| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a long rail, improving the fatigue strength of a welded part in comparison with the conventional rail. SOLUTION: The method for manufacturing the long rail is provided with: a process for manufacturing the long rail by welding at least two pieces of rails; and a process so that a lamellar of≥60% among a pearlite in the structure of less than 50μm from the surface at an end edge part is formed angle of±45°or lower to the surface by performing an ultrasonic peening treatment to the end edge part of a bead formed on the welded part of the long rail. In this way, the fatigue limit of the welded part in 2 million times for repeating loads can be made to higher than 30 MPa in comparison with non-treating material, in which the ultrasonic peening treatment is not applied. COPYRIGHT: (C)2009,JPO&INPIT |
