Forging can produce a piece that is stronger than an equivalent cast or machined part. As the metal is shaped during the forging process ,its internal grains deforms to follow the general shape of the part. As a result ,the grain is continuous through the part, giving rise to a piece with improved strength characteristics .
Some metal may be forged cold, but iron and steel are always hot forged. Hot forging prevents the work hardening that would result from cold forging, which would increase the difficulty of performing secondary machining operations on the piece. 2. Welding Operations :
There are two types of welding being done: * METAL INERT GAS WELDING ( MIG ):
It is a welding process in which an electric arc is formed between a consumable electrode wire electrode and a work piece metal, which heat the work piece metal, causing them to melt,and join. Along with a wire electrode a shielding gas is fed through the welding gun,which shields the process from contaminants in the air. The process can be semi –automatic or automatic. A constant voltage, direct current power source is most commonly used with mig ,but constant current systems ,as well as alternating current ,can be used. Mig is applied to steels because it allowed for lower welding time compared to the other welding processes.
It is most commonly industrial welding process, preferred for its versatility ,speed and the relative ease of adapting the process to robotic automation.
The basic necessary equipment is a welding gun, a wire feed unit, a welding power supply, an electrode wire, and a shielding gas supply . the control