Akimov I.V., Kubich V.I. Evaluation of frictionality of modified graphitized steels on small-sized samples

Abstract

Graphitized steels as alloys, containing carbon partly in the shape of graphite inclusions, possess a number of valuable properties. Their analysis shows that one of the possible areas of application of such steels is using them as a structural material for manufacturing of railway brake blocks. It is required to carry out a number of researches in order to confirm this assumption. These researches have to include determination of frictional and temperature dependences of such steels on their chemical composition, as well as comparison of these data with the materials used for railway blocks nowadays - grey phosphorous cast irons. Evaluation of compatibility of graphitized steel - carbon steel friction pairs has been conducted, values of power and thermal loads have been determined in this work. The direction of influence of graphitized steels' chemical composition on compatibility demonstration and frictionality of the contact with steel 40Х has been shown. It has been established that the graphitized steel of the following composition: С 1.54 %; Cu 0.85 %; Si 1.07 %; Al 0.22 %; Mn 0.41 %; Ni 0.13 %; Cr 0.15 %; S 0.022 %; P 0.018 % has higher compatibility and frictionality of the contact as compared to the presented row at sliding speed not less than 176 m/min. At the same time the temperature stress level of the contact during its unloading is lower than the standard cast iron АСЧ-2.