This paper presents an experimental study, which is performed on weld bead of the gas-tank element made of the low-alloy steel with the following chemical composition (% wt.): (C: 0.20, Si: 0.0079, Mn: 0.778, P: 0.0156, S: 0.058, Cr: 0.021, Al: 0.035, Cu: 0.012, Ni: 0.0075), and 3.3 mm of thick. This manufacturing process ends with a normalized annealing heat treatment at temperature of 920 $\pm$ 10°C. The purpose of this work is to study the effect of important parameter—the electrical voltage $V$. This welding is submerged arc welding under submerged arc-welding particle flux. The principle of the characterization taken into account consists in varying both the electrical voltage $V$, which is between 31 V and 36 V. As shown, this physical parameter directly influences the carbon content in the weld bead, the structural components and the mechanical properties ($\sigma$ and $HV_{0.3}$) of the steel under study.