The temperature dependences of kinematic viscosity, electric resistance, density and surface tension of rail steel melts, produced by different methods are investigated. A comparative metallographic analysis of cast metal specimens (M76V, K76V, 72Kh2GSAF, E76V, E76), remelted and heated up to various temperatures, is carried out. The phase transformations of all specimens under heating and cooling are studied by the method of differential thermal analysis. The results testify a microinhomogeneous structure of liquid steel and it changing at achievement of critical temperature.