The fracture toughness of the different materials at the most
severe working conditions (−40 ◦ C) has been estimated using the
Master Curve Approach [27] and the corresponding Charpy values
(in terms of T27J ) [1]. For this purpose, Eq. (7) (corresponding to
Eq. 5.43, chapter 5, in FITNET FFS Procedure) has been used, which
provides a conservative estimation of the fracture toughness,
Kmat , from the corresponding Charpy T27J . This equation provides
the fracture toughness of the material within the Transition
Zone (between Lower Shelf and Upper Shelf) in certain steels
(i.e., ferritic). The chosen failure probability was Pf = 1% and the
results are shown in Table 5.