METHOD FOR HEAT TREATMENT OF STEEL RAIL Russian patent published in 2001 - IPC

FIELD: metallurgy, namely processes for making railway road rails of high-carbon or low-alloy steel. SUBSTANCE: method for heat treatment of rail made of standard steel and having head, web and foot comprises steps of realizing successive or simultaneous preliminary heating of each cross section of rail up to temperature exceeding that of metallurgical conversion termination due to heating steel in such a way that successively or simultaneously in each cross section of rail identical austenite structure of steel is provided; performing successive or simultaneous superheating of portion of each cross section of rail corresponding to its head in such a way that temperature of said portion of each cross section of rail is at least by 40 C higher than mean temperature value of portion of the same cross section of rail corresponding to its foot; performing successive or simultaneous cooling of each cross section of treated rail until temperature lower than that of metallurgical conversion termination of steel in order to provide fine-grain perlite structure in the whole cross section of rail; if necessary remaining rail for simultaneous or successive cooling in natural condition of each cross section of rail until temperature of environment. EFFECT: possibility for providing fine-grain perlite structure in the whole cross section of rail, distribution of inner residual mechanical stresses in such a way that to prevent propagation of lengthwise cracking in web of rail. 13 cl, 2 dwg