Welder World Blog

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Welding Machine is equipment, which is used to weld or joint two metals or alloys together using another metal component as filler. Usually structure-less metals and alloys are joint using welding machines to give them desired shape and make them sturdier than they would be if it were a single piece.

These machines are available in different sizes as per their utility. A large size machine would be used in a factory and a handy machine is available for domestic purpose. Types of machines that are available in the market vary from Arc welding machine, Fusion-welding machine, Plasma Cutting machine, Resistance welding machine, Solid State Welding machine and less known types are Induction and Thyristorised welding machines.

Among all the types, Arc type machines are the most efficient and effective. According to the type of material used to weld, they are broadly classified into three categories.

Common most is the Manual Metal Arc mechanism. The tool looks like a stick, which performs the function of a main electrode, and it is covered by a flux that prevents it from oxidization. With the help of electricity, the electrode melts itself continuously for welding the metal. This equipment is mostly used for small tasks. This kind of machine is usually used in construction industry, maintenance and repair of small metals, cutting and making holes in steel products and rebuilding fixtures.

Second form is a Metal Inert Gas mechanism which is a large bobbin like formation. It is a single piece of equipment that includes a mix of argon or helium gas or both used along with the heated electrode to camouflage the metal from rusting. This makes the task easy and quicker. Metal Inert Gas equipments are mainly used in shipbuilding, power plants, aerospace equipments, automobile industry, bridge constructions and refineries.

The third kind is Tungsten Inert Gas, which has a single electrode, and the protective material is provided by another resource. The electrode does not thaw out as it has an additional tool to give it protection. This type of mechanisms is used in large factories where it is impossible to use other type of welding machines. Principally, Tungsten Inert Gas machines are used in power plants, construction industry, aerospace industry and manufacturing industry for more robust and specialized welding.

Apart from these, other type of welding machines that are available in the market are:

Carbon Arc, which is used for welding alloy steel and water jet cutting.
Orbital or Tube Arc is used in casting, shipbuilding, automotive industry etc.
Plasma Arc is used for welding of surgical instruments, food industry, dairy industry etc.
Stud Arc is mostly utilised in fabrication and machining.
Submerged Arc is chiefly used in industrial welding and pipe welding.

Any industry usually uses a combination of any of the above machines as per requirement. Welding machines are easy to use but is a complex piece of machinery and hence should be operated under expert guidance.

Welding is the most economical and efficient way to join metals permanently. Welding is very important for our economy because more than 50% of the gross national product comes from welding. There are different kinds of welding. Some processes cause sparks and others do not require extra heat. Welding can be done for various purposes outdoors, indoors and underwater, outer space.

Welders are used for various industry groups. Some of industries where welding is used is agriculture, construction, mining, bulldozers, cranes, material handling equipment, food-processing machinery, papermaking and printing equipment, textiles and office machinery.

Welding is also used in fabricated metals like pressure vessels, heat exchangers, tanks, sheet metal, prefabricated metal buildings and ornamental work. Welding is also used for transportation purpose like shipbuilding, aircraft, spacecraft, railroads, automobiles, trucks, buses, trailers and associated equipment.

Welding is also done for primary metal industries which include steel mills, iron and steel foundries, smelting and refining plants. Another group is the electrical and electronic equipment companies.

Welding is a fusion process, in which metal parts are heated to the melting point and fused together, usually with a filler of the same material melted along with the parent material. There are many types of welding processes like Oxy-acetylene Gas Welding, Arc Welding, Tungsten Inert Gas (TIG) and Metal Inert Gas (MIG).

Arc welding is mostly used for structural steel welding. Electric current that flows through a high resistance air gap generates an intense arc with temperatures ranging from 6,000 to10, 000 degrees Fahrenheit. MIG welding are mostly preferred for industrial welding applications. The two basic inert gases used for MIG are Argon and Carbon dioxide. A mixture of 75% Argon and 25% carbon dioxide is also very common.

The shielding gas that is used in TIG is Helium. This process is considered most controllable and cleanest method of welding. TIG process can weld thin, light and dissimilar materials. Soldering and Brazing are the two most common methods of joining two metals. In Soldering and brazing, parent metal is heated and the filler metal is melted into the joint where it cools. Lead based filler metals are used in soldering and brass based filler metals are used in brazing.

Uneven heating and cooling in welding operations gives rise to significant residual stresses in the vicinity of the weld. The residual stresses and discontinuities in a weld have a significant influence on the fatigue life of a part. The fatigue part of a weld is often less than the base material. Residual stresses may be removed by annealing.

Welding is not suitable for all types of metals, as some materials, such as stainless steel can get cracks when overheated. Welding has become highly automatized over the last decade, and the use of welding robots is now common place in certain industries, such as automotive manufacturing plants

How do you train to be proficient in all the types of welding. Can you learn on the job or do you have do an apprenticeship?
What are the main employers? Is there much international work available?