Welding and Forming Processes: A Comprehensive Analysis

Welding Processes

Arc Welding

Unification of metals by the heat of an arc. An electrical arc is a discharge of electricity through a gap in a circuit, reaching temperatures of up to 10,000 °F (5500 °C).

Electric Arc Welding with Consumable Electrode

Shielded Metal Arc Welding

Process using a consumable electrode and involves a filler metal rod coated with chemical materials that provide a source of protection.

Gas Metal Arc Welding

The electrode is a consumable bare metal wire, and protection is provided by flooding the arc with gas.

Flux Cored Arc Welding

Process where the electrode is a consumable tube containing deoxidizing flux at its core.

Gas Metal Arc Welding (GMAW)

Uses a continuous consumable electrode, either flux cored wire or bare wire, with shielding gas.

Submerged Arc Welding

Uses a continuous consumable bare wire electrode. The electric arc is protected by a granular flux coverage.

Plasma Arc Welding

Uses a tungsten welding arc and gas, which directs a controlled plasma arc to the welding area. Temperature reaches 50,000 °F (28,999 °C).

Electric Arc Welding Using Non-Consumable Electrode

Gas Tungsten Arc Welding (GTAW)

Process that uses a non-consumable tungsten electrode and an inert gas to protect the arc.

Forming Processes

Deformation is a process that can be used for intermediate or final form in the metal.

Deep Drawing

Deep drawing is an extension of pressing, which gives a considerable third dimension through the side. Simple pressing is performed by pressing a piece of metal between a punch and a die.

Rolling

Process which reduces the thickness of the material by passing it between a pair of rollers.

Forging

The goal is to compress the material between a hammer or an anvil, and the final shape is obtained by rotating and moving the workpiece between blows.

Drawing

Process for the production of shapes in sheet metal. The sheets are stretched over shaped molds in which they deform to take the required profiles.

Extrusion

In this process, a billet or piece of metal is forced through a die using a piston. The stretched and extruded metal has a defined cross-section. There are two types of extrusion:

• Direct Extrusion - The plunger and the die are at opposite ends of the cylinder, and the material is pushed against and through the die.
• Indirect Extrusion - The die is attached at the end of a hollow plunger and is forced against the cylinder.

Wire Drawing

A metal rod is sharpened on one end and then is pulled through the tapered hole of a die.