Postdoc Surface Quality After Reheating in Green Steel Production

This research contributes to green steelmaking by investigating the effect of tramp elements on the surface quality of steels after reheating.

Job Description

Steel production is estimated to account for approximately 7% of global CO₂ emissions. Achieving sustainable steel production requires a combination of green hydrogen usage, full recycling of scrap steel, and the electrification of processes. The adoption of new sustainable process technologies will necessitate changes in heat treatment methods, particularly in heating systems. These changes will primarily affect furnace atmospheres, which in turn influence surface reactions during steel processing.

Additionally, the increased use of recycled steel introduces trace elements—known as tramp elements—which alters steel composition. This has important implications for surface quality, surface-dependent mechanical properties, and product manufacturability.

This project aims at understanding the oxidation processes occurring in reheating furnaces, where the as-cast steel is heat-treated to optimise its mechanical properties for entering the rolling mills. The transition from fossil-based to green furnace atmospheres will lead to an increase in water and CO₂ content in the furnace, thereby affecting the kinetics of growth and morphology of the oxide layer. In green steelmaking, it is also aimed at reusing steel from scrap. The introduced tramp elements are expected to influence growth kinetics, type and morphology of the formed oxides. Important features of the oxide layer for further steps in steelmaking are the porosity, the layer thickness (loss of iron), and the adhesion of the oxide to the substrate, a key factor for the descalability.

Oxidation also causes steel surfaces to change from being reflective metals to absorbing dielectrics. The thickness and morphology of the oxide determine the emissivity, which affects both the heat transfer and the temperature profile during processing.

The research project considers first the analysis of the possible oxide phases formed and the characterisation of the external oxidation layer. The analysis includes the morphology and the specific features of oxide layers grown in wet oxidation conditions for a group of steels of interest to all partners. Next, the insights gained on surface evolution due to oxidation will be incorporated into predictive emissivity models to enable precise temperature control during reheating. Finally, the effect of tramp elements on the oxidation behaviour will be tackled.

Ultimately, the project aims to develop a predictive model for oxide growth and emissivity under sustainable reheating conditions.

We are looking for an ambitious post-doc or PhD-researcher to join this exciting and collaborative research project, which is part of the Dutch National Growth Fund program – Growth with Green Steel. As a PhD or post-doc researcher, you will work in a stimulating academic environment and collaborate with leading industrial partners. You will also have the opportunity to contribute to the academic community through discussions, the co-supervision of students, and guest lectures.

Job Requirements

• Hold an MSc-degree or PhD-degree in the field of materials science or related disciplines, with a solid background in metal/steel science.
• Have strong experience in numerical or analytical physical-chemical modelling and outstanding experimental competence.
• Have experience with microstructural and surface characterization.
• Have a critical, curious, and creative approach to the research, with excellent problem-solving skills.
• Have proven experience in writing scientific reports and preparing communications for scientific and technical meetings with project partners.
• Have excellent communication skills and the ability to work in a cross-organisational team, with industry stakeholders, academics and technicians.
• Be willing to participate in educational activities such as practical or guest lectures.

TU Delft (Delft University of Technology)

Delft University of Technology is built on strong foundations. As creators of the world-famous Dutch waterworks and pioneers in biotech, TU Delft is a top international university combining science, engineering and design. It delivers world class results in education, research and innovation to address challenges in the areas of energy, climate, mobility, health and digital society. For generations, our engineers have proven to be entrepreneurial problem-solvers, both in business and in a social context.

Faculty Mechanical Engineering

Driven by a deep-rooted desire to understand our environment and discover its underlying mechanisms, research and education at the ME faculty focuses on fundamental understanding, design, production including application and product improvement, materials, processes and (mechanical) systems. ME is a dynamic and innovative faculty with high-tech lab facilities and international reach. It’s a large faculty but also versatile, so we can often make unique connections by combining different disciplines. This is reflected in ME’s outstanding, state-of-the-art education, which trains students to become responsible and socially engaged engineers and scientists. We translate our knowledge and insights into solutions to societal issues, contributing to a sustainable society and to the development of prosperity and well-being. That is what unites us in pioneering research, inspiring education and (inter)national cooperation.

Conditions of Employment

• Duration of contract is 3 years (Temporary).
• A job of 36-40 hours per week.
• Salary and benefits are in accordance with the Collective Labour Agreement for Dutch Universities.
• An excellent pension scheme via the ABP.
• The possibility to compile an individual employment package every year.
• Discount with health insurers on supplemental packages.
• Flexible working week.
• Every year, 232 leave hours (at 38 hours). You can also sell or buy additional leave hours via the individual choice budget.
• Plenty of opportunities for education, training and courses.
• Partially paid parental leave.
• Attention for working healthy and energetically with the vitality program.
• If you need to relocate to the Netherlands for this job, TU Delft is committed to making your move as smooth as possible! The HR unit, Coming to Delft Service, offers information to help you prepare your relocation. In addition, Coming to Delft Service organises events to help you settle in the Netherlands, and expand your (social) network in Delft. A Dual Career Programme is available, to support your accompanying partner with their job search in the Netherlands.

Additional Information

For more information about this vacancy, please contact Dr. A.J.Böttger, email: A.J.Bottger@tudelft.nl.