In this study, an experimental investigation of HSLA AH40-FCA (Fatigue Crack Arrester) steel, used in marine applications, was carried out. Plates 13 mm thick were welded using FCAW-G technique and a six-D.O.F. robotic arm. Two different welding heat inputs were selected -among several bead on plate trials of different welding parameters- while the resulting weld bead geometry and dilution was studied. Fully metallographic study was performed, in butt welds, including optical and electronic microscopy and hardness testing followed by the investigation of the mechanical response of the welds via residual stress measurements, by the proposed blind-hole-drilling technique and tensile testing. Extensive experimental data were recorded leading to concluding remarks concerning the two different heat inputs.