Analysis of Different Types of Micro Grains in Stick Welded Mild Steel Plates

Abstract

Nowadays, arc welding is the most essential thing in every field. Therefore, researchers are focusing on the improvement of the quality of the arc welding. For that microstructure plays a major role in this work, mild steel plates were taken as workpiece material to do welding operation in stick welding. V-edge was prepared to conduct butt welding between the plates which has to be joined by application of 120 A current. After cooling, the microstructure of the welded specimen was observed. Importantly, two main constituents’ ferrite and pearlite were found mostly. Eight varieties of ferrite were analyzed in fusion zone and heat-affected zone. The primary ferrites were distinguished in the heat-affected zone and the Widmanstatten ferrites in fusion zone in between the dendritic structures. The primary ferrites have been more circular in nature and the Widmanstatten ferrites were columnar. The mechanical properties also vary due to the variation of ferrite structures. Pearlites were observed in between the ferrites with more percentage of carbon content which is the most distinguished feature of pearlite grains.