Multilayer surfacing of a freight car wheel rim

For a radical solution of the issue of extending the service life of wheelsets of the freight cars, it is proposed to weld not only serviceable wheels, but also wheels to be pressed against an unacceptable rim thickness. It is shown that in multilayer surfacing, the possibility of obtaining high quality metal becomes more difficult, and heating of a thin rim can have an adverse effect on the gap between the inner surfaces of the wheels. The purpose of the work is to optimize the technological parameters of the multi-electrode surfacing mode, determine the amount of warpage of the wheel disk and study the quality of the deposited metal during operational tests of wheel sets. Experimental surfacing was carried out on the optimal parameters of the multi-electrode process, and a method for measuring the value of wheel warping in conditions of multilayer surfacing was proposed. The results of studies on the influence of the multi-electrode surfacing process on the metal structure and wheel warping are presented. It is shown that under the optimal surfacing mode, favorable conditions are created for obtaining fine-grained structures in the near-seamed zone. Field tests of the freight cars wheel sets were carried out to determine the efficiency and reliability of the method of automatic multi-electrode surfacing of the wheel rim. The task of the tests was a comparative assessment of the resistance of the wheels under study to defects and wear. The implementation of the task involved obtaining data for the wheel sets being researched on the number of cases of wheel failure due to the insufficient quality of the welded surfacing metal. It was found that wheel warping does not cause any dangers that threaten traffic safety, and the weld metal has the necessary resistance to cracking under the action of operational loads.