Corrosion of steel remains a crucial issue in ship operation and maintenance. Although a variety of methods are implemented for inspection and monitoring of the damage caused by corrosion, there is still a considerable lack of understanding regarding essential aspects of the corrosion process and the factors influencing it. In this study, experimental data are presented to provide deeper insight into the corrosion of AH36 marine-grade steel and welded specimens of the same material under laboratory conditions. The specimens were characterized by Optical Microscopy and SEM techniques as well as hardness measurements. The electrochemical behavior of the specimens, immersed in 3.5% w/v sodium chloride aqueous solution for a three-month period, was investigated by DC corrosion techniques, and Electrochemical Impedance Spectroscopy and was correlated with mass loss measurements. The welded metal initially exhibits a higher corrosion rate (CR) compared to the base metal when exposed to the NaCl solution. However, after three months of immersion, they both reach a similar corrosion rate due to the formation of the corrosion product layers.