Welding is one of the most effective ways to join the any metals and its popularity drives of economy
ease of performance, possibility of performance in everywhere .
In Welding the basic goal is the conformity of quality and properties of weld matal to the base metal. There are four important elements which affects the quality of weld metal and you need to adapt them to the special welding occasion and equipment.
1- Welding current or the Ampere which flows during the welding.
2- Arc welding Length which is the distance between the tip of Electrode to the surface of the base metal which has a direct relationship to Voltage of Arc.
3- The speed of Welding.
4- The Angle of electrode with the Surface of base Metal.
One of the most important questions which rises here is that these properties are applicable about the weld metal or it would be applicable to the Heat Affected Zone (HAZ)?
We have to emphasize the properties of Weld metal and Heat Affected Zone both are important and the surrounding area of welding must have the considerable solidity to have a good weld metal.
Some features which affect the weld metal and HAZ are as below:
Health of Weld metal:Weld metal with deficiencies such as porosity and impurities ،slag inclusion , lack of penetration and lack of fusion , …… couldn’t have the necessary features of a good weld metal.
Chemical Composition:
Different elements are effective in Weld metal solely or with the other elements at the same time even the percentage of the elements are important in this effects. For instance the effect of Mn in a little amount differs from high percentage of Mn in metals. Some elements are added to the weld metal deliberately and some elements enter the environment as the impurity.
Microscopic Structure:Chemical composition , welding condition and heat treatment Cycle can form Ferrite, perlite, bainite, martensite , austenite, …… and alters the amount and quantity of microscopic Structure of weld metal.
