METHOD FOR MANUFACTURING PEARLITE-BASED RAIL HAVING EXCELLENT SURFACE DAMAGE-RESISTANCE AND INTERNAL FATIGUE DAMAGE-RESISTANCE, AND RAIL

摘要

PROBLEM TO BE SOLVED: To improve the hardness of the face part and the inner part of a rail head, to reduce the difference in hardness between the face part and inner part of the rail head, and to enhance the surface damage resistance and internal fatigue damage-resistance by controlling the addition of V, Nb and N to hypereutectoid containing rail steel, and controlling a heat treatment condition of the rail head.;SOLUTION: In the pearlite-based rail manufacturing method, in the head part of a steel rail as rolled in the austenitic temperature range containing, by mass, 0.85-1.20% C, 0.10-2.00% Si, and 0.10-2.00% Mn, further containing one or two kinds of 0.01-0.20% V and 0.020-0.050% and the balance Fe with inevitable impurities, the face part of the rail head is subjected to accelerated cooling at the cooling rate of 1-20°C, the accelerated cooling is stopped when the temperature of the face part of the steel rail head reaches 650-450°C, the face part of the rail head is heated in a range of the maximum 20-200°C from the accelerated cooling stop temperature, maintained in this temperature range for 20-600 second, and then subjected to the natural cooling or the accelerated cooling to ≤ 300°C at the cooling rate of 1-10°C/sec.;COPYRIGHT: (C)2005,JPO&NCIPI