HIGH-STRENGTH PEARLITIC STEEL RAIL HAVING EXCELLENT DELAYED FRACTURE PROPERTIES

摘要

The invention provides a high-strength pearlitic steelrail, which is inexpensive, and has a tensile strength of 1200MPa or more, and is excellent in delayed fracture properties.Specifically, the rail contains, in mass percent, C of 0.6 to1.0%, Si of 0.1 to 1.5%, Mn of 0.4 to 2.0%, P of 0.035% or less,S of 0.0005 to 0.010%, and the remainder is Fe and inevitableimpurities, wherein tensile strength is 1200 MPa or more, andsize of a long side of an A type inclusion is 250 µm or lessin at least a cross-section in a longitudinal direction of arail head, and the number of A type inclusions, each havinga size of a long side of 1 µm to 250 µm, is less than 25 perobserved area of 1 mm2 in the cross-section in the longitudinaldirection of the rail head.