Application of T 33 -Stress to Predict the Lower Bound Fracture Toughness for Increasing the Test Specimen Thickness in the Transition Temperature Region

Abstract EN

This work was motivated by the fact that although fracture toughness of a material in the ductile-to-brittle transition temperature region J c exhibits the test specimen thickness (TST) effect on J c , frequently described as J c ∝ ( TST ) - 1 / 2 , experiences a contradiction that is deduced from this empirical formulation; that is, J c = 0 for large TST.

On the other hand, our previous works have showed that the TST effect on J c could be explained as a difference in the out-of-plane constraint and correlated with the out-of-plane T 33 -stress.

Thus, in this work, the TST effect on J c for the decommissioned Shoreham reactor vessel steel A533B was demonstrated from the standpoint of out-of-plane constraint.

The results validated that T 33 was effective for describing the J c decreasing tendency.

Because the Shoreham data included a lower bound J c for increasing TST, a new finding was made that T 33 successfully predicted the lower bound of J c with increasing TST.

This lower bound J c prediction with T 33 conquered the contradiction that the empirical J c ∝ ( TST ) - 1 / 2 predicts J c = 0 for large TST.