Manganese – a promising element also in high alloy sintered steels

ABSTRACT

Manganese is a standard alloy element in many wrought steels, offering improved strength and hardenability and, in Hadfield steels, also a unique combination of strength, ductility and work hardening behaviour. In sintered steels Mn has been used rarely so far because of two reasons: one is the high oxygen affinity of Mn which promotes oxygen pickup during heat treatment and inhibits removal of oxygen in part through the ‘internal getter’ effect. The other reason is the high vapour pressure of Mn which results in Mn loss during sintering. In this presentation, these problems are discussed on Mn-alloyed sintered steels with transformation-induced plasticity behaviour. It is shown that by suitable alloying techniques, combined with adjustment of the manufacturing parameters, the problems can be overcome and the benefits of Mn addition can be reaped, obtaining PM steels for which potentially surface densification and hardening can be attained in one run.

KEYWORDS:

• Powder metallurgy
• sintered steels
• manganese
• hardening
• TRIP behaviour

Acknowledgements

This work was in part supported by the Austrian Government through the FFG (Project Re Design Gear Process). Furthermore, the authors want to thank Atomising Sytems Ltd., Sheffield UK, in particular John J. Dunkley, for preparing and supplying the masteralloy powders used.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by FFG [Project “Redesign Gear Process”, grant number 853434].

Notes on contributors

Herbert Danninger

Herbert Danninger is full professor of Chemical Technology of Inorganic Materials at Technische Universität Wien (Vienna University of Technology), Vienna, Austria. From 2011 to 2019, he was also Dean of the Faculty of Technical Chemistry. He has been active in powder metallurgy for more than 40 years and is author/co-author of 500+ publications as well as several books and book chapters. From 2009 to 2020, he was 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.

Christian Gierl-Mayer

Christian Gierl-Mayer was born in Styria, Austria, in 1969. He studied Technical Chemistry at TU Wien, got his Master 1996 and his PhD in 2000 from TU Wien. After 3 years in a 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 Metallury Steels and the Atmophere during Sintering’, and became Associate Professor in 2019. He is currently leading the research group Powder Metallurgy at TU Wien, Institute of Chemical Technologies and Analytics. His publication record is about 260 publications in journals and conference proceedings, 4 book chapters and 7 patents.

Mikhail Prokofyev

Mikhail Prokofyev was born in Leningrad (today: St. Petersburg), Russia, and went to school in Russia, Germany and Austria. He studied Technical Chemistry at TU Wien, earning his Master degree in 2017. He then continued with his doctoral thesis, earning the degree of Dr.techn. in May 2020. Since April 2020 he has been working with TÜV Austria, Vienna.

Marie-Christine Huemer

Marie-Christine Huemer studied Technical Chemistry at TU Wien, earning her Master degree in 2013. The topic of her master thesis was the effect of Mn vapour on sintering furnace linings. She then continued with a doctoral thesis on functional material design for ferrous PM precision parts, obtaining the degree of Dr.techn. in 2016.

Raquel de Oro Calderon

Raquel de Oro Calderon is Assistant Professor at the Institute of Chemical Technologies and Analytics at the Technical University of Vienna (Austria). She has been active in the field of PM for about 10 years, is author of more than 70 publications in journals, conference proceeding and book chapters, and has been invited speaker in several conferences in Europe, America and Japan. Her main areas of research are related to the study of PM processes and materials. She has intensely worked in the study of master alloys as a way to introduce oxygen-sensitive elements in PM steels, and in the design of liquid phases to tailor their behaviour during the sintering process.

Robert Hellein

Robert Hellein studied Technical Chemistry at Vienna University of Technology with PhD in the Field of ‘Co-sintering of cemented carbides’ (Institute of Chemical Technologies and Analytics) 2016 he joined Miba Sinter Austria GmbH as R&D Engineer Materials & Processing Technology. From 2018, he has been Teamleader for Material Development, R&D Sinter Group.

Alexander Müller

Alexander Müller studied Mechanical Engineering and Economics at Vienna University of Technology with a PhD thesis in the Field of RFID Technology. In 2006 he started at Miba Sinter Austria GmbH as Development engineer; from 2008, he was Teamleader in the area of R&D. In 2013 he became Manager R&D: Advanced Engineering, and since 2016, he has been Head of R&D Miba Sinter Group.

Gerold Stetina

Gerold Stetina studied Materials Science at Montanuniversität Leoben. In 2003, he joined Miba Sinter Austria GmbH as Development engineer; from 2008, he was Teamleader in the area of R&D. In 2013, he became Manager R&D: Materials & Processing Technology and in 2016, Business Unit Manager Electrification, Miba Sinter Group. Since 2019, he has been Business Unit Manager 3D Flux Technology, Miba eMobility GmbH.