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.

A track link for a ground-engaging track system includes an elongate link body having an upper rail surface located in part upon each of a first link strap, a second link strap, and a middle section of the track link. The upper rail surface is formed by a wear band of sacrificial wear material having a hardness that is varied lengthwise along the upper rail surface to retard scalloping of the track link during service and forming relatively softer zones in the first and second link straps and a relatively harder zone within the middle section. Methodology for making such a track link is also disclosed.

A track link for a ground-engaging track system includes an elongate link body having an upper rail surface located in part upon each of a first link strap, a second link strap, and a middle section of the track link. The upper rail surface is formed by a wear band of sacrificial wear material having a hardness that is varied lengthwise along the upper rail surface to retard scalloping of the track link during service and forming relatively softer zones in the first and second link straps and a relatively harder zone within the middle section. Methodology for making such a track link is also disclosed.

A device to cool a steel material having undergone hot rolling mills, the device including: a conveying mechanism which conveys the steel material while accelerating the steel material; a water cooling mechanism which cools the steel material while the conveying mechanism conveys the steel material; and a control unit which controls the conveying mechanism and the water cooling mechanism to cause the cooling of the steel material to satisfy Formula (1) below, wherein a water cooling time decrease rate in Formula (1) below is decided based on a length of a water cooling zone where the water cooling mechanism is provided and a time t.sub.c(0) required to cool a leading end portion of the steel material down to a target temperature,

t.sub.c(x)=t.sub.c(0).Math.xFormula (1),

where x: a conveyance-direction position in the steel material relative to the leading end portion of the steel material serving as a reference point, and t.sub.c(x): a time required to cool a portion at the position x of the steel material down to the target temperature.

Provided is a manufacturing method for high-toughness and plasticity hypereutectoid rail, including: a. hot rolling the steel billet into rail; b. blowing a cooling medium to the top surface of railhead, wherein, the two sides of railhead and the lower jaws on the two sides of railhead after the center of top surface of rail is air-cooled to 800-850 C., and cooling the rail until the center temperature of the top surface is 520-550 C.; c. stop blowing the cooling medium to the lower jaws on the two sides of railhead, continue blowing the cooling medium to the top surface of railhead and the two sides of railhead, and air cool the rail to room temperature after the surface temperature of railhead is cooled to 430-480 C. The resulting hypereutectoid rail has higher toughness and plasticity than existing products, which is suitable for heavy-haul railway, especially for small radius curve sections.

Provided is a manufacturing method for high-toughness and plasticity hypereutectoid rail, including: a. hot rolling the steel billet into rail; b. blowing a cooling medium to the top surface of railhead, wherein, the two sides of railhead and the lower jaws on the two sides of railhead after the center of top surface of rail is air-cooled to 800-850 C., and cooling the rail until the center temperature of the top surface is 520-550 C.; c. stop blowing the cooling medium to the lower jaws on the two sides of railhead, continue blowing the cooling medium to the top surface of railhead and the two sides of railhead, and air cool the rail to room temperature after the surface temperature of railhead is cooled to 430-480 C. The resulting hypereutectoid rail has higher toughness and plasticity than existing products, which is suitable for heavy-haul railway, especially for small radius curve sections.

A method for creating a welded joint between ends of two steel rails, wherein the two steel rails have a substantially pearlitic microstructure. The method includes a first heating step, an upsetting step, a first cooling step, and a second heating step and provides a means to influence a microstructure and hardness of an austenitic region of a heat affected zone (HAZ) and/or an extent of softening in a softened region of a HAZ.

A method for creating a welded joint between ends of two steel rails, wherein the two steel rails have a substantially pearlitic microstructure. The method includes a first heating step, an upsetting step, a first cooling step, and a second heating step and provides a means to influence a microstructure and hardness of an austenitic region of a heat affected zone (HAZ) and/or an extent of softening in a softened region of a HAZ.

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 %.

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 %.