ON THE SWERVING OF STRENGTH CURVE POR 2OCr11MoVNbNB STEEL

Study was made on the swerving of strength and hardness vs parameter P=T(20+lg t) curves of L-M for long-time aged 20Cr11MoVNbNB steel at 550, 600,650℃, where T being aging temperature in K and t being aging time in h. It seems obviously due to: (1) coarsening of mean size of principal precipitate M_(23)C_(6), (2) precipitation of Laves phase MoFe_2, (3) decrease of solution Mo content in matrix and (4) recovery and recrystallization occurred.