Based on three-dimension transient heat diffusion equation a FEM model was developed to simulate coupled thermo-mechanical deformation effects on temperature behavior for four alloys steel during turning process . Alloys used as a workpiece were AISI 1045, AISI 1030, AISI 4340 and AISI 4140, parameters such as cutting speed, feed rate were changed to explore their effect on temperature behavior. The results show that Finite element method is a successful technique to perform analysis to estimate cutting temperatures, a possibility of developing temperature forms adequately representing metal cutting temperature as a Polynomial models of third, fourth and fifth degree with time that give steady state temperature and for the four alloys steel used and different operation conditions. All alloys have a sever increasing temperature with increasing feed rate, while it looks less sharp with increasing cutting speed .Also the ratio of the number of nodes have maximum temperature for any operating conditions and any alloy used with respect to the total number of nodes is less than 1%.