Research of Rail Welding Technology Using Software Simulation
At present, thermite welding is used in the creation of railways. The peculiarity of this method is the use of a large volume of liquid metal formed as a result of the thermite reaction. This metal is held in the weld zone by a mold. Due to the high temperature, the liquid metal melts the ends of the rails to be joined and, after cooling, forms a welded joint. The gap between the rails, into which the metal is poured, is 25 mm. However, when repairing rails on the way, it may not be enough to eliminate the defective section of the rail. Therefore, a promising direction in the development of thermite welding of rails is considered to be a welding gap of up to 50 mm. This study presents the results of modeling the process of rail welding by the thermite method using the NovaFlow & Solid CV software package. The purpose of the study was to assess the change in the length of the weld zone and the heat-affected zone with an increase in the welding gap from 25 to 50 mm. To achieve this goal, an accurate three-dimensional model of a thermite welded joint was created. In the NovaFlow & Solid CV program, materials for each element of the model are specified and initial conditions are set. The results of the simulation were thermograms, reflecting the distribution of heat from the weld zone into the rails. These thermograms were used to determine the boundaries of the welded seam and the heat-affected zone. It was found that the use of a welding gap of 50 mm, instead of 25 mm, leads to an increase in the length of the welded seam by 1.3-1.6 times. The heat-affected zone reaches 80.95 mm.