Tuesday, December 6, 2011

Electric Arc Welding Technology

Electric Arc Welding
For centuries wrought las used as the primary process to connect the metal without much experience growth. In the early 19th century, found a new way, namely electric arc welding flame (Electric Arc Welding) with a carbon rod electrode without the wrapper by using the battery as a power source. The main weakness of electric welding process is the oxidation of carbon is high relative to the weld (weld easily rust) so that the welding is widely used.

At the same time, in 1877, found weld resistance (Resistance Welding). A British physicist, James Joule, recognized as the inventor. In 1856 he heat up two pieces of wire with electric current. During the heating process, the wires are pressed to each other. It turns out the two wires are tied to each other after heated.

In further development, resistance welding produces several types of welding processes, eg welding flash (Flash Welding) in the electrical resistance 1920. Welding achieve glory of being created different types of robots. Developed to meet the needs of the various forms of electrical resistance welding includes welding point, interval, seam (line) and projection. Welding Process implement this in the heat and press. Electrode serves as a channel for the flow and pressure plate-shaped workpiece.

In the next decade, introduced last hermit (Thermit Welding) by adding a chemical process is repertoire welding technology. Welding termit by pouring molten metal between two metal end which would be connected so it would melt. After freezing the fused metal and liquid metal is poured to function as an added ingredient.

In the late 19th century found oxy acetylene welding, weld it managed to shift the use of welding wrought and dominate the welding process for several decades to develop electric welding ..
In 1925, oxy acetylene welding repair is shifted by the electric arc welding in which welding arc is wrapped electrode wear. After the fire, wrapping electrode produces gas and slag. Gas protects the weld crater of oxidation during the welding process is underway. Protect the weld slag during the freezing process to cool (until the slag is cleaned). Limitations of arc welding electrode rod is limited so long electrode any given period should stop changing the welding electrode. More material efficiency is far from 100% because I had no butt.

Starting from this weakness was then in the late 1930s created an arc welding electrode coils. In principle, the welding is not necessary to stop before reaching the end of the weld line. And welding can be done by automatic or semi automatic. Used as a protective flux. Flux outlined shortly in advance so that the electrode electric arc flame hidden by the flux. Advantage, the operator is not dazzled by the flame of an electric arc, weakness, limited to the welding position just under the hands of the other positions scattered flux will fall before the function.

In 1941 in the United States found Tungsten electrode. Tungsten is not melted by the heat of the flame of an electric arc that does not feed in the weld. Core is used as a protective gas (Inert) which can persist for some time on his condition. Core gas ejected stricken welds so the welds protected from oxidation. Because it uses the core as a protective welding welding is often called TIG welding (Tungsten Inert Gas).

The successful use of gas tungsten core pad pad pad pad electrode also tried the roll in the early 1950s. This process is hereinafter referred to as Gas Metal Arc Welding (GMAW) or MIG welding (Metal Inert Gas). Because metered gas is very expensive then used a mixture of argon and oxygen gas or CO gas is quite active. Welding is commonly called the Metal Active Gas (MAG). Can also be used protective argon mixture with CO for not more than 20% the result is quite good because it does not leave the slag. Please note that the protective gas is more expensive gas, then the way is only used for special purposes.

Found the next arc welding electrode welds with a protective roll floured. In order to be used in all positions, such as perforated pipe electrodes are made to put the flux. The process is relatively cheaper than gas arc welding, it can be to any position and can be developed technical welding semi-automatic or fully automatic welding is called the flux cored arc welding electrodes (Flux Core Arc Welding) electrodes Then there are the components to be mounted on the other. This is called weld stud welding. Stud mounted on the main body through three stages, namely the setting position, the search ends and the main body studs and stud pressure on the main body shortly after the arc flame is turned off.

After that developed electric welding high frequency is 10 000 to 500 000 Hz. High-frequency electric welding is often called induction welding. Judging from the unification process of the workpiece, solid welding including welding aided by heat to break down a layer of oxidation or dirt on the surface of the workpiece. Produced heat the workpiece surface is very thin so it is suitable for welding thin plate.

In the 1950s, transforms electrical energy into a beam of electrons fired from the workpiece. Greater the heat generated and the dimensions of the former electron is much smaller than electric arc flame, welding very quickly so it is suitable for mass production. Hot region becomes more narrow so it is suitable for materials sensitive to thermal changes. Excellent weld quality and accuracy, it's just very expensive equipment. This method is called las electron (Electron Beam Welding).
Scratch Welding
In 1950, AL Chudikov, a mechanic from the Soviet Union, put forward its observations on the theory of mechanical power can be converted into heat energy. Friction that occurs in the engine parts that move caused many losses as partly generated mechanical power turns into heat. Chudikov argue, so the bias should be used in the welding process. After going through a trial and he succeeded in welding research by utilizing the heat caused by friction. To increase the heat that occurs, the workpiece is not rotated but only pressed one against another. Pressure also serves to accelerate fusion. This is called friction welding (Welding Friktion)

Plasma Welding
Electric arc plasma flame welding (Plasma Arc Welding). Plasma process is an improved welding tungsten actually, it's just an electric arc burning between the electrodes do not appear to work but the object appears between the tip electrode with the gas flowing around the core. Welding plasma was better than tungsten because of arc welding flame that appears more stable power with a smaller diameter so that the heat is more concentrated. Faster welding process bias, in addition to tungsten never touch the workpiece.

Sound Welding
Earlier in the year 1960 was marked by the discovery of welding that uses high frequency sound (Ultrasonic Welding). It also uses an electric welding process works, there is no power at the workpiece, the heat generated merely the result of processes and it is only helpful in the process of unification of the workpiece.

Voice used ranged from 10 000 to 175 000 Hz, the sound vibrations transmitted through electrode mounted on the workpiece. Then pressure is applied to the workpiece during the process. Advantages of this process is suitable for thin objects and not affected the type of material to which you connect. Not wearing thermal energy as the primary energy is its own advantages in certain materials and thin, it's just less work for the workpiece thickness above 2.5 mm x 2.

Various forms of ultrasonic welding:
Wedge reed spot.
Leteral drive spot.
Overthung copuler spot.
Line.
Ring.
Continuous seam.

Explosive Welding (Explosive Welding or EXW)
Explosive Welding (Explosive Welding or EXW) was developed from the observation of one's days of World War I, there are fragments of a powerful bomb attached to the other metals fell. Carl's research conclude that shrapnel is attached because the effects of jet in the event of collision. The effects of jet capable of cleaning dirt on the surface of the object so that it contacts between atoms both objects and generate a strong enough.
Laser Welding.
In 1955, the physicists found laser beam, simply speaking rays produced at a particular wavelength and parallel, then enlarged, light is then focused. The heat generated at the focus point is very high. By the year 1970, the laser began to apply the base pad, as the laser beam can be accurately adjusted so that the laser welding very suitable for special equipment.

Laser welding can be used to weld objects with a thickness of 0.13 mm to 29mm at the sliding speeds ranging from 21 mm / sec to 1.2 mm / s. Issues arising pedestal pad as well as laser welding electron, the workpiece is very small rift between 0.03 to 0.15. Up at this time a lot of classification methods used in the welding field, is due to the agreement in terms of these things. In the conventional ways of classifying these at this time can be divided into two groups, namely the classification based on the work and the classification based on energy use.