| 摘要 |
PROBLEM TO BE SOLVED: To homogenize the cooling rates at the head vertex central portion and the head vertex end portions of a rail while suppressing an investment cost and a running cost.SOLUTION: When a rail 1 is forcibly cooled by injecting a cooling medium to at least the head portion 11 of either a rail 1 hot-rolled to an austenite region temperature or higher, or a head 1 of the rail heated to the austenite region temperature or higher, the injection rate of the cooling medium is distributed in a direction perpendicular to the longitudinal direction of the rail 1 as to at least one of the head vertex surface or the head side surface. In the case where the injection quantity is distributed all over the head vertex surface, the injection rate is so distributed that it may be higher at the widthwise central portion than the widthwise end portions. In the case where the injection rate is distributed as to the head side surface, the cooling medium is so injected onto the widthwise end portion of the head vertex surface and the head side surface as that the injection rate of the lower portion of the head side surface may be larger than that of the higher portion.SELECTED DRAWING: Figure 1 |
