Dendritic liquation in the ingots of complex nickel alloys remelted by electron beam

Effect of surfacing rate of 1-5 kg/min on dendritic liquation during electron beam remelting of the EP742 complex nickel alloy has been investigated. X-ray emission analysis as well as microhardness measurements have been applied to the problem under study. At the surfacing rate of 1 kg/min all the alloying elements are found to be distributed uniformly over the ingot volume due to columnar structure formation under speeded up heat-dissipation conditions. Increase in the surfacing rate up to 5 kg/min results in equiaxial grain zone formation and sharp liquation degree increase