Abstract
TheÁ¨¿transformation and microstructure development of deformed austenite during continuous cooling and isothermal annealing was studied to the Mn -Cr steels for car gear,in this paper. The experimental results show that the deformation could accelerate transformation to polygonal ferrite + pearlite, but its fuction is limited; PF +P structure could be produced only when the cooling rates were slow enough which is difficult to reach in the industrial conditions ; it would be feasible to introduce direct annealing process by which the hot forged gear blanks could be isothermally annealed without reheating process.