Microstructure Analysis of Arc Welded Mild Steel Plates

In order to perform arc welding, mild steel plates of variable thickness i.e. 5 mm, 6 mm and 8mm has been chosen as parent material. Total nine numbers of experiments were conducted by considering the two factors and three levels of design according to Taguchi method. The welding current and material thickness has been selected as variable input parameters with 5mm, 6 mm, 8mm level of material thickness and 90 A, 100A, 110A level of current respectively. The microstructure of the all the nine welded material has been analysed with the help of an optical microscope which is interfaced computer. The results of microstructure obtained from the microscopic investigation have been shown. The effect of current and material on the weldment microstructure is investigated. The result also shows that the coarse structure is formed in fusion zone and fine structure is formed in Heat affected region. (paper)