The interaction between a metal melt of two-liquid metal-oxide corium and reactor vessel steel has been experimentally studied as applied to the problem of melt retention in the vessel of a pressurized-water reactor (PWR) during a severe reactor accident with melting of the core. The experiments reproduced the conditions of a melt directly contacting the surface of the inner vessel, which had not previously been in contact with the melt, and a surface that was initially coated with a corium crust.