| 摘要 |
PURPOSE:To obtain a rail of superior abrasion resistance and damage resistance at all times by cooling the rail head part of alloy steel added with Mo, V, etc. heated to high temp. uniformly under induction heating. CONSTITUTION:Inductors 2 of an induction heater are placed in proximity with the side top surfaces vulnerable to cooling of the head part of a rail 1 which is cooled from high temp. at arbitrary intended rates, and if necessary, to the side lower surfaces, and induction current is induced to heat these parts. At this time, the rail 1 and the inductors 2 are moved relatively in the longitudinal direction of the rail. The rail head part is cooled uniformly while preventing local overcooling by such heat retaining control operation wherein the angle corner parts, that is, side top surfaces or side lower surfaces of the rail head part are heated continuously with the inductors in conformity with the cooling rates for the head top surface or head side surfaces lower than these. The rail head part obtained in this way is formed with the uniform structure layer of fine pearlite similar to that in the other parts from the surface parts in its angle corner parts to the inside, and is thereby improved of strength. |
