HEAT TREATMENT METHOD FOR RAIL FLASH BUTT WELDING JOINT

摘要

#$%^&*AU2019204691A120200123.pdf#####Abstract The invention discloses a heat treatment method for a rail flash butt welding joint, and belongs to the technical field of rail welding. In order to solve technical problems of "saddle" profile wear and early fatigue fracture of the welded joint caused by low hardness of a welding area or abnormal microstructure of the joint in the service process of a rail, the invention provides a heat treatment method for a rail flash butt welding joint, wherein the welded joint enters the first cooling stage, the second cooling stage and the third cooling stage sequentially, and the cooling speed and temperature of each stage are controlled to remove any abnormal structure such as martensite and bainite from metallographic structure of the welded joint, so as to improve the "saddle" profile wear and early fatigue fracture mentioned above, and ensure safe operation of railway lines.1/3 * Eutectoid pearlite rail 600 -a---Hypereutectoid rail - Softening zone measuring line of eutectoid pearlite rail - Softening zone measuring line of hyperetectoid rail 45 400 350 300 p50 I -40 -30 -20 -10 0 10 20 30 40 Distance from center of weld seam/mm Fig. 1 Euteetoid pearlite rail -a- Hypereutectoid rail - Softening zone measuring line of eutectoid pearlite rail - Softening zone measuring line of hypereutectoid rail 45 400 350 300 -40 -30 -20 -10 0 10 20 30 40 Distance from center of weld seam/mm Fig. 2 ,-Eutectoid pearlite rail r_00 -A- Hypereutectoid rail -Softening zone measuring line of eutectoid pearlite rail -4Softening zone measuringline of hypereutectoid rail 450 350 300 -40 -30 -20 -10 0 10 20 30 40 Distance from center of weld seam/mm Fig. 3