Investigation of mechanical properties of low carbon steel weldments for different welding processes

Welding process is one of the joining methods of metals. It can be applied in the solid and fusion states. In the fusion state welding, the amount of the heat generated highly affects the quality of weldments from the mechanical properties point of view. To study this effect, three different fusion welding techniques were used to weld low carbon steel samples: Shield Metal Arc Welding (SMAW), Metal Inert Gas Welding (MIG), and Oxy Acetylene Welding (OAW). The mechanical properties of the welded joints were evaluated using mechanical tests such as tensile strength, hardness , and impact toughness. The results showed that MIG weldments have the best mechanical properties among the other welding techniques ,the reason is due to the amount of heat in the welding region in the (MIG) method is much less compared with other welding methods, which makes the size of the heat-affected zone (HAZ) less and thus obtaining smaller grains size in this area, which leads to an improvement mechanical characteristics of the welds.