A single 316L Stainless Steel welding seam, deposed on a 304L substrate plate using a GMAW source, is simulated using simufact version 2023.4. The 3D heat transfer model takes into account the added filler metal, the heat release during the solidification phase change and the heat losses by radiation and convection. The volumetric heat source is modeled by a Goldak double ellipsoid function. The rectangular weld bead shape of the added filler metal, commonly used in WAAM simulation, is analyzed in comparison with the near-to-reality convex weld bead shape. The results showed that the temperature profile of the rectangular weld bead shape only become near to these of the convex weld bead if a height correction, based on a filler material flow rate calculation, is made. Temperature evolution versus time showed also that with the height correction, the rectangular weld shape gives nearly the same results as the convex one.