Essay On Arc Welding

INTRODUCTION

Arc welding is a type of welding that uses a welding power supply to create an electric arc between an electrode and the base material to melt the metals at the welding point i.e. in arc welding the intense heat needed to melt the metal is produced by an electric arc. They can either use direct current or alternating current, and consumable or non-consumable electrode[1]. The arc is formed between the actual work piece and an electrode (stick or wire) that is manually or mechanically guided along the joint. The electrode can either be a rod in order to carry the current between the tip and the work piece, or it may be a rod or a wire that acts as a filler metal as well as conducts current. Most of the welding in the manufacture of steel products uses the second type of electrode[2]. The welding region is usually protected by some type of shielding gas, vapour or slag. Arc welding processes may be manual, semi-automatic or fully automated.

OBJECTIVE

Welding is an important aspect of manufacturing and production. From a simple cycle to huge vehicles and machines, they all go through the process of welding at some point, in their production phase.

The basic and main objective of this term paper is to have a better, deeper and more elaborate knowledge about arc welding, the concept behind welding, it’s procedure, types of arc welding, it’s uses and it’s importance.

Through this term paper we will try to have a better knowledge about the national and international works that are being carried under the topic of arc welding.

CONCEPT BEHIND WELDING

• Arc Welding Setup/Circuit:

The basic arc welding setup of an AC or DC source of current which is connected to the work ...

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...tip by an electric pinch propelling it to the molten pool.[3]

In case of consumable electrodes, the intense heat of the arc makes the tip of the electrode melt, detaching the molten droplets and transporting them to the work the arc column. A metal-arc is an arc welding system in which the electrode melts to form the weld. In certain welding, such as carbon or tungsten welding, a filler metal, which is a wire or a rod, is used and is melted into the joint.

In order to start an arc, only switching on the current with an electrically cold electrode is not sufficient. We need to have an ionised path so as to conduct electricity across a gap. There is a need to ignite the arc and for doing so either we supply an initial voltage, high enough to cause a discharge, or by touching the electrode to the work piece and withdrawing it as soon as the area of contact becomes hot.