Common failures in aluminothermic welding process and proposal for their prevention

Abstract

Aluminothermic welding of rail is still a unique method for joining the rails because of its flexibility and ease of performance, both during the reconstruction and construction of a new track, as well as in the ongoing maintenance of the continuity of the track. Although this procedure is applying for almost hundred years with constant improvements, it still has serious shortcomings. The shortcomings primarily relate to quality variability, which directly dependent on the training of the operator and their compliance with the prescribed instructions and procedures, during the welding process. The most common working mistakes are very similar to the casting failures that occur during the usual casting of steel. The process is susceptible because the welded joint is in constant strain condition caused by the structural differences between primary material and filler material (thermite steel). This paper presents some working failures on the samples from the track in exploitation, as well as the analysis of the causes of their formation. Also, the innovative way of performing aluminum welding of the rail was shown, which minimizes working mistakes and prevents working failures. The results of the quality testing of welded joints are done according to the EU standards. They pointed out that the implementation of this procedure provides greater safety of rail transport as well as its coherence because it significantly reduces the impact of faults of welding teams.