Strength mis-match effect on R-curve behaviour of austenitic steel welds

摘要

This paper deals with the influence of yield strength mis-match on crack resistance curves obtained from homogeneous and electron beam welded bimaterial SENB specimens out of two austenitic steels. CTOD ((delta)(sub 5)), standard CTOD ((delta)(sub BS)) and J(sub CMOD) R-curves were used to characterize the fracture toughness. The R-curves of the bimaterial specimens are compared with those obtained for homogeneous material. The mis-match-factor M was 1.25 or 0.80 and specimens with shallow (a/W=0.15) and deep (a/W=0.5) cracks were tested. The CTOD ((delta)(sub 5)), CTOD ((delta)(sub BS)) and J(sub CMOD) R-curves of the specimens investigated were generally independent of the mis-match configuration. The shallow cracked specimens showed significantly steeper R-curves than the deep cracked specimens in the case of CTOD ((delta)(sub BS)) and J(sub CMOD) as fracture parameter, whereas the CTOD ((delta)(sub 5)) R-curves were nearly identical. (orig.)