Design and Development of steels of the 21st century – starting from the atomic structure
On the 1st of January 2016 a new Chair of Design of Steels at the Department of Physical Metallurgy and Materials Testing was established. The Chair was founded within the framework of the FFG initiative “Production of the future” and its main research interests are directed towards developments of modern high performance steels. A special focus is put on applied fundamental research in a close collaboration with industry following current needs and state-of-the-art trends. To achieve these goals, an extensive characterization by means of modern high-resolution analytical methods is undertaken. The Chair has been integrated in the lecturing and exercise activities of the Materials Science and Metallurgy study programme. Dipl.-Ing. Dr.mont. Ronald Schnitzer has been appointed as a new Professor of the Chair of Design of Steels.
With about 1.6 billion tons produced per year, steel is still the most important construction material. Research and development of novel high performance steels will significantly contribute to the key subjects of the 21st century, such as sustainability, reduction of CO2 emissions, energy saving and recycling. The objectives of the Chair of Design of Steels are development of new and optimization of existing high performance steels, for which an integrative approach including new alloying concepts for steels and their energy-efficient production is adopted. In addition, the existing applications in the automotive industry, the energy conversion and distribution as well as traffic and transportation are taken into account. Regarding the automotive industry, the trend towards lightweight construction with an additional increase in personal safety are the driving forces for the development of new advanced high strength steels. Strength and toughness should be increased at the same time, and hence push the limits of the technological capabilities as far as possible. For applications with such requirements, new steels with improved chemical, physical and mechanical properties are necessary. Therefore, comprehensive knowledge of the metallurgical manufacturing processes, the processing procedures such as forging and rolling, the alloy design, the structure-property relationship as well as the actual applications of steels is required.
Application example: Investigation of the atomic structure of high performance materials
Atom probe tomography is one of the methods with the highest resolution which can be applied for developing and gaining understanding of modern high performance materials (see Figure 1). Thereby, it is possible to examine materials at the very atomic level, which considerably contributes to the understanding of the structure-property relationship and is indispensable for the development of new steels. Figure 2 depicts an exemplary result of an atom probe measurement. A special attention has to be paid to the lengthscale lying in the nanometer range (1 nm = 10-6 mm). Each red dot represents a single detected Fe atom. The blue spherical particles visualize precipitates in the material, which are in this case enriched in Ni and Al. A precise alloy design allows to control the number, the particle density, distance and chemical composition of these precipitates. These directly influence the mechanical properties, such as tensile strength and elongation of the steel. Thus, the properties and applicability of materials can be tailored using knowledge and modification of the atomic structure.
The steel design shall be supported by the use of simulation and modeling tools which will be applied in addition to experimental and analytical methods. This requires a strong interdisciplinary cooperation of the new Chair with other materials-related Departments and Chairs of the Montanuniversität Leoben. The research activities of the new Chair should contribute to the achievement, reinforcement and expansion of the technological leadership of the domestic steel producing and processing companies and ensure production sites in Austria. Although the Montanuniversität already possesses state-of-the-art equipment for materials characterization, additional investments in characterization techniques particularly suitable for steel research are planned in the framework of this endowed professorship. The newly founded Chair receives funds through the FFG, the industry and the Montanuniversität Leoben. One of the most important cooperation partners from the industrial side is the leading Austrian steel-based company voestalpine.