Coating is done on the materials to reduce the high temperature thermal fatigue, erosion, and formation of oxides. The history of stress intensity factor of the cracked body for different crack lengths is obtained by a closed-form integration of the stress field, using Duhamel's theory with principle of superposition and appropriate weight functions. Numerical study of thermal stresses and thermal stress intensity factor in a coated stainless steel plate was done by using FEM based software ABAQUS in this work.