23-25 May 2022 Hybrid conference
voestalpine Stahlwelt
Europe/Vienna timezone

Research and development of steel grades with elevated Mn content at voestalpine and its scientific partners

23 May 2022, 10:45
55m
Room 1

Room 1

Keynote Lecture Keynote Lecture Plenary Lecture

Speakers

Andreas Pichler (voestalpine Stahl GmbH) Prof. Reinhold Schneider (Univ. of Appl. Sciences Upper Austria) Prof. Daniel Krizan (voestalpine Steel Division GmbH Linz)

Description

After a short introduction of voestalpine, the first part of this contribution will give a brief overview of high manganese steels produced and developed by voestalpine group and of cold formable steels for the automotive industry with a special focus towards the 3-GEN advanced high strength steels (AHSS). Regarding cold rolled strip steels, the relationship between global and local formability will be elucidated, while the challenges related to their weldability will also be presented.
In the second part of this contribution, the laboratory development of high-Mn, conventional medium-Mn and lean medium-Mn Quenching and Partitioning (Q&P) will be accentuated. The application of one-step and two-step heat treatment and the benefit of the latter one with respect to the avoidance of yield point elongation and achievement of optimal mechanical properties in conventional medium-Mn steels will be illustrated. To assure an extraordinary local ductility of these steel grades, the development of a low C variant will also be presented. As an aftermath of a relatively low Mn content, lean medium-Mn Q&P steels ensure an excellent balance between local and global formability. In order to predict their microstructural evolution, a new carbon constrained equilibrium (CCE) based model, including a novel Ms-formula, an incomplete C partitioning from matrix to retained austenite and mechanical stabilization of retained austenite, was developed. The interplay between ductility and toughness of these steel grades and the forecast of their development for GA coatings will also be discussed.
The last part of this contribution focuses on the industrial development of medium-Mn steels. First, the concept with a strength level of 780 MPa, having the Mn content of about 6 wt-%, will be discussed in detail. In this context, applied two-step annealing, resulting microstructure, mechanical and service in use properties, such as weldability and formability, will be presented. In terms of their excellent deep drawability, a number of potential applications for the manufacturing of the most complex structural parts for the automotive industry will be shown. Finally, the options for medium-Mn concepts with a strength level higher than 980 MPa will be introduced.

Speaker Country Austria

Primary authors

Andreas Pichler (voestalpine Stahl GmbH) Prof. Reinhold Schneider (Univ. of Appl. Sciences Upper Austria) Prof. Daniel Krizan (voestalpine Steel Division GmbH Linz)

Presentation Materials