![Sample our Physical Sciences journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/110819/TOC-Subject-Sample-2021-Physical-Sciences.jpg"})
Abstract
For PM steel precision parts, high mechanical loading is very common in service. In particular for automotive applications, fatigue up to very high loading cycle numbers may be encountered. Advanced alloying concepts for sintered steels are required, involving also alloy elements with high oxygen affinity. In the present study, hybrid alloyed sintered steels based on prealloyed steel powder Fe-1.8%Cr were prepared by the press-and-sinter route. Mn and Ni, respectively, were admixed as well as a masteralloy containing Mn and Si, the alloy element content being varied, and the combination hardness vs. impact energy was assessed. From the most promising variants, fatigue test specimens were prepared, sinter hardened and characterized, fatigue testing being done by ultrasonic resonance up to Nmax = 10E10 cycles. Ni alloying proved to be positive both for the impact energy and the gigacycle fatigue strength while Mn resulted in high hardenability but low impact and fatigue strength, in part because of intergranular embrittlement. The grade with Mn-Si masteralloy was slightly less ductile than the Ni alloyed variant, but in particular at N > 10E8 the fatigue endurance strength was similar to that of the Ni alloyed type, however with significantly lower scatter.
Acknowledgement
The authors wish to thank Atomising Systems Ltd., Sheffield, UK, for producing and supplying the masteralloy powder used.
Disclosure statement
No potential conflict of interest was reported by the authors.
Additional information
Notes on contributors
Milad Hojati
Milad Hojati is currently a postdoctoral researcher at Technische Universität Wien, Vienna, Austria. He did his PhD with the title of “Manufacturing and characterization of sintered steels with improved mechanical and functional properties” under supervision of Professor Herbert Danninger. He also holds a bachelor in Metallurgy Engineering (2010) and a master in Materials Engineering - Corrosion and Protection of Materials (2013), both from Ferdowsi University of Mashhad, Iran. He also worked as R&D manager in Mashhad Powder Metallurgy Company (2010-2018).
Christian Gierl-Mayer
Herbert Danninger is retired professor for Chemical Technology of Inorganic Materials at Technische Universität Wien, Vienna, Austria. From 2011 to 2019 he was Dean of the Faculty of Technical Chemistry. He has been active in powder metallurgy research and education for more than 40 years and is author/co-author of 550+ publications as well as several books and book chapters. From 2009 to 2020 he was also chairman of the “Gemeinschaftsausschuss Pulvermetallurgie”, the PM association of the German-speaking countries He holds honorary doctoral degrees of Technical University Cluj-Napoca (Romania), Universidad Carlos III de Madrid (Spain) and Universitatea din Craiova (Romania) and is Fellow of APMI and EPMA. In 2020 he was awarded the “Ivor Jenkins Medal” of IOM3 (London, UK) and in 2022 the “Richard Zsigmondy Medal” of TU Wien.
Herbert Danninger
Christian Gierl-Mayer studied Technical Chemistry at TU Wien, got his Master in 1996 and his PhD in 2000 from TU Wien. After 3 years in private research institute (ofi-Austrian Research Institute of Chemistry and Technology) he re-joined the powder metallurgy group of Prof. Herbert Danninger as senior researcher. He got his habilitation in 2019 for “Thermoanalytical Investigation of Interactions between Powder Metallurgy Steels and the Atmosphere during Sintering”, and became Associate Professor in 2019 and full Professor for “Chemical Technology of Metals” 2022. He is currently leading the research group Powder Metallurgy at TU Wien and the research unit Chemical Technologies, Institute of Chemical Technologies and Analytics. His publication record is about 260 publications in journals and conference proceedings, 4 book chapters and 7 patents.