Study on Mechanical Properties of MAG Welding Joints of Steel Plates with Large Wall Thickness and Small Chamfer Angle

This paper presents experimental results of narrow gap butt welding of steel plates with greater thickness by using the Metal Active Gas (MAG) welding method. The mechanical properties of the welding joints were examined by metallographic method using the microhardness investigated in some specific sub-microstructure subzones, such as the weld center zone, heat-affected zone (HAZ), base metal region, and the boundary between the weld metal and the HAZ. The experiment’s results highlighted the graphical relation between the microhardness and the measuring distance in different subzones. The finding helps to forecast the quality and the load ability of the welding construction.