The fabrication of vanadium base alloys as candidate fusion reactor materials

Abstract

An alloy fabrication program has been initiated at Argonne National Laboratory to provide suitable materials for the evaluation of vanadium base alloys in the United States Fusion Power Program. The initial phase of the work has focused on the V-Cr-Ti ternary system. Emphasis has been placed on minimizing impurity levels in the alloy feedstock constituents and on controlling these levels during subsequent processing operations.The effort includes evaluation of the effects of processing variables on the properties of the alloys. Consideration is given to processing techniques that are applicable to larger scale production.Fabrication of 6.8 kg of V-15Cr-5Ti alloy was carried out by dc arc casting of a number of 350-g ingots. This material was processed by consumable arc melting to yield a 5.9-cm-diameter ingot of the alloy. Further consumable arc melting produced a 9.7-cm-diameter ingot that was used at the start of hot working. This cast ingot was extruded at 1125°C, with stainless steel cladding, to give a 6.6 cm × 3.3 cm × 114.3 cm bar. By scaling down this operation, a 3.5 kg heat of V-10Cr-5Ti alloy was processed from a cast ingot that was 5.9 cm in diameter. Material from both alloys has been processed further by hot and cold rolling.