For the estimation of fracture mechanics parameters of cracked weldment with mechanical heterogeneity, there exist equivalent yielding stress and equivalent strain hardening exponents in the vicinity of the crack tip keeping the assessment of fracture mechanics parameters of weldment in the same way as the homogeneous material. In this paper, the factors such as width of weld, matching property, stress condition, and the mechanical properties of base metal and weld metal affecting the equivalent yielding stress and equivalent strain hardening exponents are carefully studied. The results show that the width of weld and matching property of weldment have a strong effect on the equivalent parameters while the stress condition has little effect on the equivalent parameters. Furthermore, the two equivalent parameters change independently from each other.
