“…Consequently, the cooling rate gradient remains low giving the sufficient time for grain growth, therefore, the relatively large ferrite is observed, as shown on Figure 2(a). By increasing the welding current level up to 120 A, the peak temperature of HAZ is increased making the greater cooling rate gradient, therefore, the smaller (Figure 2c) and or even sharper grain ( Figure 2e) are noticed to be appeared indicating the presence of bainite phase which dominantly contributing the hard nature of steel [12,13] Figure 2 (b), (d), and (f) show the microstructural view of weld metal of sample welded with 80, 100, and 120 A describing the development of dark area along with the increase of welding current. This indicates that the carbon distribution played an important role to determine the weld metal property.…”