Technical background of welding:-
In all welding joint processes heat is applied to or produced at the joint and heated surfaces are brought into close contact, as result the joint surfaces to grow together into single body.
Now we will see what happen during this growing up together process. It is we all known that the matter is made of molecules which in turn into atom. The atoms of molecules are become active when the temperature of material reaches absolute zero (-2730C). At that time the molecules are moves with vibratory motion. In the higher temperature the vibratory motions of atoms is greater. During welding temperature it is sufficient to allow the atoms to make a bridge for the closely contacting surfaces. Thus there is an exchange of atoms among the molecules of the surfaces to be joined. Through this exchange of molecules of one surface interlock with adjacent other surface and this process we get weld joint.
In all welding joint processes heat is applied to or produced at the joint and heated surfaces are brought into close contact, as result the joint surfaces to grow together into single body.
Now we will see what happen during this growing up together process. It is we all known that the matter is made of molecules which in turn into atom. The atoms of molecules are become active when the temperature of material reaches absolute zero (-2730C). At that time the molecules are moves with vibratory motion. In the higher temperature the vibratory motions of atoms is greater. During welding temperature it is sufficient to allow the atoms to make a bridge for the closely contacting surfaces. Thus there is an exchange of atoms among the molecules of the surfaces to be joined. Through this exchange of molecules of one surface interlock with adjacent other surface and this process we get weld joint.
Short history of welding:
There are many different types of welding process in the welding history. The term welding, whose origin is identical with that of the word well in the sense of welling or boiling up. In the previous time known to have been familiar to some extent with the blowpipe or flame torch, but there was no record of their having ever applied it to the joining of metal by fusion process. The water-gas welding process was applied in the end of 19th century. The flame which is produced from water-gas replaced the blacksmith s hearth as a mean of heating the metal and welded the metal but this is first welding. Another type of welding is the more modern types the termed cast-welding. In this method the molten metal pouring into a mould which has runner at the point where the casting had failed to flow or wherever there was a fractured place. The molten iron poured in until it was fluid everywhere around the edge of the job and runner was stopped up, then the iron was allowed to cold in the mould. This welding process can be said modern fusion weld process, but this is slightly high cost process than other types of welding.
At that time the oxy-acetylene welding process discovering was the most vital importance invention in the welding history. That awardable invention gone to Mr. Edmund Davy in 1836. This type of welding discovery was known to chemists a long time before it became a factor of economic importance to the world.
Willson and Moisson had developed a method of making calcium carbide(CaC2) in the year of 1891. In 1895 a Frenchman had discovered the another type of welding process that equal parts of acetylene and oxygen burned together gave a higher temperature.
Another welding had been happening in 1881 by Mr. de Meritens. During his experimental works he faced with the necessity of joining together certain parts of electrical storage batteries. He placed the work-piece on a table and it connected with the positive pole of the source of current , the other pole connected a carbon rod which has kept on operator hand. Then he strike on the work, at that time first produced a arc and some heat was generated. Finally he made a fused the metallic lead of battery plate. The first job lead container which was used for some chemical container was produced with this type of arc welding process.
Elihu Thomson had made first electric welding machine patent in the year of 1886, which was big type of welding machine. His process was usually called butt-joint welding. He had also modify the other welding system later because the jaw which was used for griping the job the piece got too much hot. So he developed water cooled jaw system.