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 flexibilityand ease of performance, both during the reconstruction and construction of a new track, as well asin the ongoing maintenance of the continuity of the track. Although this procedure is applying foralmost hundred years with constant improvements, it still has serious shortcomings. Theshortcomings primarily relate to quality variability, which directly dependent on the training of theoperator and their compliance with the prescribed instructions and procedures, during the weldingprocess. The most common working mistakes are very similar to the casting failures that occur duringthe usual casting of steel. The process is susceptible because the welded joint is in constant straincondition caused by the structural differences between primary material and filler material (thermitesteel). This paper presents some working failures on the samples from the track in exploitation, aswell as the analysis of the causes of their formation. Also, the innovative way of performingaluminum welding of the rail was shown, which minimizes working mistakes and prevents workingfailures. 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 transportas well as its coherence because it significantly reduces the impact of faults of welding teams.