We modified the content of rare-earth elements (REE) in the flux-cored wire used to produce welds of high-strength low-alloy (HSLA) steel. The effect of REE addition on the microstructure as well as on the mechanical and electrochemical properties of the welded metal (WM) was investigated. REE-modified welded metals show very different responses during electrochemical impedance spectroscopy and the potentiodynamic polarization tests. The results indicate that the addition of REE of 0.3 wt.% facilitates a more uniform microstructure and improves both mechanical properties and corrosion resistance in welded metals.