Method for inoculating or refining metal melts

In a method for inoculating or refining a metal by introducing an additive into a melt of the metal under high kinetic energy and wherein the melt is poured in the form of a stream from a crucible via a casting spout thereof, the improvement wherein said step of introducing is carried out with a magnesium or a magnesium alloy additive in molten form by blowing the molten additive into the melt stream with a carrier gas while the melt is being poured, at the location of the casting spout, by forming a spray of the molten additive with the carrier gas, which spray is laterally unrestricted, to dissolve the additive immediately into the metal melt in uniform dispersion, said melt being poured from the crucible into a stacked sand casting mold to produce piston rings and the composition of the melt being such as to produce cast iron piston rings containing spheres of graphite.