Abstract：Compared with traditional high strength IF steel,the recrystallization behavior during annealing process of a high C-Nb high strength IF steel was studied by using a Gleeble-1500 simulator,The effect of annealing temperature on microstructure and mechanical properties of the high C-Nb IF steel was also investigated using salt annealing method. Results show that the recrystallization finishing temperature of the high C-Nb IF steel is 20℃ higher than that of traditional high strength IF steel.After completely recrystallized,the ferrite grains of the steel have a small growing tendency,and the average grain sizes are much finer than that of traditional IF steel, with the same heatments. For the high C-Nb IF steel,the mixture of ferrite and bainite is obtained when salt bath annealing temperature is above 870℃.In order to obtain good comprehensive mechanical properties,the optimum annealing temperature of the high C-Nb high strength IF steel should be controled between 810℃ and 830℃.
2009, Vol. 19 
