Vanadium alloys – overview and recent results

This paper reviews recent progress in research on vanadium alloys with emphasis on V–4Cr–4Ti as a reference composition. New high purity V–4Cr–4Ti ingots and products (NIFS-HEATs) were made. The improved purity of the alloys made a practical demonstration of enhanced feasibility of recycling as a method of handling after use in fusion reactors. Significant progress has been made in the understanding of physical metallurgy of V–4Cr–4Ti and effects of O, N and C on the alloy properties such as low and high temperature mechanical properties, welding properties and low temperature irradiation effects, by means of including the comparison of various large heats and model alloys with different impurity levels. The effects of other trace impurities on some of the properties are also discussed. Other current efforts to characterize V–4Cr–4Ti, to improve its properties and to explore advanced vanadium alloys are reviewed. Issues remaining for the future investigations are discussed.