Resumen
The criterion of mechanical condition of steel, basing on interconnection of a limit of contact fatigue, a limit of mechanical fatigue, a ultimate strength and a hardness. The technique of an estimation of a mechanical condition of a rail steel is developed. Experimental researches of non-thermostrengthened rails after maintenance in conditions of the subway are executed. Character of distribution of hardness on a surface of rolling of the head of a rail is investigated, characteristic zones of its straining are fixed. Microstructural explorations of a material of rails in a superficial zone of contact to a wheel are executed. During the experiments validation of the developed criterion are received.