In view of the problem of uneven performance of railhead sections of pearlitic rail manufactured with existing technique and the poor performance of the pearlitic rail obtained, the invention provides a manufacturing method for high-carbon and high-strength and toughness pearlitic rail, including the following steps to: a. hot roll the steel billet into rail, with a final rolling temperature of 900-1000 C.; b. blow a cooling medium to the top surface of railhead, wherein, the two sides of railhead and the lower jaws on two sides of railhead when the center of top surface of rail is air-cooled to 800-850 C.; then air-cool the rail to room temperature after the center of top surface of rail is cooled to 480-530 C. By controlling the composition of steel and adopting a two-stage accelerated cooling, a high-carbon rail is produced with better strength and excellent toughness which is suitable for heavy-haul railway.

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. or lower so that the cooling rate at the head surface becomes 1 C./s or higher to 20 C./s or lower.

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. or lower so that the cooling rate at the head surface becomes 1 C./s or higher to 20 C./s or lower.

Provided is a manufacturing method for high-toughness and plasticity hypereutectoid rail, including: a. hot rolling the steel billet into rail; b. blowing a cooling medium to the top surface of railhead, wherein, the two sides of railhead and the lower jaws on the two sides of railhead after the center of top surface of rail is air-cooled to 800-850 C., and cooling the rail until the center temperature of the top surface is 520-550 C.; c. stop blowing the cooling medium to the lower jaws on the two sides of railhead, continue blowing the cooling medium to the top surface of railhead and the two sides of railhead, and air cool the rail to room temperature after the surface temperature of railhead is cooled to 430-480 C. The resulting hypereutectoid rail has higher toughness and plasticity than existing products, which is suitable for heavy-haul railway, especially for small radius curve sections.

Provided is a manufacturing method for high-toughness and plasticity hypereutectoid rail, including: a. hot rolling the steel billet into rail; b. blowing a cooling medium to the top surface of railhead, wherein, the two sides of railhead and the lower jaws on the two sides of railhead after the center of top surface of rail is air-cooled to 800-850 C., and cooling the rail until the center temperature of the top surface is 520-550 C.; c. stop blowing the cooling medium to the lower jaws on the two sides of railhead, continue blowing the cooling medium to the top surface of railhead and the two sides of railhead, and air cool the rail to room temperature after the surface temperature of railhead is cooled to 430-480 C. The resulting hypereutectoid rail has higher toughness and plasticity than existing products, which is suitable for heavy-haul railway, especially for small radius curve sections.

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.

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.

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.

A method of producing a steel material, wherein when a cooling apparatus having a plurality of cooling sections disposed side by side in a longitudinal direction of a steel material cools the steel material hot worked or cooled/reheated, the steel material is conveyed at a conveyance distance L.sub.o (m) satisfying Equation (1), in one direction along with the longitudinal direction of the steel material, in the cooling apparatus, wherein L.sub.o is defined as conveyance distance (m) of steel material, m is a natural number, and L.sub.h is defined as length (m) of cooling sections in longitudinal direction of steel material:

(m0.20)L.sub.hL.sub.o(m+0.20)L.sub.h(1).

A method of producing a steel material, wherein when a cooling apparatus having a plurality of cooling sections disposed side by side in a longitudinal direction of a steel material cools the steel material hot worked or cooled/reheated, the steel material is conveyed at a conveyance distance L.sub.o (m) satisfying Equation (1), in one direction along with the longitudinal direction of the steel material, in the cooling apparatus, wherein L.sub.o is defined as conveyance distance (m) of steel material, m is a natural number, and L.sub.h is defined as length (m) of cooling sections in longitudinal direction of steel material:

(m0.20)L.sub.hL.sub.o(m+0.20)L.sub.h(1).