Improved steel quality with ultra-fast heating

(06-01-2022) In his PhD, Eliseo Hernández Durán investigates how ultrafast heating (UHF) can be optimized during the cooling process so that the quality of the steel increases.

Ultrafast heating (UFH) of steel has been increasingly in the spotlight in recent decades. The promising development of ultra-fast heated steels stems from the short time of this heat treatment due to heating rates in the order of 1000°C/s as well as the formation of grain refined multiphase microstructures after quenching.

However, the requirements for combinations of strength, ductility (cold deformability) and ductility necessary for high-impact resistant materials cannot be obtained by just rapid heating followed by direct cooling to room temperature.

Different thermal pathways can be followed after the UFH step. This is with the aim of modifying the microstructure and achieving or exceeding the mechanical requirements laid down in standard specifications.

"For the development of advanced high-strength steels (AHSS), in my thesis I studied the effectiveness of UFH in combination with various thermal treatments: direct quenching, quenching and partitioning and austempering," explains Eliseo Hernández Durán.

The results obtained suggest that the formation of multiphase microstructures has a greater impact on mechanical properties than the level of grain refinement achieved.

"By optimizing the microstructure through a combination of UFH and low-temperature thermal treatments, high-strength steels with a balanced combination of mechanical properties were produced," explains Eliseo.

More technically, the results of this study provide insight into the interplay between austenite formation and transformation, formation of chemical heterogeneities, grain refinement and texture during UFH treatment. This ensures through the design of innovative process routes that the microstructure and mechanical properties of the next generation AHSS can be created.

The full PhD is not yet available as it is embargoed until 25/10/2022.

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PhD Title: Ultrafast Heating of Advanced High Strength Steels

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Contact: Eliseo Hernández Durán, Roumen Petrov

Eliseo Hernández Durán was born on August 13th 1993 in Rancagua, Chile. In 2012, he enrolled at the University of Santiago de Chile and graduated with a diploma in Metallurgical engineering in 2016.

In 2014, he had an internship at the Quality Control department of ME Elecmetal, a world-leading Grinding Media company located in Rancagua Chile.

In 2015, he conducted his engineering thesis on the heat treatment of Wear Resistant High-Chromium Cast Irons at the Research and Development (R&D) department of ME Elecmetal.

After his graduation, he continued working as a Process analyst in the R&D department. Continuing with his education in the field of Steel Metallurgy, he returned to academia and enrolled again at the University of Santiago de Chile, starting a PhD in Materials Science and Engineering.

He received a PhD fellowship from the Chilean National Agency for Research and Development (ANID), and started planning his PhD project on the Ultrafast Heating of Steels under the guidance of Prof. Felipe Castro Cerda.

He moved to Belgium in October 2018 and started working as a Guest PhD student with Prof. Roumen Petrov, in the Department of Electromechanical, Systems & Metal Engineering of Ghent University. After 10 months of experiments and characterization sessions in Belgium, he went back to Chile. Then, he was granted a Joint PhD fellowship from AIND Chile and finally, in October 2019, he returned to Belgium and started a Joint PhD under the supervision of Prof. Roumen Petrov and Prof. Felipe Castro.

Eliseo Hernández Durán is the first author of four A1 research articles published in Materials Science and Engineering - A and Metals. Moreover, he presented part of his work at international conferences.

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Editor: Jeroen Ongenae - Final editing: Ilse Vercruysse - Illustrator: Roger Van Hecke