Strengthening railroad rails by isothermal quenching to lower bainite

A method is proposed for the isothermal quenching of rails to lower bainite with the use of cold water as the quenching medium. The cooling capacity of the water is reduced by the pulsed feed of individual portions of water to the surface of the rail head in a regime which keeps the temperature of the rail surface within the temperature range of the bainite transformation. The replacement of conventional steel with a pearlitic structure by bainitic steel improves the wear resistance of rails. The new quenching technology makes use of an environmentally clean quenching medium and forms a favorable residual-stress diagram that improves the durability of rails.