METHOD OF REHEATING RAIL WELD ZONE

Provided herein is a welded joint excellent in fatigue strength, which is capable of suppressing a fatigue crack in a rail web portion of a rail weld zone in a horizontal direction and a bending fatigue crack in a foot portion of the rail weld zone. In general terms, the invention relates to a method of reheating a rail weld zone, the method being performed after rails were welded, a distance C between a reheating region P of a rail web portion 2 and a welding center Q is set to more than or equal to 0.2 times and less than or equal to three times a HAZ length Lh of the rail weld zone. A length B of the reheating region P may be more than or equal to 0.5 times and less than or equal to five times the HAZ length Lh of the rail weld zone. A height A of the reheating region P may be more than or equal to 0.2 times a height Hw of the rail web portion 2. A temperature Th reached in a reheating process at a center of the reheating region P may be higher than or equal to 400°C and lower than or equal to 750°C, and may also have a relationship with an initial temperature Tw(°C) of the rail weld zone in the reheating process, the relationship satisfying 0.375Tw+350