Blacksmith (Forge) Welding
obvious from the title - this kind of a connection between metals used by the ancient blacksmiths.
Blacksmith (Forge) Welding Part 2
the method
Induction (high frequency) Welding
on welding of high-frequency currents. The method used in the manufacture of welded pipes.
Diffusion Welding
about diffusion welding
Casting or Foundry Welding
Casting welding an outdated method of welding, welding position in which the molten metal is poured.
Friction Welding
about friction welding
Electrolytic Welding
article on the electrolytic welding
Welding Under Water
brief article describing the process of manual arc welding under water
Explosive Welding
The specific method to obtain bimetals, welded pipe.
Showing posts with label other methods of welding. Show all posts
Showing posts with label other methods of welding. Show all posts
12:27 AM
12:15 AM
Explosion Welding
The specific method to obtain bimetals, welded pipe.
Explosive welding
It has been observed that the explosion of fluttering pieces of metal hitting the surrounding metal, sometimes permanently welded to them. The research helped to create industrially useful method of explosion welding. Its essence lies in the fact that the welded part or strike with great speed runs to the one struck details. The speed of the striking details of the time of the collision must be several hundred meters per second, approaching the speed of the projectile firearms. In the zone of collision of the metal parts to be joined is flowing like a liquid and merges into one, forming a monolithic connection.
Hit piece throws an explosive charge, which weight is 10-20% by weight of detail.
We strike the fixed part can have any mass, with details of its lack of weight is placed on the massive base - one struck the increase in mass improves the energy part of the explosion. Some of the best known applications of explosive welding - fabrication of bimetallic billets (see Fig.). main one struck a plate to increase the weight placed on a level foundation 3. Striking sheet metal 2 at an angle a = 3 - 10 grams to the surface of a plate. On the upper surface of sheet 2 evenly distribute explosives 4, as is used in different cases ammonal, thick, RDX, etc. At the lower edge of the sheet 2 have a detonator 5. The explosion propagates in the direction of the arrow and is shot as if a sheet of plate 2 in 1. First, strikes, and a plate welded to the bottom edge of the sheet 2, then the collision zone and the weld is moved to the right and the entire surface of the sheet 2 is welded to the plate 1. The boundary between the connected components on microsections has the characteristic form of a wavy line. In this way, can be connected to dissimilar metals, such as carbon steel plate can be attached sheet of stainless steel, nickel, titanium, copper, aluminum, etc. The resulting explosion of the workpiece and then rolled into sheets bimetal. The surface explosion of connected components can be several square meters. A second example of the use of explosive welding joints can be connected by pipes. used telescopic or lap joint (see Fig.), where 1 and 2 - the pipe, 3 - explosives, 4 - detonator. Explosives located at the junction of the annular band. To eliminate pipe collapse in the explosion can be used strong enough core (not shown). The use of explosive welding, of course, requires strict adherence to safety rules and storage of explosives. Explosive welding is convenient for the manufacture of individual products is relatively simple shape, control the welding process can only be approximate, since the result depends on the density of the explosive, the uniformity of its location and other parameters, giving in only about regulation. For serial and mass production of small parts is sometimes more convenient way may be magnetic-pulse welding, in many respects similar explosion welding. For example, a magnetic-pulse welding of pipe joint (see Fig.) On butt instead of a circular band of explosives put on a few turns of the coil and is fed through a powerful impulse to the electric current from the batteries of electric capacitors, the emergence of short-term high-density magnetic flux produces an effect similar explosion - the tube is firmly welded vayutsya, and they can be made of dissimilar metals such as aluminum and copper. Magnetic pulse welding allows for precise control and is suitable for mass production of similar products of small size.
See also:
Blacksmith (Forge) Welding
Blacksmith (Forge) Welding Part 2
Induction (high frequency) Welding
Diffusion Welding
Casting or Foundry Welding
Friction Welding
Electrolytic Welding
Welding Under Water
Explosive Welding
Explosive welding
It has been observed that the explosion of fluttering pieces of metal hitting the surrounding metal, sometimes permanently welded to them. The research helped to create industrially useful method of explosion welding. Its essence lies in the fact that the welded part or strike with great speed runs to the one struck details. The speed of the striking details of the time of the collision must be several hundred meters per second, approaching the speed of the projectile firearms. In the zone of collision of the metal parts to be joined is flowing like a liquid and merges into one, forming a monolithic connection.
Hit piece throws an explosive charge, which weight is 10-20% by weight of detail.
We strike the fixed part can have any mass, with details of its lack of weight is placed on the massive base - one struck the increase in mass improves the energy part of the explosion. Some of the best known applications of explosive welding - fabrication of bimetallic billets (see Fig.). main one struck a plate to increase the weight placed on a level foundation 3. Striking sheet metal 2 at an angle a = 3 - 10 grams to the surface of a plate. On the upper surface of sheet 2 evenly distribute explosives 4, as is used in different cases ammonal, thick, RDX, etc. At the lower edge of the sheet 2 have a detonator 5. The explosion propagates in the direction of the arrow and is shot as if a sheet of plate 2 in 1. First, strikes, and a plate welded to the bottom edge of the sheet 2, then the collision zone and the weld is moved to the right and the entire surface of the sheet 2 is welded to the plate 1. The boundary between the connected components on microsections has the characteristic form of a wavy line. In this way, can be connected to dissimilar metals, such as carbon steel plate can be attached sheet of stainless steel, nickel, titanium, copper, aluminum, etc. The resulting explosion of the workpiece and then rolled into sheets bimetal. The surface explosion of connected components can be several square meters. A second example of the use of explosive welding joints can be connected by pipes. used telescopic or lap joint (see Fig.), where 1 and 2 - the pipe, 3 - explosives, 4 - detonator. Explosives located at the junction of the annular band. To eliminate pipe collapse in the explosion can be used strong enough core (not shown). The use of explosive welding, of course, requires strict adherence to safety rules and storage of explosives. Explosive welding is convenient for the manufacture of individual products is relatively simple shape, control the welding process can only be approximate, since the result depends on the density of the explosive, the uniformity of its location and other parameters, giving in only about regulation. For serial and mass production of small parts is sometimes more convenient way may be magnetic-pulse welding, in many respects similar explosion welding. For example, a magnetic-pulse welding of pipe joint (see Fig.) On butt instead of a circular band of explosives put on a few turns of the coil and is fed through a powerful impulse to the electric current from the batteries of electric capacitors, the emergence of short-term high-density magnetic flux produces an effect similar explosion - the tube is firmly welded vayutsya, and they can be made of dissimilar metals such as aluminum and copper. Magnetic pulse welding allows for precise control and is suitable for mass production of similar products of small size.
Blacksmith (Forge) Welding
Blacksmith (Forge) Welding Part 2
Induction (high frequency) Welding
Diffusion Welding
Casting or Foundry Welding
Friction Welding
Electrolytic Welding
Welding Under Water
Explosive Welding
10:38 PM
Welding Under Water
brief article describing the process of manual arc welding under water
Under water, electric works in the construction of underwater parts of different structures, underwater pipelines, power stations, port facilities, bridges, etc., in the salvage, ship repair and salvage operations, and so is often necessary to perform welding work under water. While able to practically apply the water arc welding. Ability to obtain a stable arc discharge in a liquid medium - water, oil, etc. - was determined experimentally at the end of the last century. The arc burns in a gas bubble formed by continuously revolving due to evaporation and decomposition of the surrounding liquid thermal action of the arc discharge.
electric arc under water was first implemented and studied in the Soviet Union in 1932, Konstantin Konstantinovich bad. It was found that the arc of DC when powered by conventional power source burns under water is quite stable, provided that the electrode is covered with thick enough layer of waterproof coating. Particularly surprising that the water arc melts the metal is almost as fast as in air, in spite of the intense cooling of the environment. This fact is explained by self-regulation state arc discharge. Current regulation is established in the discharge source, self-regulation of the arc changes the voltage drop across the individual sectors of the discharge. Increasing the impact energy in the environment automatically increase the voltage and power of the arc to compensate for increased energy efficiency, reduction of energy losses to the environment will cause a voltage drop across the arc discharge.
Cooling the aqueous medium increases the arc voltage and arc teplomoschnost, resulting in an intense melting of the metal. To be successful welding is essential to cover the electrode, it must be sufficiently thick, 30% of the weight of the electrode rod. Coverage of the electrode, washed with water, the electrode rod is melted slowly, so when burning arc coating on the tip of the electrode forms a so-called peak, contributing to the formation and retention of gas bubbles needed for a normal arc.
Gas bubble in the arc burning steadily growing, increasing in volume, then gases erupt, and his rise to the surface, the gas bubble is reduced in volume to a minimum and then begins to rise, which is repeated several times per second. The gas bubble is composed primarily of hydrogen obtained by decomposition of water vapor, in addition, there are products of decomposition of the electrode coating, a pair of iron, water vapor, carbon monoxide, nitrogen, hydrogen, etc., • dissolves in the weld metal to form pores and reduces the plasticity metal. Therefore, a water resistant coating and a lack of moisture in it. Evaporation of water in the coating and electrolysis with abundant evolution of hydrogen on the surface of the electrode rod break down cover, pluck it from the electrode rod, and I quickly lead electrode into disrepair. Especially: to be waterproof coating to work in salt water.
Waterproof electrodes attached to special treatment. After coating, drying and calcining it, I cover is impregnated and coated with a variety of waterproof compounds. For example, boil the electrodes in molten paraffin (this part is very weak, suitable only for fresh water). Best result gives a solution of celluloid in acetone, and bakelite lacquer. The best solution is synthetic resins in dichloroethane. Welding rods electrodes steel wire Sv-08 have a diameter of 4-5 mm.
Pairs of iron and electrode coating materials in contact with water, condenses, forming tiny colloidal particles, particularly iron oxides, and these particles are deposited a long time in water and form in the weld zone of dark brown cloud of haze that interferes with the observation and operation of the welder-diver (Fig. 123). The formation of turbidity depends on the composition of the electrode coating, one of the requirements for him - the minimum turbidity formation.
When satisfactory as electrodes arc almost as stable as you would in air. Usually the work is performed at a constant current of normal polarity. Ability to work on alternating current. At a constant current is quite stable and the carbon arc, but it has no use. Intense melting metal arc allows for the usual forms of welds in all positions.
Satisfactory weld metal strength, contains an increased amount of hydrogen and its ductility indices are lowered. The affected area is narrowed, the structure of the metal is accelerated signs of cooling after welding.
Diver-welder working in a heavy soft diving equipment, telephone communications (Figure). Arc rays passing through a thick layer of water, reduce its intensity, all the same to reduce eye strain in the front window of colored glass inserted into the helmet, changing to an expansion of the head, the welder can be viewed through colored glass, or in addition to it. Electrode holder has a special design, carefully isolated over the entire surface to reduce the leakage current. The welding current is supplied through a flexible cable with reinforced insulation. The diver-welder is in a particularly difficult operating conditions. Visibility weld zone is usually sufficient. Welder hampered in his movements diving equipment, insufficient resistance welder, it constantly blows with a nyatogo-position, with each sudden movement throws the welder to the side. Therefore, for underwater welding is characterized by defects that are not found in ground works, - missing, the failure of welding line, one of the unfused seam edges, etc. Welding is possible both in fresh and salt water, the latter requires careful isolation electrode. Even small areas of bare metal can cause significant leakage current, up to several tens of amperes. In salt water can be ignited arc without touching the electrode, only when it approaches any metal object in the water, even if it is not attached to the wire current source. All metal parts in the welding zone are connected to a power source through the water. Therefore, the result of careless approach of the electrode to the metal parts of diving equipment, such as a helmet or a shirt-front chest, a diver can burn them. Despite the difficulties of the diver-welder and not a very high quality of welded joints, underwater welding was quite a wide application in the salvage, ship repair , rescue and other operations. The successful application of underwater welding contributes to suitability for underwater work without any alterations of normal conventional power sources for welding in air. In conventional studies of underwater welding current is taken in the range 180-240 A, arc voltage 30-35 V, 5-7 against the extra welding on the air going to cover the losses of heat generated by the surrounding aqueous medium. considerable interest is the possibility of welding at great depths . Experience in welding at depths of 100 m showed that the arc was burning steadily, a refiner of its action intensified, which is favorable for welding. There are laboratory studies of the arc at pressures up to 1200 am, which is higher than the pressure at the bottom of the ocean's greatest depths, arcing proceeded normally, and it maintained its usual properties. However, the conditions of underwater work very hard for a man. At a depth of over 20 m begins intensive dissolution of nitrogen in the blood rise when the diver with a decrease in pressure small bubbles of nitrogen are allocated, causing pain (caisson disease). Therefore, the rise of significant life-threatening deep diver, and it is produced slowly, with pauses for a specific schedule. In addition, with increasing pressure at considerable depths of human feeling worse. At depths of 50-70 m, the normal duration of the diver is only 15 minutes, and the duration of his head several times that amount. Therefore, the work becomes almost impossible at depths exceeding 30-40 m only way to increase the performance of underwater welding, and extending it to considerable depths - is the mechanization and automation of the welding process with a maximum reduction of the residence time of a person under water. The main goal of automation in this case, the release of a person to perform work in severe conditions. There are successful results of the semi-automatic and automatic hose in underwater conditions, with a bare wire with a diameter of about 2 mm from the injection of argon shielding gas in the area of the arc or without gas. The use of a simple hose semiautomatic increases productivity diver-welder and cuts during his stay under water by 5-10 times. In the future, with the creation of complex automated devices with TV surveillance and sea control, will be possible underwater welding work at any depth.
See also:
Blacksmith (Forge) Welding
Blacksmith (Forge) Welding Part 2
Induction (high frequency) Welding
Diffusion Welding
Casting or Foundry Welding
Friction Welding
Electrolytic Welding
Welding Under Water
Explosive Welding
Welding Underwater
Under water, electric works in the construction of underwater parts of different structures, underwater pipelines, power stations, port facilities, bridges, etc., in the salvage, ship repair and salvage operations, and so is often necessary to perform welding work under water. While able to practically apply the water arc welding. Ability to obtain a stable arc discharge in a liquid medium - water, oil, etc. - was determined experimentally at the end of the last century. The arc burns in a gas bubble formed by continuously revolving due to evaporation and decomposition of the surrounding liquid thermal action of the arc discharge.
electric arc under water was first implemented and studied in the Soviet Union in 1932, Konstantin Konstantinovich bad. It was found that the arc of DC when powered by conventional power source burns under water is quite stable, provided that the electrode is covered with thick enough layer of waterproof coating. Particularly surprising that the water arc melts the metal is almost as fast as in air, in spite of the intense cooling of the environment. This fact is explained by self-regulation state arc discharge. Current regulation is established in the discharge source, self-regulation of the arc changes the voltage drop across the individual sectors of the discharge. Increasing the impact energy in the environment automatically increase the voltage and power of the arc to compensate for increased energy efficiency, reduction of energy losses to the environment will cause a voltage drop across the arc discharge.
Cooling the aqueous medium increases the arc voltage and arc teplomoschnost, resulting in an intense melting of the metal. To be successful welding is essential to cover the electrode, it must be sufficiently thick, 30% of the weight of the electrode rod. Coverage of the electrode, washed with water, the electrode rod is melted slowly, so when burning arc coating on the tip of the electrode forms a so-called peak, contributing to the formation and retention of gas bubbles needed for a normal arc.
Gas bubble in the arc burning steadily growing, increasing in volume, then gases erupt, and his rise to the surface, the gas bubble is reduced in volume to a minimum and then begins to rise, which is repeated several times per second. The gas bubble is composed primarily of hydrogen obtained by decomposition of water vapor, in addition, there are products of decomposition of the electrode coating, a pair of iron, water vapor, carbon monoxide, nitrogen, hydrogen, etc., • dissolves in the weld metal to form pores and reduces the plasticity metal. Therefore, a water resistant coating and a lack of moisture in it. Evaporation of water in the coating and electrolysis with abundant evolution of hydrogen on the surface of the electrode rod break down cover, pluck it from the electrode rod, and I quickly lead electrode into disrepair. Especially: to be waterproof coating to work in salt water.
Waterproof electrodes attached to special treatment. After coating, drying and calcining it, I cover is impregnated and coated with a variety of waterproof compounds. For example, boil the electrodes in molten paraffin (this part is very weak, suitable only for fresh water). Best result gives a solution of celluloid in acetone, and bakelite lacquer. The best solution is synthetic resins in dichloroethane. Welding rods electrodes steel wire Sv-08 have a diameter of 4-5 mm.
Pairs of iron and electrode coating materials in contact with water, condenses, forming tiny colloidal particles, particularly iron oxides, and these particles are deposited a long time in water and form in the weld zone of dark brown cloud of haze that interferes with the observation and operation of the welder-diver (Fig. 123). The formation of turbidity depends on the composition of the electrode coating, one of the requirements for him - the minimum turbidity formation.
When satisfactory as electrodes arc almost as stable as you would in air. Usually the work is performed at a constant current of normal polarity. Ability to work on alternating current. At a constant current is quite stable and the carbon arc, but it has no use. Intense melting metal arc allows for the usual forms of welds in all positions.
Satisfactory weld metal strength, contains an increased amount of hydrogen and its ductility indices are lowered. The affected area is narrowed, the structure of the metal is accelerated signs of cooling after welding.
Diver-welder working in a heavy soft diving equipment, telephone communications (Figure). Arc rays passing through a thick layer of water, reduce its intensity, all the same to reduce eye strain in the front window of colored glass inserted into the helmet, changing to an expansion of the head, the welder can be viewed through colored glass, or in addition to it. Electrode holder has a special design, carefully isolated over the entire surface to reduce the leakage current. The welding current is supplied through a flexible cable with reinforced insulation. The diver-welder is in a particularly difficult operating conditions. Visibility weld zone is usually sufficient. Welder hampered in his movements diving equipment, insufficient resistance welder, it constantly blows with a nyatogo-position, with each sudden movement throws the welder to the side. Therefore, for underwater welding is characterized by defects that are not found in ground works, - missing, the failure of welding line, one of the unfused seam edges, etc. Welding is possible both in fresh and salt water, the latter requires careful isolation electrode. Even small areas of bare metal can cause significant leakage current, up to several tens of amperes. In salt water can be ignited arc without touching the electrode, only when it approaches any metal object in the water, even if it is not attached to the wire current source. All metal parts in the welding zone are connected to a power source through the water. Therefore, the result of careless approach of the electrode to the metal parts of diving equipment, such as a helmet or a shirt-front chest, a diver can burn them. Despite the difficulties of the diver-welder and not a very high quality of welded joints, underwater welding was quite a wide application in the salvage, ship repair , rescue and other operations. The successful application of underwater welding contributes to suitability for underwater work without any alterations of normal conventional power sources for welding in air. In conventional studies of underwater welding current is taken in the range 180-240 A, arc voltage 30-35 V, 5-7 against the extra welding on the air going to cover the losses of heat generated by the surrounding aqueous medium. considerable interest is the possibility of welding at great depths . Experience in welding at depths of 100 m showed that the arc was burning steadily, a refiner of its action intensified, which is favorable for welding. There are laboratory studies of the arc at pressures up to 1200 am, which is higher than the pressure at the bottom of the ocean's greatest depths, arcing proceeded normally, and it maintained its usual properties. However, the conditions of underwater work very hard for a man. At a depth of over 20 m begins intensive dissolution of nitrogen in the blood rise when the diver with a decrease in pressure small bubbles of nitrogen are allocated, causing pain (caisson disease). Therefore, the rise of significant life-threatening deep diver, and it is produced slowly, with pauses for a specific schedule. In addition, with increasing pressure at considerable depths of human feeling worse. At depths of 50-70 m, the normal duration of the diver is only 15 minutes, and the duration of his head several times that amount. Therefore, the work becomes almost impossible at depths exceeding 30-40 m only way to increase the performance of underwater welding, and extending it to considerable depths - is the mechanization and automation of the welding process with a maximum reduction of the residence time of a person under water. The main goal of automation in this case, the release of a person to perform work in severe conditions. There are successful results of the semi-automatic and automatic hose in underwater conditions, with a bare wire with a diameter of about 2 mm from the injection of argon shielding gas in the area of the arc or without gas. The use of a simple hose semiautomatic increases productivity diver-welder and cuts during his stay under water by 5-10 times. In the future, with the creation of complex automated devices with TV surveillance and sea control, will be possible underwater welding work at any depth.
See also:
Blacksmith (Forge) Welding
Blacksmith (Forge) Welding Part 2
Induction (high frequency) Welding
Diffusion Welding
Casting or Foundry Welding
Friction Welding
Electrolytic Welding
Welding Under Water
Explosive Welding
Welding Underwater
10:31 PM
Electrolytic Welding
article on the electrolytic welding
Electrolytic welding
Heating of the parts to be joined in the electrolytic bath is made by direct current. If you omit the two electrodes in an aqueous solution of alkali, potash or soda and skip through the electrolyte direct current from one electrode to another, with sufficient current density can be observed that the surface electrode attached to the negative pole of a current source, ie, the cathode, quickly heated to melting. Such heating is observed when feeding the DC voltage setting in the 110-220 and sufficient current densities. This phenomenon is explained by the fact that when the current passes the cathode surface is covered with a thin film of hydrogen bubbles, which increases the resistance to the passage of electric current, which creates a considerable; voltage drop and power loss in a thin layer at the cathode surface. Liberated a large thermal capacity, and goes to heating the surface layer of the cathode. For details of the welding heated compress and produce a draft. The coupled parts simultaneously heated by immersing them in the bath as the cathode. The method is rarely used to connect small parts, wires, etc.
See also:
Blacksmith (Forge) Welding
Blacksmith (Forge) Welding Part 2
Induction (high frequency) Welding
Diffusion Welding
Casting or Foundry Welding
Friction Welding
Electrolytic Welding
Welding Under Water
Explosive Welding
Electrolytic welding
Heating of the parts to be joined in the electrolytic bath is made by direct current. If you omit the two electrodes in an aqueous solution of alkali, potash or soda and skip through the electrolyte direct current from one electrode to another, with sufficient current density can be observed that the surface electrode attached to the negative pole of a current source, ie, the cathode, quickly heated to melting. Such heating is observed when feeding the DC voltage setting in the 110-220 and sufficient current densities. This phenomenon is explained by the fact that when the current passes the cathode surface is covered with a thin film of hydrogen bubbles, which increases the resistance to the passage of electric current, which creates a considerable; voltage drop and power loss in a thin layer at the cathode surface. Liberated a large thermal capacity, and goes to heating the surface layer of the cathode. For details of the welding heated compress and produce a draft. The coupled parts simultaneously heated by immersing them in the bath as the cathode. The method is rarely used to connect small parts, wires, etc.
See also:
Blacksmith (Forge) Welding
Blacksmith (Forge) Welding Part 2
Induction (high frequency) Welding
Diffusion Welding
Casting or Foundry Welding
Friction Welding
Electrolytic Welding
Welding Under Water
Explosive Welding
10:28 PM
Friction Welding
about friction welding
Friction Welding
To heat the welding can be used transformation of mechanical energy into heat through friction.
Friction welding is sometimes used for welding at the bottom of the tank for compressed gases. The length of seamless steel pipe with a pre-heated end of the skewer in the fast-rotating frame. By rotating the workpiece closer crimp face down the metal and imparts to it a hemispherical shape of the bottom of the cylinder. With the rapid rotation of the workpiece metal upsets quickly heated by friction between the crimping and the workpiece in the process of precipitation, the temperature does not decrease, but increases at the expense of mechanical friction. As a result, the friction of the bottom metal is strongly heated and facing down with the formation of bulges. To connect the circular cylindrical rods or tubes fixed in the details of the terminals of the machine and result in contact with the ends. One detail remains fixed, the other is rotated at a speed of 500 - 1500 obImin and kept pressed against the fixed part. Due to the ends of the friction parts are heated rapidly in a short time and brought to the melting, automatically turns off clutch, stopping the rotation of the spindle axis is then deposit details. In some cases the method has proved very effective. It features high performance (CPU time for different parts 1.5-50 sec), high quality and stability of the welding, because the process is automated, all parameters (speed, force of precipitation during welding) are characterized by great constancy. The method is very economical and has high efficiency of electric power consumption of 15-20 vt/mm2, and power consumption 7-40 times smaller than the contact electric welding, load three-phase network supplying the drive motor, it is quite uniform; cos f = 0.8.
The method makes it possible to weld dissimilar metals (aluminum, copper, aluminum, steel, copper and steel, etc.). The width of the zone of influence of the welded joint is not more than 2-3 mm. Especially effective welding blanks of cutting tools drills, taps, etc., of carbon and high-speed steel.
See also:
Blacksmith (Forge) Welding
Blacksmith (Forge) Welding Part 2
Induction (high frequency) Welding
Diffusion Welding
Casting or Foundry Welding
Friction Welding
Electrolytic Welding
Welding Under Water
Explosive Welding
Friction Welding
To heat the welding can be used transformation of mechanical energy into heat through friction.
Friction welding is sometimes used for welding at the bottom of the tank for compressed gases. The length of seamless steel pipe with a pre-heated end of the skewer in the fast-rotating frame. By rotating the workpiece closer crimp face down the metal and imparts to it a hemispherical shape of the bottom of the cylinder. With the rapid rotation of the workpiece metal upsets quickly heated by friction between the crimping and the workpiece in the process of precipitation, the temperature does not decrease, but increases at the expense of mechanical friction. As a result, the friction of the bottom metal is strongly heated and facing down with the formation of bulges. To connect the circular cylindrical rods or tubes fixed in the details of the terminals of the machine and result in contact with the ends. One detail remains fixed, the other is rotated at a speed of 500 - 1500 obImin and kept pressed against the fixed part. Due to the ends of the friction parts are heated rapidly in a short time and brought to the melting, automatically turns off clutch, stopping the rotation of the spindle axis is then deposit details. In some cases the method has proved very effective. It features high performance (CPU time for different parts 1.5-50 sec), high quality and stability of the welding, because the process is automated, all parameters (speed, force of precipitation during welding) are characterized by great constancy. The method is very economical and has high efficiency of electric power consumption of 15-20 vt/mm2, and power consumption 7-40 times smaller than the contact electric welding, load three-phase network supplying the drive motor, it is quite uniform; cos f = 0.8.
The method makes it possible to weld dissimilar metals (aluminum, copper, aluminum, steel, copper and steel, etc.). The width of the zone of influence of the welded joint is not more than 2-3 mm. Especially effective welding blanks of cutting tools drills, taps, etc., of carbon and high-speed steel.
See also:
Blacksmith (Forge) Welding
Blacksmith (Forge) Welding Part 2
Induction (high frequency) Welding
Diffusion Welding
Casting or Foundry Welding
Friction Welding
Electrolytic Welding
Welding Under Water
Explosive Welding
10:15 PM
Casting or Foundry Welding
Casting welding an outdated method of welding, welding position in which the molten metal is poured.
Casting or Foundry welding
The method consists in the fact that prepared the place is filled with liquid weld metal, overheated, harvested in a single product from a container, such as a crucible. The welding process is similar to the production of castings. Place welding, dried, and sometimes ignited, the product is heated and poured joint pre-prepared molten, preferably superheated metal. Thus welded products from precious metals, copper, bronze (jewelery, utensils, etc.), produced lead pipes for water. Currently casting welding is rarely used, for example, to correct iron castings.
See also:
Blacksmith (Forge) Welding
Blacksmith (Forge) Welding Part 2
Induction (high frequency) Welding
Diffusion Welding
Casting or Foundry Welding
Friction Welding
Electrolytic Welding
Welding Under Water
Explosive Welding
Casting or Foundry welding
The method consists in the fact that prepared the place is filled with liquid weld metal, overheated, harvested in a single product from a container, such as a crucible. The welding process is similar to the production of castings. Place welding, dried, and sometimes ignited, the product is heated and poured joint pre-prepared molten, preferably superheated metal. Thus welded products from precious metals, copper, bronze (jewelery, utensils, etc.), produced lead pipes for water. Currently casting welding is rarely used, for example, to correct iron castings.
See also:
Blacksmith (Forge) Welding
Blacksmith (Forge) Welding Part 2
Induction (high frequency) Welding
Diffusion Welding
Casting or Foundry Welding
Friction Welding
Electrolytic Welding
Welding Under Water
Explosive Welding
10:03 PM
Diffusion Welding
about diffusion welding
Diffusion welding
The method is based on the diffusion of metals. The coupled parts are placed in the welding chamber that is filled with an inert or reducing gas (in our industry is rarely used), while maintaining a constant vacuum of the order of (10 2 - 10 5 ) mm Hg. of Art. Details of the chamber is heated and compress specific pressure of the order of 0.5-2 kg / mm 2 . The vacuum is maintained continuously, the work of vacuum pumps, bilge gases coming into the welding chamber through leaks of the system, as well as adsorbed surfaces of equipment and allocated continuously heated metal from the surface and from the volume. Very important is the temperature of heating the metal, steel is usually heated to 800 ° C. There is a purification of the metal surface, remove surface contamination and adsorbed gases are reduced and dissolved in the metal oxides. Welding surface should be well-machined to ensure the entire surface of contact welding. Continuously active pressure crushes all projections and irregularities of hot metal and provides the necessary adhesion to the surface.
The processes of cleaning, fitting surfaces and diffusion are quite slow and it takes 5-20 minutes, and sometimes more to complete the welding process. Heating of the parts are usually electric, and in different cases, the radiation of heaters, and sometimes the heat transfer from the heater through the heat conductivity and the possible induction heating.
The heating temperature and its control are of great importance, it is a small increase dramatically accelerates the diffusion on the other hand, the heating can reduce the quality of the metal. The method is distinguished by high flexibility with respect to weld metals can be welded many combinations of dissimilar metals, and metals with metal alloys, metal ceramics, and graphite, etc. The method was already widely used for different occasions, often are difficult in other ways.
See also:
Blacksmith (Forge) Welding
Blacksmith (Forge) Welding Part 2
Induction (high frequency) Welding
Diffusion Welding
Casting or Foundry Welding
Friction Welding
Electrolytic Welding
Welding Under Water
Explosive Welding
Diffusion welding
The method is based on the diffusion of metals. The coupled parts are placed in the welding chamber that is filled with an inert or reducing gas (in our industry is rarely used), while maintaining a constant vacuum of the order of (10 2 - 10 5 ) mm Hg. of Art. Details of the chamber is heated and compress specific pressure of the order of 0.5-2 kg / mm 2 . The vacuum is maintained continuously, the work of vacuum pumps, bilge gases coming into the welding chamber through leaks of the system, as well as adsorbed surfaces of equipment and allocated continuously heated metal from the surface and from the volume. Very important is the temperature of heating the metal, steel is usually heated to 800 ° C. There is a purification of the metal surface, remove surface contamination and adsorbed gases are reduced and dissolved in the metal oxides. Welding surface should be well-machined to ensure the entire surface of contact welding. Continuously active pressure crushes all projections and irregularities of hot metal and provides the necessary adhesion to the surface.
The processes of cleaning, fitting surfaces and diffusion are quite slow and it takes 5-20 minutes, and sometimes more to complete the welding process. Heating of the parts are usually electric, and in different cases, the radiation of heaters, and sometimes the heat transfer from the heater through the heat conductivity and the possible induction heating.
The heating temperature and its control are of great importance, it is a small increase dramatically accelerates the diffusion on the other hand, the heating can reduce the quality of the metal. The method is distinguished by high flexibility with respect to weld metals can be welded many combinations of dissimilar metals, and metals with metal alloys, metal ceramics, and graphite, etc. The method was already widely used for different occasions, often are difficult in other ways.
See also:
Blacksmith (Forge) Welding
Blacksmith (Forge) Welding Part 2
Induction (high frequency) Welding
Diffusion Welding
Casting or Foundry Welding
Friction Welding
Electrolytic Welding
Welding Under Water
Explosive Welding
10:00 PM
Induction Welding
on welding of high-frequency currents. The method used in the manufacture of welded pipes.
Induction (high frequency) welding.
The metal is heated by passing through a high-frequency currents and compressed. High-frequency currents are most convenient for the introduction of the metal inductive non-contact method, in addition, they are convenient for the concentration in the heating zone with the skin effect and proximity effect and a large inductive reactance shunt tract. Therefore, almost always in high-frequency currents on the tube or engine generators. The most widely used until the pipe is a quark.
The first figure shows schematically the device pipe welding mill to supply welding current contacts. Harvesting of the pipe 1 moves progressively leading wheels, crimped crimp rollers 4. Gap workpiece prior to welding is adjusted so that the edges are at an acute angle and converge at the point of welding. The current from the high-frequency generator is fed to the workpiece through the fixed contact 3. The current density reaches a maximum value at the point of contact converging edges, there develops the highest temperature, and welding occurs under the action of crimping rollers. For reducing the shunting of welding, current is introduced into the workpiece ferrite core 2, so that the inductive impedance shunt paths for high frequency currents becomes very large and the leakage current between the contacts in addition to the welding is dramatically reduced.
The second figure shows a diagram of the device to supply the welding current to the workpiece by the induction method. Current high-frequency generator is supplied to the inductor, which induces currents in the workpiece tube. Experience has shown that in most cases, more rational way to feed an induction current to the workpiece, it simplifies the construction and operation of pipe welding mill, there is no consumption of expensive wear contacts the workpiece surface condition does not affect weld quality. Mills of this type have been successfully used for the manufacture of pipes 12-60 mm at speeds up to 50 m / min. Power produced from the shock tube generator power of 160 kW at a frequency of 440 kHz and 880. Produced and pipes of large diameters, 325 and 426 mm, wall thickness 7-8 mm, with a welding speed of 30-40 m / min. Can welding of steel and non-magnetic materials such as brass.
See also:
Blacksmith (Forge) Welding
Blacksmith (Forge) Welding Part 2
Induction (high frequency) Welding
Diffusion Welding
Casting or Foundry Welding
Friction Welding
Electrolytic Welding
Welding Under Water
Explosive Welding
Induction (high frequency) welding.
The metal is heated by passing through a high-frequency currents and compressed. High-frequency currents are most convenient for the introduction of the metal inductive non-contact method, in addition, they are convenient for the concentration in the heating zone with the skin effect and proximity effect and a large inductive reactance shunt tract. Therefore, almost always in high-frequency currents on the tube or engine generators. The most widely used until the pipe is a quark.
 |
1 - Pipe 2 - ferrite core, 3 - Contact 4 - crimping rollers 1 - Pipe 2 - inducer 3 - Core 4 - crimping rollers |
The first figure shows schematically the device pipe welding mill to supply welding current contacts. Harvesting of the pipe 1 moves progressively leading wheels, crimped crimp rollers 4. Gap workpiece prior to welding is adjusted so that the edges are at an acute angle and converge at the point of welding. The current from the high-frequency generator is fed to the workpiece through the fixed contact 3. The current density reaches a maximum value at the point of contact converging edges, there develops the highest temperature, and welding occurs under the action of crimping rollers. For reducing the shunting of welding, current is introduced into the workpiece ferrite core 2, so that the inductive impedance shunt paths for high frequency currents becomes very large and the leakage current between the contacts in addition to the welding is dramatically reduced.
The second figure shows a diagram of the device to supply the welding current to the workpiece by the induction method. Current high-frequency generator is supplied to the inductor, which induces currents in the workpiece tube. Experience has shown that in most cases, more rational way to feed an induction current to the workpiece, it simplifies the construction and operation of pipe welding mill, there is no consumption of expensive wear contacts the workpiece surface condition does not affect weld quality. Mills of this type have been successfully used for the manufacture of pipes 12-60 mm at speeds up to 50 m / min. Power produced from the shock tube generator power of 160 kW at a frequency of 440 kHz and 880. Produced and pipes of large diameters, 325 and 426 mm, wall thickness 7-8 mm, with a welding speed of 30-40 m / min. Can welding of steel and non-magnetic materials such as brass.
See also:
Blacksmith (Forge) Welding
Blacksmith (Forge) Welding Part 2
Induction (high frequency) Welding
Diffusion Welding
Casting or Foundry Welding
Friction Welding
Electrolytic Welding
Welding Under Water
Explosive Welding
9:51 PM
Blacksmith (Forge) Welding Part 2
the method
Blacksmith or forge welding depends on the properties of the weld metal and the heating temperature. The higher the heat, the less pressure is needed precipitation. Sediment can be done manually or mechanically seats forging - pressing, rolling. In this way, can be obtained, for example, multi-layer sheet steel. Similarly, the bimetal manufactured by a joint-rolling the heated workpieces, such as steel, nickel, carbon steel and stainless steel or copper, etc.
When welding blacksmiths always quite likely clears the oxides, scale and other contaminants on the surfaces of the metal to be welded. Heating to a plastic state does not provide removal of contaminants in the sediments, especially in large scale cross-sections of welding. Therefore, to improve the reliability of welding blacksmiths seek to increase the contact surface between the joined parts, to this end, the surface prior to welding appropriately prepared and cut (see Fig.).
If the deposit is made, for example, forging such a way that it reduces the cross section of a metal welding place, the resort to pre-landing of connected parts. Despite the relative simplicity of the process and the lack of consumption of scarce materials, blacksmith welding is now seldom used, going by the wayside, giving way to modern, more sophisticated and productive ways of welding.
Significant deficiencies of blacksmith welding are: slow heating of the metal and, therefore, the low productivity of the process, the complexity of the precipitation process, requiring considerable skill workers, the lack of reliability of the resulting weld. To this is added the possibility of significant grain growth, overheating and burnout of the metal due to the length of the heating process. Low productivity makes blacksmith welding expensive and weld strength is obtained by low and fluctuates widely. These reasons explain the gradual replacement of blacksmith welding in the modern workplace.
A variety of blacksmith welding are ways in which the product is to heat is not placed in a special oven, and place of special welding heat welding torches. The method of this kind is the diffusion welding. Place welding may be cheaper to heat industrial gases, combusted in a mixture with air in a special burner. For the burners should sedimentary unit in the form of hammers, producing forging seam roller mill, roller welding, rolling along the seam, producing draft and carry out such welding parts, mostly steel sheets.
There are industries where forge welding now maintains a leading position, such as the production of welded gas pipes, mostly small diameter, no greater than 100 mm. The bands were heated in a furnace, then heated with system band at the end of the mandrel is pulled through a drawing at a rate of several tens of meters per minute, folding the strip into a tube and welding the longitudinal seam. The production of such tubes is massive, and they are produced by thousands of miles for gas, water networks, etc.
Furnacemen retained value in the production of welding different components of the carpentry tools and tool carbon steel (axes, crowbars, picks, etc.).
See also:
Blacksmith (Forge) Welding
Blacksmith (Forge) Welding Part 2
Induction (high frequency) Welding
Diffusion Welding
Casting or Foundry Welding
Friction Welding
Electrolytic Welding
Welding Under Water
Explosive Welding
Blacksmith or forge welding depends on the properties of the weld metal and the heating temperature. The higher the heat, the less pressure is needed precipitation. Sediment can be done manually or mechanically seats forging - pressing, rolling. In this way, can be obtained, for example, multi-layer sheet steel. Similarly, the bimetal manufactured by a joint-rolling the heated workpieces, such as steel, nickel, carbon steel and stainless steel or copper, etc.
When welding blacksmiths always quite likely clears the oxides, scale and other contaminants on the surfaces of the metal to be welded. Heating to a plastic state does not provide removal of contaminants in the sediments, especially in large scale cross-sections of welding. Therefore, to improve the reliability of welding blacksmiths seek to increase the contact surface between the joined parts, to this end, the surface prior to welding appropriately prepared and cut (see Fig.).
If the deposit is made, for example, forging such a way that it reduces the cross section of a metal welding place, the resort to pre-landing of connected parts. Despite the relative simplicity of the process and the lack of consumption of scarce materials, blacksmith welding is now seldom used, going by the wayside, giving way to modern, more sophisticated and productive ways of welding.
Significant deficiencies of blacksmith welding are: slow heating of the metal and, therefore, the low productivity of the process, the complexity of the precipitation process, requiring considerable skill workers, the lack of reliability of the resulting weld. To this is added the possibility of significant grain growth, overheating and burnout of the metal due to the length of the heating process. Low productivity makes blacksmith welding expensive and weld strength is obtained by low and fluctuates widely. These reasons explain the gradual replacement of blacksmith welding in the modern workplace.
A variety of blacksmith welding are ways in which the product is to heat is not placed in a special oven, and place of special welding heat welding torches. The method of this kind is the diffusion welding. Place welding may be cheaper to heat industrial gases, combusted in a mixture with air in a special burner. For the burners should sedimentary unit in the form of hammers, producing forging seam roller mill, roller welding, rolling along the seam, producing draft and carry out such welding parts, mostly steel sheets.
There are industries where forge welding now maintains a leading position, such as the production of welded gas pipes, mostly small diameter, no greater than 100 mm. The bands were heated in a furnace, then heated with system band at the end of the mandrel is pulled through a drawing at a rate of several tens of meters per minute, folding the strip into a tube and welding the longitudinal seam. The production of such tubes is massive, and they are produced by thousands of miles for gas, water networks, etc.
Furnacemen retained value in the production of welding different components of the carpentry tools and tool carbon steel (axes, crowbars, picks, etc.).
See also:
Blacksmith (Forge) Welding
Blacksmith (Forge) Welding Part 2
Induction (high frequency) Welding
Diffusion Welding
Casting or Foundry Welding
Friction Welding
Electrolytic Welding
Welding Under Water
Explosive Welding
9:28 PM
Blacksmith (Forge) Welding
obvious from the title - this kind of a connection between metals used by the ancient blacksmiths.
Blacksmith or forge welding.
Blacksmith welding - an ancient form of pressure welding. For nearly three millennia of humanity widely used in iron, not being able to melt, so the iron can not be used for a long time known casting and welding was invented blacksmith welding method, as if intended for iron. Prosperity and development of welding blacksmith highly facilitated by the very method of iron production, which had existed for thousands of years until the second half of XIX century.
When blacksmith welding steel is heated to transition to a plastic state, the hot metal is subjected to strong pressure in the process of forging (forging welding), rolling, extrusion, drawing, etc., should be steel heated to 1100-1300 ° C, any event above the alpha conversion -gamma.
Let us consider briefly the main processes occurring in the metal with an increase in its temperature, stopping for an example on carbon steels. As the temperature reaches a critical point Ac3 normal alpha-iron goes into gamma-iron, a good solvent carbon in large quantities. At the same cementite and pearlite steel disappear, carbon is evenly distributed over the volume of metal that goes into a homogeneous austenite. With a further increase in temperature an increase in metal grains, ie, the boundaries between the grains disappear, a few small grains coalesce into one large grain in an effort to reduce the total free surface. At this temperature, and begins welding, ie, education in the border zone of new crystal grains, borrowing material for their growth on both parts to be united, which leads to the destruction of the physical interface between the parts.
The strength of welding increases with temperature and pressure within certain limits. When excessive rise in temperature may occur the effect of superheating and melting of some metal structural components, which leads to a decrease in the strength of welded joints.
Weldability of pressure in the plastic state is very different for different metals. Has excellent welding mild steel. With increasing carbon content weldability decreases rapidly, and began with a carbon content exceeding 0.7% of poorly welded pressure. Poorly welded and many alloy steels, nonferrous metals. Cast iron is practically no pressure welded in a plastic state.
Place of welding can be heated by various heat sources. Particularly high temperatures is not required and the necessary heat can be obtained in various kilns and furnaces, heated solid, liquid or gaseous fuel. Most ordinary combustible materials by burning them with air in the furnace proper device provides sufficient heat.
The surfaces of the workpiece, even carefully peeled in advance, during the heating process is usually much oxidized, the oxide layer makes it impossible to weld. To clean the surface of the weld from oxides is necessary to resort to chemical cleaning, applying flux, forming a fusible metal oxides compounds can easily be extruded from the joint in the process of precipitation, thus allowing lead in contact with a completely clean metal surface.
When heated, iron slag were formed, whose composition varies between the oxides FeO and Fe 3 O 4 , rather refractory and melted at white heat. These oxides are basic, so for them fluxing or slagging, ie, transfer to the fusible compound, liquid at a temperature of welding should be used acidic oxides, non-volatile and quite persistent at welding. Fluxes for blacksmith welding can include: borax Na 2 B 4 O 7 , boric acid B (OH) 3 , sodium chloride NaCl, a small river or quartz sand, the battle of window glass, and mixtures thereof.
After heating and fluxing the welding operation performed precipitation. Draught causes a significant deformation of the metal surfaces along the course of his connections, mixing, and contributing to mutual diffusion of the particles of the metal parts to be united. The value of specific pressure required for deposit.
See also:
Blacksmith (Forge) Welding
Blacksmith (Forge) Welding Part 2
Induction (high frequency) Welding
Diffusion Welding
Casting or Foundry Welding
Friction Welding
Electrolytic Welding
Welding Under Water
Explosive Welding
Blacksmith or forge welding.
Blacksmith welding - an ancient form of pressure welding. For nearly three millennia of humanity widely used in iron, not being able to melt, so the iron can not be used for a long time known casting and welding was invented blacksmith welding method, as if intended for iron. Prosperity and development of welding blacksmith highly facilitated by the very method of iron production, which had existed for thousands of years until the second half of XIX century.
When blacksmith welding steel is heated to transition to a plastic state, the hot metal is subjected to strong pressure in the process of forging (forging welding), rolling, extrusion, drawing, etc., should be steel heated to 1100-1300 ° C, any event above the alpha conversion -gamma.
Let us consider briefly the main processes occurring in the metal with an increase in its temperature, stopping for an example on carbon steels. As the temperature reaches a critical point Ac3 normal alpha-iron goes into gamma-iron, a good solvent carbon in large quantities. At the same cementite and pearlite steel disappear, carbon is evenly distributed over the volume of metal that goes into a homogeneous austenite. With a further increase in temperature an increase in metal grains, ie, the boundaries between the grains disappear, a few small grains coalesce into one large grain in an effort to reduce the total free surface. At this temperature, and begins welding, ie, education in the border zone of new crystal grains, borrowing material for their growth on both parts to be united, which leads to the destruction of the physical interface between the parts.
The strength of welding increases with temperature and pressure within certain limits. When excessive rise in temperature may occur the effect of superheating and melting of some metal structural components, which leads to a decrease in the strength of welded joints.
Weldability of pressure in the plastic state is very different for different metals. Has excellent welding mild steel. With increasing carbon content weldability decreases rapidly, and began with a carbon content exceeding 0.7% of poorly welded pressure. Poorly welded and many alloy steels, nonferrous metals. Cast iron is practically no pressure welded in a plastic state.
Place of welding can be heated by various heat sources. Particularly high temperatures is not required and the necessary heat can be obtained in various kilns and furnaces, heated solid, liquid or gaseous fuel. Most ordinary combustible materials by burning them with air in the furnace proper device provides sufficient heat.
The surfaces of the workpiece, even carefully peeled in advance, during the heating process is usually much oxidized, the oxide layer makes it impossible to weld. To clean the surface of the weld from oxides is necessary to resort to chemical cleaning, applying flux, forming a fusible metal oxides compounds can easily be extruded from the joint in the process of precipitation, thus allowing lead in contact with a completely clean metal surface.
When heated, iron slag were formed, whose composition varies between the oxides FeO and Fe 3 O 4 , rather refractory and melted at white heat. These oxides are basic, so for them fluxing or slagging, ie, transfer to the fusible compound, liquid at a temperature of welding should be used acidic oxides, non-volatile and quite persistent at welding. Fluxes for blacksmith welding can include: borax Na 2 B 4 O 7 , boric acid B (OH) 3 , sodium chloride NaCl, a small river or quartz sand, the battle of window glass, and mixtures thereof.
After heating and fluxing the welding operation performed precipitation. Draught causes a significant deformation of the metal surfaces along the course of his connections, mixing, and contributing to mutual diffusion of the particles of the metal parts to be united. The value of specific pressure required for deposit.
See also:
Blacksmith (Forge) Welding
Blacksmith (Forge) Welding Part 2
Induction (high frequency) Welding
Diffusion Welding
Casting or Foundry Welding
Friction Welding
Electrolytic Welding
Welding Under Water
Explosive Welding