*2.2. Materials and Welding Parameters*

In order to acquire both partly and fully penetrated weld pools under the same welding parameters, 2 mm and 4 mm of size 150 mm by 150 mm S235JR (1.0038) steel plate were selected as the base material, the weld bead was located in the middle of the plate. The length of the weld bead was 120 mm. The filler wire of ER70S-6 (G42) mild steel with a diameter of 1.2 mm was used for welding. The chemical composition of the base material and filler wire are given in Table 1. A mixture of 82% Ar + 18% CO2 was used as a shielding gas, with a flow rate of 15 L/min. The travel speed was kept constant at 22 cm/min. The contact tip to workpiece distance (CTWD) was 20 mm. Welding conditions were selected that give an almost constant arc length, with an average voltage of approximately 20 V. The joint type was bead-on-plate. Welding parameters are listed in Table 2.



**Table 2.** Welding parameters.
