A finite element based model was used to simulate the thermal and mechanical response of a simple geometry TIG welded joint, validated through experiments. TIG welding experiments were carried out to produce butt welds in Inconel 718 sheets of thickness 3.2 mm, followed by heat treatment. Transient temperature and strain measurements were performed during welding; residual stress measurements were carried out after welding and after heat treatment. Calculated and measured welding temperature histories, strains and residual stresses were compared. The effect of buckling occurrence on the sensitivity of the model is noted.