Numerical computer aided technique to design rails flash welds

A calculation method for computer aided design and verification of flash welds has been conceived and set up. The proposed method has been applied to the butt welding process of rails: it is based on a one-dimensional thermal analysis developed using a finite volume numerical technique. The calculation system is able to take into account some of the critical design variables for the quality of the welds, such as power input, preheating and preflashing time, flashing time, dimensions and type of welding materials and products. The use of the proposed method makes it possible to design or to assess the correct welding result, to choose the optimal process variables and to avoid possible welding defects. Using this method it is possible to run many sets of preliminary computer simulation to choose the optimal welding variables, thus drastically reducing the number of experimental welding tests for process characterization and the costs related to new product design.