Impacts of torch moving on phase change and fluid flow in weld pool of SMAW

Shield metal arc welding (SMAW) has been widely applied in the field of engineering. Phase change performs important functions on weld pool geometry and determines weld quality. Welding torch, which is moved or not, has important effects on the phase change of weld pool and the elements distributions, which affects the weld quality. In this paper, phase change and elements distribution of welding process with torch trace of moving without swing and with e-type swing was simulated. The results show that the geometry of the weld pool under torch trace of moving without swing transfers from initial V-type to final O-type. At the ending of welding, the width of weld pool reaches 12 mm. The distance between center of each symmetrical vortexes and the center of weld pool is 3 mm. The distribution of element C is typical double peak trends and the peak value of its component is 0.0482 % appeared at the center of vortex. Using SMAW with e-type-swing torch moving, the distance of weldment diffusion is changed. The unsteady vortex has a great influence on the phase change in the weld pool. The distribution of elements is single-peaked characteristic. At the center of weld pool, the contents of C, Si, P and S are highest, which contents are 0.050 %, 0.270 %, 0.016 % and 0.010 %, respectively. But the contents of Mn, Mo, Ni and Cr at the same position are lowest, which contents are 1.121 %, 0.063 %, 0.062 % and 0.005 %. The comparison of the simulation and experimental results showed that the error range of their solid-liquid interface geometry is 3.03-4.83 %.