Taguchi based optimization to improve mechanical properties of high carbon rail steels via bainitic microstructure
JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY, cilt.37, sa.5, ss.1-11, 2023 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 37 Sayı: 5
- Basım Tarihi: 2023
- Dergi Adı: JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Compendex, INSPEC, Metadex, Civil Engineering Abstracts
- Sayfa Sayıları: ss.1-11
- Ankara Yıldırım Beyazıt Üniversitesi Adresli: Evet
Özet
Rail transportation systems constantly developing as a result of the increase in demand both in high-speed and freight operations globally. According to this demand and increase in operational frequency the components fail rapidly. To extend the service lives it is desired to develop high strength materials for the critical components of the rail systems. Therefore, in this study, isothermal transformation applied to extracted high carbon rail steels in order to obtain bainitic microstructure under various boundary conditions which shows superior mechanical properties. The experimental studies were conducted under varying austenitizing temperature, transformation time and temperature. The change in microstructure result with improved mechanical properties where combined high tensile strength and toughness values were obtained. Optical and SEM micrograph, XRD analysis and mechanical tests (hardness, impact, tensile tests) were carried out to clarify characteristics of the developed materials. The optimum combination of boundary conditions was obtained by using the analysis of signal to noise (S/N) ratio. In conclusion developed rail steels show better mechanical properties than conventional ones by 21% in hardness, 16% in tensile strength, 40% in elongation and optimum parameters for heat treatment processes are clarified with Taguchi-based Gray relational analysis.