Abstract: A rail comprises a predetermined chemical composition. In a hardness distribution in a region from a rail head surface to a depth of 16.0 mm, a part having higher hardness than V1 that is minimum hardness in a first internal region is present in a second internal region, and hardness of the rail head surface is HBW 400 to 520 and average hardness in the region from the rail head surface to the depth of 16.0 mm is HBW 350 or more.

Abstract: Rail-manufacturing equipment that performs forced cooling on at least a head of a hot rail hot-rolled at or heated to the austenite region temperature or higher. The rail-manufacturing equipment includes a head-cooling header configured to jet a cooling medium toward the head of the rail, a head thermometer configured to measure surface temperature of the head of the rail, and a controller configured to adjust jet of the cooling medium from the head-cooling header. The controller includes a temperature-monitoring unit configured to monitor measurement results by the head thermometer during the forced cooling, and a cooling-rate controller.

Abstract: A rail-manufacturing method according to the present invention performs forced cooling on at least a head of a hot rail hot-rolled at or heated to the austenite region temperature or higher. The forced cooling is performed for 10 seconds from start of the forced cooling so that the cooling rate at the head surface becomes 1° C./s or higher to 20° C./s or lower, the forced cooling is performed after a lapse of 10 seconds from the start of the forced cooling until heat generation during transformation begins in the head surface so that the cooling rate at the head surface becomes 1° C./s or higher to 5° C./s or lower, the forced cooling is performed during transformation from beginning to end of the heat generation during transformation so that the cooling rate at the head surface becomes lower than 1° C./s or the temperature-rising rate becomes 5° C./s or lower, and the forced cooling is performed after the end of the heat generation during transformation until the rail-head surface temperature becomes 450° C.

Abstract: A pearlitic rail includes a composition including in % by mass: 0.70% to 0.90% of C; 0.1% to 1.5% of Si; 0.01% to 1.5% of Mn; 0.001% to 0.035% of P; 0.0005% to 0.030% of S; 0.1% to 2.0% of Cr, remainder of the composition consisting of Fe and inevitable impurities. Surface hardness of a rail top is not less than HB 430, and hardness at a depth of 25 mm from a surface of the rail top is not less than HB 410.

Abstract: Rail manufacturing method performs, on at least a head of the rail that is hot after hot-rolled at an austenite region temperature or higher or after heated to the austenite region temperature or higher, forced cooling: for 10 seconds from start of the forced cooling so that a cooling rate at a surface of the head becomes 1° C./s to 20° C./s; during a period after a lapse of 10 seconds from the start until heat generation during transformation begins at the surface so that the cooling rate becomes 1° C./s to 5° C./s; during transformation from beginning to end of the heat generation during transformation so that the cooling rate becomes lower than 1° C./s or a temperature-rising rate becomes 5° C./s or lower; and during a period after the end of the heat generation during transformation until temperature at the surface becomes 450° C. or lower so that the cooling rate becomes 1° C./s to 20° C./s.

Abstract: A method and an apparatus for manufacturing a rail having high ductility in both a head portion and a foot portion. A heated steel rail material is hot-rolled, the temperature is adjusted by cooling the hot-rolled steel rail material, the steel rail material subjected to the temperature adjustment is processed into a rail shape by means of temperature-adjusted rolling at an area reduction ratio of 20% or more, and, in adjusting the temperature of the steel rail material, the surface portions of the steel rail material corresponding to a head portion and a foot portion of the rail shape so that the temperatures of the surface portions reach 500° C. or more and 1,000° C. or less.

Abstract: A pearlitic rail includes a composition including in % by mass: 0.70% to 0.90% of C; 0.1% to 1.5% of Si; 0.01% to 1.5% of Mn; 0.001% to 0.035% of P; 0.0005% to 0.030% of S; 0.1% to 2.0% of Cr, remainder of the composition consisting of Fe and inevitable impurities. Surface hardness of a rail top is not less than HB 430, and hardness at a depth of 25 mm from a surface of the rail top is not less than HB 410.

Abstract: Rail manufacturing method performs, on at least a head of the rail that is hot after hot-rolled at an austenite region temperature or higher or after heated to the austenite region temperature or higher, forced cooling: for 10 seconds from start of the forced cooling so that a cooling rate at a surface of the head becomes 1° C./s to 20° C./s; during a period after a lapse of 10 seconds from the start until heat generation during transformation begins at the surface so that the cooling rate becomes 1° C./s to 5° C./s; during transformation from beginning to end of the heat generation during transformation so that the cooling rate becomes lower than 1° C./s or a temperature-rising rate becomes 5° C./s or lower; and during a period after the end of the heat generation during transformation until temperature at the surface becomes 450° C. or lower so that the cooling rate becomes 1° C./s to 20° C./s.