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.

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.

The present invention discloses a method for heat treatment of hypereutectoid steel rail, including the following steps: holding the temperature of the steel rail of which temperature is above 900° C. after finish rolling, conducting a first cooling stage for the steel rail at the first cooling speed after the temperature holding to reduce the temperature of railhead surface layer of the steel rail to 700-750° C., conducting a second cooling stage for the steel rail at the second cooling speed to reduce the temperature of railhead surface layer of the steel rail to 550° C., conducting a third cooling stage for the steel rail at the third cooling speed to reduce the temperature of railhead surface layer of the steel rail to 450° C. or less, and continuing to cool the steel rail in the air. While obtaining good tensile property, the steel rail treated by the method for heat treatment provided by the present invention can effectively reduce secondary cementite and have excellent resistance to abrasion and contact fatigue. The product is particularly suitable for heavy rails.

The present invention discloses a method for heat treatment of hypereutectoid steel rail, including the following steps: holding the temperature of the steel rail of which temperature is above 900° C. after finish rolling, conducting a first cooling stage for the steel rail at the first cooling speed after the temperature holding to reduce the temperature of railhead surface layer of the steel rail to 700-750° C., conducting a second cooling stage for the steel rail at the second cooling speed to reduce the temperature of railhead surface layer of the steel rail to 550° C., conducting a third cooling stage for the steel rail at the third cooling speed to reduce the temperature of railhead surface layer of the steel rail to 450° C. or less, and continuing to cool the steel rail in the air. While obtaining good tensile property, the steel rail treated by the method for heat treatment provided by the present invention can effectively reduce secondary cementite and have excellent resistance to abrasion and contact fatigue. The product is particularly suitable for heavy rails.

A manufacturing method and a manufacturing apparatus for a head hardened rail to which various alloy elements are added and which is excellent in hardness and toughness of a head portion surface layer. The method includes, when forcibly cooling at least a head portion of a hot-rolled rail or a heated rail, starting the forcible cooling from a state where a surface temperature of the head portion of the rail is not less than an austenite range temperature, and performing the forcible cooling at a cooling rate of 10° C./sec or more until the surface temperature reaches 500° C. or more and 700° C. or less after the forcible cooling is started.

A manufacturing method and a manufacturing apparatus for a head hardened rail to which various alloy elements are added and which is excellent in hardness and toughness of a head portion surface layer. The method includes, when forcibly cooling at least a head portion of a hot-rolled rail or a heated rail, starting the forcible cooling from a state where a surface temperature of the head portion of the rail is not less than an austenite range temperature, and performing the forcible cooling at a cooling rate of 10° C./sec or more until the surface temperature reaches 500° C. or more and 700° C. or less after the forcible cooling is started.

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.

Provided is a method for producing a rail, with which the sweep in the height direction of a rail before straightening can be suppressed when producing standard rails specified in JIS E 1101. The method includes subjecting a bloom having a chemical composition containing, in mass %, C: 0.60% or more and 0.85% or less, Si: 0.10% or more and 1.00% or less, and Mn: 0.10% or more and 1.30% or less, with the balance being Fe and inevitable impurities, to hot rolling to obtain a rail, subjecting the rail to accelerated cooling under conditions where a cooling start temperature T1 of rail head is 750° C. or higher and 850° C. or lower, a cooling stop temperature T2 of rail head is higher than 700 ° C., and T1−T2 is 20 ° C. or more, and then allowing the rail to be naturally cooled.

There are provided an apparatus for cooling a rail and a method for manufacturing a rail, capable of inexpensively manufacturing a rail with high hardness and high toughness. The apparatus for cooling a rail, configured to jet a cooling medium to the head portion and foot portion of a rail in an austenite temperature range to forcibly cool the rail, includes: a first cooling unit including plural first cooling headers configured to jet the cooling medium as gas to the head top face and head side of the head portion, and first driving units configured to move at least one first cooling header of the plural first cooling headers to change the jet distance of the cooling medium jetted from the first cooling header; and a second cooling unit including a second cooling header configured to jet the cooling medium as gas to the foot portion.

There are provided an apparatus for cooling a rail and a method for manufacturing a rail, capable of inexpensively manufacturing a rail with high hardness and high toughness. The apparatus for cooling a rail, configured to jet a cooling medium to the head portion and foot portion of a rail in an austenite temperature range to forcibly cool the rail, includes: a first cooling unit including plural first cooling headers configured to jet the cooling medium as gas to the head top face and head side of the head portion, and first driving units configured to move at least one first cooling header of the plural first cooling headers to change the jet distance of the cooling medium jetted from the first cooling header; and a second cooling unit including a second cooling header configured to jet the cooling medium as gas to the foot portion.