STUDY OF AGING BEHAVIOR OF Cu-Nb CONTAINING STEELS BY CREEP METHOD

A creep test was conducted on a Gleeble-1500 thermal simulator for monitoring the aging procedure of Cu-Nb ultra-low carbon steels with different contents of copper. The result indicated that during creep testing the occurrence of precipitation could make a plateau on the creep curve. The left- and right-hand ending points of the plateau can be defined as the precipitation start (Ps) and finish (Pf) times, respectively. The Pf is in coincidence with the peak time (tp) from hardness curve. The precipitation-time-temperature (PTT) diagrams of two steels were obtained.