Mechanical Characterization of Two Low-Activation Chromium Alloys in As-Received and Heat-Treated Conditions

In recent years, within the fusion long-term programmes, attention has been devoted to the characterization of Chromium (Cr) alloys, in view of their elevated corrosion resistance, low activation properties and high-temperature mechanical strength.

As part of the European Fusion Programme, an activity has been launched in 1999 with the aim of exploring the potential of Cr alloys as structural materials in fusion reactors, for example, as first wall or blanket materials. Recent investigations have focused attention on two commercially available materials: high-purity 99.7% Cr (DUCROPUR) and Cr alloyed with 5% Fe and 1%Y₂0₃ (DUCROLLOY), both of which have shown excellent low activation characteristics.

The mechanical properties of these two alloys, in both as-received and heat-treated conditions, have been characterized at SCK•CEN by means of tensile, instrumented impact and static three-point bend tests, using standard and sub-size specimens. Tensile tests have also been carried out on samples irradiated at 300 °C in the BR2 reactor in Mol up to an accumulated dose of about 0.5 dpa.