Abstract: The present disclosure relates to the technical field of rails welding, and particularly to a method for optimizing microstructure of a rail welded joint, the method comprises the following steps: step 1): subjecting a rail web area of a to-be-cooled welded joint which is obtained by flash butt welding to an accelerated cooling by means of an accelerated cooling device and by using compressed air as a cooling medium, measuring and monitoring temperature of a central position of the rail web of the welded joint while cooling; step 2): stopping the accelerated cooling when the temperature of the central position of the rail web drops to a preset temperature, then placing the welded joint in air and naturally cooling to room temperature, wherein the rail is a pearlite rail having a carbon content of 0.6-0.9 wt %.

Abstract: The present disclosure relates to the technical field of rails welding, and particularly to a method for optimizing microstructure of a rail welded joint, the method comprises the following steps: step 1): subjecting a rail web area of a to-be-cooled welded joint which is obtained by flash butt welding to an accelerated cooling by means of an accelerated cooling device and by using compressed air as a cooling medium, measuring and monitoring temperature of a central position of the rail web of the welded joint while cooling; step 2): stopping the accelerated cooling when the temperature of the central position of the rail web drops to a preset temperature, then placing the welded joint in air and naturally cooling to room temperature, wherein the rail is a pearlite rail having a carbon content of 0.6-0.9 wt %.

Abstract: The invention discloses a mobile flash butt welding method for 136RE+SS heat-treated rail, and particularly a mobile flash butt welding method for 136RE+SS heat-treated rail in the technical field of rail welding. The mobile flash butt welding method for 136RE+SS heat-treated rail in the invention includes a pre-flash stage, a flash stage, a boost stage, an upset stage and a forge stage, with a total heat input of 7.1 MJ-10.0 MJ, a total duration of 110 s-135 s and an upsetting distance of 12.8 mm-16.7 mm during the welding process. By adopting the method of the invention, mobile flash butt welding can be conducted for 136RE+SS heat-treated rail successfully, and the rail joint has less internal defects but stable welding quality, and can pass fatigue test, tensile test and slow bend test to meet the requirements. Besides, the rail joint can pass the drop weight test for 15 welds continuously, demonstrating better stability.

Abstract: The invention discloses a mobile flash butt welding method for 136RE+SS heat-treated rail, and particularly a mobile flash butt welding method for 136RE+SS heat-treated rail in the technical field of rail welding. The mobile flash butt welding method for 136RE+SS heat-treated rail in the invention includes a pre-flash stage, a flash stage, a boost stage, an upset stage and a forge stage, with a total heat input of 7.1 MJ-10.0 MJ, a total duration of 110 s-135 s and an upsetting distance of 12.8 mm-16.7 mm during the welding process. By adopting the method of the invention, mobile flash butt welding can be conducted for 136RE+SS heat-treated rail successfully, and the rail joint has less internal defects but stable welding quality, and can pass fatigue test, tensile test and slow bend test to meet the requirements. Besides, the rail joint can pass the drop weight test for 15 welds continuously, demonstrating better stability.