In this part, thermal finite element analysis(FEA) is conducted for the experiments in part 1. The molten area of base metals are analyzed by FEA results and compared with experimental ones. Temperature data from FEA results are used to calculate the IMC layer thickness analytically at the interface. IMC layer is established as a function of time and temperature when there is an interaction between solid steel and molten aluminum. The IMC layer thickness is obtained by cumulative computations using the time-temperature data from FEA results.