A process for making iron, cobalt and/or nickel base alloys containing rhenium. The process involves melting together the components that form the alloys, at least one of the components being a rhenium master alloy having 30 to 70 wt % rhenium, then casting the resultant melt and allowing the melt to solidify. Possible difficulties such as the formation of rhenium heptoxide are avoided by using a master alloy containing (i) rhenium and (ii) iron, cobalt and/or nickel, instead of sintered rhenium as the rhenium source during the melting step.