Production manner null of the bainitic steel rail which is superior in resistance surface damage

摘要

PURPOSE: To produce a bainitic steel with surface damage resistance for rapid transit railway. ;CONSTITUTION: A steel, which has a composition containing 0.15-0.45% C, 0.15-1.00% Si, 0.32-2.00% Mn, and 0.20-2.00% Cr and containing, besides the above, one or ≥2 elements among Mo, Cu, Ni, V, Nb, and B, if necessary, is used. The bainitic steel rail excellent in surface damage resistance can be produced by subjecting a high temp. rail having a temperature not lower than γ-region temp., after the completion of hot rolling or after heating for the purpose of heat treatment, to accelerated cooling at a rate of (1 to 10)°C/sec from the side face of a railhead and regulating the hardness at the surface of a railhead corner part to ≥Hv300. By this method, dark spot damage occurring in a rail for rapid transit railway, in a straight line section, can be removed by abrasive wear, and also the formation of flaking in a curve section can be prevented by applying heat treatment to a rail GC.;COPYRIGHT: (C)1994,JPO