Creep crack growth and constraints in weldments

This paper is concerned with creep crack growth in the heat affected zone of a weldment (HAZ). The paper presents creep crack growth testing results obtained on modified 9Cr steel (P91). The test program is addressing creep crack growth in the heat affected zone by testing welded compact tension specimens in which the crack was growing along the intercritical zone. The constraint effect arising due to the presence of different material properties was studied numerically, and different methods for estimating a fracture mechanics parameter for the case of it welded specimen were investigated by means of finite element analysis.