Hot cracking susceptibility of F82H with controlled Ta content

An important issue in current fusion materials research is finalizing the detailed manufacturing specification for ITER test blanket modules. The objective of this study is to clarify Ta effects of the hot cracking susceptibility of welds in F82H steels with controlled Ta contents up to 0.14%. Hot cracking susceptibility was evaluated with transverse-Varestraint testing. Hot cracks that occurred in the weld bead during the test were mainly solidification cracks. Maximum length slightly increased with increased Ta content. On the basis of the brittleness temperature range (BTR), evaluated by measuring maximum crack length and welding thermal cycle the BTR was slightly wider due to the increase in Ta content. However, the value of the temperature ranges was about 10 K. The hot cracking susceptibility of F82H steel was the same or better than commercial steels.