High-strength bainitic steel rail and producing method thereof

摘要

The present invention belongs to the steel making field, in particular relates to a high-strength bainitic steel rail and a producing method thereof The microscopic structure in the round corner part and in the tread center of the rail head is a multi-phase structure 5 composing of bainitic ferrite strips in 0.2-1.0[ m width, filmy residual austenite in 0.01~0.1Im thickness distributed alternatively between the bainitic ferrite strips, and 1~5% martensite. The producing method of the steel rail comprises: utilizing the residual heat in the steel rail, accelerated cooling the rail head part of the steel rail at a 3.0~6.0C/s cooling rate when the tread of the rail head is cooled naturally to 450-500'C, and stopping the accelerated 10 cooling when the temperature of the tread center of the rail head drops to 220-300'C and then air-cooling to room temperature. A multi-phase steel rail consisting of carbide-free bainite + a small amount of martensite + a small amount of residual austenite is obtained in the present invention, and the steel rail has an outstanding wear resistance property and is suitable for heavy-duty railroad. 6704019_1 (GHMatters) P100429.AU Fig. 1