Effects of electro-slag remelting on inclusion formation and impact property of reduced activation ferritic/martensitic steels

Abstract

The effects of the second refining process, Electro-Slag Remelting (ESR), were investigated on Ta rich inclusion formation in the Vacuum Induction Melted (VIM) Reduced Activation Ferritic/Martensitic steel (RAFM), F82H (Fe-8Cr-2W-V-Ta). The Ta rich oxides such as TaOx and TaO x-Al2O3 are major inclusion in VIMed F82H, and those were correlated with the reduction of the Charpy impact property, as those were found at the crack initiation points. It was revealed that the ESR process was effective on removing those Ta rich oxides. On the other hand, ESR process increased MnS and Al2O3 instead, and these inclusions were found at the crack initiation points. These could explain the little difference on Ductile-Brittle Transition Temperature (DBTT) of as-VIMed and ESRed F82H. © 2008 The Japan Institute of Metals.