Creep strength breakdown and microstructure evolution in a 3%Co modified P92 steel

Microstructure and hardness in the grip and gage sections of ruptured 3%Со modified P92 steel specimens were examined after creep tests under applied stresses ranging from 200 to 100 MPa at T=650 °C. Under long-term aging, the depletion of W from solid solution leads to precipitation of the Laves phase. In addition, coarsening of MX carbonitrides occurs after 34 h of aging. The final dimensions of these particles are independent of further aging...