Taking lower speed gas tungsten arc welding of thin stainless steel plate as study case, two dimensional and symmetric Gaussian distribution mode of heat flux from the arc is applied to calculate the temperature field and thermal cycles. APDL of three or two dimensional array is effective to express the planar load of heat flux. The dynamic variation of welding temperature field and thermal cycles at different points are numerically simulated. The effect of the distribution parameter σq of Gaussian heat flux on the temperature profiles is investigated. The increasing of σ q causes the dropping of the maximum temperature, and this decreasing is clearer at the range of distance 0 -4 mm away from the weld centerline. Beyond the range with a distance 4 - 10 mm along the transverse direction, minor vibration of temperature occurs, but the temperature difference is limited. As the value of σq rises, the calculated weld pool shape gets contracted. The predicted weld widths at both top and bottom surfaces match well with the experimentally measured ones.
