Creep behavior and microstructure of a 9Cr–3Co–3W martensitic steel

Microstructure evolution under long-term aging and creep was studied in a 9wt%Cr–3wt%Co–3wt%W martensitic steel at a temperature of 650 °C and stress ranging from 100 to 220 MPa with a step of 20 MPa. This steel exhibited creep strength breakdown at an applied stress of 160 MPa and a rupture time of 1703 h. However, this creep strength breakdown did not coincide with the transition from short-term creep conditions to long-term creep, because...