the dimensions of the heating chamber will be suitable. One of the best closed-type forges for forging is one that uses gas as fuel.
The open type is usually heated using solid fuel, it is poured onto the grate from above, and air will be supplied below. IN this type The forge workpiece must be placed on fuel. Using this type of stove, you can perform forging on fairly large workpieces; there are no size restrictions.
The main part of the stove is the table; on its upper part there is the hearth itself and the necessary preparations. It is advisable to make the height of the furnace according to the height of the blacksmith, while the table will fluctuate within the normal range from 700 to 800 mm. The surface can be any size you want, but it is customary to make it 80x80 cm or 100x150 cm.
To forge large metal workpieces, it is enough to increase the size of the table; you can make a special removable tabletop. It is made using corners and metal plates the right size. In the center of the table there is a hearth nest, which consists of a tuyere, as well as a grate, this is necessary for the air supply.
Forge diagram: 1 - exhaust pipe; 2 - exhaust hood; 3 - forge box; 4 - tuyere; 5 - pipeline from the blowing fan.
As a rule, a special brick is used for the furnace cover, which has fireproof property, and clay. All this will do this design quite heavy. And in such a situation, there is a way out if you are not satisfied with the weight category of this equipment.
You can make a stove out of metal; it will have a special lid made of 4 mm sheet and a cast iron grate. The grate must be placed in the center of the stove for forging metal. An important attribute for this stove is the hood, which is installed directly above it. The exhaust duct can be made independently from metal with thin walls.
It is customary to begin metal forging directly by pouring fuel onto the grate. Many craftsmen lay out their preparations directly on the coals, and then add another layer on top. A small arch will be formed inside the coal, and the required temperature will rise.