Creep damage evaluation for HAZ of Mod. 9Cr-lMo steels under multi-axial stress conditions

This study is concerned with the creep damage evaluation for fine grained heat affected zone (HAZ) of Mod. 9Cr-lMo steel. Circumferentially notched bar creep rupture tests have been conducted in order to examine the effect of multiaxial stress state on creep rupture and creep damage of the fined grained HAZ. The simulated fine grained HAZ has been used. Finite element predictions based on a continuum damage mechanics model with ductility exhaustion approach has been used to predict the creep rupture and the creep damage in the notched specimens. It is found that a ductility exhaustion approach provides very large creep damage which leads to too conservative prediction of creep life for notched specimens. © 2011 Published by Elsevier Ltd. Selection and peer-review under responsibility of ICM11