| 摘要 |
PROBLEM TO BE SOLVED: To improve the ductility of a rail head part and the used service life of the rail, for which the fining of an austenite structure is obtained without developing pro-eutectoid cementite structure and martensite structure, etc., giving the bad effect to the ductility, and high hardness and fine pearlite structure is obtained by controlling the temperature rising amount after the last-pass and further, performing the suitable heat-treatment with suitable temperature range and cooling speed after rolling from this temperature range, in the production of a high carbon-containing steel rail. SOLUTION: In the case of producing the rail from a steel slab for rolling the rail, containing > 0.85 to 1.40% C, in a finish-rolling in the range of 800-1,000°C of the rail head part surface temperature at the rolling time, accelerated cooling is performed from the temperature range, in which the temperature of final pass starting temperature +5 to 30°C to at least 600°C of the rail head part surface at 2-30°C/sec cooling speed, and thereafter, radiation-cooling is performed. Desirably, rolling is further performed, in which the finish-rolling is successively applied to≥2 passes, and the maximum time between rolling passes is made to be≤1 sec. COPYRIGHT: (C)2005,JPO&NCIPI |
