Provided is a rail that is effective in improving wear resistance and rolling contact fatigue (RCF) resistance. The rail has a metallic structure including a pearlitic structure and a structure other than the pearlitic structure in a surface layer from a surface of a rail head to a depth of at least 0.5 mm, where the pearlitic structure has Vickers hardness of 420 HV or more and 520 HV or less, and the structure other than the pearlitic structure has Vickers hardness of 350 HV or more and 420 HV or less.

The present invention relates to a rail which has a predetermined chemical composition and in which at least 90% of a metallographic structure from an outer surface of the rail bottom portion, as the origin, to a depth of 5 mm is a pearlite structure, a surface hardness HC of a foot-bottom central portion is in a range of Hv 360 to 500, a surface hardness HE of a foot-edge portion is in a range of Hv 260 to 315, and HC, HE, and a surface hardness HM of a middle portion positioned between the foot-bottom central portion and the foot-edge portion satisfy HC≧HM≧HE.

A welded rail according to an aspect of the present invention includes: a plurality of rail portions having a head portion and a web portion and having a height h; and a welded joint portion that joins the rail portions together, in which the rail portion has a predetermined chemical composition, a HAZ width of the welded joint portion is 60 mm or less, in a region of 0 to (⅔)×h from a head top portion outer surface in a cross section of the welded joint portion which is parallel to a longitudinal direction and an up-down direction of the welded rail and passes through a center of the welded joint portion and of ±5 mm in the longitudinal direction from a welding center, an area ratio of a martensite structure is 0.0006% or more and 0.1000% or less, and in the region, the number of martensite structures having a grain size of 20 to 200 μm is 3 to 80.

A welded rail according to an aspect of the present invention includes: a plurality of rail portions having a head portion and a web portion and having a height h; and a welded joint portion that joins the rail portions together, in which the rail portion has a predetermined chemical composition, a HAZ width of the welded joint portion is 60 mm or less, in a region of 0 to (⅔)×h from a head top portion outer surface in a cross section of the welded joint portion which is parallel to a longitudinal direction and an up-down direction of the welded rail and passes through a center of the welded joint portion and of ±5 mm in the longitudinal direction from a welding center, an area ratio of a martensite structure is 0.0006% or more and 0.1000% or less, and in the region, the number of martensite structures having a grain size of 20 to 200 μm is 3 to 80.

A rail fastening system (10) comprises a base plate (12) configured to sit on a support (14) and having a first recess 16 for receiving a length of a rail (18). The system (10) also includes a plurality of spring clips (20i) and (20t) arranged to clamp the base plate (12) between the rail (18) and the support (14); and in doing so fasten the rail (18) to the support (14). A resilient rail pad (21) may be placed in the recess (16) prior to the recess receiving the rail (18), so that the rail (18) sits on top of the rail pad (21). The plate (12) is not secured to the support before application of the clips. The clips are applied by pushing them over the base plate in direction perpendicular to the extent of the rail.

A rail fastening system (10) comprises a base plate (12) configured to sit on a support (14) and having a first recess 16 for receiving a length of a rail (18). The system (10) also includes a plurality of spring clips (20i) and (20t) arranged to clamp the base plate (12) between the rail (18) and the support (14); and in doing so fasten the rail (18) to the support (14). A resilient rail pad (21) may be placed in the recess (16) prior to the recess receiving the rail (18), so that the rail (18) sits on top of the rail pad (21). The plate (12) is not secured to the support before application of the clips. The clips are applied by pushing them over the base plate in direction perpendicular to the extent of the rail.

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.

According to one aspect of the present invention, what is provided is a rail including, by mass %: C: 0.75% to 1.20%; Si: 0.10% to 2.00%; Mn: 0.10% to 2.00%; Cr: 0.10% to 1.20%; V: 0.010% to 0.200%; N: 0.0030% to 0.0200%; P≤0.0250%; S≤0.0250%; Mo: 0% to 0.50%, Co: 0% to 1.00%; B: 0% to 0.0050%; Cu: 0% to 1.00%; Ni: 0% to 1.00%; Nb: 0% to 0.0500%; Ti: 0% to 0.0500%; Mg: 0% to 0.0200%; Ca: 0% to 0.0200%; REM: 0% to 0.0500%; Zr: 0% to 0.0200%; Al: 0% to 1.00%; and a remainder consisting of Fe and impurities, in which a structure ranging from an outer surface of a head portion as an origin to a depth of 25 mm includes 95% or greater of a pearlite structure by area ratio, the hardness of the structure is in a range of Hv 360 to 500, and in ferrite of the pearlite structure at a position at a depth of 25 mm from the outer surface of the head portion as the origin, the number density of a V nitride having a grain size of 0.5 to 4.0 nm and including Cr is in a range of 1.0×10.sup.17 to 5.0×10.sup.17 cm.sup.−3.

According to one aspect of the present invention, what is provided is a rail including, by mass %: C: 0.75% to 1.20%; Si: 0.10% to 2.00%; Mn: 0.10% to 2.00%; Cr: 0.10% to 1.20%; V: 0.010% to 0.200%; N: 0.0030% to 0.0200%; P≤0.0250%; S≤0.0250%; Mo: 0% to 0.50%, Co: 0% to 1.00%; B: 0% to 0.0050%; Cu: 0% to 1.00%; Ni: 0% to 1.00%; Nb: 0% to 0.0500%; Ti: 0% to 0.0500%; Mg: 0% to 0.0200%; Ca: 0% to 0.0200%; REM: 0% to 0.0500%; Zr: 0% to 0.0200%; Al: 0% to 1.00%; and a remainder consisting of Fe and impurities, in which a structure ranging from an outer surface of a head portion as an origin to a depth of 25 mm includes 95% or greater of a pearlite structure by area ratio, the hardness of the structure is in a range of Hv 360 to 500, and in ferrite of the pearlite structure at a position at a depth of 25 mm from the outer surface of the head portion as the origin, the number density of a V nitride having a grain size of 0.5 to 4.0 nm and including Cr is in a range of 1.0×10.sup.17 to 5.0×10.sup.17 cm.sup.−3.