Novel cross wedge rolling method for producing railcar axles

Abstract

Railcar axles are large-size parts manufactured in large batches using forging methods. More efficient methods of manufacturing railcar axles are currently being sought. A promising line of research in this respect is connected with the use of cross wedge rolling (CWR). Nonetheless, there exist no rolling mills that would make it possible to manufacture such large-size parts as railcar axles. A solution to this problem was inspired by the symmetric shape of a railcar axle, which makes it possible to roll this part in two passes using the same tools. Taking advantage of the potential offered by numerical modelling, simulations were made of two rolling processes for producing a railcar axle type BA302, i.e. one process was conducted with the use of two rolls and the other with two flat tools moving in the opposite directions. Numerical results demonstrated that railcar axles produced by the proposed rolling process had neither external nor internal (cracks) defects. The effectiveness of the developed CWR method was ultimately confirmed by the high quality of railcar axles that were produced (in a scale of 1:5) under industrial conditions at the Lublin University of Technology.