Fracture Characterization of Structural Steel S275JR Using Conventional CT Specimens, Mini-CT Specimens and Small Punch Specimens: A Comparison

Abstract Miniaturized specimens, such as mini-CT specimens and Small Punch (SP) specimens, are a solid alternative when characterizing the fracture behavior of structural materials but there are restrictions related to the amount of material available, irradiation issues or material inhomogeneities, among other possible concerns. Moreover, in ferritic-pearlitic steels, fracture characterization is of particular interest within the ductile-to-brittle transition zone (DBTZ), and it is often performed through the definition of the Reference Temperature (T0) and the Master Curve (MC) methodology. The use of mini-CT specimens has been validated in a number of steels used in the nuclear industry, but its application in other types of ferritic-pearlitic steels is very limited. In this regard, this work provides an overview of the fracture characterization results (T0) in structural steel S275JR, which have been obtained by using conventional standardized Compact-Tension (CT) specimens, mini-CT specimens and SP specimens. This steel is a low carbon non-alloyed steel which is widely used in civil engineering structures. Here, it is shown how, for this particular structural steel, the use of miniaturized specimens provides T0 estimations which are comparable to those values obtained from conventional larger specimens, and also that the MC approach accurately reflects the fracture behavior in the DBTZ.