Welding can easily defined as process for joining different materials whether they are made of the same or different kinds of metals. Though this process is mostly used to join metals and their alloys it is also used to join different kinds of thermoplastics. The welding process consists of a number of processes in which the materials to be welded are joined together by the application of heat. To know more about Machinery Manufacturing, visit us now.
As early mentioned the most essential element for this joining process is heat. Without it welding cannot be done. There are many types of welding. In some methods the application of pressure is also essential. It is one of the most used processes in manufacturing whether it is cars, planes, electronic equipments or anything solid. Welding was invented in the early 1900's and played a big role in post industrial revolution.
Welding processes are classified into:
Gas welding: This is the most used method of joining metals in small-scale industries. Here a mixture of Oxygen and Acetylene is burned to attain the high temperature required for the process.
Arc Welding: here the heat required for melting the metals is generated by means of an electric arc. The most commonly used arc welding method is TIG (Tungsten Inert Gas).
Resistance Welding: In this process the heat required to melt the material is obtained though the resistance offered by that material to the flow of electric current.
Advantages:
A good joint created though this process is as strong as the base metal
General welding equipment is not so costly
Portable welding equipments are available
Welding permits considerable freedom in design
A large number of metals/alloys both similar and dissimilar can be joined by welding
Disadvantages:
Though manufacturing is almost impossible without this process, it has several disadvantages.
This process creates harmful radiations in the form of light. Ultraviolet rays produced during the welding processes are harmful to the naked eye.
If not done properly the material may get distorted. Also residual stresses can be created in the materials which can affect the strength of the welded joint.
Jigs and fixtures are generally required to hold and position in the parts to be welded.
Edge preparation of the work pieces is generally required before joining them.
A skilled worker is a must to produce a good welding job.
The heat produced in the process causes metallurgical changes. The structure of the welded joint is not the same as that of the parent metal.
A welded joint, for many reasons, needs stress-relief heat-treatment.