L. Trško et al.: Fatigue life analysis of die forged railways axle manufactured from C30 steel Materials Engineering - Materiálové inžinierstvo 21 (2014) 104-108 104 FATIGUE LIFE ANALYSIS OF DIE FORGED RAILWAY AXLE MANUFACTURED FROM C30 STEEL Libor Trško 1,* , Otakar Bokůvka 2 , František Nový 2 , Branislav Hadzima 1,2 1 Research centre of University of Žilina, Univerzitná 8215/1, 010 26 Žilina, Slovak Republic 2 Faculty of Mechanical Engineering, University of Žilina, Univerzitná 8215/1, 010 26 Žilina, Slovak Republic * corresponding author: e-mail: libor.trsko@rc.uniza.sk Resume With respect to the manufacturing process, different parts of one structural component can have different fatigue properties. In this study, the fatigue life of a railway axle manufactured from C30 steel by die forging is evaluated in the part of the axle bolster and axle body. According to the fatigue test results obtained at high frequency tension - compression fatigue tests (f ≈ 20 kHz, R = -1, T = 20 ± 5 °C), due to the higher level of work hardening of the axle bolster, the fatigue strength of material in this part is significantly higher than in the axle body. Different fatigue strength of these parts were observed despite the fact, that results of static tensile tests did not proved any important differences in the ultimate tensile strength, yield point and elongation. Available online: http://fstroj.uniza.sk/journal-mi/PDF/2014/15-2014.pdf Article info Article history: Received 10 December 2013 Accepted 7 February 2014 Online 15 September 2014 Keywords: Railway axle; High frequency fatigue testing; Steel C30; Modulus of elasticity. ISSN 1335-0803 (print version) ISSN 1338-6174 (online version) 1. Introduction Even due to years of intensive research, fatigue of metals is still a serious engineering problem and fatigue fractures appear very frequently on common cyclically loaded structural components. One of the reasons why the problem of material fatigue was not solved until today is, that fatigue life of material is influenced by many factors which can be divided into two types. One type of factors influencing the fatigue life are so called “internal” what means, that these are connected with the material characteristics e. g. microstructural state, work hardening level, the surface state and so on. The second type of factors include so called “external” which are represented by the working conditions, type of applied load and environment. Various combinations of these factors create the very complex character of fatigue damage which is the reason, why fatigue failures are still present in all types of structural components [1, 2]. With respect to the technology used for manufacturing, different microstructural and work hardening state can be present in just one structural component. This means, that different parts of the component can have different fatigue properties and tests done with use of specimens prepared from various parts are not equal [3, 4]. In this study is analysed fatigue life of specimens prepared from different parts of a railway axle, manufactured from steel C30. 2. Experimental material and procedures As experimental material was used C30 steel obtained from a manufactured railway axle. Quantitative chemical analysis (Table 1) confirmed that the chemical composition fulfil the prescribed standard for this steel [5]. To produce a railway axle are used large steel ingots, This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-nd/3.0/ or send a letter to Creative Commons, 444 Castro Street, Suite 900, Mountain View, California, 94041, USA. This copy of the article was downloaded from http://www.mateng.sk , online version of Materials Engineering - Materiálové inžinierstvo (MEMI) journal, ISSN 1335-0803 (print version), ISSN 1338-6174 (online version). Online version of the journal is supported by www.websupport.sk .