Why welded joint is more strong then base metal ?

Why welded joint is more strong then base metal ?

The joining of metals is an impotent part of the work in many industries. Technicians make use of many different metal joining techniques in order to ensure that the finished parts will posses the required strength.welding of steel is of particular importance to constructional engineers. most of the metal fabrication industries have adopted welding procedures as an efficient and economical means of joining two metal pieces permanent.

What is welding ?

Process of making a permanent joint by creating inter atomic bonds between two or more pieces of metal by using heat or heat and pressure (or) Welding also used as a means of repairing broken parts.

Applications : The welding extensively employed in the fabrication and erection of steel structures. Metal plates, rolled sections casting, forging, and other metal pieces are welded to produce desired shapes.

What is advantages of welding ?

• welded joint is more strong then base metal.
• Not costly and very portable.
• Any types similar or dissimilar metals can be welded.
• Weld ments are lighter and stronger.
• Joints are easier to inspect.

What is Dis-advantages of welding ?

• Requires skilled operator.
• Welding results in residual stresses and distortion of work pieces, there fore , it needs heat treatment to relieve internal stress.
• Requires edge preparation.
• Gives out harmful radiation and fumes
• The structure of welded joint is not same as the base metal.

Classification of welding :

Choice welding process depends on the following factors 

• Application.
• Joint design.
• Material.
• Thickness,size,shape.
• Operator skills.
• Cost.

                     Flow diagram of welding types