ATOMIC DIFFUSION CONTROL DURING TEMPERING OF STEEL 20Cr11MoVNbNB

Studies were made of the effect of tempering at temperatures from 25 to 750℃ for 0.5 to100 h on changes of hardness,precipitated phase and its alloying element content as well asactivation energy of tempering for quenched steel 20Cr11MoVNbNB.Tempering of the steelat temperatures below 400℃ may be controlled by the diffusion of C atoms in α-Fe,andabove 400℃,by diffusion of Cr,also Mo or V,in α-Fe.