FEM models are established for calculations of the temperature fields during cooling and the internal stress field of a medium-high carbon steel specimen after hard-face-welding(hardfacing) by using an electrode with lower carbon content. The martensite transformations in both welded metal and matrix are considered in the model for calculation of the internal stress field. The validity of these models was verified by the experimental results of temperature field, as well as the residual(internal) stress field, determined at the surface of the specimen.Based on the calculated results, the effect of martensite transformation points on the residual stress fields is analyzed.