High temperature creep flow and damage properties of 9Cr1MoNbV steels: Base metal and weldment

High temperature creep flow and damage properties of 9Cr1MoNbV steel and weldment are investigated in the present study. First, an experimental database is built to compare both creep flow and damage properties of the base metal and the weldment. Metallurgical investigations before and after creep tests revealed that the microstructural state is responsible for the lower creep strength in the weldment. A simple analysis based on the description of the steady-state creep stage and on use of empirical lifetime prediction relationships is performed. It allows to predict the weldment creep lifetime without performing an extensive number of experiments.